The removal of harmful cyanobacterial blooms(HCBs)and reuse of the resulting algal sludge are pressing issues in current environmental governance and ecological conservation.Aiming at tackling the abovementioned chall...The removal of harmful cyanobacterial blooms(HCBs)and reuse of the resulting algal sludge are pressing issues in current environmental governance and ecological conservation.Aiming at tackling the abovementioned challenges,titanium(Ti)-based coagulants are promising candidates.However,most of them suffer from poor stability and weak actual algal removal ability,and recycling of the algal sludge usually produces titanium dioxide(TiO_(2))with low photocatalytic ability.In this work,a lanthanum(La)-modified polytitanium chloride(La-PTC)coagulant is reported.La in the La-PTC coagulant serves a"kill two birds with one stone"strategy in algae removal and algae sludge reuse.Owing to the introduction of La ions,the La-PTC coagulant exhibits ultra-high stability and excellent algae removal capability with an efficiency of 98.71%,which is 7.25%higher than that of PTC coagulant.Moreover,recycling algae sludge can prepare high catalytic(2.45 times the commercial P25 TiO_(2))La/C-TiO_(2),where the presence of La enhances its visible light response range and inhibits electron hole recombination.The strategy of this La modified coagulant can not only achieve efficient re moval of HCBs,but also transfo rm the recovered algal sludge into photocatalysts with higher catalytic capacity.展开更多
Marine algae and shellfish are contributing positively to carbon sinks.As the world’s largest algae and shellfish producer,the carbon sinks potential in China is crucial.Here,the situation of algae and shellfish cult...Marine algae and shellfish are contributing positively to carbon sinks.As the world’s largest algae and shellfish producer,the carbon sinks potential in China is crucial.Here,the situation of algae and shellfish cultivation in China’s offshore from 2011 to 2020 was elaborated.The intensity of carbon sequestration by algae and shellfish annually was estimated.In 2020,the production of algae and shellfish in China has already reached to 2.62 million tons and 14.8 million tons,with an annual growth rate of 7.03%and 3.14%,respectively.Their annual productivity also maintained an increasing trend,while the rate of productivity increase decreased over ten years except for Porphyra haitanensis,Sinonovacula constricta,and Haliotis discus hannai.Crassostrea gigas and Rudi-tapes philippinarum were the highest fixed carbon shellfish,and Saccharina japonica was the dominant algae.Meanwhile,the rela-tively high carbon sink intensity was found in Shandong,Fujian,and Liaoning.In the last decade,the total carbon sink of algae and shellfish was 1.62 million tons and 7.16 million tons,with an increase of 90.55%and 31.73%,respectively.This created an economic value of 3.293 billion dollars.Results indicated that China’s offshore mariculture algae and shellfish assumed the considerable car-bon sink capacity.Through rational utilization of the carbon sink resources in algae and shellfish,it provides potential ideas for Chi-na to pursue personalized carbon neutrality.展开更多
Biological invasions have become recognized as one of the greatest threats to ecosystems.Codium,a genus of invasive green algae,has frequent global outbreaks and damages local marine ecosystems.It is now generally acc...Biological invasions have become recognized as one of the greatest threats to ecosystems.Codium,a genus of invasive green algae,has frequent global outbreaks and damages local marine ecosystems.It is now generally accepted that light is one of the main factors affecting the luxuriant growth of macroalgae such as Codium.In this study,to investigate the invasive photo-adaptation strategy of Codium fragile,the photo-adaptation characteristics of C.fragile and Codium.cylindricum from the Nan’ao Island of China were compared and explored.The effect of light intensity on the photosynthetic properties of the two species was investigated:the maximum quantum yield of photosystemⅡ(Fv/Fm)of C.fragile was significantly higher at low light intensity.At a light intensity of 90μmol/(m^(2)·s),maximum relative electron transport rate(rETR_(max))of the thalli was maximum,and the minimum saturating irradiance(Ek)was significantly increased.The photosynthetic rate(αvalue)of thalli was highest at a light intensity of 30μmol/(m^(2)·s).The photochemical quenching(qP)was enhanced but non-photochemical quenching(NPQ)was reduced at high light intensities.As for C.cylindricum,the optimal photochemical efficiency of the thalli at low light intensity was higher.High light intensity significantly reduced the rETR of the thalli.At low light intensity,αwas significantly higher,Ek was significantly lower,and NPQ was also significantly decreased.The response relationship between light acclimation and antioxidant capacity of the thalli of two species of Codium was investigated:there was no significant effect of light intensity variation on the total antioxidant capacity of C.fragile.In the case of C.cylindricum,the degree of membrane lipid peroxidation was significantly increased at low light intensity,and its antioxidant capacity was significantly reduced when the light intensity was too high or too low.It can be hypothesized that the self-protection ability of C.fragile may be stronger than that of C.cylindricum under low and high light intensities,which is closely related to the strong invasiveness of C.fragile.展开更多
Freshwater ecosystems are crucial in the global emissions of greenhouse gases(GHGs)such as CH_(4).Macrophytes are the main organic matter(i.e.,detritus)supplier to the sediment of these systems,thus controlling CH_(4)...Freshwater ecosystems are crucial in the global emissions of greenhouse gases(GHGs)such as CH_(4).Macrophytes are the main organic matter(i.e.,detritus)supplier to the sediment of these systems,thus controlling CH_(4) production.However,species-specific differences(structure and composition)may determine contrasting patterns of detritus transformation into CH_(4).Furthermore,eutrophication can affect the degradation and,consequently,CH_(4) production.We performed a 64-day microcosm experiment with anoxic incubations of detritus from seven phylogenetically different macrophytes(two charophytes,filamentous algae–Spirogyra,Cladophora–,three submerged plants and an amphibious one),under two trophic conditions(oligo-versus eutrophic)and with/without sediment.We assessed the CH_(4) and CO_(2) production and the changes in the detritus quality at the end of the experiment.The ranking in the mean cumulative CH_(4) production was:Chara hispida>Nitella hyalina>Najasmarina≈Teucrium scordium>Stuckenia pectinata≈Myriophyllum spicatum>filamentous algae,and it was related to the detritus quality.GHGs maximumproduction rates were 1.6(N.marina)-1.2(C.hispida)mmol CH_(4)/(g OC·day)and 1.7(N.marina)-1.5(C.hispida)mmol CO_(2)/(g OC·day).The CO_(2):CH_(4) ratiowas biased towards CO_(2) during the first 10 days(average ratio of 200)and fell afterwards to about 1 for all macrophyte species and treatments.The sediment favored detritus decomposition(probably due to the“positive priming effect”),increasing GHGs production.The influence of nutrient enrichment was not evident.Delving into themacrophyte detritus quality-GHGs production relationship is needed to forecast the GHGs emissions in macrophyte-dominated systems.展开更多
Using phosphorus(P)fertilizers has historically increased agricultural productivity,yet the highly dissipative nature of phosphate rock and the low effciency due to soil fxation and runoff raise sustainability concern...Using phosphorus(P)fertilizers has historically increased agricultural productivity,yet the highly dissipative nature of phosphate rock and the low effciency due to soil fxation and runoff raise sustainability concerns.Algae fertilizers have emerged as a promising eco-friendly alternative.However,the potential of algae fertilizers for providing sustained P availability and their impacts on plant growth,soil microbes,and nutrient cycling remains to be explored.In this study,we developed a polyphosphate-enriched algae fertilizer(PEA)and conducted comparative experiments with chemical P fertilizers(CP)through soil and solution cultures,as well as crop growth trials.Soil cultivation experiments showed that PEA released twice as much labile P as initially available in the soil,and it functioned as a slow-release P source.In contrast,soils treated with CP initially exhibited high levels of labile P,which was gradually converted to stable forms,but it dropped to 30%of the labile P level in PEA after three months.Further tests revealed that the slow release of P from PEA was linked to increased microbial activity,and the microbial biomass P(MBP)content was about eight times higher than in soils treated with CP after three months,resulting in a 75%decline in the microbial biomass carbon(MBC)to MBP ratio.Microbial diversity analysis showed that algae fertilizers could recruit more benefcial microbes than CP,like phosphorus-solubilizing bacteria,plant growth-promoting bacteria,and stress-resistant bacteria.Crop pot experiments,along with amplicon and metagenomic analysis of tomato root-associated microbes,revealed that algae fertilizers including PEA promoted plant growth comparable to CP,and enhanced soil P cycling and overall nutrient dynamics.These data showed that algae fertilizers,especially PEA,can stabilize soil P fertility and stimulate plant growth through their slow P release and the recruitment of benefcial microbes.Our study highlights the potential of PEA to foster sustainable agriculture by mitigating the P scarcity and soil P loss associated with chemical fertilizers and improving plant growth and soil health.展开更多
The adhesion of Shewanella algae(S.algae)on the surface of stainless steel induced the formation and coverage of calcium carbonate minerals in the aerobic environment,and the effect of these minerals on the passive fi...The adhesion of Shewanella algae(S.algae)on the surface of stainless steel induced the formation and coverage of calcium carbonate minerals in the aerobic environment,and the effect of these minerals on the passive film of stainless steel was investigated by focused ion beam-scanning electron microscopy/transmission electron microscopy(FIB-SEM/TEM)and electron energy loss spectroscopy(EELS)techniques.The TEM and energy-dispersive X-ray spectroscopy(EDS)results revealed that the passive film in the region covered by mineralized particles underwent chelation between Fe and Cr compounds with CaCO_(3),forming an unstable amorphous layer,which accelerated the loss of Fe and Cr elements.EELS analysis showed that the loss of Fe element in the passive film was the most significant,with a transition from Fe^(3+)to soluble Fe^(2+)occurring,which caused by the iron-reducing property and metabolic activities of the adherent S.algae.The loss of the main metal elements caused the accelerated degradation of the passive film beneath the minerals.展开更多
Alga toxins have recently emerged as an environmental risk factor,especially to neurodegenerative diseases,such as Alzheimer's disease,Parkinson's disease and amyotrophic lateral sclerosis.However,the associat...Alga toxins have recently emerged as an environmental risk factor,especially to neurodegenerative diseases,such as Alzheimer's disease,Parkinson's disease and amyotrophic lateral sclerosis.However,the association between the alga toxinsβ-N-methylamino-L-alanine(BMAA),brevetoxin B,cyanoginosin LR,okadaic acid and neurodegenerative diseases remains inadequately investigated.Therefore,the aim of this study was to elucidate the potential associations.Four sets of differentially expressed genes related with BMAA,brevetoxin B,cyanoginosin LR and okadaic acid in Homo sapiens and genes linked to neurodegenerative disease development were respectively collected from the Comparative Toxicogenomic Database.Metascape analysis and cluster community analysis of four alga toxins highlighted protein-protein interaction enrichment and hub genes,while biological processes analysis showed that the dominant pathways involved in harmful effects triggered by four alga toxins were the apoptotic signaling pathway,regulation of amyloid protein formation,inflammatory response and endoplasmic reticulum stress.Genes related to the interactions between four alga toxins and neurodegenerative diseases were selected and analyzed,revealing that the relevant pathways and genes were those involved in apoptotic mitochondrial changes and neuroinflammatory response pathways.The adverse outcome pathway frameworks were constructed according to the analysis results for toxins and associated neurodegenerative diseases.These discoveries provide a new perspective for us to gain a deeper understanding of the neurotoxic effects of four alga toxins.展开更多
The inaugural meeting of the National Fossil Algae Research Group of PSC and the l st fossil algae symposium were held from December 2-7,1981 in Nanjing.117 Chinese fossil algae of China",in which he gave an geol...The inaugural meeting of the National Fossil Algae Research Group of PSC and the l st fossil algae symposium were held from December 2-7,1981 in Nanjing.117 Chinese fossil algae of China",in which he gave an geological colleges,geological survey,petroleum prospecting units,coal and metallurgical industry enterprises took part in the meeting,which marks a new stage in Chinese fossil algae researeh.展开更多
Algae-lysing bacteria A1 has good control effect on the moss through its extracellular secretion. In order to further study its control mechanism, the sin- gle-factor tests of temperature and pH value, the activated c...Algae-lysing bacteria A1 has good control effect on the moss through its extracellular secretion. In order to further study its control mechanism, the sin- gle-factor tests of temperature and pH value, the activated carbon adsorption test, the organic solvent extraction test and the crude extract of active substance test were carried out to explore the characteristics of active substances. The results showed that the algae-lysing active ingredient of A1 strain had strong thermal stabili- ty, which still had good algae-lysing effect after being treated at 121 ℃ ; when the pH values of fermentation liquid were adjusted to 2.0 and 4.0 respectively, the active substances lost their activities, but their control ability against moss would be enhanced under the alkaline conditions ; the active substances could not be ad- sorbed by activated carbon; the algae-lysing active substances showed strong hydrophilie ability when they were extracted by ethyl acetate, petroleum ether and chloroform. Therefore, it could be speculated that the active substances belonged to carbohydrates. The crude extract results of algae-lysing active substances showed that the active substances secreted by A1 strain were composed by a variety of algae-lysing active substances.展开更多
Most phaeophytes （brown algae） and rhodophytes （red algae） dwell exclusively in marine habitats and play important roles in marine ecology and biodiversity. Many of these brown and red algae are also important res...Most phaeophytes （brown algae） and rhodophytes （red algae） dwell exclusively in marine habitats and play important roles in marine ecology and biodiversity. Many of these brown and red algae are also important resources for industries such as food, medicine and materials due to their unique metabolisms and me-tabolites. However, many fundamental questions surrounding their origins, early diversification, taxonomy, and special metabolisms remain unsolved because of poor molecular bases in brown and red algal study. As part of the 1 000 Plant Project, the marine macroalgal transcriptomes of 19 Phaeophyceae species and 21 Rhodophyta species from China＇s coast were sequenced, covering a total of 2 phyla, 3 classes, 11 orders, and 19 families. An average of 2 Gb per sample and a total 87.3 Gb of RNA-seq raw data were generated. Approxi-mately 15 000 to 25 000 unigenes for each brown algal sample and 5 000 to 10 000 unigenes for each red algal sample were annotated and analyzed. The annotation results showed obvious differences in gene expres-sion and genome characteristics between red algae and brown algae;these differences could even be seen between multicellular and unicellular red algae. The results elucidate some fundamental questions about the phylogenetic taxonomy within phaeophytes and rhodophytes, and also reveal many novel metabolic pathways. These pathways include algal CO2 fixation and particular carbohydrate metabolisms, and related gene/gene family characteristics and evolution in brown and red algae. These findings build on known algal genetic information and significantly improve our understanding of algal biology, biodiversity, evolution, and potential utilization of these marine algae.展开更多
To understand the potential impact of the Three Gorges Reservoir on the aquatic ecosystem after the damming of the Yangtze River,we studied the community composition and temporal abundance distribution of algae in two...To understand the potential impact of the Three Gorges Reservoir on the aquatic ecosystem after the damming of the Yangtze River,we studied the community composition and temporal abundance distribution of algae in two types of water bodies:a segment of the Jialing River near its confluence with the Yangtze River as an example of the river-lake type,and Shuanglong Lake in Chongqing as an example of the lake type.In total,107 species belonging to 58 genera of 7 phyla were identified in the study area of the Jialing River,dominated by three groups with 49.5% diatoms,29.0% chlorophytes,and 11.4% cyanobacteria in the community composition.There were 122 species belonging to 66 genera of 8 phyla in Shuanglong Lake,dominated by the same three groups with 19.7% diatoms,48.4% chlorophytes,and 22.2% cyanobacteria.The densities of total algae and individual dominant groups were all much higher in the lake.More species of diatoms were found in the river-lake segment;whereas more chlorophyte species and cyanobacteriaum species were in the lake.There were 17 dominant species including 8 diatoms,4 chlorophytes,3 cyanobacteria and 2 cryptophytes in the river-lake segment,and 21 species in the lake,including 2 diatoms,9 chlorophytes,6 cyanobacteria,3 cryptophytes and a dinoflagellate.In eutrophic conditions,chlorophytes and cyanobacteria may proliferate in a lake-type area and diatoms may cause algal bloom in a relatively faster-flow lake-river type area.展开更多
By mild PAGE method, 11, 11, 7 and 9 chlorophyll_protein complexes were isolated from two species of siphonous green algae (Codium fragile (Sur.) Hariot and Bryopsis corticulans Setch.), green alga (Ulothrix flacca (D...By mild PAGE method, 11, 11, 7 and 9 chlorophyll_protein complexes were isolated from two species of siphonous green algae (Codium fragile (Sur.) Hariot and Bryopsis corticulans Setch.), green alga (Ulothrix flacca (Dillw.) Thur.), and spinach (Spinacia oleracea Mill.), respectively. Apparent molecular weights, Chl a/b ratios, distribution of chlorophyll, absorption spectra, low temperature fluorescence spectra of these complexes were determined, and compared with one another. PSⅠ complexes of two siphonous green algae are larger in apparent molecular weight because of the attachment of relative highly aggregated LHCⅠ. Four isolated light_harvesting complexes of PSⅡ are all siphonaxanthin_Chl a/b_protein complexes, and they are not monomers and oligomers like those in higher plants. Especially, the absence of 730 nm fluorescence in PSⅠ complexes indicates a distinct structure and energy transfer pattern.展开更多
The microbiotic crust study is among new focuses in investigating on the desertification control. Based on determination of algal crusts with different successive ages (4-, 8-, 17-, 34-, 42-year-old) and unconsolidate...The microbiotic crust study is among new focuses in investigating on the desertification control. Based on determination of algal crusts with different successive ages (4-, 8-, 17-, 34-, 42-year-old) and unconsolidated sand in the desert area, species composition and clustering analyses were carried out in this study. Results on successional orientation revealed that (1) the abundance of Cyanophyta, specially of Scytonema javanicum gradually decreased; (2) the abundance of Chlorophyta, Bacillariophyta and a species of Cyanophyta, Phormidium tenue increased; (3) the biodiversity increased gradually with the community succession; and (4) biomass of microalgae increased at the early stage, but decreased at the later stage due to the abundance of lichens and mosses. But, the speed of natural succession was so slow that the community-building species was still the first dominant species after 42 years, except that its dominant degree decreased just slightly. However, successive speed and trend were affected by water, vegetation coverage, terrain, time and soil physico-chemical properties as well, especially Mn content in the soil appeared to have a threshold effect.展开更多
To understand the spatial and temporal variation characteristics of blue algae in summer in Lake Dianshan,the phytoplankton in Lake Dianshan from June to September in 2009 was surveyed. It found 11 genera and 28 speci...To understand the spatial and temporal variation characteristics of blue algae in summer in Lake Dianshan,the phytoplankton in Lake Dianshan from June to September in 2009 was surveyed. It found 11 genera and 28 species blue algae in total. Microcystis,Oscillatoria and Chroococcus were the main composition communities of blue algae in Lake Dianshan in summer. In the survey period,the average density of blue algae in Lake Dianshan was 16.48×106 cells/L which changed during 1.01×106-59.76×106 cells/L. The characteristics were:September > July > August > June. The mass propagation and aggregation of Microcystis in September caused that the water blooms phenomenon in the partial water areas was serious. In the space,the average density of blue algae in the west and southwest parts of Lake Dianshan was bigger than in the east and southeast. When the nutritive matter was sufficient,the temperature was the main factor which affected the generation and disappearance of blue algae water blooms. The wind direction was also an important factor which affected the distribution of blue algae.展开更多
[Objective] The biological characteristics and pathogenicities of Shewanella algae and Shewanella abalone from Babylonia were studied in this paper. [Method]The hemolytic bacteria were isolated from the hepatopancreas...[Objective] The biological characteristics and pathogenicities of Shewanella algae and Shewanella abalone from Babylonia were studied in this paper. [Method]The hemolytic bacteria were isolated from the hepatopancreas of Babylonia suffered from proboscis edema with blood agar plate. The dominant bacterial community in the ill Babylonia was identified by 16 S r DNA sequence analysis, and the bacterial cultural and biochemical characteristics and pathogenicities were studied. [Result]The Shewanella bacteria, including Shewanella algae and Shewanella abalone, are the dominant bacterial community in Babylonia suffered from proboscis edema.The colony characteristics of Shewanella algae in nutrient agar medium, TCBS agar medium and CHROMagar vibrio colored medium were similar to those of Shewanella abalone. Shewanella algae possessed β-hemolysis and Shewanella abalone possessed α-hemolysis in the blood agar plate. The biochemical reaction of Shewanella algae and Shewanella abalone was all of non-fermentation type. The results of artificial infection test showed that half lethal dose（LD50） of the test strains of Shewanella algae was 10-5.50/0.1 ml. The test strains of Shewanella algae have strong toxicity, and could cause mice and chickens to die of sepsis with mortality of100%. The mortality of Babylonia infected with Shewanella algae was 10%; while the survived Babylonia lost the ability of moving and intaking for a long time, but they were not suffered from proboscis edema. There was no death in mice or chicks infected with Shewanella abalone, but their livers and spleens were slightly hyperemic and swelling. There was also no death in Babylonia infected with Shewanella abalone, but their intaking and moving ability was lost for a short time.[Conclusion] Although Shewanella algae and Shewanella abalone were the dominant bacteria in Babylonia suffered from proboscis edema, they were not the main pathogenic bacteria for proboscis edema. Shewanella algae had strong pathogenicity to mice, chicks and Babylonia, while Shewanella abalone showed no marked pathogenicity to those experimental animals in this study.展开更多
[Objective] The research aimed to know the ecological environment pollution characteristics of Hongfeng Lake water area and the evolution rule,which provided the theory basis for improving the water quality condition....[Objective] The research aimed to know the ecological environment pollution characteristics of Hongfeng Lake water area and the evolution rule,which provided the theory basis for improving the water quality condition.[Method] Based on the investigation and research of indoor and outdoor,the water quality,aquatic ecosystem,pollution characteristic of sediment and occurrence law of algae blooms in Hongfeng Lake were comprehensively analyzed by combining with the relevant literatures.[Result] Hongfeng Lake was in moderate-heavy eutrophication situation,and the water quality was V-bad V class.The sediment accumulated a lot of nutrient salt,which was the important pollution source of eutrophication in Hongfeng Lake Reservoir.The aquatic ecosystem degraded,and it was easy to form the algae blooms.[Conclusion] The pollution treatment of Hongfeng Lake was extremely urgent.展开更多
In order to better monitor N and P pollutants, heavy metals, pesticides and other organic pollutants in water areas, we researched sensitivity and tolerance of aquatic algae on water environment and effects of the pol...In order to better monitor N and P pollutants, heavy metals, pesticides and other organic pollutants in water areas, we researched sensitivity and tolerance of aquatic algae on water environment and effects of the pollutants on algae population, analyzing toxin and enrichment of pollutants on algae. The results indicated that aquatic alga is a better indicator for some pollutants in water, for which water contamination can be surveyed and analyzed rapidly.展开更多
Microcystins (MCYSTs) isolated from blue-green algae,are hepatotoxic polypeptides.It will induce severe intrahepatic hemorrhage and liver necrosis at low concentrations in rats and mice.MCYST- LR is one of MCYSTs whic...Microcystins (MCYSTs) isolated from blue-green algae,are hepatotoxic polypeptides.It will induce severe intrahepatic hemorrhage and liver necrosis at low concentrations in rats and mice.MCYST- LR is one of MCYSTs which consists of 2 variable L- amino acids(leucine and arginine),3 D-amino acids and 2 unusualamino acids(including Adda).MCYSTs bind to protein phosphatase 1 and 2A,and strongly inhibit their activities.The resultant increase of phosphoprotein was referred to be involved in tumor-promoting activity in liver.According to the above results and animal study,MCYST-LR is a potent liver tumor promoter.There were 9 positive from 30 samples of pond-ditch water in high endemic county-Haimen by high-peformance liquid chromatograph and 3 already confirmed by liquid chromograph/mass spectrometer.The quantities of MCYSTs were different between drinking water of liver cancer cases and controls groups.122±0.057and 0.072±0.044μg/200ml respectively) by ELISA. It is not easy to remove by conventional water treatment procedures.The relationship between MCYSTs and oncogenes and anti-oncogenes are under studying.展开更多
Silver nanoparticles,endowed with powerful antimicrobial property,are the most widely used nanomaterial in consumer products,with associated risk of their easy access to environment and freshwater ecosystems by surfac...Silver nanoparticles,endowed with powerful antimicrobial property,are the most widely used nanomaterial in consumer products,with associated risk of their easy access to environment and freshwater ecosystems by surface runoff.Although toxic effects of nanosilver on bacterial,fungal and mammalian cells have been documented,its impact on algal growth remains unknown.Pithophora oedogonia and Chara vulgaris are predominant members of photosynthetic eukaryotic algae,which form major component of global aquatic ecosystem.Here we report for the first time that nanosilver has significant adverse effects on growth and morphology of these filamentous green algae in a dose-dependent manner.Exposure of algal thalli to increasing concentrations of silver nanoparticles resulted in progressive depletion in algal chlorophyll content,chromosome instability and mitotic disturbance,associated with morphological malformations in algal filaments.SEM micrographs revealed dramatic alterations in cell wall in nanoparticle-treated algae,characterized with cell wall rupture and degradation in Pithophora.Although these observations underscore severe deleterious effects of nanosilver on aquatic environment,the information can also be exploited as a bioengineering strategy to control unwanted and persistent growth of noxious algal weeds that clog the municipal water supply and water channels and produce fouling of water bodies.展开更多
Alga-lysing bacteria have been paid much attention to in recent years. In this study, the alga-lysing strain P05 which was isolated from an immobilizing biosystem was immobilized by coke and elastic filler, forming tw...Alga-lysing bacteria have been paid much attention to in recent years. In this study, the alga-lysing strain P05 which was isolated from an immobilizing biosystem was immobilized by coke and elastic filler, forming two biological reactors. The removal efficiencies of algae, NH4^＋-N and organic matter using the two reactors were studied. The results showed that strain P05 was an ideal algal-lysing bacteria strain because it was easy to be immobilized by coke and elastic filler which are of cheap, low biodegradability and the simple immobilization procedure. After 7 d filming, the biological film could be formed and the reactors were used to treat the eutrophic water. These two reactors were of stability and high effect with low cost and easy operation. The optimal hydraulic retention time （HRT） of each reactor was 4 h. The algae removal rates were 80.38% and 82.1% （in term of Chl-α） of coke reactor and filler reactor, respectively. And that of NH4^＋-N were 52.3% and 52.7%. The removal rates of CODMn were 39.03% and 39.64%. The strain P05 was identified as Bacillus sp. by PCR amplification of the 16S rRNA gene, BLAST analysis, and comparison with sequences in the GenBank nucleotide database.展开更多
基金Project supported by the National Natural Science Foundation of China(62175266,61775245)。
文摘The removal of harmful cyanobacterial blooms(HCBs)and reuse of the resulting algal sludge are pressing issues in current environmental governance and ecological conservation.Aiming at tackling the abovementioned challenges,titanium(Ti)-based coagulants are promising candidates.However,most of them suffer from poor stability and weak actual algal removal ability,and recycling of the algal sludge usually produces titanium dioxide(TiO_(2))with low photocatalytic ability.In this work,a lanthanum(La)-modified polytitanium chloride(La-PTC)coagulant is reported.La in the La-PTC coagulant serves a"kill two birds with one stone"strategy in algae removal and algae sludge reuse.Owing to the introduction of La ions,the La-PTC coagulant exhibits ultra-high stability and excellent algae removal capability with an efficiency of 98.71%,which is 7.25%higher than that of PTC coagulant.Moreover,recycling algae sludge can prepare high catalytic(2.45 times the commercial P25 TiO_(2))La/C-TiO_(2),where the presence of La enhances its visible light response range and inhibits electron hole recombination.The strategy of this La modified coagulant can not only achieve efficient re moval of HCBs,but also transfo rm the recovered algal sludge into photocatalysts with higher catalytic capacity.
基金funded by the Social Science Research Project of Fujian Provincial Department of Education(No.JAT22073)the Fujian‘Young Eagle Program’Youth Top Talent Program.
文摘Marine algae and shellfish are contributing positively to carbon sinks.As the world’s largest algae and shellfish producer,the carbon sinks potential in China is crucial.Here,the situation of algae and shellfish cultivation in China’s offshore from 2011 to 2020 was elaborated.The intensity of carbon sequestration by algae and shellfish annually was estimated.In 2020,the production of algae and shellfish in China has already reached to 2.62 million tons and 14.8 million tons,with an annual growth rate of 7.03%and 3.14%,respectively.Their annual productivity also maintained an increasing trend,while the rate of productivity increase decreased over ten years except for Porphyra haitanensis,Sinonovacula constricta,and Haliotis discus hannai.Crassostrea gigas and Rudi-tapes philippinarum were the highest fixed carbon shellfish,and Saccharina japonica was the dominant algae.Meanwhile,the rela-tively high carbon sink intensity was found in Shandong,Fujian,and Liaoning.In the last decade,the total carbon sink of algae and shellfish was 1.62 million tons and 7.16 million tons,with an increase of 90.55%and 31.73%,respectively.This created an economic value of 3.293 billion dollars.Results indicated that China’s offshore mariculture algae and shellfish assumed the considerable car-bon sink capacity.Through rational utilization of the carbon sink resources in algae and shellfish,it provides potential ideas for Chi-na to pursue personalized carbon neutrality.
基金The National Natural Science Foundation of China under contract Nos 32270219 and 31970216.
文摘Biological invasions have become recognized as one of the greatest threats to ecosystems.Codium,a genus of invasive green algae,has frequent global outbreaks and damages local marine ecosystems.It is now generally accepted that light is one of the main factors affecting the luxuriant growth of macroalgae such as Codium.In this study,to investigate the invasive photo-adaptation strategy of Codium fragile,the photo-adaptation characteristics of C.fragile and Codium.cylindricum from the Nan’ao Island of China were compared and explored.The effect of light intensity on the photosynthetic properties of the two species was investigated:the maximum quantum yield of photosystemⅡ(Fv/Fm)of C.fragile was significantly higher at low light intensity.At a light intensity of 90μmol/(m^(2)·s),maximum relative electron transport rate(rETR_(max))of the thalli was maximum,and the minimum saturating irradiance(Ek)was significantly increased.The photosynthetic rate(αvalue)of thalli was highest at a light intensity of 30μmol/(m^(2)·s).The photochemical quenching(qP)was enhanced but non-photochemical quenching(NPQ)was reduced at high light intensities.As for C.cylindricum,the optimal photochemical efficiency of the thalli at low light intensity was higher.High light intensity significantly reduced the rETR of the thalli.At low light intensity,αwas significantly higher,Ek was significantly lower,and NPQ was also significantly decreased.The response relationship between light acclimation and antioxidant capacity of the thalli of two species of Codium was investigated:there was no significant effect of light intensity variation on the total antioxidant capacity of C.fragile.In the case of C.cylindricum,the degree of membrane lipid peroxidation was significantly increased at low light intensity,and its antioxidant capacity was significantly reduced when the light intensity was too high or too low.It can be hypothesized that the self-protection ability of C.fragile may be stronger than that of C.cylindricum under low and high light intensities,which is closely related to the strong invasiveness of C.fragile.
基金supported by Spanish Ministry of Science and Innovation (No.PID2020–116147GB-C22)funded by the European Union (Next Generation UE)+1 种基金funded by the Programa de Posgrado en Ciencias del Mar y Limnología (UNAM)CONAHCYT (CVU:828722).
文摘Freshwater ecosystems are crucial in the global emissions of greenhouse gases(GHGs)such as CH_(4).Macrophytes are the main organic matter(i.e.,detritus)supplier to the sediment of these systems,thus controlling CH_(4) production.However,species-specific differences(structure and composition)may determine contrasting patterns of detritus transformation into CH_(4).Furthermore,eutrophication can affect the degradation and,consequently,CH_(4) production.We performed a 64-day microcosm experiment with anoxic incubations of detritus from seven phylogenetically different macrophytes(two charophytes,filamentous algae–Spirogyra,Cladophora–,three submerged plants and an amphibious one),under two trophic conditions(oligo-versus eutrophic)and with/without sediment.We assessed the CH_(4) and CO_(2) production and the changes in the detritus quality at the end of the experiment.The ranking in the mean cumulative CH_(4) production was:Chara hispida>Nitella hyalina>Najasmarina≈Teucrium scordium>Stuckenia pectinata≈Myriophyllum spicatum>filamentous algae,and it was related to the detritus quality.GHGs maximumproduction rates were 1.6(N.marina)-1.2(C.hispida)mmol CH_(4)/(g OC·day)and 1.7(N.marina)-1.5(C.hispida)mmol CO_(2)/(g OC·day).The CO_(2):CH_(4) ratiowas biased towards CO_(2) during the first 10 days(average ratio of 200)and fell afterwards to about 1 for all macrophyte species and treatments.The sediment favored detritus decomposition(probably due to the“positive priming effect”),increasing GHGs production.The influence of nutrient enrichment was not evident.Delving into themacrophyte detritus quality-GHGs production relationship is needed to forecast the GHGs emissions in macrophyte-dominated systems.
基金supported by the National Key Research and Development Program of China(2021YFF1000404)the National Natural Science Foundation of China(32472823 and 32102478)+1 种基金the Innovation Program of Chinese Academy of Agricultural Sciences(CAAS-CSAL-202301)the China Postdoctoral Science Foundation(2021M693447,2021M693449 and 2022T150707)。
文摘Using phosphorus(P)fertilizers has historically increased agricultural productivity,yet the highly dissipative nature of phosphate rock and the low effciency due to soil fxation and runoff raise sustainability concerns.Algae fertilizers have emerged as a promising eco-friendly alternative.However,the potential of algae fertilizers for providing sustained P availability and their impacts on plant growth,soil microbes,and nutrient cycling remains to be explored.In this study,we developed a polyphosphate-enriched algae fertilizer(PEA)and conducted comparative experiments with chemical P fertilizers(CP)through soil and solution cultures,as well as crop growth trials.Soil cultivation experiments showed that PEA released twice as much labile P as initially available in the soil,and it functioned as a slow-release P source.In contrast,soils treated with CP initially exhibited high levels of labile P,which was gradually converted to stable forms,but it dropped to 30%of the labile P level in PEA after three months.Further tests revealed that the slow release of P from PEA was linked to increased microbial activity,and the microbial biomass P(MBP)content was about eight times higher than in soils treated with CP after three months,resulting in a 75%decline in the microbial biomass carbon(MBC)to MBP ratio.Microbial diversity analysis showed that algae fertilizers could recruit more benefcial microbes than CP,like phosphorus-solubilizing bacteria,plant growth-promoting bacteria,and stress-resistant bacteria.Crop pot experiments,along with amplicon and metagenomic analysis of tomato root-associated microbes,revealed that algae fertilizers including PEA promoted plant growth comparable to CP,and enhanced soil P cycling and overall nutrient dynamics.These data showed that algae fertilizers,especially PEA,can stabilize soil P fertility and stimulate plant growth through their slow P release and the recruitment of benefcial microbes.Our study highlights the potential of PEA to foster sustainable agriculture by mitigating the P scarcity and soil P loss associated with chemical fertilizers and improving plant growth and soil health.
基金supported by the National Natural Science Foundation of China(52161160308)the Basic and Applied Basic Research Foundation of Guangdong Province(2021B1515130009)+1 种基金the China Postdoctoral Science Foundation(2022M720401)the Postdoctoral Fellowship Program of CPSF(GZC20240101).
文摘The adhesion of Shewanella algae(S.algae)on the surface of stainless steel induced the formation and coverage of calcium carbonate minerals in the aerobic environment,and the effect of these minerals on the passive film of stainless steel was investigated by focused ion beam-scanning electron microscopy/transmission electron microscopy(FIB-SEM/TEM)and electron energy loss spectroscopy(EELS)techniques.The TEM and energy-dispersive X-ray spectroscopy(EDS)results revealed that the passive film in the region covered by mineralized particles underwent chelation between Fe and Cr compounds with CaCO_(3),forming an unstable amorphous layer,which accelerated the loss of Fe and Cr elements.EELS analysis showed that the loss of Fe element in the passive film was the most significant,with a transition from Fe^(3+)to soluble Fe^(2+)occurring,which caused by the iron-reducing property and metabolic activities of the adherent S.algae.The loss of the main metal elements caused the accelerated degradation of the passive film beneath the minerals.
基金supported by the Natural Science Foundation of Shandong province(Nos.ZR2019MH048 and ZR2022QC149)the Double First-class Disciplines Construction Fund Project from Harbin Institute of Technology at Weihai(No.2023SYLHY18)Weihai Science and Technology Development Program。
文摘Alga toxins have recently emerged as an environmental risk factor,especially to neurodegenerative diseases,such as Alzheimer's disease,Parkinson's disease and amyotrophic lateral sclerosis.However,the association between the alga toxinsβ-N-methylamino-L-alanine(BMAA),brevetoxin B,cyanoginosin LR,okadaic acid and neurodegenerative diseases remains inadequately investigated.Therefore,the aim of this study was to elucidate the potential associations.Four sets of differentially expressed genes related with BMAA,brevetoxin B,cyanoginosin LR and okadaic acid in Homo sapiens and genes linked to neurodegenerative disease development were respectively collected from the Comparative Toxicogenomic Database.Metascape analysis and cluster community analysis of four alga toxins highlighted protein-protein interaction enrichment and hub genes,while biological processes analysis showed that the dominant pathways involved in harmful effects triggered by four alga toxins were the apoptotic signaling pathway,regulation of amyloid protein formation,inflammatory response and endoplasmic reticulum stress.Genes related to the interactions between four alga toxins and neurodegenerative diseases were selected and analyzed,revealing that the relevant pathways and genes were those involved in apoptotic mitochondrial changes and neuroinflammatory response pathways.The adverse outcome pathway frameworks were constructed according to the analysis results for toxins and associated neurodegenerative diseases.These discoveries provide a new perspective for us to gain a deeper understanding of the neurotoxic effects of four alga toxins.
文摘The inaugural meeting of the National Fossil Algae Research Group of PSC and the l st fossil algae symposium were held from December 2-7,1981 in Nanjing.117 Chinese fossil algae of China",in which he gave an geological colleges,geological survey,petroleum prospecting units,coal and metallurgical industry enterprises took part in the meeting,which marks a new stage in Chinese fossil algae researeh.
基金Supported by Scientific and Technological Research Projects in Suihua University(KQ1002004)~~
文摘Algae-lysing bacteria A1 has good control effect on the moss through its extracellular secretion. In order to further study its control mechanism, the sin- gle-factor tests of temperature and pH value, the activated carbon adsorption test, the organic solvent extraction test and the crude extract of active substance test were carried out to explore the characteristics of active substances. The results showed that the algae-lysing active ingredient of A1 strain had strong thermal stabili- ty, which still had good algae-lysing effect after being treated at 121 ℃ ; when the pH values of fermentation liquid were adjusted to 2.0 and 4.0 respectively, the active substances lost their activities, but their control ability against moss would be enhanced under the alkaline conditions ; the active substances could not be ad- sorbed by activated carbon; the algae-lysing active substances showed strong hydrophilie ability when they were extracted by ethyl acetate, petroleum ether and chloroform. Therefore, it could be speculated that the active substances belonged to carbohydrates. The crude extract results of algae-lysing active substances showed that the active substances secreted by A1 strain were composed by a variety of algae-lysing active substances.
基金The National Natural Science Foundation of China under contract Nos 31140070,31271397 and 41206116the algal transcrip-tome sequencing was supported by 1KP Project(www.onekp.com)
文摘Most phaeophytes （brown algae） and rhodophytes （red algae） dwell exclusively in marine habitats and play important roles in marine ecology and biodiversity. Many of these brown and red algae are also important resources for industries such as food, medicine and materials due to their unique metabolisms and me-tabolites. However, many fundamental questions surrounding their origins, early diversification, taxonomy, and special metabolisms remain unsolved because of poor molecular bases in brown and red algal study. As part of the 1 000 Plant Project, the marine macroalgal transcriptomes of 19 Phaeophyceae species and 21 Rhodophyta species from China＇s coast were sequenced, covering a total of 2 phyla, 3 classes, 11 orders, and 19 families. An average of 2 Gb per sample and a total 87.3 Gb of RNA-seq raw data were generated. Approxi-mately 15 000 to 25 000 unigenes for each brown algal sample and 5 000 to 10 000 unigenes for each red algal sample were annotated and analyzed. The annotation results showed obvious differences in gene expres-sion and genome characteristics between red algae and brown algae;these differences could even be seen between multicellular and unicellular red algae. The results elucidate some fundamental questions about the phylogenetic taxonomy within phaeophytes and rhodophytes, and also reveal many novel metabolic pathways. These pathways include algal CO2 fixation and particular carbohydrate metabolisms, and related gene/gene family characteristics and evolution in brown and red algae. These findings build on known algal genetic information and significantly improve our understanding of algal biology, biodiversity, evolution, and potential utilization of these marine algae.
基金Funded by the Natural Science Foundation of China (No.50178070)the Natural Science Foundation of Chongqing (Nos. 8091 and 7136)
文摘To understand the potential impact of the Three Gorges Reservoir on the aquatic ecosystem after the damming of the Yangtze River,we studied the community composition and temporal abundance distribution of algae in two types of water bodies:a segment of the Jialing River near its confluence with the Yangtze River as an example of the river-lake type,and Shuanglong Lake in Chongqing as an example of the lake type.In total,107 species belonging to 58 genera of 7 phyla were identified in the study area of the Jialing River,dominated by three groups with 49.5% diatoms,29.0% chlorophytes,and 11.4% cyanobacteria in the community composition.There were 122 species belonging to 66 genera of 8 phyla in Shuanglong Lake,dominated by the same three groups with 19.7% diatoms,48.4% chlorophytes,and 22.2% cyanobacteria.The densities of total algae and individual dominant groups were all much higher in the lake.More species of diatoms were found in the river-lake segment;whereas more chlorophyte species and cyanobacteriaum species were in the lake.There were 17 dominant species including 8 diatoms,4 chlorophytes,3 cyanobacteria and 2 cryptophytes in the river-lake segment,and 21 species in the lake,including 2 diatoms,9 chlorophytes,6 cyanobacteria,3 cryptophytes and a dinoflagellate.In eutrophic conditions,chlorophytes and cyanobacteria may proliferate in a lake-type area and diatoms may cause algal bloom in a relatively faster-flow lake-river type area.
文摘By mild PAGE method, 11, 11, 7 and 9 chlorophyll_protein complexes were isolated from two species of siphonous green algae (Codium fragile (Sur.) Hariot and Bryopsis corticulans Setch.), green alga (Ulothrix flacca (Dillw.) Thur.), and spinach (Spinacia oleracea Mill.), respectively. Apparent molecular weights, Chl a/b ratios, distribution of chlorophyll, absorption spectra, low temperature fluorescence spectra of these complexes were determined, and compared with one another. PSⅠ complexes of two siphonous green algae are larger in apparent molecular weight because of the attachment of relative highly aggregated LHCⅠ. Four isolated light_harvesting complexes of PSⅡ are all siphonaxanthin_Chl a/b_protein complexes, and they are not monomers and oligomers like those in higher plants. Especially, the absence of 730 nm fluorescence in PSⅠ complexes indicates a distinct structure and energy transfer pattern.
文摘The microbiotic crust study is among new focuses in investigating on the desertification control. Based on determination of algal crusts with different successive ages (4-, 8-, 17-, 34-, 42-year-old) and unconsolidated sand in the desert area, species composition and clustering analyses were carried out in this study. Results on successional orientation revealed that (1) the abundance of Cyanophyta, specially of Scytonema javanicum gradually decreased; (2) the abundance of Chlorophyta, Bacillariophyta and a species of Cyanophyta, Phormidium tenue increased; (3) the biodiversity increased gradually with the community succession; and (4) biomass of microalgae increased at the early stage, but decreased at the later stage due to the abundance of lichens and mosses. But, the speed of natural succession was so slow that the community-building species was still the first dominant species after 42 years, except that its dominant degree decreased just slightly. However, successive speed and trend were affected by water, vegetation coverage, terrain, time and soil physico-chemical properties as well, especially Mn content in the soil appeared to have a threshold effect.
基金Supported by The Project of Shanghai Scientific and Technological Commission(08DZ1203102,08dz1203002,08dz1203101)
文摘To understand the spatial and temporal variation characteristics of blue algae in summer in Lake Dianshan,the phytoplankton in Lake Dianshan from June to September in 2009 was surveyed. It found 11 genera and 28 species blue algae in total. Microcystis,Oscillatoria and Chroococcus were the main composition communities of blue algae in Lake Dianshan in summer. In the survey period,the average density of blue algae in Lake Dianshan was 16.48×106 cells/L which changed during 1.01×106-59.76×106 cells/L. The characteristics were:September > July > August > June. The mass propagation and aggregation of Microcystis in September caused that the water blooms phenomenon in the partial water areas was serious. In the space,the average density of blue algae in the west and southwest parts of Lake Dianshan was bigger than in the east and southeast. When the nutritive matter was sufficient,the temperature was the main factor which affected the generation and disappearance of blue algae water blooms. The wind direction was also an important factor which affected the distribution of blue algae.
基金Supported by Special Project for Marine Fisheries Science and Technology and Industrial Development of Guangdong Province(A201508A05)Regional Demonstration Project of Marine Economy Innovation and Development of Guangdong Province(GD2012-A03-012)~~
文摘[Objective] The biological characteristics and pathogenicities of Shewanella algae and Shewanella abalone from Babylonia were studied in this paper. [Method]The hemolytic bacteria were isolated from the hepatopancreas of Babylonia suffered from proboscis edema with blood agar plate. The dominant bacterial community in the ill Babylonia was identified by 16 S r DNA sequence analysis, and the bacterial cultural and biochemical characteristics and pathogenicities were studied. [Result]The Shewanella bacteria, including Shewanella algae and Shewanella abalone, are the dominant bacterial community in Babylonia suffered from proboscis edema.The colony characteristics of Shewanella algae in nutrient agar medium, TCBS agar medium and CHROMagar vibrio colored medium were similar to those of Shewanella abalone. Shewanella algae possessed β-hemolysis and Shewanella abalone possessed α-hemolysis in the blood agar plate. The biochemical reaction of Shewanella algae and Shewanella abalone was all of non-fermentation type. The results of artificial infection test showed that half lethal dose（LD50） of the test strains of Shewanella algae was 10-5.50/0.1 ml. The test strains of Shewanella algae have strong toxicity, and could cause mice and chickens to die of sepsis with mortality of100%. The mortality of Babylonia infected with Shewanella algae was 10%; while the survived Babylonia lost the ability of moving and intaking for a long time, but they were not suffered from proboscis edema. There was no death in mice or chicks infected with Shewanella abalone, but their livers and spleens were slightly hyperemic and swelling. There was also no death in Babylonia infected with Shewanella abalone, but their intaking and moving ability was lost for a short time.[Conclusion] Although Shewanella algae and Shewanella abalone were the dominant bacteria in Babylonia suffered from proboscis edema, they were not the main pathogenic bacteria for proboscis edema. Shewanella algae had strong pathogenicity to mice, chicks and Babylonia, while Shewanella abalone showed no marked pathogenicity to those experimental animals in this study.
基金Supported by Department of Education Key Item in Guizhou Province (200910040)Guizhou Province UNRISD Research Item (SY20103176)Guizhou Province Fund Item(20082239)~~
文摘[Objective] The research aimed to know the ecological environment pollution characteristics of Hongfeng Lake water area and the evolution rule,which provided the theory basis for improving the water quality condition.[Method] Based on the investigation and research of indoor and outdoor,the water quality,aquatic ecosystem,pollution characteristic of sediment and occurrence law of algae blooms in Hongfeng Lake were comprehensively analyzed by combining with the relevant literatures.[Result] Hongfeng Lake was in moderate-heavy eutrophication situation,and the water quality was V-bad V class.The sediment accumulated a lot of nutrient salt,which was the important pollution source of eutrophication in Hongfeng Lake Reservoir.The aquatic ecosystem degraded,and it was easy to form the algae blooms.[Conclusion] The pollution treatment of Hongfeng Lake was extremely urgent.
基金Supported by China Agriculture Research System (CARS-49)~~
文摘In order to better monitor N and P pollutants, heavy metals, pesticides and other organic pollutants in water areas, we researched sensitivity and tolerance of aquatic algae on water environment and effects of the pollutants on algae population, analyzing toxin and enrichment of pollutants on algae. The results indicated that aquatic alga is a better indicator for some pollutants in water, for which water contamination can be surveyed and analyzed rapidly.
文摘Microcystins (MCYSTs) isolated from blue-green algae,are hepatotoxic polypeptides.It will induce severe intrahepatic hemorrhage and liver necrosis at low concentrations in rats and mice.MCYST- LR is one of MCYSTs which consists of 2 variable L- amino acids(leucine and arginine),3 D-amino acids and 2 unusualamino acids(including Adda).MCYSTs bind to protein phosphatase 1 and 2A,and strongly inhibit their activities.The resultant increase of phosphoprotein was referred to be involved in tumor-promoting activity in liver.According to the above results and animal study,MCYST-LR is a potent liver tumor promoter.There were 9 positive from 30 samples of pond-ditch water in high endemic county-Haimen by high-peformance liquid chromatograph and 3 already confirmed by liquid chromograph/mass spectrometer.The quantities of MCYSTs were different between drinking water of liver cancer cases and controls groups.122±0.057and 0.072±0.044μg/200ml respectively) by ELISA. It is not easy to remove by conventional water treatment procedures.The relationship between MCYSTs and oncogenes and anti-oncogenes are under studying.
基金supported by grants received by Anjali Dash from DST Women Scientist Scheme (DST WOSA)by D.Dash from the Department of Biotechnology (DBT),Govt.of Indiathe Indian Council of Medical Research (ICMR)
文摘Silver nanoparticles,endowed with powerful antimicrobial property,are the most widely used nanomaterial in consumer products,with associated risk of their easy access to environment and freshwater ecosystems by surface runoff.Although toxic effects of nanosilver on bacterial,fungal and mammalian cells have been documented,its impact on algal growth remains unknown.Pithophora oedogonia and Chara vulgaris are predominant members of photosynthetic eukaryotic algae,which form major component of global aquatic ecosystem.Here we report for the first time that nanosilver has significant adverse effects on growth and morphology of these filamentous green algae in a dose-dependent manner.Exposure of algal thalli to increasing concentrations of silver nanoparticles resulted in progressive depletion in algal chlorophyll content,chromosome instability and mitotic disturbance,associated with morphological malformations in algal filaments.SEM micrographs revealed dramatic alterations in cell wall in nanoparticle-treated algae,characterized with cell wall rupture and degradation in Pithophora.Although these observations underscore severe deleterious effects of nanosilver on aquatic environment,the information can also be exploited as a bioengineering strategy to control unwanted and persistent growth of noxious algal weeds that clog the municipal water supply and water channels and produce fouling of water bodies.
基金Project supported by the Special Funds for Ph. D Research Station of University (No. 20020422045)the Science Foundation of Shandong Province (No. Z2003B01)the Environmental Protection Bureau of Shandong Province, China.
文摘Alga-lysing bacteria have been paid much attention to in recent years. In this study, the alga-lysing strain P05 which was isolated from an immobilizing biosystem was immobilized by coke and elastic filler, forming two biological reactors. The removal efficiencies of algae, NH4^＋-N and organic matter using the two reactors were studied. The results showed that strain P05 was an ideal algal-lysing bacteria strain because it was easy to be immobilized by coke and elastic filler which are of cheap, low biodegradability and the simple immobilization procedure. After 7 d filming, the biological film could be formed and the reactors were used to treat the eutrophic water. These two reactors were of stability and high effect with low cost and easy operation. The optimal hydraulic retention time （HRT） of each reactor was 4 h. The algae removal rates were 80.38% and 82.1% （in term of Chl-α） of coke reactor and filler reactor, respectively. And that of NH4^＋-N were 52.3% and 52.7%. The removal rates of CODMn were 39.03% and 39.64%. The strain P05 was identified as Bacillus sp. by PCR amplification of the 16S rRNA gene, BLAST analysis, and comparison with sequences in the GenBank nucleotide database.
