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
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
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
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
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
[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
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
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 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
[Objective] The research aimed to improve the method of isolation of algae.[Method] The samples were cultured in liquid medium after pre-culture in natural medium.[Result]12 species of algae were isolated from the sam...[Objective] The research aimed to improve the method of isolation of algae.[Method] The samples were cultured in liquid medium after pre-culture in natural medium.[Result]12 species of algae were isolated from the sample.[Conclusion] The method is useful and easy to be handled.展开更多
Based on the data of 18 cases during the past 30 years from 1978 to 2007,the major meteorological conditions for outbreak of blue-green alga in Hongze Lake were analyzed.The results showed that the main meteorological...Based on the data of 18 cases during the past 30 years from 1978 to 2007,the major meteorological conditions for outbreak of blue-green alga in Hongze Lake were analyzed.The results showed that the main meteorological conditions that affected the production and outbreak of blue-green alga were unusual high monthly average temperature,less precipitation and more sunshine hours in ten days.Through the selection of 1 or 0 factors on the values of above meteorological conditions over the years,if the conditions were accorded with the outbreak of blue-green alga,the factor was signed as 1,or it would be signed as 0;if there was outbreak of blue-green alga within ten days,it was signed as 1,or it would be signed as 0;crossing interrelated and integrated prediction method was adopted to establish the prediction equation for outbreak of blue-green alga,the historical fitting rate was 87.5%,and the predicting accuracy rate in 2008-2009 was 87.5%.In addition to meteorological conditions,outbreak of blue-green alga was also influenced by industrial pollutions,etc.,which should be considered in the forecasting procedures.展开更多
Algae play a crucial role in the evolution of earth and life on earth,and also the cycle of matter.With its unique physiological and ecological properties and strong reproductive capacity,algae deeply influence the fo...Algae play a crucial role in the evolution of earth and life on earth,and also the cycle of matter.With its unique physiological and ecological properties and strong reproductive capacity,algae deeply influence the formation and development of karst.During the formation of tufa landscapes in Huanglong Scenic Area,the coloration,precipitation and corrosion of algae acting on tufa always concordantly exist.The algae living in water add gay colors to the tufa landscapes.The carbonate precipitation facilitated by algae is an important biological cause of the formation of tufa.As the external environmental conditions change,for instance,the shortage of karst water in tufa landscapes,the coloration and powerful corrosion of algae will stand out,which will badly affect the development and visual value of tufa landscapes.By studying the functions of algae in the tufa landscapes of Huanglong Scenic Area,this research was to provide scientific basis for the future study and protection of tufa landscapes.展开更多
Ultrasonic and jet combined process was studied to remove determined by static experiments, and stability of this combined process algae in lake type raw water. The optimum reaction time was was checked by dynamic exp...Ultrasonic and jet combined process was studied to remove determined by static experiments, and stability of this combined process algae in lake type raw water. The optimum reaction time was was checked by dynamic experiments. The results was showed that ultrasonic/jet combined process has excellent removal efficiency on algae in lake type raw water, and it＇s a simple operation, and has no secondary pollution. When the pH, temperature, chlorophyll-a（Chl-a） and cell concentration（OD560） of raw water are 7.69, 25.8 ℃, 29.003 mg/m^3 and 0.091, the average removal efficiency on Chl-a and OD560 are 81.60% and 80.22%, respectively, which are stable by this combined process when it is operating in 36 hours, and samples are analyzed each 4 hours.展开更多
Antioxidant efficiency was studied in fresh edible algae： Cladophora, Microspara and Nostochopsis spp. from Nan River, Nan province. The samples were collected from Pua and Tha-Wang-Pha district, studied antioxidant ...Antioxidant efficiency was studied in fresh edible algae： Cladophora, Microspara and Nostochopsis spp. from Nan River, Nan province. The samples were collected from Pua and Tha-Wang-Pha district, studied antioxidant activity and compared the antioxidant efficacy of the extracts from the three fresh edible algae with a standard solution, 3-tert-butyl-4-hydroxyanisole （BHA）. This study found that an extract ofNostochopsis spp. was the highest antioxidant activity to DPPH free radical between 32.1 and 87.5, the highest amount of beta-carotene was 4.71-7.09 mg/g and the highest amount of phenol in fresh edible algae extracts from Microspora was between 9.37 and 37.02 mg/g. The highest vitamin C in Microspora was between 110.41-138.53 mg/100 g.展开更多
Three different solvents viz ethanol, acetone and methanol toluene (3:1) were used to extract antibiotics from 23 species of marine algae belonging to the Chlorophyta, Phaeophyta and Rhodophyta. Their crude extracts w...Three different solvents viz ethanol, acetone and methanol toluene (3:1) were used to extract antibiotics from 23 species of marine algae belonging to the Chlorophyta, Phaeophyta and Rhodophyta. Their crude extracts were tested for antibacterial and antifungal activities. Among them, the ethanol extract showed the strongest activity against the bacteria and fungi tested. Four species of the Rhodophyta ( Laurencia okamurai, Dasya scoparia, Grateloupia filicina and plocamium telfairiae ) showed a wide spectrum of antibacterial activity. Every solvent extract from the four species was active against all the bacteria tested. The test bacterium Pseudomonas solancearum and the fungus Penicilium citrinum were most sensitive to the extracts of marine algae. In general, the extracts of seaweeds inhibited bacteria more strongly than fungi and species of the Rhodophyta showed the greatest activity against the bacteria and fungi tested.展开更多
This work aims at characterizing organic matter produced by an alga Euglena gracil~ and a cyanobacteria Microcystis aeruginosa and assessing the evolution of its characteristics during growth. A culture medium was opt...This work aims at characterizing organic matter produced by an alga Euglena gracil~ and a cyanobacteria Microcystis aeruginosa and assessing the evolution of its characteristics during growth. A culture medium was optimized. The species growth phases were monitored using both visible spectrophotometry and flow cytometry cell counting. Organic matter fractionation according to hydrophobicity and specific UV absorbance （SUVA） index were used to specifically characterize the produced algal organic matter （AOM）. The AOM characteristics were both growth phase and species dependent. However, a similar evolution was observed. The hydrophilic fraction （HPI） was the major fraction whatever the growth phases and was almost the only one produced during lag and exponential phases. It represented around 75% of AOM during exponential phase and then decreased when the stationary phase appeared. It represented 46% and 60% of the AOM during late decline phase for the cyanobacteria and the alga respectively. The hydrophobic （HPO） and transphilic （TPH） fractions started to appear from the beginning of the stationary phase with more hydrophobic compounds coming from intracellular organic material of dying cells. HPO and TPH percentages still increased during the decline phase probably because of two additional processes： photo-dissolution and leaching of particulate organic matter from cells fragments. A comparison of AOM during late decline phase and natural organic matter （NOM） from Glane River （France） underlined that AOM was more fiydrophilic and presented a lower SUVA for each fractions than NOM. However, the difference between NOM and AOM hydrophobicity narrowed during decline phase.展开更多
Photodegradation of Norfloxacin in aqueous solution containing algae under a medium pressure mercury lamp （15 W, λmax -365nm） was investigated. Results indicated that the photodegradation of Norfloxacin could be in...Photodegradation of Norfloxacin in aqueous solution containing algae under a medium pressure mercury lamp （15 W, λmax -365nm） was investigated. Results indicated that the photodegradation of Norfloxacin could be induced by the algae in the heterogeneous algaewater systems. The photodegradation rate of Norfloxacin increased with increasing algae concentration, and was greatly influenced by the temperature and pH of solution. Meanwhile, the cooperation action of algae and Fe（III）, and the ultrasound were beneficial to photodegradation of Norfloxacin. The degradation kinetics of Norfloxacin was found to follow the pseudo zero-order reaction in the suspension of algae. In addition, we discussed the photodegradation mechanism of Norfloxacin in the suspension of algae. This work will be helpful for understanding the photochemical degradation of antibiotics in aqueous environment in the presence of algae, for providing a new method to deal with antibiotics pollution.展开更多
Experiments on the effects of nitric oxide （NO） and iron on the growth of marine microalgae Skeletonema costatum were conducted. The results are as follows： exogenous NO could increase the growth rate of marine alg...Experiments on the effects of nitric oxide （NO） and iron on the growth of marine microalgae Skeletonema costatum were conducted. The results are as follows： exogenous NO could increase the growth rate of marine algae and raise the biomass remarkably under iron-deficient conditions. But it was a complicated process that the phytoplankton growth was influenced by NO and iron, which was controlled by the NO concentration, the nutrition level of the culture medium and the iron concentration, etc. Meanwhile, the iron concentration in the medium also has a direct influence on the growth and NO release capacity of the algae. Therefore, the effects of NO and iron on the growth of marine phytoplankton were mutual.展开更多
Besides competing with algae for light and mineral nutrients (i. e. N, P, etc.), the root system of Acorus tatarinowii excretes some chemical substances, which injure and eliminate alga cells, to inhibit the growth of...Besides competing with algae for light and mineral nutrients (i. e. N, P, etc.), the root system of Acorus tatarinowii excretes some chemical substances, which injure and eliminate alga cells, to inhibit the growth of the algae. When the algae cells were treated in 'A. tatarinowii water', some of the chlorophyll a were destroyed and the photosynthetic rate of algae decreased markedly and the ability of alga cells to deoxidize triphenyltetrazolium chloride (TTC) reduced greatly. Then alga cells turned from bright red to bluish green under fluorescence microscope. These showed that the allelopathic effects of A. tatarinowii on algae were obvious and planting A. tatarinowii can control some green algae. The experiment on the extractions of the secretions of the root system showed that the inhibitory effect had a concentration effect. If the concentration of the root secretion was below 30 μl/disc, the inhibitory rate was negative; if it was over 45 μl/disc, the inhibitory rate was positive. This proved that the influence of the root secretion on the same acceptor was a kind of concentration effect. When the concentration of the root secretion was low, it promoted the growth of algae; when the concentration reached a definite threshold value, it restrained the growth of algae. In present case, the threshold value was between 30 μl/disc and 45 μl/disc.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.
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.
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 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.
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 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.
文摘[Objective] The research aimed to improve the method of isolation of algae.[Method] The samples were cultured in liquid medium after pre-culture in natural medium.[Result]12 species of algae were isolated from the sample.[Conclusion] The method is useful and easy to be handled.
文摘Based on the data of 18 cases during the past 30 years from 1978 to 2007,the major meteorological conditions for outbreak of blue-green alga in Hongze Lake were analyzed.The results showed that the main meteorological conditions that affected the production and outbreak of blue-green alga were unusual high monthly average temperature,less precipitation and more sunshine hours in ten days.Through the selection of 1 or 0 factors on the values of above meteorological conditions over the years,if the conditions were accorded with the outbreak of blue-green alga,the factor was signed as 1,or it would be signed as 0;if there was outbreak of blue-green alga within ten days,it was signed as 1,or it would be signed as 0;crossing interrelated and integrated prediction method was adopted to establish the prediction equation for outbreak of blue-green alga,the historical fitting rate was 87.5%,and the predicting accuracy rate in 2008-2009 was 87.5%.In addition to meteorological conditions,outbreak of blue-green alga was also influenced by industrial pollutions,etc.,which should be considered in the forecasting procedures.
基金Supported by the National Natural Science Fund ( 40872197, 40402004,40872168)~~
文摘Algae play a crucial role in the evolution of earth and life on earth,and also the cycle of matter.With its unique physiological and ecological properties and strong reproductive capacity,algae deeply influence the formation and development of karst.During the formation of tufa landscapes in Huanglong Scenic Area,the coloration,precipitation and corrosion of algae acting on tufa always concordantly exist.The algae living in water add gay colors to the tufa landscapes.The carbonate precipitation facilitated by algae is an important biological cause of the formation of tufa.As the external environmental conditions change,for instance,the shortage of karst water in tufa landscapes,the coloration and powerful corrosion of algae will stand out,which will badly affect the development and visual value of tufa landscapes.By studying the functions of algae in the tufa landscapes of Huanglong Scenic Area,this research was to provide scientific basis for the future study and protection of tufa landscapes.
文摘Ultrasonic and jet combined process was studied to remove determined by static experiments, and stability of this combined process algae in lake type raw water. The optimum reaction time was was checked by dynamic experiments. The results was showed that ultrasonic/jet combined process has excellent removal efficiency on algae in lake type raw water, and it＇s a simple operation, and has no secondary pollution. When the pH, temperature, chlorophyll-a（Chl-a） and cell concentration（OD560） of raw water are 7.69, 25.8 ℃, 29.003 mg/m^3 and 0.091, the average removal efficiency on Chl-a and OD560 are 81.60% and 80.22%, respectively, which are stable by this combined process when it is operating in 36 hours, and samples are analyzed each 4 hours.
文摘Antioxidant efficiency was studied in fresh edible algae： Cladophora, Microspara and Nostochopsis spp. from Nan River, Nan province. The samples were collected from Pua and Tha-Wang-Pha district, studied antioxidant activity and compared the antioxidant efficacy of the extracts from the three fresh edible algae with a standard solution, 3-tert-butyl-4-hydroxyanisole （BHA）. This study found that an extract ofNostochopsis spp. was the highest antioxidant activity to DPPH free radical between 32.1 and 87.5, the highest amount of beta-carotene was 4.71-7.09 mg/g and the highest amount of phenol in fresh edible algae extracts from Microspora was between 9.37 and 37.02 mg/g. The highest vitamin C in Microspora was between 110.41-138.53 mg/100 g.
基金ThisworkwassupportedbyProject(JB 980 2 5 )ofFujianProvince China .
文摘Three different solvents viz ethanol, acetone and methanol toluene (3:1) were used to extract antibiotics from 23 species of marine algae belonging to the Chlorophyta, Phaeophyta and Rhodophyta. Their crude extracts were tested for antibacterial and antifungal activities. Among them, the ethanol extract showed the strongest activity against the bacteria and fungi tested. Four species of the Rhodophyta ( Laurencia okamurai, Dasya scoparia, Grateloupia filicina and plocamium telfairiae ) showed a wide spectrum of antibacterial activity. Every solvent extract from the four species was active against all the bacteria tested. The test bacterium Pseudomonas solancearum and the fungus Penicilium citrinum were most sensitive to the extracts of marine algae. In general, the extracts of seaweeds inhibited bacteria more strongly than fungi and species of the Rhodophyta showed the greatest activity against the bacteria and fungi tested.
基金the FEDER (European Found forRegional Development)the Regional Council of Limousin for their financial supportnt
文摘This work aims at characterizing organic matter produced by an alga Euglena gracil~ and a cyanobacteria Microcystis aeruginosa and assessing the evolution of its characteristics during growth. A culture medium was optimized. The species growth phases were monitored using both visible spectrophotometry and flow cytometry cell counting. Organic matter fractionation according to hydrophobicity and specific UV absorbance （SUVA） index were used to specifically characterize the produced algal organic matter （AOM）. The AOM characteristics were both growth phase and species dependent. However, a similar evolution was observed. The hydrophilic fraction （HPI） was the major fraction whatever the growth phases and was almost the only one produced during lag and exponential phases. It represented around 75% of AOM during exponential phase and then decreased when the stationary phase appeared. It represented 46% and 60% of the AOM during late decline phase for the cyanobacteria and the alga respectively. The hydrophobic （HPO） and transphilic （TPH） fractions started to appear from the beginning of the stationary phase with more hydrophobic compounds coming from intracellular organic material of dying cells. HPO and TPH percentages still increased during the decline phase probably because of two additional processes： photo-dissolution and leaching of particulate organic matter from cells fragments. A comparison of AOM during late decline phase and natural organic matter （NOM） from Glane River （France） underlined that AOM was more fiydrophilic and presented a lower SUVA for each fractions than NOM. However, the difference between NOM and AOM hydrophobicity narrowed during decline phase.
基金supported by A Project Funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions (PAPD) (No. 1105007001)
文摘Photodegradation of Norfloxacin in aqueous solution containing algae under a medium pressure mercury lamp （15 W, λmax -365nm） was investigated. Results indicated that the photodegradation of Norfloxacin could be induced by the algae in the heterogeneous algaewater systems. The photodegradation rate of Norfloxacin increased with increasing algae concentration, and was greatly influenced by the temperature and pH of solution. Meanwhile, the cooperation action of algae and Fe（III）, and the ultrasound were beneficial to photodegradation of Norfloxacin. The degradation kinetics of Norfloxacin was found to follow the pseudo zero-order reaction in the suspension of algae. In addition, we discussed the photodegradation mechanism of Norfloxacin in the suspension of algae. This work will be helpful for understanding the photochemical degradation of antibiotics in aqueous environment in the presence of algae, for providing a new method to deal with antibiotics pollution.
基金The authors thank Zhu Mingyuan for critically reading the manuscript.This study was supported by the National Natural Science Foundation of China under contract Nos 40076020 and 40376022the National“973”Project of China under coutract No.2001CB409700the Doctoral Program of Higher Education of China under contract No.20030423007.
文摘Experiments on the effects of nitric oxide （NO） and iron on the growth of marine microalgae Skeletonema costatum were conducted. The results are as follows： exogenous NO could increase the growth rate of marine algae and raise the biomass remarkably under iron-deficient conditions. But it was a complicated process that the phytoplankton growth was influenced by NO and iron, which was controlled by the NO concentration, the nutrition level of the culture medium and the iron concentration, etc. Meanwhile, the iron concentration in the medium also has a direct influence on the growth and NO release capacity of the algae. Therefore, the effects of NO and iron on the growth of marine phytoplankton were mutual.
基金TheNationalNaturalScienceFoundationofChinaandthe"Ninth five"significantBitem (No .KZ 95 1 B1 2 0 1)oftheChineseAcademyofScie
文摘Besides competing with algae for light and mineral nutrients (i. e. N, P, etc.), the root system of Acorus tatarinowii excretes some chemical substances, which injure and eliminate alga cells, to inhibit the growth of the algae. When the algae cells were treated in 'A. tatarinowii water', some of the chlorophyll a were destroyed and the photosynthetic rate of algae decreased markedly and the ability of alga cells to deoxidize triphenyltetrazolium chloride (TTC) reduced greatly. Then alga cells turned from bright red to bluish green under fluorescence microscope. These showed that the allelopathic effects of A. tatarinowii on algae were obvious and planting A. tatarinowii can control some green algae. The experiment on the extractions of the secretions of the root system showed that the inhibitory effect had a concentration effect. If the concentration of the root secretion was below 30 μl/disc, the inhibitory rate was negative; if it was over 45 μl/disc, the inhibitory rate was positive. This proved that the influence of the root secretion on the same acceptor was a kind of concentration effect. When the concentration of the root secretion was low, it promoted the growth of algae; when the concentration reached a definite threshold value, it restrained the growth of algae. In present case, the threshold value was between 30 μl/disc and 45 μl/disc.
