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
This study analyzes the community structure, the quantity changes of the algae and the effect of important environmental factors and estimates the total biomass of the attached green algae in the survey areas. The stu...This study analyzes the community structure, the quantity changes of the algae and the effect of important environmental factors and estimates the total biomass of the attached green algae in the survey areas. The study uses data from surveys of the attached green algae on the Porphyra yezoensis aquaculture rafts and data regarding the environmental factors from October 2010 to April 2011 in the Subei Shoal. The attached green algae on the rafts included Ulva prolifera, Capsosiphon groenlandicus, U. linza, U. intestinalis, U. clathrata, and U. cornpressa. The biomass changes of the attached green algae exhibited an inverted parabola： the biomass was the highest （14 898 t） in April, and was the second highest （2 034 t） in November; it was lowest in February （only 729 t） and increased sharply from March to April. The species diversity differed significantly among the seasons. In September and October, when the P. yezoensis aquaculture rafts were initially set up, the attached green algae had a high biodiversity, while from December to the next February, a variety of green algae species coexisted on the rafts, although the biomass was low, and from March to April, as the biomass increased sharply, the species diversity dropped to the minimum. During this time, C. groenlandicus was apparently dominant with the maximum biomass proportion up to 80%, while the U. prolifera proportion increased exponentially to 20% to 40%. The water temperature had a direct regulating effect on the biomass and the species succession of the attached green algae. The estimation of the community dynamics and the biomass of the green algae provided the evidence needed to track the origin of the large-scale green tide in the southern Yellow Sea.展开更多
The toxicity of methyl tert-butyl ether （MTBE） to Chlorella ellipsoidea and Aphanizomenon flos-aquae was tested and assessed for a 15-d incubation with concentrations of MTBE from high （2.00×10^4 mg/L） to low...The toxicity of methyl tert-butyl ether （MTBE） to Chlorella ellipsoidea and Aphanizomenon flos-aquae was tested and assessed for a 15-d incubation with concentrations of MTBE from high （2.00×10^4 mg/L） to low （2 mg/L）. The results showed that the toxicity was low when the concentration of MTBE was in the range 1.00× 10^4-2.00× 10^4 mg/L （the greatest inhibition of growth-rate was 70%-71%, occurred during the day 1-5）. Low concentrations （2-500 rag/L） stimulated algal growth up to the greatest effect of 85%-200% when the concentration of MTBE was 50-100 mg/L during day 3-5. The toxicity of MTBE （72-120 h EC50） was 6.65×10^3-9.58×10^3 mg/L for C. ellipsoidea and that is 1.14× 10^4-2.00× 10^4 mg/L for A. floc-aquae. We found that the toxicity and ecological risk of MTBE for the algal community structure were low and the toxicity was influenced by the duration time of the test.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
We report that green algae in lakes and rivers can serve as precursors of halobenzoquinone（HBQ） disinfection byproducts（DBPs） produced during chlorination. Chlorination of a common green alga, Chlorella vulgaris, ...We report that green algae in lakes and rivers can serve as precursors of halobenzoquinone（HBQ） disinfection byproducts（DBPs） produced during chlorination. Chlorination of a common green alga, Chlorella vulgaris, produced 2,6-dichloro-1,4-benzoquinone（2,6-DCBQ）, the most prevalent HBQ DBP in disinfected water. Under varying p H conditions（p H 6.0–9.0）, 2,6-DCBQ formation ranged from 0.3 to 2.1 μg/mg C with maximum formation at p H 8.0. To evaluate the contribution of organic components of C. vulgaris to 2,6-DCBQ formation, we separated the organics into two fractions, the protein-rich fraction of intracellular organic matter（IOM） and the polysaccharide-laden fraction of extracellular organic matter（EOM）. Chlorination of IOM and EOM produced 1.4 μg/mg C and 0.7 μg/mg C of 2,6-DCBQ, respectively. The IOM generated a two-fold higher 2,6-DCBQ formation potential than the EOM fraction, suggesting that proteins are potent 2,6-DCBQ precursors. This was confirmed by the chlorination of proteins extracted from C. vulgaris： the amount of 2,6-DCBQ produced is linearly correlated with the concentration of total algal protein（R2= 0.98）. These results support that proteins are the primary precursors of 2,6-DCBQ in algae, and control of green algal bloom outbreaks in source waters is important for management of HBQ DBPs.展开更多
To provide theoretical and technical basis for the application of preparations of bamboo vinegar and copper sulfate in the prevention of green algae in floating system for tobacco seeding,the soaking and spraying meth...To provide theoretical and technical basis for the application of preparations of bamboo vinegar and copper sulfate in the prevention of green algae in floating system for tobacco seeding,the soaking and spraying methods were employed to study the effect of different concentrations of preparations of bamboo vinegar and copper sulfate on green algae and tobacco seedling growth. The results showed that the preparations of bamboo vinegar and copper sulfate of different concentrations played a strong role in inhibiting green algae growth and had better effect than copper sulfate. Spraying 1∶ 200 preparations of bamboo vinegar and copper sulfate could significantly promote tobacco seedling growth,and the leaf fresh weight increased by 15. 80% compared with CK,with significant difference; spraying 1∶ 50 preparations was not conducive to tobacco seedling growth. It was recommended to spray 1∶ 200 preparations of bamboo vinegar and copper sulfate in floating system for tobacco seeding,which could promote tobacco seedling growth and reduce green algae to varying degrees.展开更多
Reduced walleye (<i></span><i><span style="font-family:Verdana;">Sander vitreus</span></i><span style="font-family:Verdana;"></i></span><spa...Reduced walleye (<i></span><i><span style="font-family:Verdana;">Sander vitreus</span></i><span style="font-family:Verdana;"></i></span><span style="font-family:Verdana;">) fingerling production possibly related to nuisance filamentous green algae and overly</span></span><span style="font-family:""> </span><span style="font-family:""><span style="font-family:Verdana;">stable water chemistry patterns is a concern in earthen-substrate ponds at Blue Dog State Fish Hatchery, South Dakota, USA. We describe the success of alfalfa (<i></span><i><span style="font-family:Verdana;">Medicago sativa</span></i><span style="font-family:Verdana;"></i></span><span style="font-family:Verdana;">) meal (AFM, n</span></span><span style="font-family:""> </span><span style="font-family:Verdana;">=</span><span style="font-family:""> </span><span style="font-family:""><span style="font-family:Verdana;">2), alfalfa meal plus soybean (<i></span><i><span style="font-family:Verdana;">Glycine max</span></i><span style="font-family:Verdana;"></i></span><span style="font-family:Verdana;">) meal (AFM</span></span><span style="font-family:""> </span><span style="font-family:Verdana;">+</span><span style="font-family:""> </span><span style="font-family:Verdana;">SBM, n</span><span style="font-family:""> </span><span style="font-family:Verdana;">=</span><span style="font-family:""> </span><span style="font-family:Verdana;">1), and alfalfa meal plus liquid 28N:0P:0K (AFM</span><span style="font-family:""> </span><span style="font-family:Verdana;">+</span><span style="font-family:""> </span><span style="font-family:Verdana;">28:0:0, n</span><span style="font-family:""> </span><span style="font-family:Verdana;">=</span><span style="font-family:""> </span><span style="font-family:Verdana;">1) at achieving</span><span style="font-family:Verdana;"> walleye production objectives (>104,000 walleye and 32 kilograms/hectare) as well as the occurrence of filamentous green algae and the associated patterns of ammonia-nitrogen, pH, and dissolved oxygen in earthen-substrate ponds. Walleye production objectives were only achieved when filamentous green algae were absent preceding harvest, which occurred in one pond that received AFM and in the pond that received AFM</span><span style="font-family:""> </span><span style="font-family:Verdana;">+</span><span style="font-family:""> </span><span style="font-family:Verdana;">28:0:0.</span><span style="font-family:""> </span><span style="font-family:Verdana;">The presence of filamentous green algae preceding harvest was associated with higher dissolved oxygen and pH, whereas declines in these variables occurred when filamentous green algae were absent. Organic fertilizer alone exhibited low ammonia-nitrogen (<0.1 mg/L) despite the substitution of higher protein content soybean meal, but supplementation with 28:0:0 increased ammonia-nitrogen to 0.23 mg/L. These findings highlight the reduction in walleye fingerling production that occurred in the presence of filamentous green algae and the unpredictability of results when two earthen-substrate ponds are treated exactly the same with alfalfa meal. Achievement of walleye production objectives, lack of nuisance filamentous green algae, and promotion of</span><span style="font-family:""> </span><span style="font-family:Verdana;">favorable patterns in water chemistry warrant future experimentation with alfalfa meal supplemented with 28:0:0 in earthen-substrate ponds at this hatchery.展开更多
In general, many pollutants co\|exist in natural aquatic ecosystems. They affect each other and occur different results, such as synergism, addition and antagonism. So the research at mixtoxicity of contaminants to aq...In general, many pollutants co\|exist in natural aquatic ecosystems. They affect each other and occur different results, such as synergism, addition and antagonism. So the research at mixtoxicity of contaminants to aquatic organism is more important than monotoxicity. In this paper, 50% effectual inhibition concentration 48h \%EC\%\-\{50\} values of 6 kinds of nitroaromatic compounds to the green algae, \%Scenedesmus obliquus,\% were investigated. Mixtoxic experiments, in which any combination of 2,4\|DNT and other 6 kinds of compounds, indicate: (1) synergisms between 2,4\|DNT and 4\|NAn, as well as 4\|NAnis, 1,4\|DNB; (2) antagonisms between 2,4\|DNT and 4\|NT, as well as 4\|NPh, 4\|NCB.展开更多
Macroalgae blooms of Ulva prolifera have occurred every summer in the southern Yellow Sea since 2007,inducing severe ecological problems and huge economic losses.Genesis and secular movement of green algae blooms have...Macroalgae blooms of Ulva prolifera have occurred every summer in the southern Yellow Sea since 2007,inducing severe ecological problems and huge economic losses.Genesis and secular movement of green algae blooms have been well monitored by using remote sensing and other methods.In this study,green algae were detected and traced by using Geostationary Ocean Color Imager(GOCI),and a novel biomass estimation model was developed from the relationship between biomass measurements and previously published satellite-derived biomass indexes.The results show that the green algae biomass can be determined most accurately with the biomass index of green algae for GOCI(BIGAG),which is calculated from the Rsurf data that had been atmospherically corrected by ENVI/QUAC method.For the first time,dynamic changes in green algae biomass were studied over an hourly scale.Short-term biomass changes were highly influenced by Photosynthetically Available Radiation(PAR)and tidal phases,but less by sea surface temperature variations on a daily timescale.A new parameter of biomass changes(PBC),calculated by the ratio of the biomass growth rate to movement velocity,could provide an effective way to assess and forecast green tide in the southern Yellow Sea and similar areas.展开更多
With the proceeding of global warming and water eutrophication,the phenomenon of green tide has garnered significant societal interest.Consequently,researchers had increasingly focused on the potential applications of...With the proceeding of global warming and water eutrophication,the phenomenon of green tide has garnered significant societal interest.Consequently,researchers had increasingly focused on the potential applications of green algae biomass,particularly its polysaccharides.The polysaccharide serves as the primary active constituent of green algae and has demonstrated numerous advantageous biological activities,including antioxidant,antiviral,anticoagulant,hypolipidemic and immuno-modulatory activities.The favorable bioavailability and solubility of green algae oligosaccharides are attributed to their low molecular weight.So there has been a growing interest in researching green algae polysaccharides and oligosaccharides for the utilization of marine biological resources.This review summarized the extraction,purification,chemical structure,composition,biological activity,and potential applications prospect of polysaccharides and oligosaccharides derived from green algae.The review could be helpful for expanding the applications of polysaccharides and oligosaccharides of green algae.展开更多
A gradient reversed-phase high-performance liquid chromatography(HPLC)method using a C30 col-umn was developed for the simultaneous determination of astaxanthin,astaxanthin monoesters and astaxanthin diesters in the g...A gradient reversed-phase high-performance liquid chromatography(HPLC)method using a C30 col-umn was developed for the simultaneous determination of astaxanthin,astaxanthin monoesters and astaxanthin diesters in the green algae Chlorococcum sp.,Chlorella zofingiensis,Haematococcus plu-vialis and the mutant E1,which was obtained from the mutagenesis of H.pluvialis by exposure to UV-irradiation and ethyl methanesulphonate(EMS)with subsequent screening using nicotine.The re-sults showed that the contents of total astaxanthins including free astaxanthin and astaxanthin esters ranged from 1.4 to 30.9 mg/g dry biomass in these green algae.The lower total astaxanthin levels(<2 mg/g dry biomass)were detected in the green algae Chlorococcum sp.and C.zofingiensis.The higher total astaxanthin levels(>16 mg/g dry biomass)were found in the green alga H.pluvialis and its mutant E1.It is notable that the mutant E1 is found to have considerably higher amounts of total astaxanthin(30.9 mg/g)as compared to the wild strain of H.pluvialis(16.1 mg/g).This indicates that UV-irradiation and EMS compound mutagenesis with subsequent screening using nicotine is an effective method for breeding of a high-producing astaxanthin strain of H.pluvialis.In addition,the green alga C.zofingien-sis had a remarkably higher percentage of astaxanthin diesters(76.3%of total astaxanthins)and a re-markably lower percentage of astaxanthin monoesters(18.0%of total astaxanthins)in comparison with H.pluvialis(35.5%for diesters and 60.9%for monoesters),the mutant E1(49.1%and 48.1%)and Chlorococcum sp.(18.0%and 58.6%).展开更多
Microalgae,such as Chlorella vulgaris Beijerinck(green algae),are beneficial microscopic organisms that may help plants to improve nutrient uptake,growth,and abiotic tolerance to stressors.The current study was perfor...Microalgae,such as Chlorella vulgaris Beijerinck(green algae),are beneficial microscopic organisms that may help plants to improve nutrient uptake,growth,and abiotic tolerance to stressors.The current study was performed to investigate the effectiveness of algae(Chlorella vulgaris Beijerinck)foliar applications[1%,3%,or 5%(v/v)]on mitigation of drought stress in broccoli plants subjected to water deficit at 25%of field capacity.The results showed that the broccoli plants grown under drought stress alone exhibited severe disturbance in growth with considerable reductions in the shoot length,and fresh and dry weights,leaf area,relative water content,leaf water potential,and photosynthetic pigment contents and elevated levels of the lipid peroxidation product malondialdehyde in the leaves.Additionally,the foliar application of microalgae mitigated the detrimental effects of drought,leading to better growth performance(increase of 9%–132%)when compared with the drought-stressed plants that had not received an application of microalgae.Microalgae-mediated beneficial effects were particularly evident in the enhancement of the photosynthetic pigment contents,including chlorophyll-a(6%–60%),chlorophyll-b(19%–55%),and total carotenoids(26%–114%).Exogenous microalgae also contributed to the reduction of membrane damage,as proven by significantly decreased levels of malondialdehyde(10%–39%)in the leaves of the broccoli plants exposed to drought stress.The application of microalgae increased the total flavonoid and phenolic contents,and nutrition uptake.Furthermore,the activities of enzymatic antioxidants like ascorbate peroxidase,catalase,glutathione reductase,and superoxide dismutase increased in response to mediation,resulting in significant alleviation of drought-induced oxidative damage.The most effective application concentration of microalgae was determined as 5%.Overall investigations revealed that the foliar application of microalgae could be recommended as a sustainable strategy to improve the defense system of drought-stressed broccoli plants.展开更多
The marine green alga Chaetomorpha valida fouls aquaculture ponds along the coastal cities of Dalian and Rongcheng, China. Unialgal cultures were observed under a microscope to determine the developmental morphologica...The marine green alga Chaetomorpha valida fouls aquaculture ponds along the coastal cities of Dalian and Rongcheng, China. Unialgal cultures were observed under a microscope to determine the developmental morphological characters of C. valida. Results reveal that gametophytic filaments often produce lateral branches under laboratory culture conditions, suggesting an atypical heteromorphic life cycle of C. valida between unbranched sporophytes and branched gametophytes, which differs from typical isomorphic alternation of Chaetomorpha species. The shape of the basal attachment cell, an important taxonomic character within the genus, was found variable depending on environmental conditions. The 18S rDNA and 28S rDNA regions were used to explore the phylogenetic affinity of the taxa. Inferred trees from 18S rDNA sequences revealed a close relationship between C. valida and Chaetomorpha moniligera. These results would enrich information in general biology and morphological plasticity of C. valida and provided a basis for future identification of green tide forming algae.展开更多
The Mesozoic and Cenozoic strata in the Junggar basin developed two sets of shallow to semi-deep lacustrine shale, namely, the Cretaceous Qingshuihe Formation (K_(1q)) and the Paleogene Anjihaihe Formation (E_(2-3a))....The Mesozoic and Cenozoic strata in the Junggar basin developed two sets of shallow to semi-deep lacustrine shale, namely, the Cretaceous Qingshuihe Formation (K_(1q)) and the Paleogene Anjihaihe Formation (E_(2-3a)). Through organic petrology and scanning electron microscope (SEM) observation, it is found that the primary hydrocarbon-generating organic matter (OM) in the two sets of strata is different. The biological precursor of the E_(2-3a) OM is mainly green algae (Pediastrum), while the precursor of K_(1q) kerogen is mainly cyanobacteria (Oscillatoria). Then, the E_(2-3a) green algae-rich shale and K_(1q) cyanobacteria-rich shale were subjected to hydrous pyrolysis and kinetic analysis, respectively. The results show that the evolution modes of hydrocarbon generation of the typical shales are very different. Green algae have the characteristics of a low oil generation threshold, heavy oil quality, and no prominent oil peak, while cyanobacteria have the characteristics of late oil generation, concentrated hydrocarbon generation, and relatively light oil quality. The characteristics of oil generation can also be well reflected in the composition evolution of the crude oil components. The carbon isotope of gas, kerogen, and extracts of the E_(2-3a) green algae-rich shale are significantly heavier than the K_(1q) cyanobacteria-rich shale, which may be related to the living habits of their biological precursors, carbon source usage, photosynthesis efficiency, and carbon fixation efficiency.展开更多
All algae documented so far are of unknown origin. Here, we provide a taxonomic description of the first origin-known alga TDX16-DE that arises from the <i><span style="font-family:Verdana;">Chro...All algae documented so far are of unknown origin. Here, we provide a taxonomic description of the first origin-known alga TDX16-DE that arises from the <i><span style="font-family:Verdana;">Chroococcidiopsis</span></i><span style="font-family:Verdana;">-like endosymbiotic cyanobacterium TDX16 by de novo organelle biogenesis after acquiring its green algal host</span><i><span style="font-family:Verdana;"> Haematococcus pluvialis</span></i><span style="font-family:Verdana;">’s DNA. TDX16-DE is spherical or oval, with a diameter of 2.0-3.6 μm, containing typical chlorophyte pigments of chlorophyll a, chlorophyll b and lutein and reproducing by autosporulation, whose 18S rRNA gene sequence shows the highest similarity of 99.7% to that of </span><i><span style="font-family:Verdana;">Chlorella vulgaris</span></i><span style="font-family:Verdana;">. However, TDX16-DE is only about half the size of</span><i><span style="font-family:Verdana;"> C. vulgaris </span></i><span style="font-family:Verdana;">and structurally similar to</span><i><span style="font-family:Verdana;"> C. vulgaris</span></i><span style="font-family:Verdana;"> only in having a chloroplast-localized pyrenoid, but differs from</span><i><span style="font-family:Verdana;"> C. vulgaris</span></i><span style="font-family:Verdana;"> in that 1) it possesses a double-membraned cytoplasmic envelope but lacks endoplasmic reticulum and Golgi apparatus;and 2) its nuc</span><span style="font-family:Verdana;">leus is enclosed by two sets of envelopes (four</span><span style="font-family:;" "=""> </span><span style="font-family:Verdana;">unit membranes). Therefore</span><span style="font-family:;" "=""><span style="font-family:Verdana;">, based on these characters and the cyanobacterial origin, we describe TDX16-DE as a new genus and species, </span><i><span style="font-family:Verdana;">Chroococcidiorella tianjinensis</span></i><span style="font-family:Verdana;"> gen. et sp. nov., which sets the basis for multidisciplinary research.</span></span>展开更多
Combining some information from field investigation of algae along the coastal areas in China and a few pictures materialized from the western Yellow Sea in 2008,authors analyze the necessary conditions and possible w...Combining some information from field investigation of algae along the coastal areas in China and a few pictures materialized from the western Yellow Sea in 2008,authors analyze the necessary conditions and possible water area in China producing a large biomass,some reasons for firestorm,and the possibility of the reappearance of marine bloom green alga Enteromorpha prolifera.The change of habitats and the increase of nutritional levels related to the water area could be considered as direct reasons.It was transferred northward by the combination of the flow of rainwater,wind and alongshore marine current.The original region of large biomass produced is possibly located in the southwestern Yellow sea.It will possibly be appearing again in the coming years or in the future.A summary is also given referring to its reproduction,development and distribution worldwide.展开更多
A new halogenated biindole and a new apo-carotenone have been isolated from the ethanolic extract of the green alga Chaetomorpha basiretorsa Sethcell. On the basis of chemical and spectroscopic methods including 2D NM...A new halogenated biindole and a new apo-carotenone have been isolated from the ethanolic extract of the green alga Chaetomorpha basiretorsa Sethcell. On the basis of chemical and spectroscopic methods including 2D NMR technique, their structures have been elucidated as 4,4′-dichloro-5,5′-dibromo-7,7′-dimethoxy-2,2′-bi-1H-indole and 1′S*,4′R*-8-(4′-hydroxy-2′,6′,6′- trimethylcyclohex-2-enyl)-6-methyloct-3E,5E,7E-trien-2-one, respectively.展开更多
Six cycloartanes were isolated from ethanol extract of marine green alga Cladophora fascicularis by column chromatography. Procedure of isolation and description of these compounds are given in this paper. The structu...Six cycloartanes were isolated from ethanol extract of marine green alga Cladophora fascicularis by column chromatography. Procedure of isolation and description of these compounds are given in this paper. The structures were elucidated as （1）. 24-hydroperoxycycloart-25- en-3β-ol; （2）. cycloart-25-en-3β 24-diol; （3）. 25-hydroperoxycycloart-23-en-3β-ol; （4）. cycloart-23-en-3β, 25-diol; （5）. cycloart-23, 25-dien-3β-ol; and （6）. cycloart-24-en-3β-ol by spectroscopic （MS, 1D and 2D NMR） data analysis. Cycloartane derivatives are widely distributed the alga. All these compounds that have been isolated alga for the first time. in terrestrial plants, but only few were obtained in from terrestrial plants, were found in the marine alga for the first time.展开更多
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The National Basic Research Program (973 Program) of China under contract No.2010CB428703the National Natural Science Foundation of China under contract No.41306171+3 种基金the National Research Foundation-Shandong Province United Fund under contract No.U1406403the Qingdao Public Domain to Support Science and Technology Project under contract No.13–4–1–68–hythe Marine and Basic Research Funds of the First Institute of Oceanography,SOA under contract No.2015G09MOST International S&T Cooperation Program under contract No.2010DFA24340
文摘This study analyzes the community structure, the quantity changes of the algae and the effect of important environmental factors and estimates the total biomass of the attached green algae in the survey areas. The study uses data from surveys of the attached green algae on the Porphyra yezoensis aquaculture rafts and data regarding the environmental factors from October 2010 to April 2011 in the Subei Shoal. The attached green algae on the rafts included Ulva prolifera, Capsosiphon groenlandicus, U. linza, U. intestinalis, U. clathrata, and U. cornpressa. The biomass changes of the attached green algae exhibited an inverted parabola： the biomass was the highest （14 898 t） in April, and was the second highest （2 034 t） in November; it was lowest in February （only 729 t） and increased sharply from March to April. The species diversity differed significantly among the seasons. In September and October, when the P. yezoensis aquaculture rafts were initially set up, the attached green algae had a high biodiversity, while from December to the next February, a variety of green algae species coexisted on the rafts, although the biomass was low, and from March to April, as the biomass increased sharply, the species diversity dropped to the minimum. During this time, C. groenlandicus was apparently dominant with the maximum biomass proportion up to 80%, while the U. prolifera proportion increased exponentially to 20% to 40%. The water temperature had a direct regulating effect on the biomass and the species succession of the attached green algae. The estimation of the community dynamics and the biomass of the green algae provided the evidence needed to track the origin of the large-scale green tide in the southern Yellow Sea.
基金supported by the National Natural Science Foundation of China (No. 20476099)
文摘The toxicity of methyl tert-butyl ether （MTBE） to Chlorella ellipsoidea and Aphanizomenon flos-aquae was tested and assessed for a 15-d incubation with concentrations of MTBE from high （2.00×10^4 mg/L） to low （2 mg/L）. The results showed that the toxicity was low when the concentration of MTBE was in the range 1.00× 10^4-2.00× 10^4 mg/L （the greatest inhibition of growth-rate was 70%-71%, occurred during the day 1-5）. Low concentrations （2-500 rag/L） stimulated algal growth up to the greatest effect of 85%-200% when the concentration of MTBE was 50-100 mg/L during day 3-5. The toxicity of MTBE （72-120 h EC50） was 6.65×10^3-9.58×10^3 mg/L for C. ellipsoidea and that is 1.14× 10^4-2.00× 10^4 mg/L for A. floc-aquae. We found that the toxicity and ecological risk of MTBE for the algal community structure were low and the toxicity was influenced by the duration time of the test.
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supported by the National Natural Science Foundation of China (Nos. 21277114, and 21577117)the Natural Sciences and Engineering Research Council of Canada (NSERC)
文摘We report that green algae in lakes and rivers can serve as precursors of halobenzoquinone（HBQ） disinfection byproducts（DBPs） produced during chlorination. Chlorination of a common green alga, Chlorella vulgaris, produced 2,6-dichloro-1,4-benzoquinone（2,6-DCBQ）, the most prevalent HBQ DBP in disinfected water. Under varying p H conditions（p H 6.0–9.0）, 2,6-DCBQ formation ranged from 0.3 to 2.1 μg/mg C with maximum formation at p H 8.0. To evaluate the contribution of organic components of C. vulgaris to 2,6-DCBQ formation, we separated the organics into two fractions, the protein-rich fraction of intracellular organic matter（IOM） and the polysaccharide-laden fraction of extracellular organic matter（EOM）. Chlorination of IOM and EOM produced 1.4 μg/mg C and 0.7 μg/mg C of 2,6-DCBQ, respectively. The IOM generated a two-fold higher 2,6-DCBQ formation potential than the EOM fraction, suggesting that proteins are potent 2,6-DCBQ precursors. This was confirmed by the chlorination of proteins extracted from C. vulgaris： the amount of 2,6-DCBQ produced is linearly correlated with the concentration of total algal protein（R2= 0.98）. These results support that proteins are the primary precursors of 2,6-DCBQ in algae, and control of green algal bloom outbreaks in source waters is important for management of HBQ DBPs.
文摘To provide theoretical and technical basis for the application of preparations of bamboo vinegar and copper sulfate in the prevention of green algae in floating system for tobacco seeding,the soaking and spraying methods were employed to study the effect of different concentrations of preparations of bamboo vinegar and copper sulfate on green algae and tobacco seedling growth. The results showed that the preparations of bamboo vinegar and copper sulfate of different concentrations played a strong role in inhibiting green algae growth and had better effect than copper sulfate. Spraying 1∶ 200 preparations of bamboo vinegar and copper sulfate could significantly promote tobacco seedling growth,and the leaf fresh weight increased by 15. 80% compared with CK,with significant difference; spraying 1∶ 50 preparations was not conducive to tobacco seedling growth. It was recommended to spray 1∶ 200 preparations of bamboo vinegar and copper sulfate in floating system for tobacco seeding,which could promote tobacco seedling growth and reduce green algae to varying degrees.
文摘Reduced walleye (<i></span><i><span style="font-family:Verdana;">Sander vitreus</span></i><span style="font-family:Verdana;"></i></span><span style="font-family:Verdana;">) fingerling production possibly related to nuisance filamentous green algae and overly</span></span><span style="font-family:""> </span><span style="font-family:""><span style="font-family:Verdana;">stable water chemistry patterns is a concern in earthen-substrate ponds at Blue Dog State Fish Hatchery, South Dakota, USA. We describe the success of alfalfa (<i></span><i><span style="font-family:Verdana;">Medicago sativa</span></i><span style="font-family:Verdana;"></i></span><span style="font-family:Verdana;">) meal (AFM, n</span></span><span style="font-family:""> </span><span style="font-family:Verdana;">=</span><span style="font-family:""> </span><span style="font-family:""><span style="font-family:Verdana;">2), alfalfa meal plus soybean (<i></span><i><span style="font-family:Verdana;">Glycine max</span></i><span style="font-family:Verdana;"></i></span><span style="font-family:Verdana;">) meal (AFM</span></span><span style="font-family:""> </span><span style="font-family:Verdana;">+</span><span style="font-family:""> </span><span style="font-family:Verdana;">SBM, n</span><span style="font-family:""> </span><span style="font-family:Verdana;">=</span><span style="font-family:""> </span><span style="font-family:Verdana;">1), and alfalfa meal plus liquid 28N:0P:0K (AFM</span><span style="font-family:""> </span><span style="font-family:Verdana;">+</span><span style="font-family:""> </span><span style="font-family:Verdana;">28:0:0, n</span><span style="font-family:""> </span><span style="font-family:Verdana;">=</span><span style="font-family:""> </span><span style="font-family:Verdana;">1) at achieving</span><span style="font-family:Verdana;"> walleye production objectives (>104,000 walleye and 32 kilograms/hectare) as well as the occurrence of filamentous green algae and the associated patterns of ammonia-nitrogen, pH, and dissolved oxygen in earthen-substrate ponds. Walleye production objectives were only achieved when filamentous green algae were absent preceding harvest, which occurred in one pond that received AFM and in the pond that received AFM</span><span style="font-family:""> </span><span style="font-family:Verdana;">+</span><span style="font-family:""> </span><span style="font-family:Verdana;">28:0:0.</span><span style="font-family:""> </span><span style="font-family:Verdana;">The presence of filamentous green algae preceding harvest was associated with higher dissolved oxygen and pH, whereas declines in these variables occurred when filamentous green algae were absent. Organic fertilizer alone exhibited low ammonia-nitrogen (<0.1 mg/L) despite the substitution of higher protein content soybean meal, but supplementation with 28:0:0 increased ammonia-nitrogen to 0.23 mg/L. These findings highlight the reduction in walleye fingerling production that occurred in the presence of filamentous green algae and the unpredictability of results when two earthen-substrate ponds are treated exactly the same with alfalfa meal. Achievement of walleye production objectives, lack of nuisance filamentous green algae, and promotion of</span><span style="font-family:""> </span><span style="font-family:Verdana;">favorable patterns in water chemistry warrant future experimentation with alfalfa meal supplemented with 28:0:0 in earthen-substrate ponds at this hatchery.
基金Foundationitem :theNationalNaturalScienceFoundationofChina (No .992 90 60 0 )
文摘In general, many pollutants co\|exist in natural aquatic ecosystems. They affect each other and occur different results, such as synergism, addition and antagonism. So the research at mixtoxicity of contaminants to aquatic organism is more important than monotoxicity. In this paper, 50% effectual inhibition concentration 48h \%EC\%\-\{50\} values of 6 kinds of nitroaromatic compounds to the green algae, \%Scenedesmus obliquus,\% were investigated. Mixtoxic experiments, in which any combination of 2,4\|DNT and other 6 kinds of compounds, indicate: (1) synergisms between 2,4\|DNT and 4\|NAn, as well as 4\|NAnis, 1,4\|DNB; (2) antagonisms between 2,4\|DNT and 4\|NT, as well as 4\|NPh, 4\|NCB.
基金the National Natural Science Foundation of China(Nos.41776052,41476031)the Research Fund of State Key Laboratory of Marine Geology(No.MG20190104)the China Scholarship Council(No.CSC201906260052).
文摘Macroalgae blooms of Ulva prolifera have occurred every summer in the southern Yellow Sea since 2007,inducing severe ecological problems and huge economic losses.Genesis and secular movement of green algae blooms have been well monitored by using remote sensing and other methods.In this study,green algae were detected and traced by using Geostationary Ocean Color Imager(GOCI),and a novel biomass estimation model was developed from the relationship between biomass measurements and previously published satellite-derived biomass indexes.The results show that the green algae biomass can be determined most accurately with the biomass index of green algae for GOCI(BIGAG),which is calculated from the Rsurf data that had been atmospherically corrected by ENVI/QUAC method.For the first time,dynamic changes in green algae biomass were studied over an hourly scale.Short-term biomass changes were highly influenced by Photosynthetically Available Radiation(PAR)and tidal phases,but less by sea surface temperature variations on a daily timescale.A new parameter of biomass changes(PBC),calculated by the ratio of the biomass growth rate to movement velocity,could provide an effective way to assess and forecast green tide in the southern Yellow Sea and similar areas.
基金supported by the National Natural Science Foundation of China(32372268)the China Postdoctoral Science Foundation(2023M743532).
文摘With the proceeding of global warming and water eutrophication,the phenomenon of green tide has garnered significant societal interest.Consequently,researchers had increasingly focused on the potential applications of green algae biomass,particularly its polysaccharides.The polysaccharide serves as the primary active constituent of green algae and has demonstrated numerous advantageous biological activities,including antioxidant,antiviral,anticoagulant,hypolipidemic and immuno-modulatory activities.The favorable bioavailability and solubility of green algae oligosaccharides are attributed to their low molecular weight.So there has been a growing interest in researching green algae polysaccharides and oligosaccharides for the utilization of marine biological resources.This review summarized the extraction,purification,chemical structure,composition,biological activity,and potential applications prospect of polysaccharides and oligosaccharides derived from green algae.The review could be helpful for expanding the applications of polysaccharides and oligosaccharides of green algae.
基金Supported by the Frontier Research Grant of the SCSIOthe Hundred Talents program of Chinese Academy of SciencesNational Natural Sciences of China projects(Grant No.40776087)
文摘A gradient reversed-phase high-performance liquid chromatography(HPLC)method using a C30 col-umn was developed for the simultaneous determination of astaxanthin,astaxanthin monoesters and astaxanthin diesters in the green algae Chlorococcum sp.,Chlorella zofingiensis,Haematococcus plu-vialis and the mutant E1,which was obtained from the mutagenesis of H.pluvialis by exposure to UV-irradiation and ethyl methanesulphonate(EMS)with subsequent screening using nicotine.The re-sults showed that the contents of total astaxanthins including free astaxanthin and astaxanthin esters ranged from 1.4 to 30.9 mg/g dry biomass in these green algae.The lower total astaxanthin levels(<2 mg/g dry biomass)were detected in the green algae Chlorococcum sp.and C.zofingiensis.The higher total astaxanthin levels(>16 mg/g dry biomass)were found in the green alga H.pluvialis and its mutant E1.It is notable that the mutant E1 is found to have considerably higher amounts of total astaxanthin(30.9 mg/g)as compared to the wild strain of H.pluvialis(16.1 mg/g).This indicates that UV-irradiation and EMS compound mutagenesis with subsequent screening using nicotine is an effective method for breeding of a high-producing astaxanthin strain of H.pluvialis.In addition,the green alga C.zofingien-sis had a remarkably higher percentage of astaxanthin diesters(76.3%of total astaxanthins)and a re-markably lower percentage of astaxanthin monoesters(18.0%of total astaxanthins)in comparison with H.pluvialis(35.5%for diesters and 60.9%for monoesters),the mutant E1(49.1%and 48.1%)and Chlorococcum sp.(18.0%and 58.6%).
文摘Microalgae,such as Chlorella vulgaris Beijerinck(green algae),are beneficial microscopic organisms that may help plants to improve nutrient uptake,growth,and abiotic tolerance to stressors.The current study was performed to investigate the effectiveness of algae(Chlorella vulgaris Beijerinck)foliar applications[1%,3%,or 5%(v/v)]on mitigation of drought stress in broccoli plants subjected to water deficit at 25%of field capacity.The results showed that the broccoli plants grown under drought stress alone exhibited severe disturbance in growth with considerable reductions in the shoot length,and fresh and dry weights,leaf area,relative water content,leaf water potential,and photosynthetic pigment contents and elevated levels of the lipid peroxidation product malondialdehyde in the leaves.Additionally,the foliar application of microalgae mitigated the detrimental effects of drought,leading to better growth performance(increase of 9%–132%)when compared with the drought-stressed plants that had not received an application of microalgae.Microalgae-mediated beneficial effects were particularly evident in the enhancement of the photosynthetic pigment contents,including chlorophyll-a(6%–60%),chlorophyll-b(19%–55%),and total carotenoids(26%–114%).Exogenous microalgae also contributed to the reduction of membrane damage,as proven by significantly decreased levels of malondialdehyde(10%–39%)in the leaves of the broccoli plants exposed to drought stress.The application of microalgae increased the total flavonoid and phenolic contents,and nutrition uptake.Furthermore,the activities of enzymatic antioxidants like ascorbate peroxidase,catalase,glutathione reductase,and superoxide dismutase increased in response to mediation,resulting in significant alleviation of drought-induced oxidative damage.The most effective application concentration of microalgae was determined as 5%.Overall investigations revealed that the foliar application of microalgae could be recommended as a sustainable strategy to improve the defense system of drought-stressed broccoli plants.
基金Supported by General and Major Projects of the National Natural Science Foundation of China(Nos.31070185,31093440)the Science and Technology Project of Guangdong Province(Nos.2011B031100010,2012A020200007)+3 种基金the Talent Introduction Projects of Guangdong Province Universities and Collegesthe Team Project of Natural Science Foundation of Guangdong Province(No.S2011030005257)the Grant of the Key Laboratory of Integrated Marine Monitoring and Applied Technologies for Harmful Algal Blooms,SOA(MATHAB)(No.MATHAB20100301)the Science and Technology Project of Shantou City,China(No.2011-162)
文摘The marine green alga Chaetomorpha valida fouls aquaculture ponds along the coastal cities of Dalian and Rongcheng, China. Unialgal cultures were observed under a microscope to determine the developmental morphological characters of C. valida. Results reveal that gametophytic filaments often produce lateral branches under laboratory culture conditions, suggesting an atypical heteromorphic life cycle of C. valida between unbranched sporophytes and branched gametophytes, which differs from typical isomorphic alternation of Chaetomorpha species. The shape of the basal attachment cell, an important taxonomic character within the genus, was found variable depending on environmental conditions. The 18S rDNA and 28S rDNA regions were used to explore the phylogenetic affinity of the taxa. Inferred trees from 18S rDNA sequences revealed a close relationship between C. valida and Chaetomorpha moniligera. These results would enrich information in general biology and morphological plasticity of C. valida and provided a basis for future identification of green tide forming algae.
基金supported by Xinjiang Oilfield Company of China(No.2020-C4006).
文摘The Mesozoic and Cenozoic strata in the Junggar basin developed two sets of shallow to semi-deep lacustrine shale, namely, the Cretaceous Qingshuihe Formation (K_(1q)) and the Paleogene Anjihaihe Formation (E_(2-3a)). Through organic petrology and scanning electron microscope (SEM) observation, it is found that the primary hydrocarbon-generating organic matter (OM) in the two sets of strata is different. The biological precursor of the E_(2-3a) OM is mainly green algae (Pediastrum), while the precursor of K_(1q) kerogen is mainly cyanobacteria (Oscillatoria). Then, the E_(2-3a) green algae-rich shale and K_(1q) cyanobacteria-rich shale were subjected to hydrous pyrolysis and kinetic analysis, respectively. The results show that the evolution modes of hydrocarbon generation of the typical shales are very different. Green algae have the characteristics of a low oil generation threshold, heavy oil quality, and no prominent oil peak, while cyanobacteria have the characteristics of late oil generation, concentrated hydrocarbon generation, and relatively light oil quality. The characteristics of oil generation can also be well reflected in the composition evolution of the crude oil components. The carbon isotope of gas, kerogen, and extracts of the E_(2-3a) green algae-rich shale are significantly heavier than the K_(1q) cyanobacteria-rich shale, which may be related to the living habits of their biological precursors, carbon source usage, photosynthesis efficiency, and carbon fixation efficiency.
文摘All algae documented so far are of unknown origin. Here, we provide a taxonomic description of the first origin-known alga TDX16-DE that arises from the <i><span style="font-family:Verdana;">Chroococcidiopsis</span></i><span style="font-family:Verdana;">-like endosymbiotic cyanobacterium TDX16 by de novo organelle biogenesis after acquiring its green algal host</span><i><span style="font-family:Verdana;"> Haematococcus pluvialis</span></i><span style="font-family:Verdana;">’s DNA. TDX16-DE is spherical or oval, with a diameter of 2.0-3.6 μm, containing typical chlorophyte pigments of chlorophyll a, chlorophyll b and lutein and reproducing by autosporulation, whose 18S rRNA gene sequence shows the highest similarity of 99.7% to that of </span><i><span style="font-family:Verdana;">Chlorella vulgaris</span></i><span style="font-family:Verdana;">. However, TDX16-DE is only about half the size of</span><i><span style="font-family:Verdana;"> C. vulgaris </span></i><span style="font-family:Verdana;">and structurally similar to</span><i><span style="font-family:Verdana;"> C. vulgaris</span></i><span style="font-family:Verdana;"> only in having a chloroplast-localized pyrenoid, but differs from</span><i><span style="font-family:Verdana;"> C. vulgaris</span></i><span style="font-family:Verdana;"> in that 1) it possesses a double-membraned cytoplasmic envelope but lacks endoplasmic reticulum and Golgi apparatus;and 2) its nuc</span><span style="font-family:Verdana;">leus is enclosed by two sets of envelopes (four</span><span style="font-family:;" "=""> </span><span style="font-family:Verdana;">unit membranes). Therefore</span><span style="font-family:;" "=""><span style="font-family:Verdana;">, based on these characters and the cyanobacterial origin, we describe TDX16-DE as a new genus and species, </span><i><span style="font-family:Verdana;">Chroococcidiorella tianjinensis</span></i><span style="font-family:Verdana;"> gen. et sp. nov., which sets the basis for multidisciplinary research.</span></span>
基金Supported by general and major projects of National Natural Science Foundation of China (Nos 40876081,30570125,and 30499340(partly)the National High Technology Research and Development Program of China (863 Program)(No 2008BAC49B01)Knowledge Innovation Project of Chinese Academy of Sciences (No KSCX2-YW-Z-018)
文摘Combining some information from field investigation of algae along the coastal areas in China and a few pictures materialized from the western Yellow Sea in 2008,authors analyze the necessary conditions and possible water area in China producing a large biomass,some reasons for firestorm,and the possibility of the reappearance of marine bloom green alga Enteromorpha prolifera.The change of habitats and the increase of nutritional levels related to the water area could be considered as direct reasons.It was transferred northward by the combination of the flow of rainwater,wind and alongshore marine current.The original region of large biomass produced is possibly located in the southwestern Yellow sea.It will possibly be appearing again in the coming years or in the future.A summary is also given referring to its reproduction,development and distribution worldwide.
基金supported by national 863 project(Grant No.2004AA625030,2001AA620503)NNSFC(Grant No.20432030)Key Innovative Project of the Academy(Grant No.KZCX3-SW-215).
文摘A new halogenated biindole and a new apo-carotenone have been isolated from the ethanolic extract of the green alga Chaetomorpha basiretorsa Sethcell. On the basis of chemical and spectroscopic methods including 2D NMR technique, their structures have been elucidated as 4,4′-dichloro-5,5′-dibromo-7,7′-dimethoxy-2,2′-bi-1H-indole and 1′S*,4′R*-8-(4′-hydroxy-2′,6′,6′- trimethylcyclohex-2-enyl)-6-methyloct-3E,5E,7E-trien-2-one, respectively.
基金Supported by the National High-Tech R&D Program (863 Program) (Nos. 2001AA620403, 2003AA620403 and 2002AA217081) the State Major Basic Research Development Program of China (973 Program, No. 2002CB41240)+1 种基金 the Major Program of CAS (No. KJCX315-215) NSFC(Nos. 40176038, 30171106, and 30530080) and the International Cooperation Projects of BMBF-CNCBD
文摘Six cycloartanes were isolated from ethanol extract of marine green alga Cladophora fascicularis by column chromatography. Procedure of isolation and description of these compounds are given in this paper. The structures were elucidated as （1）. 24-hydroperoxycycloart-25- en-3β-ol; （2）. cycloart-25-en-3β 24-diol; （3）. 25-hydroperoxycycloart-23-en-3β-ol; （4）. cycloart-23-en-3β, 25-diol; （5）. cycloart-23, 25-dien-3β-ol; and （6）. cycloart-24-en-3β-ol by spectroscopic （MS, 1D and 2D NMR） data analysis. Cycloartane derivatives are widely distributed the alga. All these compounds that have been isolated alga for the first time. in terrestrial plants, but only few were obtained in from terrestrial plants, were found in the marine alga for the first time.
