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1.
Environ Sci Pollut Res Int ; 27(5): 4814-4829, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31845243

RESUMO

The phytoplankton (internal driving forces) and environmental variables that affect complex biochemical reactions (external driving forces) play an important role in regulating photosynthetic carbon fixation. Ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) exists in various phytoplankton species and is an important enzyme in the photosynthetic process. To investigate the phytoplankton composition (internal driving forces), we selected the functional gene of the Rubisco large subunit (rbcL) as the target gene for this study. Phytoplankton gross primary productivity was measured using light and dark biological oxygen demand bottles to assess the carbon sequestration potential. The fundamental environmental indicators were determined to analyze the mechanisms that drive the carbon fixation process. The correlation results indicated that green algae were only controlled by nitrate, and that diatoms were positively correlated with phosphate. The cluster analysis results demonstrated that nitrite was the major driver controlling phytoplankton primary productivity. During the wet seasons (spring and summer), the contribution of the planktonic community respiration to the carbon sequestration potential was higher than net primary productivity (NPP), followed by dissolved organic carbon and nitrate. During the dry season (autumn), NPP, total nitrogen, and nitrite ranked highest in terms of carbon sequestration potential. The contributions of green algae and diatoms to the carbon sequestration potential were temporally higher than those of cyanobacteria. The maximum carbon sequestration potential occurred during autumn because of diatom production and the function of phosphate, whereas the minimum carbon sequestration potential occurred in summer. Spatially, the upstream carbon sequestration potential was higher compared with downstream because of the effect (contribution) of cyanobacteria (Phormidium), diatoms (Surirella solea and Thalassiosira pseudonana), and environmental variable (nitrite). These findings provide a better understanding of the underlying mechanisms of phytoplankton productivity and the influences of environmental variables on carbon sequestration in urban river ecosystems.

2.
Environ Monit Assess ; 191(11): 688, 2019 Oct 29.
Artigo em Inglês | MEDLINE | ID: mdl-31664528

RESUMO

Understanding the relative impact sizes of environmental factors and nutrients on the high annual variation of phytoplankton abundance in eutrophic rivers is important for aquatic ecosystem management efforts. In this study, we used phytoplankton dynamic datasets in the eutrophic Fenhe River to show the variations and drivers of phytoplankton abundance under complex, fluctuating environmental conditions during 2012-2017. The temporal and spatial variations of nutrients in the river depicted that the total phosphorus (TP) concentration was higher in the wet season and in downstream. There were increases in total nitrogen (TN) concentration in the normal season and in upstream. The structural equation model (SEM) showed that the phytoplankton abundance increased during the wet season despite the decrease in the TN:TP ratio and was reduced upstream due to the highest TN:TP ratio. Among the environmental variables, water temperature (WT) was an important predictor and positively correlated temporally and spatially to phytoplankton. The interaction of nutrients with the phytoplankton community at different temperature levels indicated that different phytoplankton groups have different nutrient requirements. We can conclude that enhances in temperature and TP concentration will significantly increase phytoplankton abundance and dominance of cyanobacteria and green algae in the future, whereas there was insignificant effect on diatoms. These data indicated that temperature and TP content were the important abiotic factors influencing the phytoplankton growth of the water body, which could provide a reference for the evaluation of environmental alterations in the future.


Assuntos
Monitoramento Ambiental , Fitoplâncton/crescimento & desenvolvimento , Temperatura Ambiente , Poluentes da Água/análise , China , Clorófitas , Cianobactérias/crescimento & desenvolvimento , Diatomáceas/crescimento & desenvolvimento , Ecossistema , Eutrofização , Nitrogênio/análise , Nutrientes , Fósforo/análise , Rios/química , Estações do Ano
3.
Bioresour Technol ; 288: 121568, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31154280

RESUMO

In this study, the performance of Chlorococcum sp. GD in synthetic medium with different glucose concentrations (ranging from 1 to10 g/L) was investigated. Moreover, transcriptome sequencing was conducted to clarify the response of the microalga to glucose concentrations. High concentration of glucose (6-10 g/L) not only did not provide a higher yield of biomass but also inhibited photosynthesis. Transcriptomic analysis revealed that the glucose metabolism mainly depended on the glycolysis and the pentose phosphate pathway (PPP) as the microalga was cultivated with 10 g/L glucose. Meanwhile the tricarboxylic acid (TCA) cycle, oxidative phosphorylation and photosynthesis were significantly inhibited. The significant change on carbon metabolic flux caused by the increase in glucose concentration affected the synthesis of reducing power and ATP, which ultimately influenced the growth of the microalga. Appropriate supplement of organic carbon not only enhances the biomass accumulation but also increases the utilization efficiency of organic carbon.


Assuntos
Fotossíntese , Transcriptoma , Biomassa , Carbono , Glucose
4.
Artigo em Inglês | MEDLINE | ID: mdl-30987041

RESUMO

In order to study the effects of nitrogen stress on the lipid synthesis of Parachlorella kessleri TY02 and to understand the changes in growth, photosynthetic pigments, total protein and total carbohydrate contents during lipid accumulation, the cells of the strain were cultured in nitrogen-deficient (N-) and nitrogen-rich (N⁺) media for one week. Changes in cell growth, chlorophyll content, chlorophyll fluorescence parameters, neutral lipid and total lipid content, total protein content and total carbohydrate content were measured and analyzed. The results showed that, under nitrogen stress, the algal strain grew slowly, and chlorophyll and total protein contents decreased, while total carbohydrate and total lipid contents increased. This indicated that, under nitrogen stress, most of the carbon flowed to the synthesis of lipids and carbohydrates. Meanwhile, reducing the nitrogen content was a relatively economical and easy to operate method of promoting lipid accumulation.


Assuntos
Clorófitas/fisiologia , Metabolismo dos Lipídeos , Estresse Fisiológico , Carboidratos/análise , Carbono/metabolismo , Clorofila/metabolismo , Clorófitas/crescimento & desenvolvimento , Clorófitas/metabolismo , Nitrogênio/metabolismo , Fotossíntese , Proteínas de Plantas/metabolismo
5.
Ecotoxicol Environ Saf ; 171: 274-280, 2019 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-30612015

RESUMO

There is a concern about the increasing prevalence of health problems related to the ingestion of fluoride (F-) in the developing world. Drinking water is one important source of F-, and the concentration of F- needs to be known to ensure the safety of drinking water. In this study, F- levels in drinking water were investigated across Taiyuan in Shanxi Province, China. Spatial-temporal distribution characteristics and potential associated health risks were analyzed using GIS. We collected 485 samples from shallow wells without any defluoridation treatments between 2008 and 2016. After analyzing the samples of F- content we found that mean F- levels of urban areas (0.61 ±â€¯0.39 mg L-1), suburban areas (0.70 ±â€¯0.87 mg L-1) and for all of Taiyuan city (0.63 ±â€¯0.56 mg L-1) were in optimum range based on the recommendation by USEPA. However, individual locations within industrial areas (e.g. Gujiao District) had higher F- levels (1.06 mg L-1). A concerning result showed that 12.37% of tested locations had F- concentrations larger than 1.0 mg L-1. We calculated F- Health Risk Indices (HRIsF) and found that highest were associated with suburban areas, especially in the year 2009 and 2010. However, from 2008 to 2016, overall F- levels and HRIsF of the sampled groundwater in Taiyuan City showed a decreasing trend. HRIsF in suburban areas was higher than urban areas, possible due to the heavily prevalent coal mining industry in those areas. Specific policies should be formulated to address HRIsF.


Assuntos
Água Potável/química , Fluoretos/análise , Água Subterrânea/química , Poluentes Químicos da Água/análise , China/epidemiologia , Monitoramento Ambiental , Sistemas de Informação Geográfica , Humanos , Medição de Risco , Análise Espaço-Temporal , Saúde Suburbana , Saúde da População Urbana
6.
Environ Monit Assess ; 191(1): 29, 2018 Dec 27.
Artigo em Inglês | MEDLINE | ID: mdl-30591969

RESUMO

In this paper, the algal cell density of cyanobacteria, green algae, and diatoms and their responses to the hydrochemical factors were analyzed to reveal the structural characteristics of water quality in an urban river. A total of nine sampling sites from upstream to downstream was explored in our study. At each site, the density of algae was identified every week during the wet season (June-October) from 2012 to 2017, and in situ detection was used for the relative 11 hydrochemical variables. The temporal and spatial characteristics of 14 variables were analyzed using a heatmap coupled with the cluster analysis method. The trend of each parameter was analyzed using the smoothing method with locally weighted regression. The nonmetric multidimensional scaling method was employed to detect the temporal and spatial similarities among algae along hydrochemical gradients. The responses of algal density to hydrochemical variables were analyzed using a redundancy analysis. The results showed that the water temperature (Wtemp), pH, dissolved oxygen (DO), cyanobacteria, and diatoms exhibited significant declining trends, and significant increasing trends were shown in the permanganate index, chemical oxygen demand, total nitrogen, ammonia nitrogen, and total phosphorus; the cyanobacteria exhibited certain differences with green algae and diatoms in summer and the downstream areas of the river. The temporal-spatial homogeneity of algal to hydrochemical variables showed the key influencing factors of Wtemp for cyanobacteria density, chlorophyll for green algae density, DO, and pH for diatoms. The results presented here are valuable for deepening our understanding of river ecosystem evaluations and effective environmental management, as well as an important reference for the sustainable development of aquatic biological resources.


Assuntos
Clorófitas/citologia , Cianobactérias/citologia , Diatomáceas/citologia , Monitoramento Ambiental/métodos , Rios/química , Movimentos da Água , China , Clorofila/análise , Clorófitas/crescimento & desenvolvimento , Cianobactérias/crescimento & desenvolvimento , Diatomáceas/crescimento & desenvolvimento , Ecossistema , Eutrofização , Nitrogênio/análise , Fósforo/análise , Estações do Ano , Urbanização , Qualidade da Água
7.
Environ Sci Pollut Res Int ; 25(24): 23917-23928, 2018 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-29881967

RESUMO

The ability of the agricultural residue of Phragmites australis to serve as an absorbent material used to remove phenol from aqueous solutions in batch and continuous fixed-bed columns was investigated. Prepared adsorbents were characterized by SEM, FTIR, and pHpzc methods. The equilibrium adsorption (qe) of phenol was increased from 9.61 to 29.40 mg/g when the initial phenol concentrations increased from 50 to 150 mg/L. The max adsorption capacity of Phragmites australis was found to be 29.60 mg/g at 30 °C. In column studies, a higher flow rate, higher initial concentration of phenol, and shorter packing layer height increase the column adsorption capacity of phenol. In a batch and continuous fixed-bed column studies, the experiment data was evaluated by some classic models. Fitting degree between the experimental results shows that the pseudo-second-order adsorption kinetics and Langmuir model were the best. Thomas and Yoon-Nelson models were in good agreement with the experimental breakthrough curve data. Both batch and continuous investigation indicated that Phragmites australis could be used as a fine adsorbent to remove phenol and that the adsorption efficiency improved significantly in the column experiment.


Assuntos
Fenol/isolamento & purificação , Poaceae/química , Poluentes Químicos da Água/isolamento & purificação , Purificação da Água/métodos , Adsorção , Cinética , Modelos Teóricos , Fenol/química , Soluções/química , Poluentes Químicos da Água/química , Purificação da Água/instrumentação
8.
Bioresour Technol ; 264: 311-318, 2018 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-29857286

RESUMO

Chlorella vulgaris was selected from five freshwater microalgal strains of Chlorophyta, and showed a good potential in nutrients removal from undiluted cattle farm wastewater. By the end of treatment, 62.30%, 81.16% and 85.29% of chemical oxygen demand (COD), ammonium (NH4+-N) and total phosphorus (TP) were removed. Then two two-stage processes were established to enhance nutrients removal efficiency for meeting the discharge standards of China. The process A was the biological treatment via C. vulgaris followed by the biological treatment via C. vulgaris, and the process B was the biological treatment via C. vulgaris followed by the activated carbon adsorption. After 3-5 d of treatment of wastewater via the two processes, the nutrients removal efficiency of COD, NH4+-N and TP were 91.24%-92.17%, 83.16%-94.27% and 90.98%-94.41%, respectively. The integrated two-stage process could strengthen nutrients removal efficiency from undiluted cattle farm wastewater with high organic substance and nitrogen concentration.


Assuntos
Chlorella vulgaris , Eliminação de Resíduos Líquidos , Águas Residuárias , Animais , Bovinos , China , Fazendas , Microalgas , Nitrogênio , Fósforo
9.
PLoS One ; 13(5): e0197729, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29813098

RESUMO

The Rhodophyta Sheathia arcuata is exclusively distributed in freshwater, constituting an important component in freshwater flora. This study presents the first transcriptome profiling of freshwater Rhodophyta taxa. A total of 161,483 assembled transcripts were identified, annotated and classified into different biological categories and pathways based on BLAST against diverse databases. Different gene expression patterns were caused principally by different irradiances considering the similar water conditions of the sampling site when the specimens were collected. Comparison results of gene expression levels under different irradiances revealed that photosynthesis-related pathways significantly up-regulated under the weak light. Molecular responses for improved photosynthetic activity include the transcripts corresponding to antenna proteins (LHCA1 and LHCA4), photosynthetic apparatus proteins (PSBU, PETB, PETC, PETH and beta and gamma subunits of ATPase) and metabolic enzymes in the carbon fixation. Along with photosynthesis, other metabolic activities were also regulated to optimize the growing and development of S. arcuata under appropriate sunlight. Protein-protein interactive networks revealed the most responsive up-expressed transcripts were ribosomal proteins. The de-novo transcriptome assembly of S. arcuata provides a foundation for further investigation on the molecular mechanism of photosynthesis and environmental adaption for freshwater Rhodophyta.


Assuntos
Proteínas de Algas/genética , Perfilação da Expressão Gênica/métodos , Rodófitas/crescimento & desenvolvimento , Regulação da Expressão Gênica no Desenvolvimento , Regulação da Expressão Gênica de Plantas , Luz , Anotação de Sequência Molecular , Fotossíntese , Rodófitas/genética , Análise de Sequência de RNA/métodos
10.
Artigo em Inglês | MEDLINE | ID: mdl-29498694

RESUMO

The performance of a self-flocculating microalga Chlorococcum sp. GD on the flocculation, growth, and lipid accumulation in wastewater with different ammonia nitrogen concentrations was investigated. It was revealed that relative high ammonia nitrogen concentration (20-50 mg·L-1) was beneficial to the flocculation of Chlorococcum sp. GD, and the highest flocculating efficiency was up to 84.4%. It was also found that the highest flocculating efficiency occurred in the middle of the culture (4-5 days) regardless of initial ammonia concentration in wastewater. It was speculated that high flocculating efficiency was likely related to the production of extracellular proteins. 20 mg·L-1 of ammonia was found to be a preferred concentration for both biomass production and lipid accumulation. 92.8% COD, 98.8% ammonia, and 69.4% phosphorus were removed when Chlorococcum sp. GD was cultivated in wastewater with 20 mg·L-1 ammonia. The novelty and significance of the investigation was the integration of flocculation, biomass production, wastewater treatment, and lipid accumulation, simultaneously, which made Chlorococcum sp. GD a potential candidate for wastewater treatment and biodiesel production if harvested in wastewater with suitable ammonia nitrogen concentration.


Assuntos
Amônia/metabolismo , Clorofíceas/fisiologia , Microalgas/fisiologia , Nitrogênio/metabolismo , Águas Residuárias , Poluentes Químicos da Água/metabolismo , Purificação da Água/métodos , Biomassa , Floculação , Águas Residuárias/química , Águas Residuárias/microbiologia
11.
J Food Sci ; 82(11): 2591-2597, 2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-29023815

RESUMO

This study examined the effect of Spirulina platensis polysaccharides (SPP) at 0.1%, 0.25%, and 0.5% (wt/wt) of Chinese-style sausages on lipid peroxidation, microbiological and sensory properties during 24 d stored at 4 °C. During the storage, pH, lightness (L* ) values, DPPH radical scavenging activity and sensory scores decreased with time and TBARS, TVB-N, mesophilic, and psychrotrophic total viable counts increased. However, the magnitude of the changes was attenuated with the addition of SPP as compared to control. Samples containing SPP had significantly (P ≤ 0.05) higher DPPH radical scavenging activity and lower TBARS values compared with the control, and the antioxidant effect was dose-dependent. The addition of 0.5% SPP maintained stable redness (a* ) values of sausages, although there was no positive effect on the microbiological status. Moreover, the addition of SPP prevented the decrease of aroma, flavor and sensory acceptance of samples. The results suggested incorporation of SPP could decrease lipid peroxidation and improve sensory properties of Chinese-style sausage. PRACTICAL APPLICATION: There is a great need for adding natural antioxidants to healthier meat and meat products. Spirulina platensis polysaccharides (SPP) had strong antioxidant activity. The addition of SPP to Chinese-style pork sausage could inhibit lipid peroxidation, to extend the shelf life of meat products. SPP were very potential to be used to replace synthetic antioxidants in meat and meat products.


Assuntos
Antioxidantes/análise , Produtos da Carne/análise , Polissacarídeos/análise , Spirulina/química , Animais , Cor , Aromatizantes , Peroxidação de Lipídeos/efeitos dos fármacos , Produtos da Carne/microbiologia , Polissacarídeos/administração & dosagem , Sensação/efeitos dos fármacos , Suínos , Paladar/efeitos dos fármacos , Substâncias Reativas com Ácido Tiobarbitúrico/análise
12.
Sci Rep ; 7(1): 2934, 2017 06 07.
Artigo em Inglês | MEDLINE | ID: mdl-28592899

RESUMO

Freshwater representatives of Rhodophyta were sampled and the complete chloroplast and mitochondrial genomes were determined. Characteristics of the chloroplast and mitochondrial genomes were analyzed and phylogenetic relationship of marine and freshwater Rhodophyta were reconstructed based on the organelle genomes. The freshwater member Compsopogon caeruleus was determined for the largest chloroplast genome among multicellular Rhodophyta up to now. Expansion and subsequent reduction of both the genome size and GC content were observed in the Rhodophyta except for the freshwater Compsopogon caeruleus. It was inferred that the freshwater members of Rhodophyta occurred through diverse origins based on evidence of genome size, GC-content, phylogenomic analysis and divergence time estimation. The freshwater species Compsopogon caeruleus and Hildenbrandia rivularis originated and evolved independently at the inland water, whereas the Bangia atropurpurea, Batrachospermum arcuatum and Thorea hispida are derived from the marine relatives. The typical freshwater representatives Thoreales and Batrachospermales are probably derived from the marine relative Palmaria palmata at approximately 415-484 MYA. The origin and evolutionary history of freshwater Rhodophyta needs to be testified with more organelle genome sequences and wider global sampling.


Assuntos
Evolução Biológica , Água Doce , Rodófitas/classificação , Rodófitas/genética , Evolução Molecular , Genes de Plantas , Variação Genética , Genoma de Cloroplastos , Genoma Mitocondrial , Genômica/métodos , Filogenia
13.
Bioresour Technol ; 234: 289-296, 2017 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-28334665

RESUMO

Sulfate is a primary sulfur source and can be available in wastewaters. Nevertheless, effect of sulfate ions on growth and pollutants removal of microalgae seems to be less investigated. At the present study, self-flocculating microalga Chlorococcum sp. GD was grown in synthetic municipal wastewater with different sulfate concentrations. Results indicated that Chlorococcum sp. GD grew better in synthetic municipal wastewater with 18, 45, 77, 136 and 271mg/L SO42- than in wastewater without SO42-. Chlorococcum sp. GD had also excellent removal efficiencies of nitrogen and phosphorus and effectively flocculated in sulfate wastewater. Sulfate deprivation weakened the growth, pollutants removal and self-flocculation of Chlorococcum sp. GD in wastewater. Antioxidative enzymes activity significantly increased and photosynthetic activity significantly decreased when Chlorococcum sp. GD was cultivated in sulfate-free wastewater. Sulfate deprivation probably reduced cell activity of growth, pollutants removal and flocculation via inducing the over-accumulation of reactive oxygen species (ROS).


Assuntos
Microalgas , Águas Residuárias , Clorófitas , Fósforo , Sulfatos
14.
Int J Mol Sci ; 18(1)2017 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-28045437

RESUMO

Eutrophication of water catchments and the greenhouse effect are major challenges in developing the global economy in the near future. Secondary effluents, containing high amounts of nitrogen and phosphorus, need further treatment before being discharged into receiving water bodies. At the same time, new environmentally friendly energy sources need to be developed. Integrating microalgal cultivation for the production of biodiesel feedstock with the treatment of secondary effluent is one way of addressing both issues. This article provides a comprehensive review of the latest progress in microalgal cultivation in secondary effluent to remove pollutants and accumulate lipids. Researchers have discovered that microalgae remove nitrogen and phosphorus effectively from secondary effluent, accumulating biomass and lipids in the process. Immobilization of appropriate microalgae, and establishing a consortium of microalgae and/or bacteria, were both found to be feasible ways to enhance pollutant removal and lipid production. Demonstrations of pilot-scale microalgal cultures in secondary effluent have also taken place. However there is still much work to be done in improving pollutants removal, biomass production, and lipid accumulation in secondary effluent. This includes screening microalgae, constructing the consortium, making use of flue gas and nitrogen, developing technologies related to microalgal harvesting, and using lipid-extracted algal residues (LEA).


Assuntos
Poluentes Ambientais/isolamento & purificação , Microalgas/crescimento & desenvolvimento , Nitrogênio/isolamento & purificação , Fósforo/isolamento & purificação , Eliminação de Resíduos Líquidos/métodos , Biodegradação Ambiental , Biomassa , Poluentes Ambientais/metabolismo , Metabolismo dos Lipídeos , Microalgas/metabolismo , Nitrogênio/metabolismo , Fósforo/metabolismo
15.
PLoS One ; 11(10): e0164744, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27741305

RESUMO

Phenol components are major industry contaminants of aquatic environment. Among all practical methods for removing phenol substances from polluted water, activated carbon absorption is the most effective way. Here, we have produced low-cost activated carbon using Polygonum orientale Linn, a wide spreading species with large biomass. The phenol adsorption ability of this activated carbon was evaluated at different physico-chemical conditions. Average equilibrium time for adsorption was 120 min. The phenol adsorption ability of the P. orientale activated carbon was increased as the pH increases and reached to the max at pH 9.00. By contrast, the ionic strength had little effect on the phenol absorption. The optimum dose for phenol adsorption by the P. orientale activated carbon was 20.00 g/L. The dominant adsorption mechanism of the P. orientale activated carbon was chemisorption as its phenol adsorption kinetics matched with the pseudo-second-order kinetics. In addition, the equilibrium data were fit to the Langmuir model, with the negative standard free energy and the positive enthalpy, suggesting that adsorption was spontaneous and endothermic.


Assuntos
Carvão Vegetal/química , Fenol/química , Polygonum/química , Poluentes Químicos da Água/química , Adsorção , Concentração de Íons de Hidrogênio , Cinética , Concentração Osmolar , Polygonum/metabolismo , Espectroscopia de Infravermelho com Transformada de Fourier , Temperatura Ambiente , Termodinâmica , Fatores de Tempo
16.
Ecotoxicol Environ Saf ; 134P1: 273-279, 2016 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-27643987

RESUMO

Severe eutrophication and harmful cyanobacterial blooms of freshwater ecosystems is a persistent environmental topic in recent decades. Pyrogallol (polyphenol) was confirmed to exhibit one of the most intensive inhibitory effects on the Microcystis aeruginosa. In this study, the expression of genes, release of microcystins (MCs) and antioxidant system of pyrogallol on Microcystis aeruginosa TY001 were investigated. The results revealed that the expression of stress response genes (prx, ftsH, grpE and fabZ) and DNA repair genes (recA and gyrB) were up-regulated. Meanwhile, the antioxidant enzymes, including superoxide dismutase (SOD), catalase (CAT) and peroxidase (POD) activity, were increased, and the stress caused lipid peroxidation to occur and malondialdehyde (MDA) levels to change. Unexpectedly, the relative transcript abundance of microcystin synthesis genes (mcyB, mcyD and ntcA) and the contents of microcystins (MCs) significantly increased compared with the control in the culture medium. In conclusion, oxidative damage and DNA damage are the primary mechanisms for the allelopathic effect of pyrogallol on M. aeruginosa TY001.

17.
BMC Genomics ; 17(1): 612, 2016 08 11.
Artigo em Inglês | MEDLINE | ID: mdl-27516065

RESUMO

BACKGROUND: Porphyridium purpureum has been utilized in important industrial and pharmaceutical fields. The identification of microRNAs (miRNAs) in this unique species is of great importance: such identification can help fill gaps in the small RNA (sRNA) studies of this organism and help to elucidate essential biological processes and their regulation mechanisms in this special micro alga. RESULTS: In this study, 254 high-confidence miRNAs (203 conserved miRNAs and 51 novel miRNAs) were identified by sRNA deep sequencing (sRNA-seq) combined with bioinformatics. A total of 235 putative miRNA families were predicted, including 192 conserved families and 43 species-specific families. The conservation and diversity of predicted miRNA families were analysed in different plant species. Both the 100 % northern blot validation rate (VR) of four randomly selected miRNAs and the results of stem-loop quantitative real time RT-PCR (qRT-PCR) assays of 25 randomly selected miRNAs demonstrated that the majority of the miRNAs identified in this study are credible. A total of 14,958 and 2184 genes were predicted to be targeted by the 186 conserved and 41 novel miRNAs. Gene ontology (GO) annotation and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis indicated that some target genes likely provide valuable references for further understanding of vital functions in P. purpureum. In addition, a cytoscape network will provide some clues for research into the complex biological processes that occur in this unique alga. CONCLUSIONS: We first identified a large set of conserved and novel miRNAs in P. purpureum. The characteristic and validation analysis on miRNAs demonstrated authenticity of identification data. Functional annotation of target genes and metabolic pathways they involved in illuminated the direction for further utilization and development this micro alga based on its unique properties.


Assuntos
Proteínas de Algas/genética , Regulação da Expressão Gênica de Plantas , Genoma de Planta , MicroRNAs/genética , Porphyridium/genética , RNA de Plantas/genética , Biologia Computacional , Sequência Conservada , Ontologia Genética , Sequenciamento de Nucleotídeos em Larga Escala , Redes e Vias Metabólicas/genética , Anotação de Sequência Molecular
18.
Huan Jing Ke Xue ; 37(4): 1353-61, 2016 Apr 15.
Artigo em Chinês | MEDLINE | ID: mdl-27548956

RESUMO

In order to explore the structural characteristics of phytoplankton community and the water quality and the water quality of the Fenhe scenic spot in Taiyuan, the species composition and the biomass of phytoplankton as well as their correlation with the environmental factors were monitored. The survey selected 9 sampling sites along the up and lower reaches in Fenhe scenic spot of Taiyuan, from Chaicun Bridge to Xiangyun Bridge. During the wet season (June-Octoher) in 2014, specimens were collected, qualitative and quantitative investigation on the algae and monitoring on physicochemical indexes of the water were studied. Meanwhile, the water quality was analyzed and evaluated combining all the physicochemical indexes and cell density. Correlation analysis and RDA were conducted to analyze the relationship of algal community structure and the environmental factors. The main results showed that the dominant phytoplanktons were Cyanophyta, Chlorophyta and Bacillariophyta. The algal biomass first increased and then reduced during the wet season, and the maximum value of hiomass occurred in July. There were many differences among different sampling points. The cell densities of phytoplankton were much higher in three central areas than the other sampling sites. Physical and chemical factors showed a variation tendency in time and space. Based on the results of RDA hetween phytoplankton cell densities and the physic-chemical parameters, the cell densities and the physic..chemical parameters had different correlations. The total cell density had significant positive correlation with dissolved oxygen, and negative correlation with COD. There were extremely significant positive correlations between diatom cell densities and water temperature, air temperature. But the diatom cell density was obviously negatively correlated with COD. It was distinct that the functions of the environment factors were different in temporal and spatial distrihution. The state index of comprehensive nutrition indicated that the total nitrogen content was beyond the standard in all sampling sites during the whole wet season. The water quality varied from oligotrophic to light eutrophic.


Assuntos
Monitoramento Ambiental , Fitoplâncton/crescimento & desenvolvimento , Qualidade da Água , Biomassa , China , Clorófitas , Cianobactérias , Diatomáceas , Nitrogênio , Oxigênio , Estações do Ano , Temperatura Ambiente
19.
Environ Monit Assess ; 188(9): 526, 2016 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-27542668

RESUMO

1,4-Dichlorobenzene (1,4-DCB) is a common organic contaminant in water. To determine the effects of this contaminant on photosynthesis in the freshwater alga Chlorella pyrenoidosa, algal cells were treated with 1,4-DCB at different concentrations for various times, and their photosynthetic pigment contents and chlorophyll fluorescence traits were analyzed. The results showed that 1,4-DCB exerted toxic effects on photosynthesis in C. pyrenoidosa, especially at concentrations exceeding 10 mg/L. The inhibitory effects of 1,4-DCB were time- and concentration-dependent. After treatment with 1,4-DCB (≥10 mg/L), the contents of photosynthetic pigments decreased significantly, the photosystem II reaction center was irreversibly damaged, and the quantum yield of photosystem II decreased significantly. Also, there were sharp decreases in the efficiency of photosynthetic electron transport and energy conversion. Photosystem II became overloaded as the amount of excitation energy distributed to it increased. All of these events weakened the photochemical reaction, and ultimately led to serious inhibition of photosynthesis.


Assuntos
Chlorella/efeitos dos fármacos , Clorobenzenos/toxicidade , Monitoramento Ambiental/métodos , Fotossíntese/efeitos dos fármacos , Poluentes Químicos da Água/toxicidade , Chlorella/metabolismo , Chlorella/fisiologia , Clorofila/metabolismo , Relação Dose-Resposta a Droga , Transporte de Elétrons/efeitos dos fármacos , Complexo de Proteína do Fotossistema II/metabolismo
20.
Biol Open ; 5(9): 1317-23, 2016 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-27543061

RESUMO

A symbiotic alga was successfully isolated from the soil moss Entodon obtusatus found in the Guandi Mountains, Shanxi Province, China, and cultivated under axenic conditions. Morphological observations showed that the symbiotic alga was similar to Chlorococcum Based on phylogenetic analysis of 18S rRNA and rbcL genes and internal transcribed spacer (ITS) regions, Chlorococcum sp. GD was identified as Chlorococcum sphacosum The three data sets were congruent for those aspects of the topologies that were relatively robust, and differed for those parts of the topologies that were not. This strain was cultured in BG11 medium to test its growth and biodiesel properties. It produced a lipid content of nearly 40%, and achieved biomass concentration of 410 mg l(-1) and lipid productivity of 6.76 mg l(-1) day(-1), with favorable C16:0 (23.10%) and C18:1 (21.62%) fatty acid content. This alga appears to have potential for use in biodiesel production.

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