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1.
Sci Rep ; 14(1): 8340, 2024 04 09.
Artigo em Inglês | MEDLINE | ID: mdl-38594439

RESUMO

The community structure and co-occurrence pattern of eukaryotic algae in Yuncheng Salt Lake were analyzed based on marker gene analysis of the 18S rRNA V4 region to understand the species composition and their synergistic adaptations to the environmental factors in different salinity waters. The results showed indicated that the overall algal composition of Yuncheng Salt Lake showed a Chlorophyta-Pyrrophyta-Bacillariophyta type structure. Chlorophyta showed an absolute advantage in all salinity waters. In addition, Cryptophyta dominated in the least saline waters; Pyrrophyta and Bacillariophyta were the dominant phyla in the waters with salinity ranging from 13.2 to 18%. Picochlorum, Nannochloris, Ulva, and Tetraselmis of Chlorophyta, Biecheleria and Oxyrrhis of Pyrrophyta, Halamphora, Psammothidium, and Navicula of Bacillariophyta, Guillardia and Rhodomonas of Cryptophyta were not observed in previous surveys of the Yuncheng Salt Lake, suggesting that the algae are undergoing a constant turnover as the water environment of the Salt Lake continues to change. The network diagram demonstrated that the algae were strongly influenced by salinity, NO3-, and pH, changes in these environmental factors would lead to changes in the algal community structure, thus affecting the stability of the network structure.


Assuntos
Clorófitas , Diatomáceas , Dinoflagellida , Lagos/química , Fitoplâncton , Salinidade , Clorófitas/genética , China
2.
Environ Res ; 246: 118107, 2024 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-38181848

RESUMO

Microbial communities are pivotal in aquatic ecosystems, as they affect water quality, energy dynamics, nutrient cycling, and hydrological stability. This study explored the effects of rainfall on hydrological and photosynthetic parameters, microbial composition, and functional gene profiles in the Fen River. Our results demonstrated that rainfall-induced decreases in stream temperature, dissolved oxygen, pH, total phosphorus, chemical oxygen demand, and dissolved organic carbon concentrations. In contrast, rainfall increased total dissolved solids, salinity, and ammonia-nitrogen concentrations. A detailed microbial community structure analysis revealed that Cyanobacteria was the dominant microbial taxon in the Fen River, accounting for approximately 75% and 25% of the microalgal and bacterial communities, respectively. The abundance of Chlorophyta and Bacillariophyta increased by 47.66% and 29.92%, respectively, whereas the relative abundance of Bacteroidetes decreased by 37.55% under rainfall conditions. Stochastic processes predominantly affected the assembly of the bacterial community on rainy days. Functional gene analysis revealed variations in bacterial functions between sunny (Sun) and rainy (Rain) conditions, particularly in genes associated with the carbon cycle. The 3-oxoacyl-[acyl-carrier-protein] reductase gene was more abundant in the Fen River bacterial community. Particular genes involved in metabolism and environmental information processing, including the acetyl-CoA C-acetyltransferase (atoB), enoyl-CoA hydratase (paaF), and branched-chain amino acid transport system gene (livK), which are integral to environmental information processing, were more abundant in Sun than the Rain conditions. In contrast, the phosphate transport system gene, the galactose metabolic gene, and the pyruvate metabolic gene were more abundant in Rain. The excitation-emission matrix analysis with parallel factor analysis identified four fluorescence components (C1-C4) in the river, which were predominantly protein- (C1) and humic-like (C2-C4) substances. Rainfall affected organic matter production and transport, leading to changes in the degradation and stability of dissolved organic matter. Overall, this study offers insight into how rainfall affects aquatic ecosystems.


Assuntos
Matéria Orgânica Dissolvida , Rios , Rios/química , Ecossistema , Qualidade da Água , Nitrogênio , Bactérias/genética , Espectrometria de Fluorescência
3.
Mar Environ Res ; 194: 106346, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38215625

RESUMO

Marine dissolved organic matter (DOM) is a principal reservoir involved in biogeochemical cycles and exerts a pivotal influence on global carbon flux dynamics. In this study, excitation-emission matrix fluorescence spectroscopy combined with parallel factor analysis (EEM-PARAFAC) was conducted on 230 DOM samples collected from 21 sites between February and April 2022 in the Western Pacific Ocean (WPO). We identified five distinct fluorescence peaks (peaks B, T, A, C, and M), predominantly protein-like and humic-like components. These findings, marked by significant differences (p < 0.01) in fluorescence intensities and spectral indices, characterized the transformation of DOM with ocean depth, illustrating a transition from active to recalcitrant forms. Additionally, random forest analysis (RFA) identified depth as a key factor influencing marine dissolved organic carbon (DOC), with a 32.59% importance value. Correlations between hydrological and fluorescent parameters underscored the complexity of DOM sources and influencing processes. Overall, this work broadens our understanding of DOM variability in the upper 5000 m of the WPO, enhancing our knowledge of the marine environment's role in the global carbon cycle.


Assuntos
Matéria Orgânica Dissolvida , Água , Oceano Pacífico , Espectrometria de Fluorescência/métodos , Qualidade da Água
4.
Toxics ; 11(7)2023 Jul 23.
Artigo em Inglês | MEDLINE | ID: mdl-37505604

RESUMO

In this work, the overall adsorption kinetic process of hydroquinone on Phragmites australis biochar (PAC) was analyzed in depth. A 3D mass transfer model of pore volume and surface diffusion was established, and the diffusion mechanism was analyzed. The characterization results show PAC has a higher porosity value, which is conducive to the adsorption of hydroquinone. The adsorption process modeling results show that the combined effect of pore volume diffusion and surface diffusion promotes the total diffusion process of hydroquinone in the PAC particles, and the two mechanisms of pore volume and surface diffusion exist simultaneously. Under the different operating concentrations, the range of surface diffusion coefficient Ds is 2.5 × 10-10-1.74 × 10-9 cm2/s, and the contribution rate of surface diffusion SDCP% is close to 100%, which is much larger than pore volume diffusion, revealing that regardless of the contact time and position, surface diffusion occupies the main position in intraparticle diffusion.

5.
J Environ Manage ; 345: 118547, 2023 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-37433233

RESUMO

Indigenous bacteria popularly exist in real wastewater. Therefore, the potential interaction between bacteria and microalgae is inevitable in microalgae-based wastewater treatment systems. It is likely to affect the performance of systems. Accordingly, the characteristics of indigenous bacteria is worth serious concerning. Here we investigated the response of indigenous bacterial communities to variant inoculum concentrations of Chlorococcum sp. GD in municipal wastewater treatment systems. The removal efficiency of COD, ammonium and total phosphorus were 92.50%-95.55%, 98.00%-98.69%, and 67.80%-84.72%, respectively. The bacterial community responded differently to different microalgal inoculum concentrations, which was mainly affected by microalgal number, ammonium and nitrate. Besides, there were differential co-occurrence patterns and carbon and nitrogen metabolic function of indigenous bacterial communities. All these results indicated that bacterial communities responded significantly to environmental changes caused by the change of microalgal inoculum concentrations. The response of bacterial communities to different microalgal inoculum concentrations was beneficial for forming a stable symbiotic community of both microalgae and bacteria to remove pollutants in wastewater.


Assuntos
Compostos de Amônio , Microalgas , Águas Residuárias , Microalgas/metabolismo , Biomassa , Bactérias/metabolismo , Nitrogênio/metabolismo , Fósforo
6.
Sci Total Environ ; 878: 162559, 2023 Jun 20.
Artigo em Inglês | MEDLINE | ID: mdl-36907406

RESUMO

Rivers are severely polluted by multiple anthropogenic stressors. An unevenly distributed landscape pattern can aggravate the deterioration of water quality in rivers. Identifying the impacts of landscape patterns on the spatial characteristics of water quality is helpful for river management and water sustainability. Herein we quantified the nationwide water quality degradation in China's rivers and analyzed its responses to spatial patterns of anthropogenic landscapes. The results showed that the spatial patterns of river water quality degradation had a strong spatial inequality and worsened severely in eastern and northern China. The spatial aggregation of agricultural/urban landscape and the water quality degradation exhibits high consistency. Our findings suggested that river water quality would further deteriorate from high spatial aggregation of cities and agricultures, which reminded us that the dispersion of anthropogenic landscape patterns might effectively alleviate water quality pressures.

7.
Environ Pollut ; 319: 120987, 2023 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-36592883

RESUMO

The contamination of the aquatic environment with microplastics has become a global environmental concern. Microplastic particles can be shredded to form smaller nanoplastics, and knowledge on their impacts on phytoplankton, especially freshwater microalgae, is still limited. To investigate this issue, the microalga Scenedesmus quadricauda was exposed to polystyrene nanoplastics (PS-NPs) of five concentrations (10, 25, 50, 100, and 200 mg/L). The growth; the contents of antioxidant enzymes superoxide dismutase (SOD), catalase (CAT), and peroxidase (POD); the chlorophyll content; and concentrations of soluble protein and soluble polysaccharide were accordingly measured. The results showed that the microalgal density increased with the increase of the polystyrene nanoplastic concentrations, and the physiological features of alga were enhanced after the stimulation of nanoplastics. Furthermore, a high concentration (200 mg/L) of nanoplastics increased the contents of chlorophyll, soluble protein, and polysaccharide (P < 0.05). The antioxidant enzyme activities of Scenedesmus quadricauda were significantly activated by nanoplastics. Lastly, we propose three possible algal recovery mechanisms in response to nanoplastics in which Scenedesmus quadricauda was tolerant with PS-NPs by cell wall thickening, internalization, and aggregation. The results of this study contribute to understanding of the ecological risks of nanoplastics on freshwater microalgae.


Assuntos
Microalgas , Scenedesmus , Poluentes Químicos da Água , Poliestirenos/química , Antioxidantes/metabolismo , Microplásticos/toxicidade , Microplásticos/metabolismo , Plásticos/metabolismo , Microalgas/metabolismo , Clorofila/metabolismo , Scenedesmus/metabolismo , Poluentes Químicos da Água/metabolismo
8.
Plants (Basel) ; 11(24)2022 Dec 13.
Artigo em Inglês | MEDLINE | ID: mdl-36559598

RESUMO

Batrachospermaceae is the largest family of freshwater red algae, widely distributed around the world, and plays an important role in maintaining the balance of spring and creek ecosystems. The deterioration of the current global ecological environment has also destroyed the habitat of Batrachospermaceae. The research on the environmental factors of Batrachospermaceae and the accurate classification of the genus is necessary for the protection, restoration, excavation, and utilization of Batrachospermaceae resources. In this paper, the database of geographical distribution and environmental factors of Batrachospermaceae was sorted out, and the relationship between the classification of genus and environmental factors in Batrachospermaceae was analyzed based on two machine learning methods, random forest and XGBoost. The result shows: (1) The models constructed by the two machine learning methods can effectively distinguish the genus of Batrachospermaceae based on environmental factors; (2) The overall AUC score of the random forest model for the classification and prediction of the genus of Batrachospermaceae reached 90.41%, and the overall AUC score of the taxonomic prediction of each genus of Batrachospermaceae reached 85.85%; (3) Combining the two methods, it is believed that the environmental factors that affect the distinction of the genus of Batrachospermaceae are mainly altitude, average relative humidity, average temperature, and minimum temperature, among which altitude has the greatest influence. The results can further clarify the taxonomy of the genus in Batrachospermaceae and enrich the research on the differences in environmental factors of Batrachospermaceae.

9.
PhytoKeys ; 193: 107-123, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35586127

RESUMO

The freshwater red algal order Thoreales has a triphasic life history, of which the "Chantransia" phase is a small filamentous sporophyte. The "Chantransia" stage is difficult to distinguish from species in the genus Audouinella by its morphological characteristics. In this study, five "Chantransia" isolates (GX41, GX81, GD224, GD225, GD228) were collected from Guangxi Zhuang Autonomous Region and Guangdong Province in China. Based on morphological data, all five isolates were similar to A.pygmaea, whereas sequence data from the large subunit of ribulose-1,5-bisphosphate carboxylase/oxygenase (rbcL) gene and the 5' region of the mitochondrial cytochrome oxidase I gene (COI-5P) determined that these specimens represented the "Chantransia" stage of two species in the genus Thorea rather than Audouinella. Phylogenetic analyses of the concatenated genes supported the proposal of a new species, T.baiyunensis, and a new geographic record of T.okadae, a species previously described only in Japan. Therefore, combined with previous records, four species of this genus are now recognized in China, including T.hispida, T.violacea, T.baiyunensis and T.okadae.

10.
Foods ; 11(2)2022 Jan 13.
Artigo em Inglês | MEDLINE | ID: mdl-35053947

RESUMO

By separating and extracting algae from the collected water samples, an oil-producing diatom strain was obtained. Microscopic observation of the strain revealed that its morphological characteristics were highly similar to those of the genus Cyclotella. The cloning of 18S rDNA and phylogenetic analysis showed that the algae were clustered with Cyclotella menegheniana with a high support rate, indicating that the alga was C. menegheniana. The fatty acid content of the alga was determined and found to be mainly C14, C16, and C18 fatty acids, which were in accordance with the relevant standards for edible oil. In this study, different gradient levels of salinity and light were set to investigate the culture and bioactive substance production of C. menegheniana. The results showed that the best growth condition was achieved when the salinity was 15 g·L-1, and its biomass and oil content were the highest at 0.27 g·L-1 and 21%, respectively. The final biomass was the highest when the light intensity was 2000 Lux and the oil content was 18.7%. The results of the study provided a basis for the large-scale production of edible oils and biodiesel.

11.
J Eukaryot Microbiol ; 69(1): e12872, 2022 01.
Artigo em Inglês | MEDLINE | ID: mdl-34618995

RESUMO

Members of coccoid green algae have been documented in various extreme environments. In this article, a unicellular green alga was found to slowly grow in high concentration (3.6 g/L) and pure calcium chloride solution in the laboratory. It was successfully cultured and a taxonomic study combined approaches of morphological and molecular methods was conducted to determine its classification attribution, which was followed by a preliminary physiology research to explore its unique tolerance characteristics against calcium chloride stress. The strain was identified as Parachlorella kessleri by very similar morphology and the same phylogenetic position. The morphological differences among the three species in genus Parachlorella were then discussed and the characteristic traits of absent or thin mucilaginous envelop and mantel-shaped chloroplast for P. kessleri were supported. In addition, the almost strictly spherical shape of adult cells could further distinguish the P. kessleri from the other two species. The tolerant characteristics to CaCl2  stress for this strain were confirmed and the limit concentration was revealed as between 2000 and 4000 times than the standard BG11 culture concentration. Therefore, this P. kessleri strain is expected to be a good material to explore the mechanism of resistance to calcium ions stress for eukaryotic microbiology.


Assuntos
Clorófitas , Cloreto de Cálcio , Clorófitas/genética , Cloroplastos , Filogenia
12.
Mol Biol Rep ; 49(3): 1749-1761, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-34813000

RESUMO

BACKGROUND: Salinity is an essential abiotic stress in plants. Dunaliella is a genus of high-salt-tolerant microalgae. The present study aimed to compare the characterizations of D. bioculata and D. quartolecta at different levels and investigate novel genes response to salt stress. METHODS AND RESULTS: High chlorophyll contents were detected in D. bioculata on the 35th d of salt stress, while high lipid and carotenoid contents were detected in D. quartolecta via morphological and biochemical analyses. Physiological analysis showed that D. quartolecta cells had a smaller increase in osmotic potential, a smaller decrease in the Na+/K+ ratio and photochemical efficiency (Fv/Fm), and a lower relative conductivity than D. bioculata cells. The genomic lengths of D. quartolecta and D. bioculata were 396,013,629 bp (scaffold N50 = 1954 bp) and 427,667,563 bp (scaffold N50 = 3093 bp) via high-throughput sequencing and de novo assembly, respectively. Altogether, 25,751 and 26,620 genes were predicted in their genomes by annotation analysis with various biodatabases. The D. bioculata genome showed more segmental duplication events via collinearity analysis. More single nucleotide polymorphisms and insertion-deletion variants were detected in the D. bioculata genome. Both algae, which showed a close phylogenetic relationship, may undergo positive selection via bioinformatics analysis. A total of 382 and 85 novel genes were screened in D. bioculata and D. quartolecta, with 138 and 51 enriched KEGG pathways, respectively. Unlike the novel genes adh1, hprA and serA, the relative expression of livF and phbB in D. bioculata was markedly downregulated as salinity increased, as determined by qPCR analysis. The relative expression of leuB, asd, pstC and proA in D. quartolecta was markedly upregulated with the same salinity increase. CONCLUSION: Dunaliella quartolecta is more halophilic than D. bioculata, with more effective responses to high salt stress based on the multiphase comparative data.


Assuntos
Microalgas , Estresse Salino , Genômica , Microalgas/genética , Filogenia , Salinidade , Estresse Salino/genética , Estresse Fisiológico/genética
13.
Int J Mol Sci ; 24(1)2022 Dec 30.
Artigo em Inglês | MEDLINE | ID: mdl-36614098

RESUMO

Salt stress is one of the abiotic stress factors that affect the normal growth and development of higher plants and algae. However, few research studies have focused on calcium stress, especially in algae. In this study, the mechanism of tolerance to high calcium stress of a Parachlorella kessleri strain was explored by the method of transcriptomics combined with physiological and morphological analysis. Concentrations of CaCl2 100 times (3.6 g/L) and 1000 times (36 g/L) greater than the standard culture were set up as stresses. The results revealed the algae could cope with high calcium stress mainly by strengthening photosynthesis, regulating osmotic pressure, and inducing antioxidant defense. Under the stress of 3.6 g/L CaCl2, the algae grew well with normal cell morphology. Although the chlorophyll content was significantly reduced, the photosynthetic efficiency was well maintained by up-regulating the expression of some photosynthesis-related genes. The cells reduced oxidative damage by inducing superoxide dismutase (SOD) activities and selenoprotein synthesis. A large number of free amino acids were produced to regulate the osmotic potential. When in higher CaCl2 stress of 36 g/L, the growth and chlorophyll content of algae were significantly inhibited. However, the algae still slowly grew and maintained the same photosynthetic efficiency, which resulted from significant up-regulation of massive photosynthesis genes. Antioxidant enzymes and glycerol were found to resist oxidative damage and osmotic stress, respectively. This study supplied algal research on CaCl2 stress and provided supporting data for further explaining the mechanism of plant salt tolerance.


Assuntos
Antioxidantes , Clorófitas , Antioxidantes/metabolismo , Cloreto de Cálcio/farmacologia , Cálcio/metabolismo , Fotossíntese , Clorofila/metabolismo , Estresse Fisiológico/genética , Clorófitas/metabolismo , Perfilação da Expressão Gênica
14.
Sci Rep ; 11(1): 23147, 2021 11 30.
Artigo em Inglês | MEDLINE | ID: mdl-34848755

RESUMO

The seasonal and spatial eukaryotic phytoplankton composition in the Fenhe River was investigated based on the 18S rDNA V4 region. The relationship between phytoplankton functional groups and environmental factors was explored to effectively capture the responses of these taxa to environmental gradients and their effects on ecosystem function. Our results indicated that the Chlorophyta and Bacillariophyta had higher relative abundance than other taxa, and their diversity and richness indices in spring were higher than those in other seasons. The linear discriminant analysis effect size (LEfSe) analyses detected that the potential seasonal biomarkers included Desmodesmus, Cyclotella, Pseudoschroederia, Discostella, Scenedesmus, Monoraphidium, and Nannochloropsis; the spatial biomarkers included Amphora, Neochloris, Hindakia, Pseudomuriella, Coccomyxa, Chloroidium, Scherffelia, Chromochloris, and Scotinosphaera. The systemic evolution and distribution characteristics of the first 50 representative sequences showed that the dominant genus included Desmodesmus in spring, Pseudopediastrum in summer, Mychonastes in autumn, and Monoraphidium in winter. Main seasonal variation of phytoplankton functional groups was as follows: spring (J + F + C + X1) → summer (J + F + X1 + X2) → autumn (J + F + X1 + C) → winter (X1 + J + B + X2). Pearson correlation, redundancy analysis, and variance partitioning analysis showed temperature and phosphate were the determining factors causing the changes of phytoplankton functional groups and community composition in the Fenhe River.


Assuntos
Fitoplâncton/fisiologia , Rios/microbiologia , Estações do Ano , Microbiologia da Água , Biodiversidade , Biomarcadores , Clorófitas , Cidades , DNA Ribossômico/metabolismo , Diatomáceas/classificação , Análise Discriminante , Ecologia , Ecossistema , Monitoramento Ambiental/métodos , Água Doce/microbiologia , Nitratos/análise , Nitritos/análise , Fosfatos/análise , Filogenia , RNA Ribossômico 18S/metabolismo , Temperatura
15.
Mitochondrial DNA B Resour ; 6(8): 2408-2409, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34345710

RESUMO

Parachlorella kessleri TY isolated from the lawn soil belongs to Trebouxiophyceae, Chlorophyta. The complete mitogenome of P. kessleri sequenced and described. It is a circular duplex molecule 64,744 bp in length consisting of 28 protein-coding genes, 23 transfer RNA (tRNA) genes, four ribosomal RNA (rRNA) genes, and one putative open reading frames (ORFs). Phylogenetic analysis places P. kessleri mitogenome in a branch sister to Picochlorum sp., Lobosphaera incisa, and Chloroparvula sp., clade in which Picochlorum as P. kessleri also reported as oil-rich green microalgae.

16.
Iran J Biotechnol ; 19(2): e2671, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-34435056

RESUMO

BACKGROUND: As a thermoacidophilic microalga, Galdieria sulphuraria has a unique biological function. MicroRNA (miRNA) plays an important regulating role in plant various stress responses. OBJECTIVE: In this study, we identified lots of conserved and novel miRNAs in G. sulphuraria (gsu-miRNAs), and predicted their putative targets for the first time. MATERIALS AND METHODS: Conserved and novel gsu-miRNAs were predicted via deep sequencing on the Illumina HiSeq 4000 platform combined with bioinformatics analysis with a series of filtration criteria. Characterization of gsu-miRNAs and their targets were searched by different bioinformatics software. Some gsu-miRNAs were validated by Northern blot and RT-PCR analysis. MiRNA target gene function was predicted via GO and KEGG analysis. The interrelationship between gsu-miRNAs and target genes was constructed via Cytoscape networks analysis. RESULTS: A total of 134 gsu-miRNAs belonging to 124 MIRNA families were identified. Characterization analysis and experimental validation revealed that most of them were credible. A few miRNAs showed conservatism between G. sulphuraria and 20 representative plants. 1,589 putative miRNA targets were predicted. GO analysis revealed that the genes targeted by gsu-miRNAs involved in some important physiological processes of this alga, such as the ETC, and KEGG pathway analysis revealed that RNA transport and the PPP were predicted to be the two most enriched pathways. Cytoscape networks between miRNAs and target genes indicated their various interactions. CONCLUSIONS: Research on gsu-miRNAs, which act as key regulators during gene expression in G. sulphuraria will open a new avenue for further developing this thermoacidophilic alga at the post-transcriptional level.

17.
Environ Sci Pollut Res Int ; 28(45): 64666-64673, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34312760

RESUMO

Environment-friendly sound measures with high algal growth inhibition efficiency are required to control and eliminate CyanoHABs. This study examined the effects of protopine on growth, gene expression, and antioxidant system of the M. aeruginosa TY001 and explored possible damage mechanism. The results revealed that higher concentrations of protopine seriously inhibited the growth of M. aeruginosa. Quantitative real-time PCR analysis showed downregulated expression of stress response genes (prx and fabZ), and DNA repair gene (recA) on days 3 and 5. The activities of antioxidant enzymes were also decreased markedly, including superoxide dismutase (SOD), catalase (CAT), and peroxidase (POD). Additionally, protopine stress can significantly increase the malondialdehyde (MDA) level in cells. In conclusion, oxidative damage and DNA damage are the main mechanisms of protopine inhibition on M. aeruginosa TY001. Our studies provide evidence that alkaloid compounds such as protopine may have a potential use value as components of aquatic management strategies.


Assuntos
Microcystis , Antioxidantes , Benzofenantridinas , Alcaloides de Berberina , Catalase/genética , Expressão Gênica , Malondialdeído , Microcystis/genética , Superóxido Dismutase
18.
Sci Total Environ ; 773: 145003, 2021 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-33940709

RESUMO

Shanxi Province of northern China is a typical mining concentration and arsenism area. Years of mining activities have resulted in serious regional groundwater problems in Shanxi. Therefore, it is of great significance to know the health risk of groundwater arsenic on residents under the background of mining activities. Kriging interpolation was used to illustrate the spatio-temporal dynamics of the health risks on groundwater arsenic based on a ten-year investigation. The groundwater arsenic concentrations decreased over time and the distribution of high arsenic concentrations shrank. High arsenic concentrations were mainly distributed in the northern and middle basin areas. The forecasted area of high risks in coal mining areas was 5623 km2, which was larger than that in non-coal mining areas. The residents living around mining areas were more vulnerable to exposure to groundwater arsenic. Further, the output map outlines the high-risk zones in order to protect the safety of drinking water for residents. This study may be helpful for the policy-makers to adopt a lower limit for groundwater arsenic to the worst affected regions and groups.


Assuntos
Arsênio , Água Subterrânea , Poluentes Químicos da Água , Arsênio/análise , China , Carvão Mineral , Poluentes Químicos da Água/análise
19.
Int J Mol Sci ; 22(3)2021 Jan 28.
Artigo em Inglês | MEDLINE | ID: mdl-33525606

RESUMO

The oleaginous microalgae species Chlorococcum sphacosum GD is a promising feedstock for biodiesel production from soil. However, its metabolic mechanism of lipid production remains unclear. In this study, the lipid accumulation and metabolism mechanisms of Chlorococcum sphacosum GD were analyzed under salt stress based on transcriptome sequencing. The biomass and lipid content of the alga strain were determined under different NaCl concentrations, and total RNA from fresh cells were isolated and sequenced by HiSeq 2000 high throughput sequencing technology. As the salt concentration increased in culture medium, the algal lipid content increased but the biomass decreased. Following transcriptome sequencing by assembly and splicing, 24,128 unigenes were annotated, with read lengths mostly distributed in the 200-300 bp interval. Statistically significant differentially expressed unigenes were observed in different experimental groups, with 2051 up-regulated genes and 1835 down-regulated genes. The lipid metabolism pathway analysis showed that, under salt stress, gene-related fatty acid biosynthesis (ACCase, KASII, KAR, HAD, FATA) was significantly up-regulated, but some gene-related fatty acid degradation was significantly down-regulated. The comprehensive results showed that salt concentration can affect the lipid accumulation and metabolism of C. sphacosum GD, and the lipid accumulation is closely related to the fatty acid synthesis pathway.


Assuntos
Proteínas de Algas/genética , Clorofíceas/fisiologia , Perfilação da Expressão Gênica/métodos , Solo/química , Clorofíceas/genética , Regulação da Expressão Gênica/efeitos dos fármacos , Redes Reguladoras de Genes , Sequenciamento de Nucleotídeos em Larga Escala , Lipídeos/biossíntese , Anotação de Sequência Molecular , Estresse Salino , Análise de Sequência de RNA , Cloreto de Sódio/farmacologia
20.
J Food Sci ; 86(3): 987-995, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33598924

RESUMO

Active films from chitosan incorporated with Arthrospira platensis polysaccharide (APP) of various ratios (0.0%, 0.5%, and 1.0%, w/v) were developed by solution casting. The effect of APP on the structural, physicochemical, mechanical, antimicrobial, and antioxidant properties of the chitosan-APP films (CA-film) was investigated. Fourier transform infrared spectra (FTIR) confirmed successful incorporation of chitosan and APP. The compact structure of the films was observed clearly in scanning electron microscopy (SEM) and atomic force microscopy (AFM) images. X-ray diffraction (XRD) patterns suggest the semi-crystalline structure was increased upon addition of APP. The composite films showed an improved water resistance and vapor barrier properties, and reduced by at least 27.4% and 32.1% in swelling degree (Sd ) and water vapor permeability (WVP) compared with chitosan film (C-film), respectively. However, the transparency decreased slightly, which may be due to the shrinkage of the spacing of the polymer interchain. The composite films also displayed enhanced the mechanical properties. The antimicrobial activity of the CA-film showed an increase of at least of 0.41-fold in inhibition zone diameter for E. coli. At a concentration of 1.2 mg/mL, the antioxidant activity of CA-film was enhanced by more than threefold compared with C-film. Therefore, CA-films have good potential as sources of active packaging material for the food industry.


Assuntos
Quitosana/química , Embalagem de Alimentos/instrumentação , Polissacarídeos/química , Spirulina/química , Anti-Infecciosos/farmacologia , Antioxidantes/farmacologia , Fenômenos Químicos , Escherichia coli/efeitos dos fármacos , Estrutura Molecular , Permeabilidade , Vapor
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