Frontiers in Marine Science
·
2022
·
IF 5.247
Xu Haiqing,Yang Jinzhi,Wang Xu,Peng Qing,Han Yanxia,Liu Xudong,Liu Kexin,Dou Shijuan,Li Liyun,Liu Guozhen,Yang Ming
Microalgae can effectively accumulate starch by using nutritional limitation methods in the context of bioalcohol fuel production. However, relatively few studies have focused on starch accumulation in microalgae and its molecular basis, especially under sulfur limitation conditions. In this study, the starch accumulation dynamics and physiological responses of Chlorella sorokiniana under sulfur starvation (SS) and sulfur replenishment (SR) conditions were investigated, and the genes involved in the transcriptional regulation were explored using RNA-seq. The starch content in C. sorokiniana cells significantly increased from 1.6% to 55.0% of dry weight within 24 h under SS conditions, and then, it decreased to 3.4% within 12 h after transition to SR conditions. However, cell growth was inhibited, and pigment content decreased under SS conditions. Using RNA-seq analysis, a total of 9720 differentially expressed genes (DEGs) induced by sulfur status were obtained. These genes were narrowed down to 454 starvation and replenishment cross-validated (SRV)-DEGs, among which 283 SRV-DEGs were significantly up-regulated and 171 SRV-DEGs were down-regulated under SS conditions, and returned to their previous state under SR conditions. The SRV-DEGs enriched in the sulfate metabolism pathway were all up-regulated under SS conditions after 6 h to speed up the sulfur metabolic cycle, and the transcriptional abundance of a sulfate transporter (SULTR4), cysteine synthase[O-acetylserine(thiol)-lyase] (OASTL), serine acetyltransferase (SAT), and methanethiol oxidase (SELENBP1) increased 8.6-fold, 12.6-fold, 8.7-fold, and 12.4-fold, respectively. Protein synthesis was correspondingly inhibited, which resulted in the reallocation of carbon and elevated the starch synthesis pathway, in which the expressions of glycogen branching enzyme (GBE) and starch synthase (SS) were up-regulated 12.0- and 3.0-fold, respectively. The fatty acid desaturase (FAD) and phosphatidic acid phosphatase (PAP) in the lipid synthesis pathway were strongly up-regulated 8.8- and 16.2-fold, respectively, indicating the competitive synthesis of lipids. The down-regulation of SRV-DEGs associated with carbon fixation, such as those in the Calvin cycle, possibly affected cell growth. The time-resolved transcriptional analysis identified the SRV-DEGs, revealing the underlying starch accumulation mechanism, as well as the relationship with cell growth and lipid synthesis.
研究领域:
微生物学
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分子生物学
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生物技术
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生物能源
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产品关联
DOI
高影响因子
CHEMOSPHERE
·
2023
·
IF 8.8
Zhilin Zhao,Xiaoying Zheng,Zongshuo Han,Shanshan Yang,Huijie Zhang,Tao Lin,Chao Zhou
Co-pollution of microplastics and per- and polyfluoroalkyl substances (PFAS) is prevailing in the aquatic environment. However, the risks of coexisting microplastics and PFAS on organisms remain unknown. This study investigated the response mechanisms of Chlorella sorokiniana ( C. sorokiniana ) under polystyrene microplastics (PS-MPs) and perfluorooctanoic acid (PFOA) stress, including toxicity and defense mechanisms. C. sorokiniana was exposed to PS-MPs (10 mg/L) and PFOA (0.05, 0.5, and 5 mg/L) and their mixtures for 96 h, respectively. We found that the dominant toxicity mechanism of PFOA and PS-MPs to C. sorokiniana was dissimilar. PS-MPs mainly inhibited photosynthesis through shading effect, while PFOA mainly induced oxidative stress by reactive oxygen species . The co-exposure of PFOA and PS-MPs aggravated biotoxicity (maximum inhibition rate: 27.27 ± 2.44%), such as photosynthesis inhibition, physical damage, and oxidative stress, compared with individuals. To alleviate toxicity, C. sorokiniana activated defense mechanisms. Extracellular polymeric substances were the first barrier to protect cells, the effect on its secretion was ordered PS-MPs+5PFOA > PS-MPs > 5PFOA, and IBRv2 values were 2.37, 1.35, 1.11, respectively. Antioxidant system was thought of second defense pathway, the influence order of treatment groups was PS-MPs+5PFOA > 5PFOA > PS-MPs, and its IBRv2 values were 2.89, 1.69, 0.25, respectively. Our findings provide valuable information on the complex impacts of PFOA and PS-MPs, which facilitate the ecological risk assessment of multiple pollutants.
研究领域:
环境科学
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生态毒理学
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水生生物学
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产品关联
DOI
PubMed
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2023
·
IF 15.1
Dongyang Liu,Wenfeng Yang,Yuanfei Lv,Shuangxi Li,Mingxiang Qv,Dian Dai,Liandong Zhu
With the continuous increase of e-waste, more and more pollutants such as tetrabromobisphenol A (TBBPA) and bivalent cadmium ions (Cd(Ⅱ)) are often detected in the surface water. However, their combined toxicity to microalgae is still unclear. Therefore, this study comprehensively explored effects of TBBPA and Cd(Ⅱ) on freshwater microalgae Chlorella sorokiniana , in terms of growth, photosynthetic activity, biochemical characteristics and molecular level. Results showed that Cd(Ⅱ) below 1 mg/L could promote the growth of microalgae, while TBBPA with various dosages showed inhibitory effects. The coexistence of TBBPA and Cd(Ⅱ) had a significant effect on photosynthetic activity, enzyme activity and chlorophylls content. Simultaneously, the release of dissolved organic matters reduced the damage of pollutants to algae. Moreover, C. sorokiniana had a good removal effect on Cd(Ⅱ), and the removal efficiency could reach 72.83%. Interestingly, addition of Cd(Ⅱ) could enhance the removal effect of C. sorokiniana on TBBPA, and the highest removal reached 44.16%. Transcriptome analysis showed that C. sorokiniana had different responses to Cd(Ⅱ) and TBBPA stress, while both caused the regulation of protein synthesis-related genes. Additionally, exposure to Cd(II) upregulated DNA replication-related genes in microalgae, thereby promoting cell proliferation. This study provides insights into toxic mechanisms of TBBPA and Cd(Ⅱ) to microalgae together with their removal patterns, which offers a theoretical basis for further assessment of the actual risk of Cd(II) and TBBPA to aquatic organisms.
研究领域:
环境科学
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生态毒理学
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分子生物学
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水生生态学
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产品关联
DOI
高影响因子
CHEMOSPHERE
·
2022
·
IF 8.943
Dongyang Liu,Mingxiang Qv,Dian Dai,Xu Wang,Liandong Zhu
Flame retardants , such as Tetrabromobisphenol A (TBBPA), Tris(1,3-dichloro-2-propyl) phosphate (TDCPP) and tributyl phosphate (TBP), are frequently detected in surface water. However, the effects of FRs exposure on aquatic organisms especially freshwater microalgae are still unclear. In this study, the toxicities of TBBPA, TDCPP and TBP to microalgae Chlorella sorokiniana , in terms of growth inhibition, photosynthetic activity inhibition and oxidative damage, were investigated, and according ecological risks were assessed. The results showed that TBBPA, TDCPP and TBP had inhibitory effects on C. sorokiniana , with 96 h EC 50 (concentration for 50% of maximal effect) values of 7.606, 41.794 and 49.996 mg/L, respectively. Fv / Fm decreased as the increase of exposure time under 15 mg/L TBBPA. Under 50 mg/L TDCPP and 80 mg/L TBP exposure, Fv / Fm decreased significantly after 24 h. However, Fv / Fm rose after 96 h, indicating that the damaged photosynthetic activity was reversible. The content of chlorophyll a decreased, as the increase of TBBPA concentration from 3 to 15 mg/L. However, chlorophyll a increased first and then decreased, as the increase of TDCPP and TBP concentrations from 0 to 50 mg/L and 0–80 mg/L, respectively. Results indicated that C. sorokiniana could use the phosphorus of TDCPP and TBP to ensure the production of chlorophyll a . The risen content of reactive oxygen species , malondialdehyde as well as superoxide dismutase activity indicated that exposure to FRs induced oxidative stress . Additionally, the risk quotients showed that tested FRs had ecological risks in natural waters or wastewaters. This study provides insights into the toxicological mechanisms of different FRs toward freshwater microalgae for better understanding of according environmental risks.
研究领域:
环境科学
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毒理学
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水生生物学
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产品关联
DOI
PubMed
高影响因子
ENVIRONMENTAL GEOCHEMISTRY AND HEALTH
·
2020
·Vol. 42
·期 9
·2881-2894
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IF 3.472
Ding Na,Wang Lu,Kang Yuan,Luo Kesong,Zeng Diya,Man Yu Bon,Zhang Qiuyun,Zeng Lixuan,Luo Jiwen,Jiang Feng
The transcriptomic response of green microalga Chlorella sorokiniana exposure to environmentally relevant concentration of cadmium(II) (Cd) and 4- n -nonylphenol (4- n -NP) was compared in the present study. Cd and 4- n -NP exposure showed a similar pattern of dys-regulated pathways. The photosystem was affected due to suppression of chlorophyll biosynthesis via down-regulation of Mg-protoporphyrin IX chelatase subunit ChlD (CHLD) and divinyl chlorophyllide a 8-vinyl-reductase (DVR) in Cd group and via down-regulation of DVR in 4- n -NP group. Furthermore, the reactive oxygen species (ROS) could be induced through down-regulation of solanesyl diphosphate synthase 1 (SPS1) and homogentisate phytyltransferase (HPT) in Cd group and via down-regulation of HPT in 4- n -NP group. Additionally, Cd and 4- n -NP would both cause the dys-regulation of carbohydrate metabolism and protein synthesis. On the other hand, there are some different responses or detoxification mechanism of C. sorokiniana to 4- n -NP stress compared to Cd exposure. The increased ROS would cause the DNA damage and protein destruction in Cd exposure group. Simultaneously, the RNA transcription was dys-regulated and a series of changes in gene expressions were observed. This included lipid metabolism, protein modification, and DNA repair, which involved in response of C. sorokiniana to Cd stress or detoxification of Cd. For 4- n -NP exposure, no effect on lipid metabolism and DNA repair was observed. The nucleotide metabolism including pyrimidine metabolism and purine metabolism was significantly up-regulated in the 4- n -NP exposure group, but not in the Cd exposure group. In addition, 4- n -NP would induce the ubiquitin-mediated proteolysis and proteasomal degradation to diminish the misfolded protein caused by ROS and down-regulation of heat shocking protein 40. In sum, the Cd and 4- n -NP could cause the same toxicological effects via the common pathways and possess similar detoxification mechanism. They also showed different responses in nucleotide metabolism, lipid metabolism, and DNA repair.
研究领域:
环境毒理学
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分子生物学
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微藻研究
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产品关联
DOI
PubMed
高影响因子
ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY
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2018
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IF 3.974
Lu Wang,Yuan Kang,Siyun Liang,Danying Chen,Qiuyun Zhang,Lixuan Zeng,Jiwen Luo,Feng Jiang
Toxicological effect of freshwater algae co-exposure to Cd and 4-n-nonylphenol (4-n-NP) was seldom reported. In the present study, Chlorella sorokiniana was selected for testing the single and combined effect of Cd and 4-n-NP by detecting the growth inhibition and oxidative stress after exposure for 48 h, 72 h, and 96 h. The combined effects were evaluated by using toxic units (TU) method and concentration addition（CA）model. The synergistic effect of mixture on algal growth inhibition was both observed at 48 h and 72 h, and the additive effect was observed at 96 h. In addition, the significant alterations of superoxide, thiobarbituric acid reactive substances and antioxidant defenses (superoxide dismutase, catalase , glutathione) have been detected. It could be observed that the mixture predominantly lead to synergistic effects in superoxide induction, and the antagonistic effects in the GSH induction. A similar trend between the superoxide induction and growth inhibition were observed, which may indicate that the oxidative effects of Chlorella sorokiniana contributed to the growth inhibition after exposure to Cd and 4-n-NP. These findings may have important implications in the risk assessments of heavy metals and endocrine disruptors in the aquatic environment.
研究领域:
环境毒理学
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水生生物学
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生态毒理学
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产品关联
DOI
PubMed
高影响因子
ENVIRONMENTAL RESEARCH
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2022
·
IF 8.431
Shuai Wu,Jingmiao Zhang,Ao Xia,Yun Huang,Xianqing Zhu,Xun Zhu,Qiang Liao
Microalgae-based technology provides a potential approach to biologically treating oxytetracycline (OTC) wastewater due to its environmental friendliness, low cost, and high efficiency. However, the OTC degradation and transformation characteristics by microalgae are still unclear and need further exploration. This study used microalgae Chlorella sorokiniana MB-1 for OTC wastewater treatment . The OTC with an initial concentration less than 50 mg L −1 promoted microalgae growth, while OTC with a concentration higher than 100 mg L −1 inhibited microalgae growth significantly. More than 99% OTC was removed with the biomass productivity up to 1.8 g L −1 when treated OTC with 10 mg L −1 initial concentration for 7 days. Chlorophyll and total sugar contents decreased, while protein and lipid contents increased compared to the control without OTC. The malondialdehyde content firstly reduced but subsequently enhanced when increased OTC concentration, while superoxide dismutase content gradually enhanced, manifesting that traces of OTC stimulate microalgae antioxidant capacity, while the increasing OTC caused further oxidative damage to microalgae cells. The removal pathways of OTC mainly include photolysis (75.8%), biodegradation (17.8%), biosorption (3.6%), and hydrolysis (2.7%). Overall, removing OTC by microalgae was confirmed to be an excellent technology for treating antibiotics wastewater whilst accumulating microalgae biomass.
研究领域:
环境工程
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生物技术
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废水处理
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产品关联
DOI
PubMed
高影响因子
BIOTECHNOLOGY AND BIOENGINEERING
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2025
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IF 3.6
Dong-Ao Li,Guang-Hui Xu,Jie Shen,Hong Zhang
This study explores the mechanisms of oxidative damage in Chlorella sorokiniana under continuous gas-liquid phase plasma exposure. The oxidative damage mechanism of C. sorokiniana was revealed through multiple analytical techniques, including scanning electron microscopy (SEM), flow cytometry (FCM), and fluorescence excitation-emission matrix (EEM). Plasma-induced damage to algal cell membranes, causing seepage of photosynthetic pigments and dissolved organic matter; chlorophyll fluorescence changes confirmed damage to the photosynthetic system. Alterations in MDA, intracellular ROS/NO, and antioxidant enzyme activities reflect lipid peroxidation and oxidative stress levels. These results show that plasma induces oxidative damage to algal membranes, intracellular components, and photosystems via reactive oxygen and nitrogen species (RONS). C. sorokiniana activates its antioxidant defense system under stress. This gradual, cumulative damage exerts distinct biological effects at different times. The findings support the precise control of low-temperature plasma for beneficial microorganisms and provide a basis for advancing microalgae transformation technologies.
研究领域:
环境微生物学
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等离子体生物学
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氧化应激
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微藻生理学
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光合作用
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分子生态毒理学
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产品关联
DOI
PubMed
高影响因子
Fermentation-Basel
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2023
·Vol. 9
·期 3
·284
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IF 3.7
Jinzhi Yang,Di Cai,Xudong Liu,Liqi Zhu,Changwei Zhang,Qing Peng,Yanxia Han,Guozhen Liu,Ming Yang
Microalgae, which accumulate considerable carbohydrates, are a potential source of glucose for biofuel fermentation. In this study, we investigated the enzymatic hydrolysis efficiency of wet microalgal biomass compared with freeze-dried and oven-dried biomasses, both with and without an acidic pretreatment. With the dilute sulfuric acid pretreatment followed by amy (α-amylase and amyloglucosidase) and cellulase hydrolysis, approximately 95.4% of the glucose was recovered; however, 88.5% was released by the pretreatment with 2% (w/v) sulfuric acid, which indicates the potential of the acids for direct saccharification process. There were no considerable differences in the glucose yields among the three kinds of materials. In the direct amy hydrolysis without any pretreatment, a 78.7% glucose yield was obtained, and the addition of cellulase had no significant effect on the hydrolysis to glucose. Compared with the oven-dried biomass, the wet biomass produced a substantially higher glucose yield, which is possibly because the cross-linked cells of the oven-dried biomass prevented the accessibility of the enzymes. According to the results, the fresh microalgal biomass without cell disruption can be directly used for enzymatic hydrolysis to produce glucose. The enzymatic hydrolysate of the wet microalgal biomass was successfully used for acetone–butanol–ethanol (ABE) fermentation, which produced 7.2 g/L of ABE, indicating the application potential of wet microalgae in the bioalcohol fuel fermentation process.Keywords:wet microalgae;pretreatment;enzymatic hydrolysis;glucose
研究领域:
生物技术
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能源生物学
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产品关联
DOI
高影响因子
MARINE ENVIRONMENTAL RESEARCH
·
2022
·
IF 3.737
Wenjing Wang,Yanqing Sheng
Decabromodiphenyl ethane is a novel brominated flame retardant , that has always been dissolved in organic solvents to explore its activities on aquatic organisms. In this study, the influences of decabromodiphenyl ethane on the microalga Chlorella sorokiniana ( C. sorokiniana ) were studied, and three microalgae treatments, including decabromodiphenyl ethane dissolved in dimethyl sulfoxide solvent (DBDPE treatment), dimethyl sulfoxide alone (control II) or untreated (control I) were used in the experiment, respectively. The results showed that the growth of C. sorokiniana was remarkably enhanced in the DBDPE treatment compared with the control I and II groups. Conjoint analysis of transcriptomics and quantitative proteome displayed that the upregulated differentially expressed genes and proteins of DBDPE:control I were enriched in 6 pathways, and downregulated genes/proteins of DBDPE:control I were enriched in 3 pathways. The upregulated differentially expressed genes and proteins of DBDPE:control II were enriched in 4 pathways, and downregulated genes/proteins of DBDPE:control II were enriched in 6 pathways. In addition, decabromodiphenyl ethane changed the fatty acid concentration in C. sorokiniana cells. The activities of superoxide dismutase were enhanced when C. sorokiniana were treated by decabromodiphenyl ethane. The data highlighted that the mRNA and protein expression relating to the fatty acid production, of C. sorokiniana were significantly affected by decabromodiphenyl ethane, and decabromodiphenyl ethane pollution changed the physiological metabolism of microalgae and had harmful effects on natural environments.
研究领域:
环境科学
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微生物学
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分子生物学
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毒理学
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DOI
PubMed
高影响因子
SCIENCE OF THE TOTAL ENVIRONMENT
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2024
·
IF 8.2
Tong Wang,Dan Li,Xin Tian,Guolin Huang,Meilin He,Changhai Wang,Ali Nawaz Kumbhar,Abeselom Ghirmai Woldemicael
Salinity stress in estuarine environments poses a significant challenge for microalgal survival and proliferation. The interaction between microalgae and bacteria shows promise in alleviating the detrimental impacts of salinity stress on microalgae. Our study investigates this interaction by co-cultivating Chlorella sorokiniana , a freshwater microalga, with a marine growth-promoting bacterium Pseudomonas gessardii , both of which were isolated from estuary. In this study, bacteria were encapsulated using sodium alginate microspheres to establish an isolated co-culture system, preventing direct exposure between microalgae and bacteria. We evaluated microalgal responses to different salinities (5 PSU, 15 PSU) and interaction modes (free-living, gel-encapsulated), focusing on growth, photosynthesis, cellular metabolism, and extracellular polymeric substances (EPS) properties. High salinity inhibited microalgal proliferation, while gel-fixed interaction boosted Chlorella growth rate by 50.7 %. Both attached and free-living bacteria restored Chlorella 's NPQ to normal levels under salt stress. Microalgae in the free-living interaction group exhibited a significantly lower respiratory rate compared to the pure algae group (−17.2 %). Increased salinity led to enhanced EPS polysaccharide secretion by microalgae, particularly in interaction groups (19.7 %). Both salt stress and interaction increased the proportion of aromatic proteins in microalgae's EPS, enhancing its stability by modulating EPS glycosidic bond C-O-C and protein vibrations. This alteration caused microalgal cells to aggregate, free-living bacteria co-culture group, and fixed co-culture group increasing by 427.5 %, 567.1 %, and 704.1 %, respectively. In gel-fixed bacteria groups, reduced neutral lipids don't accumulate starch instead, carbon redirects to cellular growth, aiding salt stress mitigation. These synergistic activities between salinity and bacterial interactions are vital in mitigating salinity stress, improving the resilience and growth of microalgae in saline conditions. Our research sheds light on the mechanisms of microalgal-bacterial interactions in coping with salt stress, offering insights into the response of estuarine microorganisms to global environmental changes and their ecological stability.
研究领域:
微生物学
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环境科学
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海洋生物学
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植物生理学
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生物技术
✓ 已验证
产品关联
DOI
PubMed
高影响因子
WATER RESEARCH
·
2025
·
IF 12.4
Di Zhou,Liandong Zhu
Organophosphate esters (OPEs) are typical types of emerging contaminants that are widely presented in wastewater. While they can serve as phosphorus (P) sources for microalgae growth, their toxicity disrupts metabolic processes, posing challenges to microalgae-based bioremediation. This study elucidated the regulatory effects of OPEs on the removal of ammonia (NH 4 + -N) and phosphate (PO 4 3- -P) from synthetic wastewater by Chlorella sorokiniana , as well as the concurrent OPEs degradation, while unveiling the molecular mechanism of these interactions. OPEs exposure (1 and 10 mg/L) initially inhibited nutrient assimilation, reducing NH₄⁺-N and PO₄³⁻-P removal by 21.78 %-46.59 % and 7.46 %-26.07 %, respectively. The suppression was primarily attributed to oxidative stress-induced DNA damage, leading to G2/S cell cycle arrest, and metabolic disruptions particularly in crucial nitrogen assimilation enzymes (GS, GDH) and genes ( IMPL2, IPPK ) related to Pi supply strategy adjustment. Meanwhile, OPEs continuously impaired heterotrophy (NaAc matabolism), restricting energy supply for nutrient uptake. Despite this initial inhibition, microalgae exhibited adaptive recovery through photosynthetic regulation and EPS secretion. Enhanced linear electron transfer (LET) and Calvin cycle facilitated photoautotrophy, while EPS played a crucial role in OPEs adsorption and degradation via photosensitization and biosorption, achieving 41.53 %-54.50 % OPEs removal without additional energy input. Transcriptome analysis, combined with KEGG-based pathway annotation, was performed to elucidate the molecular mechanisms underlying these physiological responses. This study unveils a novel stress adaptation mechanism in microalgae, demonstrating their ability to mitigate OPEs toxicity and restore nutrient removal efficiency. The findings provide new insights into the synergistic bioremediation of emerging and conventional pollutants, offering a sustainable strategy for low-carbon wastewater treatment.
研究领域:
环境科学
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微生物学
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环境生物技术
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分子生态毒理学
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废水处理
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微藻生理学
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污染物协同修复
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）