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Ma M, Jiang L, He Y, Hu J, Pei H. Multi-faceted effects of NaCl on salt-tolerant microalgaeGolenkiniasp. SDEC-16. BIORESOURCE TECHNOLOGY 2024:131016. [PMID: 38906195 DOI: 10.1016/j.biortech.2024.131016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/11/2024] [Revised: 06/17/2024] [Accepted: 06/18/2024] [Indexed: 06/23/2024]
Abstract
The salt-tolerant microalgae are extremely few and salt-tolerance mechanism is unclear, requiring urgent exploration of salt-tolerance mechanism of known microalgae. This study was first to reveal the salt-tolerance mechanism of Golenkinia sp. SDEC-16 by investigating the growth and metabolism under different salinities and high salinity long-term cultivation. SDEC-16 can survive under high salinity and resume normal growth after NaCl removal. Under long-term stress, SDEC-16 had higher lipid content and productivity than BG11. However, the suppressed F v/ F m (58.4%) and F v/ F 0 (84.0%) along with the increased reactive oxygen species (×6.6), and superoxide dismutase (×1.7) during the treatment revealed NaCl-induced photosynthetic inhibition and oxidative stress. RNA sequencing results showed inhibition of the photosynthetic system, and the enhancement of pathways such as nitrogen metabolism, energy metabolism, and lipid synthesis contributed to the good function of chloroplast, energy supply, and metabolic activity of SDEC-16. This study provides theoretical support for large-scale microalgal cultivation in seawater.
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Affiliation(s)
- Meng Ma
- (School of Environmental Science and Engineering), (Shandong University), Qingdao, 266237, China; (Shandong Provincial Engineering Centeron Environmental Science and Technology), Jinan, 250061, China
| | - Liqun Jiang
- (School of Environmental Science and Engineering), (Shandong University), Qingdao, 266237, China; (Department of Environmental Science and Engineering), (Fudan University), Shanghai, 200433, China
| | - Yuqing He
- (Department of Environmental Science and Engineering), (Fudan University), Shanghai, 200433, China
| | - Jibo Hu
- (China Medical University-The Queen's University of Belfast Joint College), (China Medical University), Shenyang, 110122, China
| | - Haiyan Pei
- (School of Environmental Science and Engineering), (Shandong University), Qingdao, 266237, China; (Department of Environmental Science and Engineering), (Fudan University), Shanghai, 200433, China; (Shandong Provincial Engineering Centeron Environmental Science and Technology), Jinan, 250061, China.
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Zhou JL, Vadiveloo A, Chen DZ, Gao F. Regulation effects of indoleacetic acid on lipid production and nutrient removal of Chlorella pyrenoidosa in seawater-containing wastewater. WATER RESEARCH 2024; 248:120864. [PMID: 37979569 DOI: 10.1016/j.watres.2023.120864] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/23/2023] [Revised: 10/12/2023] [Accepted: 11/11/2023] [Indexed: 11/20/2023]
Abstract
The utilization of seawater supplemented with wastewater nutrients for microalgae cultivation represents a promising and cost-effective approach that combines the benefits of wastewater treatment and microalgal resource recovery. However, the high salt content in seawater poses a significant challenge, hindering microalgal growth and reducing the removal of nitrogen and phosphorus on a large scale. The phytohormone indoleacetic acid (IAA) was used in this study to enhance stress resistance and lipid production of Chlorella pyrenoidosa grown in seawater-wastewater medium. Compared to the control groups involving regular wastewater and seawater-containing wastewater without IAA, Chlorella pyrenoidosa cultivated in the seawater-containing wastewater supplemented with IAA exhibited remarkable outcomes. Specifically, microalgae in IAA-enhanced seawater-containing wastewater achieved the highest lipid productivity (22.67 mg L-1 d-1) along with impressive nitrogen (99.3 %) and phosphorus (97.3 %) removal rates. Moreover, their cell sedimentation ratio reached 76.6 %, indicating enhanced settling properties. Additionally, the physiological mechanism changes after exposure to seawater stress and IAA were revealed based on the changes in antioxidant enzymes, endogenous hormones, and fatty acid saturation. Furthermore, the transcriptomic analysis elucidated the molecular mechanisms underlying microalgal lipid synthesis and their response to antioxidant stress when exposed to seawater. The supplementation of IAA under seawater stress stimulated energy metabolism and the antioxidant response in microalgal cells, effectively mitigating the adverse effects of seawater stress and promoting overall algal lipid productivity. Overall, this study unveiled the potential of exogenous plant hormones, particularly IAA, in enhancing stress resistance and lipid productivity of microalgae grown in seawater-wastewater medium, which significantly contributed towards the efficient use of seawater resources for microalgae cultivation and biofuel production.
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Affiliation(s)
- Jin-Long Zhou
- School of Petrochemical Engineering & Environment, Zhejiang Ocean University, Zhoushan 316000, China; Zhejiang Key Laboratory of Petrochemical Environmental Pollution Control, Zhoushan, 316000, China
| | - Ashiwin Vadiveloo
- Centre for Water, Energy and Waste, Harry Butler Institute, Murdoch University, Murdoch, WA 6150, Australia
| | - Dong-Zhi Chen
- School of Petrochemical Engineering & Environment, Zhejiang Ocean University, Zhoushan 316000, China; Zhejiang Key Laboratory of Petrochemical Environmental Pollution Control, Zhoushan, 316000, China
| | - Feng Gao
- School of Petrochemical Engineering & Environment, Zhejiang Ocean University, Zhoushan 316000, China; Zhejiang Key Laboratory of Petrochemical Environmental Pollution Control, Zhoushan, 316000, China.
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Singh RP, Yadav P, Kumar A, Hashem A, Avila-Quezada GD, Abd_Allah EF, Gupta RK. Salinity-Induced Physiochemical Alterations to Enhance Lipid Content in Oleaginous Microalgae Scenedesmus sp. BHU1 via Two-Stage Cultivation for Biodiesel Feedstock. Microorganisms 2023; 11:2064. [PMID: 37630624 PMCID: PMC10459255 DOI: 10.3390/microorganisms11082064] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2023] [Revised: 08/05/2023] [Accepted: 08/08/2023] [Indexed: 08/27/2023] Open
Abstract
In the recent past, various microalgae have been considered a renewable energy source for biofuel production, and their amount and extent can be enhanced by applying certain types of stress including salinity. Although microalgae growing under salinity stress result in a higher lipid content, they simultaneously reduce in growth and biomass output. To resolve this issue, the physiochemical changes in microalgae Scenedesmus sp. BHU1 have been assessed through two-stage cultivation. In stage-I, the maximum carbohydrate and lipid contents (39.55 and 34.10%) were found at a 0.4 M NaCl concentration, while in stage-II, the maximum carbohydrate and lipid contents (42.16 and 38.10%) were obtained in the 8-day-old culture. However, under increased salinity, Scenedesmus sp. BHU1 exhibited a decrease in photosynthetic attributes, including Chl-a, Chl-b, Fv/Fm, Y(II), Y(NPQ), NPQ, qP, qL, qN, and ETRmax but increased Y(NO) and carotenoids content. Apart from physiological attributes, osmoprotectants, stress biomarkers, and nonenzymatic antioxidants were also studied to elucidate the role of reactive oxygen species (ROS) facilitated lipid synthesis. Furthermore, elemental and mineral ion analysis of microalgal biomass was performed to evaluate the biomass quality for biofuel and cell homeostasis. Based on fluorometry analysis, we found the maximum neutral lipids in the 8-day-old grown culture at stage-II in Scenedesmus sp. BHU1. Furthermore, the use of Fourier-transform infrared (FT-IR) and nuclear magnetic resonance (NMR) spectroscopy analyses confirmed the presence of higher levels of hydrocarbons and triacylglycerides (TAGs) composed of saturated fatty acids (SFAs) and monounsaturated fatty acids (MUFAs) in the 8-day-old culture. Therefore, Scenedesmus sp. BHU1 can be a promising microalga for potential biodiesel feedstock.
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Affiliation(s)
- Rahul Prasad Singh
- Laboratory of Algal Research, Centre of Advanced Study in Botany, Institute of Science, Banaras Hindu University, Varanasi 221005, India; (R.P.S.); (P.Y.)
| | - Priya Yadav
- Laboratory of Algal Research, Centre of Advanced Study in Botany, Institute of Science, Banaras Hindu University, Varanasi 221005, India; (R.P.S.); (P.Y.)
| | - Ajay Kumar
- Amity Institute of Biotechnology, Amity University, Noida 201303, India
| | - Abeer Hashem
- Botany and Microbiology Department, College of Science, King Saud University, P.O. Box. 2460, Riyadh 11451, Saudi Arabia;
| | | | - Elsayed Fathi Abd_Allah
- Plant Production Department, College of Food and Agricultural Sciences, King Saud University, P.O. Box. 2460, Riyadh 11451, Saudi Arabia;
| | - Rajan Kumar Gupta
- Laboratory of Algal Research, Centre of Advanced Study in Botany, Institute of Science, Banaras Hindu University, Varanasi 221005, India; (R.P.S.); (P.Y.)
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Koh HG, Cho JM, Jeon S, Chang YK, Lee B, Kang NK. Transcriptional insights into Chlorella sp. ABC-001: a comparative study of carbon fixation and lipid synthesis under different CO 2 conditions. BIOTECHNOLOGY FOR BIOFUELS AND BIOPRODUCTS 2023; 16:113. [PMID: 37454088 PMCID: PMC10350272 DOI: 10.1186/s13068-023-02358-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/21/2023] [Accepted: 06/11/2023] [Indexed: 07/18/2023]
Abstract
BACKGROUND Microalgae's low tolerance to high CO2 concentrations presents a significant challenge for its industrial application, especially when considering the utilization of industrial exhaust gas streams with high CO2 content-an economically and environmentally attractive option. Therefore, the objectives of this study were to investigate the metabolic changes in carbon fixation and lipid accumulation of microalgae under ambient air and high CO2 conditions, deepen our understanding of the molecular mechanisms driving these processes, and identify potential target genes for metabolic engineering in microalgae. To accomplish these goals, we conducted a transcriptomic analysis of the high CO2-tolerant strain, Chlorella sp. ABC-001, under two different carbon dioxide levels (ambient air and 10% CO2) and at various growth phases. RESULTS Cells cultivated with 10% CO2 exhibited significantly better growth and lipid accumulation rates, achieving up to 2.5-fold higher cell density and twice the lipid content by day 7. To understand the relationship between CO2 concentrations and phenotypes, transcriptomic analysis was conducted across different CO2 conditions and growth phases. According to the analysis of differentially expressed genes and gene ontology, Chlorella sp. ABC-001 exhibited the development of chloroplast organelles during the early exponential phase under high CO2 conditions, resulting in improved CO2 fixation and enhanced photosynthesis. Cobalamin-independent methionine synthase expression was also significantly elevated during the early growth stage, likely contributing to the methionine supply required for various metabolic activities and active proliferation. Conversely, the cells showed sustained repression of carbonic anhydrase and ferredoxin hydrogenase, involved in the carbon concentrating mechanism, throughout the cultivation period under high CO2 conditions. This study also delved into the transcriptomic profiles in the Calvin cycle, nitrogen reductase, and lipid synthesis. Particularly, Chlorella sp. ABC-001 showed high expression levels of genes involved in lipid synthesis, such as glycerol-3-phosphate dehydrogenase and phospholipid-diacylglycerol acyltransferase. These findings suggest potential targets for metabolic engineering aimed at enhancing lipid production in microalgae. CONCLUSIONS We expect that our findings will help understand the carbon concentrating mechanism, photosynthesis, nitrogen assimilation, and lipid accumulation metabolisms of green algae according to CO2 concentrations. This study also provides insights into systems metabolic engineering of microalgae for improved performance in the future.
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Affiliation(s)
- Hyun Gi Koh
- Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL, USA
| | - Jun Muk Cho
- Department of Chemical and Biomolecular Engineering, KAIST, 291 Daehak-ro, Yuseong-gu, Daejeon, 34141, Republic of Korea
| | - Seungjib Jeon
- Department of Chemical and Biomolecular Engineering, KAIST, 291 Daehak-ro, Yuseong-gu, Daejeon, 34141, Republic of Korea
| | - Yong Keun Chang
- Department of Chemical and Biomolecular Engineering, KAIST, 291 Daehak-ro, Yuseong-gu, Daejeon, 34141, Republic of Korea
| | - Bongsoo Lee
- Department of Microbial Biotechnology, College of Science and Technology, Mokwon University, 88 Doanbuk-ro, Seo-gu, Daejeon, 35349, Republic of Korea.
| | - Nam Kyu Kang
- Department of Chemical Engineering, College of Engineering, Kyung Hee University, Yongin, 17104, Republic of Korea.
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Zhou Y, Meng F, Han K, Zhang K, Gao J, Chen F. Screening and validating of endogenous reference genes in Chlorella sp. TLD 6B under abiotic stress. Sci Rep 2023; 13:1555. [PMID: 36707665 PMCID: PMC9883494 DOI: 10.1038/s41598-023-28311-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2022] [Accepted: 01/17/2023] [Indexed: 01/28/2023] Open
Abstract
Chlorella sp. TLD 6B, a microalgae growing in the Taklamakan Desert, Xinjiang of China, is a good model material for studying the physiological and environmental adaptation mechanisms of plants in their arid habitats, as its adaptation to the harsh desert environment has led to its strong resistance. However, when using real-time quantitative polymerase chain reaction (RT-qPCR) to analyze the gene expression of this algae under abiotic stress, it is essential to find the suitable endogenous reference genes so to obtain reliable results. This study assessed the expression stability of 9 endogenous reference genes of Chlorella sp. TLD 6B under four abiotic stresses (drought, salt, cold and heat). These genes were selected based on the analysis results calculated by the three algorithmic procedures of geNorm, NormFinder, and BestKeeper, which were ranked by refinder. Our research showed that 18S and GTP under drought stress, 18S and IDH under salt stress, CYP and 18S under cold stress, GTP and IDH under heat stress were the most stable endogenous reference genes. Moreover, UBC and 18S were the most suitable endogenous reference gene combinations for all samples. In contrast, GAPDH and α-TUB were the two least stable endogenous reference genes in all experimental samples. Additionally, the selected genes have been verified to be durable and reliable by detecting POD and PXG3 genes using above endogenous reference genes. The identification of reliable endogenous reference genes guarantees more accurate RT-qPCR quantification for Chlorella sp. TLD 6B, facilitating functional genomics studies of deserts Chlorella as well as the mining of resistance genes.
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Affiliation(s)
- Yongshun Zhou
- College of Life Sciences, Shihezi University, Shihezi, Xinjiang, 832000, People's Republic of China
| | - Fanze Meng
- College of Life Sciences, Shihezi University, Shihezi, Xinjiang, 832000, People's Republic of China
| | - Kai Han
- College of Life Sciences, Shihezi University, Shihezi, Xinjiang, 832000, People's Republic of China
| | - Kaiyue Zhang
- College of Life Sciences, Shihezi University, Shihezi, Xinjiang, 832000, People's Republic of China
| | - Jianfeng Gao
- College of Life Sciences, Shihezi University, Shihezi, Xinjiang, 832000, People's Republic of China.
| | - Fulong Chen
- College of Life Sciences, Shihezi University, Shihezi, Xinjiang, 832000, People's Republic of China.
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Shah S, Li X, Jiang Z, Fahad S, Hassan S. Exploration of the phytohormone regulation of energy storage compound accumulation in microalgae. Food Energy Secur 2022. [DOI: 10.1002/fes3.418] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Affiliation(s)
- Saud Shah
- College of Life Science, Linyi University Linyi City Shandong China
| | - Xiuling Li
- College of Life Science, Linyi University Linyi City Shandong China
| | - Zhaoyu Jiang
- College of Life Science, Linyi University Linyi City Shandong China
| | - Shah Fahad
- Hainan Key Laboratory for Sustainable Utilization of Tropical Bioresource College of Tropical Crops, Hainan University Haikou Hainan China
- Department of Agronomy University of Haripur Haripur Khyber Pakhtunkhwa Pakistan
| | - Shah Hassan
- Department of Agriculture Extenstion The University of Agriculture Peshawar Haripur Khyber Pakhtunkhwa Pakistan
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Fal S, Aasfar A, Rabie R, Smouni A, Arroussi HEL. Salt induced oxidative stress alters physiological, biochemical and metabolomic responses of green microalga Chlamydomonas reinhardtii. Heliyon 2022; 8:e08811. [PMID: 35118209 PMCID: PMC8792077 DOI: 10.1016/j.heliyon.2022.e08811] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2021] [Revised: 12/05/2021] [Accepted: 01/18/2022] [Indexed: 12/17/2022] Open
Abstract
Salinity is one of the most significant environmental factors limiting microalgal biomass productivity. In the present study, the model microalga Chlamydomonas reinhardtii (C. reinhardtii) was exposed to 200 mM NaCl for eight days to explore the physiological, biochemical and metabolomic changes. C. reinhradtii exhibited a significant decrease in growth rate, and Chl a and Chl b levels. 200 mM NaCl induced ROS generation in C. reinhardtii with increase in H2O2 content. This caused lipid peroxidation with increase in MDA levels. C. reinhardtii also exhibited an increase in carbohydrate and lipid accumulation under 200 mM NaCl conditions as storage molecules in cells to maintain microalgal survival. In addition, NaCl stress increased the content of carotenoids, polyphenols and osmoprotectant molecules such as proline. SOD and APX activities decreased, while ROS-scavenger enzymes (POD and CAT) decreased. Metabolomic response showed an accumulation of the major molecules implicated in membrane remodelling and stress resistance such oleic acid (40.29%), linolenic acid (19.29%), alkanes, alkenes and phytosterols. The present study indicates the physiological, biochemical and metabolomic responses of C. reinhardtii to salt stress.
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Affiliation(s)
- Soufiane Fal
- Green Biotechnology Laboratory, Moroccan Foundation for Advanced Science, Innovation and Research (MASCIR), Rabat Design Center, Rue Mohamed Al Jazouli – Madinat Al Irfane, Rabat, Morocco
- Plant Physiology and Biotechnology Team, Center of Plant and Microbial Biotechnology, Biodiversity and Environment, Faculty of Sciences, Mohammed V University in Rabat, Morocco
| | - Abderahim Aasfar
- Green Biotechnology Laboratory, Moroccan Foundation for Advanced Science, Innovation and Research (MASCIR), Rabat Design Center, Rue Mohamed Al Jazouli – Madinat Al Irfane, Rabat, Morocco
| | - Reda Rabie
- Green Biotechnology Laboratory, Moroccan Foundation for Advanced Science, Innovation and Research (MASCIR), Rabat Design Center, Rue Mohamed Al Jazouli – Madinat Al Irfane, Rabat, Morocco
- University Sidi Mohamed Ben Abdellah, Faculty of Sciences and Techniques of Fez, Laboratory of Applied Organic Chemistry, Fez, Morocco
| | - Abelaziz Smouni
- Plant Physiology and Biotechnology Team, Center of Plant and Microbial Biotechnology, Biodiversity and Environment, Faculty of Sciences, Mohammed V University in Rabat, Morocco
| | - Hicham EL. Arroussi
- Green Biotechnology Laboratory, Moroccan Foundation for Advanced Science, Innovation and Research (MASCIR), Rabat Design Center, Rue Mohamed Al Jazouli – Madinat Al Irfane, Rabat, Morocco
- Agrobiosciences Program, University Mohamed 6 Polytechnic (UM6P), Ben-Guerir, Morocco
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