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Fan S, Li Y, Wang Q, Jin M, Yu M, Zhao H, Zhou C, Xu J, Li B, Li X. The role of cis-zeatin in enhancing high-temperature resistance and fucoxanthin biosynthesis in Phaeodactylum tricornutum. Appl Environ Microbiol 2024:e0206823. [PMID: 38786362 DOI: 10.1128/aem.02068-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2023] [Accepted: 04/25/2024] [Indexed: 05/25/2024] Open
Abstract
Phaeodactylum tricornutum a prominent source of industrial fucoxanthin production, faces challenges in its application due to its tolerance to high-temperature environments. This study investigates the physiological responses of P. tricornutum to high-temperature stress and its impact on fucoxanthin content, with a specific focus on the role of cis-zeatin. The results reveal that high-temperature stress inhibits P. tricornutum's growth and photosynthetic activity, leading to a decrease in fucoxanthin content. Transcriptome analysis shows that high temperature suppresses the expression of genes related to photosynthesis (e.g., psbO, psbQ, and OEC) and fucoxanthin biosynthesis (e.g., PYS, PDS1, and PSD2), underscoring the negative effects of high temperature on P. tricornutum. Interestingly, genes associated with cis-zeatin biosynthesis and cytokinesis signaling pathways exhibited increased expression under high-temperature conditions, indicating a potential role of cis-zeatin signaling in response to elevated temperatures. Content measurements confirm that high temperature enhances cis-zeatin content. Furthermore, the exogenous addition of cytokinesis mimetics or inhibitors significantly affected P. tricornutum's high-temperature resistance. Overexpression of the cis-zeatin biosynthetic enzyme gene tRNA DMATase enhanced P. tricornutum's resistance to high-temperature stress, while genetic knockout of tRNA DMATase reduced its resistance to high temperatures. Therefore, this research not only uncovers a novel mechanism for high-temperature resistance in P. tricornutum but also offers a possible alga species that can withstand high temperatures for the industrial production of fucoxanthin, offering valuable insights for practical utilization.IMPORTANCEThis study delves into Phaeodactylum tricornutum's response to high-temperature stress, specifically focusing on cis-zeatin. We uncover inhibited growth, reduced fucoxanthin, and significant cis-zeatin-related gene expression under high temperatures, highlighting potential signaling mechanisms. Crucially, genetic engineering and exogenous addition experiments confirm that the change in cis-zeatin levels could influence P. tricornutum's resistance to high-temperature stress. This breakthrough deepens our understanding of microalgae adaptation to high temperatures and offers an innovative angle for industrial fucoxanthin production. This research is a pivotal step toward developing heat-resistant microalgae for industrial use.
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Affiliation(s)
- Sizhe Fan
- School of Marine Sciences, Ningbo University, Ningbo, China
| | - Yixuan Li
- College of Food and Pharmaceutical Sciences, Ningbo University, Ningbo, China
| | - Qi Wang
- College of Food and Pharmaceutical Sciences, Ningbo University, Ningbo, China
| | - Mengjie Jin
- College of Food and Pharmaceutical Sciences, Ningbo University, Ningbo, China
| | - Mange Yu
- School of Marine Sciences, Ningbo University, Ningbo, China
| | - Hejing Zhao
- School of Marine Sciences, Ningbo University, Ningbo, China
| | - Chengxu Zhou
- College of Food and Pharmaceutical Sciences, Ningbo University, Ningbo, China
| | - Jilin Xu
- School of Marine Sciences, Ningbo University, Ningbo, China
| | - Bing Li
- School of Civil & Environmental Engineering and Geography Science, Ningbo University, Ningbo, China, Ningbo, China
| | - Xiaohui Li
- College of Food and Pharmaceutical Sciences, Ningbo University, Ningbo, China
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Liao J, Sun B, Wang C, Cao Z, Wu Z, An X, Liang Z, Huang X, Lu Y. Uptake and cellular responses of Microcystis aeruginosa to PFOS in various environmental conditions. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2024; 272:116041. [PMID: 38350213 DOI: 10.1016/j.ecoenv.2024.116041] [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: 10/18/2023] [Revised: 01/18/2024] [Accepted: 01/27/2024] [Indexed: 02/15/2024]
Abstract
Although PFOS has been banned as a persistent organic pollutant, it still exists in large quantities within the environment, thus impacting the health of aquatic ecosystems. Previous studies focused solely on high PFOS concentrations, disregarding the connection with environmental factors. To gain a more comprehensive understanding of the PFOS effects on aquatic ecosystems amidst changing environmental conditions, this study investigated the cellular responses of Microcystis aeruginosa to varying PFOS concentrations under heatwave and nutrient stress conditions. The results showed that PFOS concentrations exceeding 5.0 µg/L had obvious effects on multiple physiological responses of M. aeruginosa, resulting in the suppression of algal cell growth and the induction of oxidative damage. However, PFOS concentration at levels below 20.0 µg/L has been found to enhance the growth of algal cells and trigger significant oxidative damage under heatwave conditions. Heatwave conditions could enhance the uptake of PFOS in algal cells, potentially leading to heightened algal growth when PFOS concentration was equal to or less than 5.0 µg/L. Conversely, deficiency or limitation of nitrogen and phosphorus significantly decreased algal abundance and chlorophyll content, inducing severe oxidative stress that could be mitigated by exposure to PFOS. This study holds significance in managing the impact of PFOS on algal growth across diverse environmental conditions.
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Affiliation(s)
- Jieming Liao
- State Key Laboratory of Marine Environmental Science and Key Laboratory of the Ministry of Education for Coastal Wetland Ecosystems, College of the Environment and Ecology, Xiamen University, Fujian 361102, China
| | - Bin Sun
- State Key Laboratory of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; University of Chinese Academic of Sciences, Beijing 100049, China
| | - Cong Wang
- State Key Laboratory of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; University of Chinese Academic of Sciences, Beijing 100049, China
| | - Zhiwei Cao
- State Key Laboratory of Marine Environmental Science and Key Laboratory of the Ministry of Education for Coastal Wetland Ecosystems, College of the Environment and Ecology, Xiamen University, Fujian 361102, China
| | - Zhaoyang Wu
- State Key Laboratory of Marine Environmental Science and Key Laboratory of the Ministry of Education for Coastal Wetland Ecosystems, College of the Environment and Ecology, Xiamen University, Fujian 361102, China
| | - Xupeng An
- State Key Laboratory of Marine Environmental Science and Key Laboratory of the Ministry of Education for Coastal Wetland Ecosystems, College of the Environment and Ecology, Xiamen University, Fujian 361102, China
| | - Zi'an Liang
- State Key Laboratory of Marine Environmental Science and Key Laboratory of the Ministry of Education for Coastal Wetland Ecosystems, College of the Environment and Ecology, Xiamen University, Fujian 361102, China
| | - Xinyi Huang
- State Key Laboratory of Marine Environmental Science and Key Laboratory of the Ministry of Education for Coastal Wetland Ecosystems, College of the Environment and Ecology, Xiamen University, Fujian 361102, China
| | - Yonglong Lu
- State Key Laboratory of Marine Environmental Science and Key Laboratory of the Ministry of Education for Coastal Wetland Ecosystems, College of the Environment and Ecology, Xiamen University, Fujian 361102, China; State Key Laboratory of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; University of Chinese Academic of Sciences, Beijing 100049, China.
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Varunraj R, Priyadharshini U, Vijay K, Balamurugan S. Adaptive laboratory evolution empowers lipids and biomass overproduction in Chlorella vulgaris for environmental applications. ENVIRONMENTAL RESEARCH 2023; 238:117125. [PMID: 37709245 DOI: 10.1016/j.envres.2023.117125] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/15/2023] [Revised: 09/01/2023] [Accepted: 09/11/2023] [Indexed: 09/16/2023]
Abstract
Microalgal strain improvement with commercial features is needed to generate green biological feedstock to produce lipids for bioenergy. Hence, improving algal strain with enhanced lipid content without hindering cellular physiological parameters is pivotal for commercial applications of microalgae. In this report, we demonstrated the adaptive laboratory evolution (ALE) by hypersaline conditions to improve the algal strains for increasing the lipid overproduction capacity of Chlorella vulgaris for environmental applications. The evolved strains (namely E2 and E2.5) without notable impairment in general physiological parameters were scrutinized after 35 cycles. Conventional gravimetric lipid analysis showed that total lipid accumulation was hiked by 2.2-fold in the ALE strains compared to the parental strains. Confocal observation of algal cells stained with Nile-red showed that the abundance of lipid droplets was higher in the evolved strains without any apparent morphological aberrations. Furthermore, evolved strains displayed notable antioxidant potential than the control cells. Interestingly, carbohydrates and protein content were significantly decreased in the evolved cells, indicating that carbon flux was redirected into lipogenesis in the evolved cells. Altogether, our findings demonstrated a potential and feasible strategy for microalgal strain improvement for simultaneous lipids and biomass hyperaccumulation.
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Affiliation(s)
- Rajendran Varunraj
- Microalgal Biotechnology Laboratory, Department of Biotechnology, Bharathidasan University, Tiruchirappalli, 620024, India
| | - Uthayakumar Priyadharshini
- Microalgal Biotechnology Laboratory, Department of Biotechnology, Bharathidasan University, Tiruchirappalli, 620024, India
| | - Kannusamy Vijay
- Microalgal Biotechnology Laboratory, Department of Biotechnology, Bharathidasan University, Tiruchirappalli, 620024, India
| | - Srinivasan Balamurugan
- Microalgal Biotechnology Laboratory, Department of Biotechnology, Bharathidasan University, Tiruchirappalli, 620024, India.
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Lin JY, Ng IS. Enhanced carbon capture, lipid and lutein production in Chlamydomonas reinhardtii under meso-thermophilic conditions using chaperone and CRISPRi system. BIORESOURCE TECHNOLOGY 2023:129340. [PMID: 37343802 DOI: 10.1016/j.biortech.2023.129340] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/18/2023] [Revised: 06/13/2023] [Accepted: 06/14/2023] [Indexed: 06/23/2023]
Abstract
Microalgae are widely recognized as a promising bioresource for producing renewable fuels and chemicals. Microalgal biorefinery has tremendous potential for incorporation into circular bioeconomy, including sustainability, cascading use, and waste reduction. In this study, genetic engineering was used to enhance the growth, lipid and lutein productivity of Chlamydomonas reinhardtii including strains of CC400, PY9, pCHS, and PG. Notably, CRISPRi mediated on phosphoenolpyruvate carboxylase (PEPC1) gene to down-regulate the branch pathway from glycolysis to partitioning more carbon flux to lipid was explored under meso-thermophilic condition. The best chassis PGi, which has overexpressed chaperone GroELS and applied CRISPRi resulting in the highest biomass of 2.56 g/L and also boosted the lipids and lutein with 893 and 23.5 mg/L, respectively at 35 °C. Finally, all strains with CRISPRi exhibited higher transcriptional levels of the crucial genes from photosynthesis, starch, lipid and lutein metabolism, thus reaching a CO2 assimilation of 1.087 g-CO2/g-DCW in mixotrophic condition.
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Affiliation(s)
- Jia-Yi Lin
- Department of Chemical Engineering, National Cheng Kung University, Tainan 70101, Taiwan
| | - I-Son Ng
- Department of Chemical Engineering, National Cheng Kung University, Tainan 70101, Taiwan.
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Photosynthetic and transcriptomic responses of Chlorella sp. to tigecycline. ALGAL RES 2023. [DOI: 10.1016/j.algal.2023.103033] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/03/2023]
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Vadrale AP, Dong CD, Haldar D, Wu CH, Chen CW, Singhania RR, Patel AK. Bioprocess development to enhance biomass and lutein production from Chlorella sorokiniana Kh12. BIORESOURCE TECHNOLOGY 2023; 370:128583. [PMID: 36610481 DOI: 10.1016/j.biortech.2023.128583] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/14/2022] [Revised: 01/02/2023] [Accepted: 01/03/2023] [Indexed: 06/17/2023]
Abstract
Present study focused on optimizing bioprocess condition for microalgal lutein production. From previous baseline yields of biomass (3.46 g/L) and lutein (13.7 mg/g), this study examined few key parameters. The 3X:3X ratio macro- and micronutrients was the most affecting parameter with highest biomass and lutein yields of 4.61 g/L and 14.3 mg/g. Temperature 30 °C enhanced the lutein up to 17.3 mg/g but reduced the biomass to 3 g/L. The light effects study showed 10 k lux was most effective for lutein up to 14 mg/g, and effect of increasing salinity (25-75 %) was detrimental. All the above parameters' optimization resulted in a lipid content of 22.5-26.5 %. A maximum lutein productivity and yield of 0.451 mg/L/d and 65.74 mg/L with a 3X:3X macro- and micronutrient ratio was achieved. The Chlorella sorokiniana Kh12 strain exhibited one of the highest yields among recent reports; hence it could be a source for commercial lutein production.
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Affiliation(s)
- Akash Pralhad Vadrale
- Institute of Aquatic Science and Technology, College of Hydrosphere, National Kaohsiung University of Science and Technology, Kaohsiung City 81157, Taiwan
| | - Cheng-Di Dong
- Institute of Aquatic Science and Technology, College of Hydrosphere, National Kaohsiung University of Science and Technology, Kaohsiung City 81157, Taiwan; Department of Marine Environmental Engineering, National Kaohsiung University of Science and Technology, Kaohsiung City, Taiwan
| | - Dibyajyoti Haldar
- Department of Biotechnology, Karunya Institute of Technology and Sciences, Coimbatore 641114, India
| | - Chien-Hui Wu
- Department of Seafood Science, National Kaohsiung University of Science and Technology, Kaohsiung City 81157, Taiwan
| | - Chiu-Wen Chen
- Institute of Aquatic Science and Technology, College of Hydrosphere, National Kaohsiung University of Science and Technology, Kaohsiung City 81157, Taiwan; Department of Marine Environmental Engineering, National Kaohsiung University of Science and Technology, Kaohsiung City, Taiwan
| | - Reeta Rani Singhania
- Department of Marine Environmental Engineering, National Kaohsiung University of Science and Technology, Kaohsiung City, Taiwan; Centre for Energy and Environmental Sustainability, Lucknow-226 029, Uttar Pradesh, India
| | - Anil Kumar Patel
- Institute of Aquatic Science and Technology, College of Hydrosphere, National Kaohsiung University of Science and Technology, Kaohsiung City 81157, Taiwan; Centre for Energy and Environmental Sustainability, Lucknow-226 029, Uttar Pradesh, India.
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Lim JM, Jung S, In JS, Park YI, Jeong WJ. Heterologous overexpression of the cyanobacterial alcohol dehydrogenase sysr1 confers cold tolerance to the oleaginous alga Nannochloropsis salina. FRONTIERS IN PLANT SCIENCE 2023; 14:1045917. [PMID: 36760652 PMCID: PMC9905847 DOI: 10.3389/fpls.2023.1045917] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/16/2022] [Accepted: 01/13/2023] [Indexed: 06/18/2023]
Abstract
Temperature is an important regulator of growth in algae and other photosynthetic organisms. Temperatures above or below the optimal growth temperature could cause oxidative stress to algae through accumulation of oxidizing compounds such as reactive oxygen species (ROS). Thus, algal temperature stress tolerance could be attained by enhancing oxidative stress resistance. In plants, alcohol dehydrogenase (ADH) has been implicated in cold stress tolerance, eliciting a signal for the synthesis of antioxidant enzymes that counteract oxidative damage associated with several abiotic stresses. Little is known whether temperature stress could be alleviated by ADH in algae. Here, we generated transgenic lines of the unicellular oleaginous alga Nannochloropsis salina that heterologously expressed sysr1, which encodes ADH in the cyanobacterium Synechocystis sp. PCC 6906. To drive sysr1 expression, the heat shock protein 70 (HSP70) promoter isolated from N. salina was used, as its transcript levels were significantly increased under either cold or heat stress growth conditions. When subjected to cold stress, transgenic N. salina cells were more cold-tolerant than wild-type cells, showing less ROS production but increased activity of antioxidant enzymes such as superoxide dismutase, ascorbate peroxidase, and catalase. Thus, we suggest that reinforcement of alcohol metabolism could be a target for genetic manipulation to endow algae with cold temperature stress tolerance.
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Affiliation(s)
- Jong-Min Lim
- Cell Factory Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon, Republic of Korea
| | - Sokyong Jung
- Cell Factory Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon, Republic of Korea
| | - Jae-Sun In
- Cell Factory Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon, Republic of Korea
| | - Youn-Il Park
- Department of Biological Sciences, Chungnam National University, Daejeon, Republic of Korea
| | - Won-Joong Jeong
- Cell Factory Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon, Republic of Korea
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Cvetkovska M, Vakulenko G, Smith DR, Zhang X, Hüner NPA. Temperature stress in psychrophilic green microalgae: Minireview. PHYSIOLOGIA PLANTARUM 2022; 174:e13811. [PMID: 36309822 DOI: 10.1111/ppl.13811] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/21/2022] [Revised: 10/18/2022] [Accepted: 10/23/2022] [Indexed: 06/16/2023]
Abstract
Photosynthetic algae are the main primary producers in polar regions, form the basis of polar food webs, and are responsible for a significant portion of global carbon fixation. Many cold-water algae are psychrophiles that thrive in the cold but cannot grow at moderate temperatures (≥20°C). Polar regions are at risk of rapid warming caused by climate change, and the sensitivity of psychrophilic algae to rising temperatures makes them, and the ecosystems they inhabit, particularly vulnerable. Recent research on the Antarctic psychrophile Chlamydomonas priscuii, an emerging algal model, has revealed unique adaptations to life in the permanent cold. Additionally, genome sequencing of C. priscuii and its relative Chlamydomonas sp. ICE-L has given rise to a plethora of computational tools that can help elucidate the genetic basis of psychrophily. This minireview summarizes new advances in characterizing the heat stress responses in psychrophilic algae and examines their extraordinary sensitivity to temperature increases. Further research in this field will help determine the impact of climate change on psychrophiles from threatened polar environments.
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Affiliation(s)
- Marina Cvetkovska
- Department of Biology, University of Ottawa, Ottawa, Ontario, Canada
| | - Galyna Vakulenko
- Department of Biology, University of Ottawa, Ottawa, Ontario, Canada
| | - David R Smith
- Department of Biology, University of Western Ontario, London, Canada
| | - Xi Zhang
- Institute for Comparative Genomics, Department of Biochemistry and Molecular Biology, Dalhousie University, Halifax, Canada
| | - Norman P A Hüner
- Department of Biology, University of Western Ontario, London, Canada
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