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Xu Y, Shui X, Gao M, Zhang Y, Zhang Z, Zhu Z, Zhao B, Sun D. Toxicological effects and mechanisms of lithium on growth, photosynthesis and antioxidant system in the freshwater microalga Chromochloris zofingiensis. JOURNAL OF HAZARDOUS MATERIALS 2024; 469:133898. [PMID: 38422737 DOI: 10.1016/j.jhazmat.2024.133898] [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: 12/21/2023] [Revised: 02/02/2024] [Accepted: 02/24/2024] [Indexed: 03/02/2024]
Abstract
The growing prevalence of lithium (Li) batteries has drawn public attention to Li as an emerging pollutant. The present study investigates the toxicity of Li+ on Chromochloris zofingiensis, examining physiological, biochemical and omics aspects. Results reveal hormesis effects of Li+ on C. zofingiensis growth. At Li+ concentrations below 5 mg L-1, Li+ can enhance chlorophyll content, mitochondrial activity, and antioxidant capacity, leading to increased dry cell weight and cell number. Conversely, when it exceeded 10 mg L-1, Li+ can reduce chlorophyll content, induce oxidative stress, and disrupt chloroplast and mitochondria structure and function, ultimately impeding cell growth. In addition, under 50 mg L-1 Li+ stress, microalgae optimize absorbed light energy use (increasing Fv/Fm and E TR ) and respond to stress by up-regulating genes in starch and lipid biosynthesis pathways, promoting the accumulation of storage components. Weighted gene co-expression network analysis indicates that peptidylprolyl cis/trans isomerase, GTPase and L-ascorbate oxidase might be the key regulators in response to Li+ stress. This research marks the toxic effects and molecular mechanisms of Li+ on freshwater microalga, which would improve our understanding of Li's toxicology and contributing to the establishment of Li pollution standards.
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Affiliation(s)
- Yaqi Xu
- Ministry of Education Key Laboratory of Molecular and Cellular Biology, Hebei Collaborative Innovation Center for Eco-Environment, Hebei Research Center of the Basic Discipline of Cell Biology, College of Life Sciences, Hebei Normal University, Shijiazhuang 050024, China
| | - Xiaoxi Shui
- Ministry of Education Key Laboratory of Molecular and Cellular Biology, Hebei Collaborative Innovation Center for Eco-Environment, Hebei Research Center of the Basic Discipline of Cell Biology, College of Life Sciences, Hebei Normal University, Shijiazhuang 050024, China
| | - Min Gao
- Ministry of Education Key Laboratory of Molecular and Cellular Biology, Hebei Collaborative Innovation Center for Eco-Environment, Hebei Research Center of the Basic Discipline of Cell Biology, College of Life Sciences, Hebei Normal University, Shijiazhuang 050024, China
| | - Yushu Zhang
- School of Life Sciences, Hebei University, Baoding 071000, China
| | - Zhao Zhang
- Ministry of Education Key Laboratory of Molecular and Cellular Biology, Hebei Collaborative Innovation Center for Eco-Environment, Hebei Research Center of the Basic Discipline of Cell Biology, College of Life Sciences, Hebei Normal University, Shijiazhuang 050024, China
| | - Zhengge Zhu
- Ministry of Education Key Laboratory of Molecular and Cellular Biology, Hebei Collaborative Innovation Center for Eco-Environment, Hebei Research Center of the Basic Discipline of Cell Biology, College of Life Sciences, Hebei Normal University, Shijiazhuang 050024, China
| | - Baohua Zhao
- Ministry of Education Key Laboratory of Molecular and Cellular Biology, Hebei Collaborative Innovation Center for Eco-Environment, Hebei Research Center of the Basic Discipline of Cell Biology, College of Life Sciences, Hebei Normal University, Shijiazhuang 050024, China
| | - Dongzhe Sun
- Ministry of Education Key Laboratory of Molecular and Cellular Biology, Hebei Collaborative Innovation Center for Eco-Environment, Hebei Research Center of the Basic Discipline of Cell Biology, College of Life Sciences, Hebei Normal University, Shijiazhuang 050024, China.
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Li Y, Zhao T, Gao W, Miao B, Fu Z, Zhang Z, Li Q, Sun D. Regulatory mechanisms of autophagy on DHA and carotenoid accumulation in Crypthecodinium sp. SUN. BIOTECHNOLOGY FOR BIOFUELS AND BIOPRODUCTS 2024; 17:50. [PMID: 38566214 PMCID: PMC10985998 DOI: 10.1186/s13068-024-02493-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/30/2023] [Accepted: 03/14/2024] [Indexed: 04/04/2024]
Abstract
BACKGROUND Autophagy is a crucial process of cellular self-destruction and component reutilization that can affect the accumulation of total fatty acids (TFAs) and carotenoids in microalgae. The regulatory effects of autophagy process in a docosahexaenoic acid (DHA) and carotenoids simultaneously producing microalga, Crypthecodinium sp. SUN, has not been studied. Thus, the autophagy inhibitor (3-methyladenine (MA)) and activator (rapamycin) were used to regulate autophagy in Crypthecodinium sp. SUN. RESULTS The inhibition of autophagy by 3-MA was verified by transmission electron microscopy, with fewer autophagy vacuoles observed. Besides, 3-MA reduced the glucose absorption and intracellular acetyl-CoA level, which resulting in the decrease of TFA and DHA levels by 15.83 and 26.73% respectively; Surprisingly, 3-MA increased intracellular reactive oxygen species level but decreased the carotenoids level. Comparative transcriptome analysis showed that the downregulation of the glycolysis, pentose phosphate pathway and tricarboxylic acid cycle may underlie the decrease of acetyl-CoA, NADPH and ATP supply for fatty acid biosynthesis; the downregulation of PSY and HMGCR may underlie the decreased carotenoids level. In addition, the class I PI3K-AKT signaling pathway may be crucial for the regulation of carbon and energy metabolism. At last, rapamycin was used to activate autophagy, which significantly enhanced the cell growth and TFA level and eventually resulted in 1.70-fold increase in DHA content. CONCLUSIONS Our findings indicate the mechanisms of autophagy in Crypthecodinium sp. SUN and highlight a way to manipulate cell metabolism by regulating autophagy. Overall, this study provides valuable insights to guide further research on autophagy-regulated TFA and carotenoids accumulation in Crypthecodinium sp. SUN.
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Affiliation(s)
- Yiming Li
- Ministry of Education Key Laboratory of Molecular and Cellular Biology, Hebei Collaborative Innovation Center for Eco-Environment, Hebei Research Center of the Basic Discipline of Cell Biology, College of Life Sciences, Hebei Normal University, Shijiazhuang, 050024, China
- School of Life Sciences, Hebei University, Baoding, 071000, China
| | - Tiantian Zhao
- Ministry of Education Key Laboratory of Molecular and Cellular Biology, Hebei Collaborative Innovation Center for Eco-Environment, Hebei Research Center of the Basic Discipline of Cell Biology, College of Life Sciences, Hebei Normal University, Shijiazhuang, 050024, China
| | - Weizheng Gao
- School of Life Sciences, Hebei University, Baoding, 071000, China
| | - Bowen Miao
- School of Life Sciences, Hebei University, Baoding, 071000, China
| | - Zhongxiang Fu
- School of Life Sciences, Hebei University, Baoding, 071000, China
| | - Zhao Zhang
- School of Life Sciences, Hebei University, Baoding, 071000, China
| | - Qingyang Li
- Ministry of Education Key Laboratory of Molecular and Cellular Biology, Hebei Collaborative Innovation Center for Eco-Environment, Hebei Research Center of the Basic Discipline of Cell Biology, College of Life Sciences, Hebei Normal University, Shijiazhuang, 050024, China.
| | - Dongzhe Sun
- Ministry of Education Key Laboratory of Molecular and Cellular Biology, Hebei Collaborative Innovation Center for Eco-Environment, Hebei Research Center of the Basic Discipline of Cell Biology, College of Life Sciences, Hebei Normal University, Shijiazhuang, 050024, China.
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Zhang Y, Sun D, Gao W, Zhang X, Ye W, Zhang Z. The metabolic mechanisms of Cd-induced hormesis in photosynthetic microalgae, Chromochloris zofingiensis. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 912:168966. [PMID: 38043816 DOI: 10.1016/j.scitotenv.2023.168966] [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: 09/11/2023] [Revised: 11/22/2023] [Accepted: 11/26/2023] [Indexed: 12/05/2023]
Abstract
Cadmium, an environmental pollutant, is highly toxic and resistant to degradation. It exhibits toxicity at elevated doses but triggers excitatory effects at low doses, a phenomenon referred to as hormesis. Microalgae, as primary producers in aquatic ecosystems, demonstrate hormesis induced by cadmium, though the specific mechanisms are not yet fully understood. Consequently, we examined the hormesis of cadmium in Chromochloris zofingiensis. A minimal Cd2+ concentration (0.05 mg L-1) prompted cell proliferation, whereas higher concentrations (2.50 mg L-1) inhibited growth. The group exposed to higher doses exhibited increased levels of reactive oxygen species (ROS), malondialdehyde (MDA), glutathione (GSH), superoxide dismutase (SOD), and catalase (CAT). Contrastingly, the group exposed to low doses exhibited a moderate antioxidant response without significantly increasing ROS. This implies that increased levels of antioxidative components counteract excessive ROS, maintaining cellular redox balance and promoting growth under conditions of low Cd2+. Validation experiments have established that NADPH oxidase-derived ROS primarily coordinates the hormesis effect in microalgae. Comparative transcriptome analysis has proved the involvement of antioxidant systems and photosynthesis in regulating hormesis. Notably, Aurora A kinases consistently displayed varying expression levels across all Cd2+ treatments, and their role in microalgal hormesis was confirmed through validation with SNS-314 mesylate. This study unveils the intricate regulatory mechanisms of Cd-induced hormesis in C. zofingiensis, with implications for environmental remediation and industrial microalgae applications.
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Affiliation(s)
- Yushu Zhang
- Ministry of Education Key Laboratory of Molecular and Cellular Biology, Hebei Collaborative Innovation Center for Eco-Environment, Hebei Research Center of the Basic Discipline of Cell Biology, College of Life Sciences, Hebei Normal University, Shijiazhuang 050024, China; Institute of Life Sciences and Green Development, Hebei University, Baoding 071000, China
| | - Dongzhe Sun
- Ministry of Education Key Laboratory of Molecular and Cellular Biology, Hebei Collaborative Innovation Center for Eco-Environment, Hebei Research Center of the Basic Discipline of Cell Biology, College of Life Sciences, Hebei Normal University, Shijiazhuang 050024, China
| | - Weizheng Gao
- Institute of Life Sciences and Green Development, Hebei University, Baoding 071000, China
| | - Xinwei Zhang
- Institute of Life Sciences and Green Development, Hebei University, Baoding 071000, China
| | - Wenqi Ye
- Institute of Life Sciences and Green Development, Hebei University, Baoding 071000, China
| | - Zhao Zhang
- Ministry of Education Key Laboratory of Molecular and Cellular Biology, Hebei Collaborative Innovation Center for Eco-Environment, Hebei Research Center of the Basic Discipline of Cell Biology, College of Life Sciences, Hebei Normal University, Shijiazhuang 050024, China; Institute of Life Sciences and Green Development, Hebei University, Baoding 071000, China; Hebei Innovation Center for Bioengineering and Biotechnology, Baoding 071000, China.
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Zhang X, Zhang Z, Peng Y, Zhang Y, Li Q, Sun D. Salicylic acid enhances cell growth, fatty acid and astaxanthin production in heterotrophic Chromochloris zofingiensis without reactive oxygen species elevation. BIOTECHNOLOGY FOR BIOFUELS AND BIOPRODUCTS 2024; 17:1. [PMID: 38172878 PMCID: PMC10765886 DOI: 10.1186/s13068-023-02449-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/19/2023] [Accepted: 12/13/2023] [Indexed: 01/05/2024]
Abstract
BACKGROUND The induction of lipid and astaxanthin accumulation in microalgae is often achieved through abiotic stress. However, this approach usually leads to oxidative stress, which results in relatively low growth rate. Phytohormones, as important small molecule signaling substances, not only affect the growth and metabolism of microalgae but also influence the intracellular reactive oxygen species level. This study aimed to screen phytohormones that could promote the fatty acids and astaxanthin yield of heterotrophic Chromochloris zofingiensis without causing oxidative damage, and further investigate the underlying mechanisms. RESULTS In the present study, among all the selected phytohormones, the addition of exogenous salicylic acid (SA) could effectively promote cell growth along with the yield of total fatty acids (TFA) and astaxanthin in heterotrophic C. zofingiensis. Notably, the highest yields of TFA and astaxanthin were achieved at 100 μM SA, 43% and 97.2% higher compared with the control, respectively. Interestingly, the intracellular reactive oxygen species (ROS) levels, which are usually increased with elevated TFA content under abiotic stresses, were significantly decreased by SA treatment. Comparative transcriptome analysis unveiled significant alterations in overall carbon metabolism by SA. Specifically, the upregulation of fatty acid synthesis pathway, upregulation of β-carotene-4-ketolase (BKT) in carotenoid synthesis aligned with biochemical findings. Weighted gene co-expression network analysis highlighted ABC transporters and GTF2B-like transcription factor as potential key regulators. CONCLUSION This study found that salicylic acid can serve as an effective regulator to promote the celling growth and accumulation of fatty acids and astaxanthin in heterotrophic C. zofingiensis without ROS elevation, which provides a promising approach for heterotrophic production of TFA and astaxanthin without growth inhibition.
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Affiliation(s)
- Xinwei Zhang
- Ministry of Education Key Laboratory of Molecular and Cellular Biology, Hebei Collaborative Innovation Center for Eco-Environment, Hebei Research Center of the Basic Discipline of Cell Biology, College of Life Sciences, Hebei Normal University, Shijiazhuang, 050024, China
- School of Life Sciences, Hebei University, Baoding, 071000, China
| | - Zhao Zhang
- Ministry of Education Key Laboratory of Molecular and Cellular Biology, Hebei Collaborative Innovation Center for Eco-Environment, Hebei Research Center of the Basic Discipline of Cell Biology, College of Life Sciences, Hebei Normal University, Shijiazhuang, 050024, China
- School of Life Sciences, Hebei University, Baoding, 071000, China
- Institute of Life Sciences and Green Development, Hebei University, Baoding, 071000, China
| | - Yanmei Peng
- School of Life Sciences, Hebei University, Baoding, 071000, China
| | - Yushu Zhang
- School of Life Sciences, Hebei University, Baoding, 071000, China
| | - Qingyang Li
- Ministry of Education Key Laboratory of Molecular and Cellular Biology, Hebei Collaborative Innovation Center for Eco-Environment, Hebei Research Center of the Basic Discipline of Cell Biology, College of Life Sciences, Hebei Normal University, Shijiazhuang, 050024, China.
| | - Dongzhe Sun
- Ministry of Education Key Laboratory of Molecular and Cellular Biology, Hebei Collaborative Innovation Center for Eco-Environment, Hebei Research Center of the Basic Discipline of Cell Biology, College of Life Sciences, Hebei Normal University, Shijiazhuang, 050024, China.
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Fu Z, Zhao T, Chu B, Gao W, Li T, Zhang Z, Li Q, Sun D. Low and high temperatures promote docosahexaenoic acid accumulation in Crypthecodinium sp. SUN by regulating the polyunsaturated fatty acid synthase pathway and the expression of saturated fatty acid preferred diacylglycerol acyltransferases. BIORESOURCE TECHNOLOGY 2023; 389:129850. [PMID: 37813314 DOI: 10.1016/j.biortech.2023.129850] [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: 08/24/2023] [Revised: 10/06/2023] [Accepted: 10/06/2023] [Indexed: 10/11/2023]
Abstract
Low (15 °C) and high (35 °C) temperatures significantly increased DHA as a percentage of total fatty acids (TFAs) to 43.6 % and 40.46 %, respectively (1.28- and 1.18-fold of that at 25 °C, respectively). The incompleteness of the FAS pathway indicates that DHA synthesis does not occur via this pathway. Meanwhile, Comparative transcriptome analysis showed that the PUFA synthase pathway might be responsible for DHA synthesis in C. sp. SUN. Additionally, the three diacylglycerol acyltransferases all had a substrate preference for saturated fatty acid (SFA)-CoA, which also contributed to the decreased SFA and increased DHA at both low and high temperatures. Additionally, WGCNA analysis identifies key regulatory genes that may be involved in temperature-regulated DHA proportion. The findings of this study indicate the mechanisms of temperature-regulated DHA accumulation in C. sp. SUN and shed light on the manipulation of DHA proportion by changes in temperature.
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Affiliation(s)
- Zhongxiang Fu
- Ministry of Education Key Laboratory of Molecular and Cellular Biology, College of Life Sciences, Hebei Normal University, Shijiazhuang 050024, China; School of Life Sciences, Hebei University, Baoding 071000, China
| | - Tiantian Zhao
- Ministry of Education Key Laboratory of Molecular and Cellular Biology, College of Life Sciences, Hebei Normal University, Shijiazhuang 050024, China
| | - Baijun Chu
- Nutrition & Health Research Institute, China National Cereals, Oils and Foodstuffs Corporation (COFCO), Beijing 102209, China
| | - Weizheng Gao
- School of Life Sciences, Hebei University, Baoding 071000, China
| | - Tong Li
- School of Life Sciences, Hebei University, Baoding 071000, China
| | - Zhao Zhang
- School of Life Sciences, Hebei University, Baoding 071000, China
| | - Qingyang Li
- Ministry of Education Key Laboratory of Molecular and Cellular Biology, College of Life Sciences, Hebei Normal University, Shijiazhuang 050024, China.
| | - Dongzhe Sun
- Ministry of Education Key Laboratory of Molecular and Cellular Biology, College of Life Sciences, Hebei Normal University, Shijiazhuang 050024, China.
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Wang D, He Z, Xia H, Huang J, Jin Y, Zhou R, Hao L, Wu C. Engineering acetyl-CoA metabolism to enhance stress tolerance of yeast by regulating membrane functionality. Food Microbiol 2023; 115:104322. [PMID: 37567632 DOI: 10.1016/j.fm.2023.104322] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2023] [Revised: 06/06/2023] [Accepted: 06/11/2023] [Indexed: 08/13/2023]
Abstract
Zygosaccharomyces rouxii has excellent fermentation performance and good tolerance to osmotic stress. Acetyl-CoA is a crucial intermediate precursor in the central carbon metabolic pathway of yeast. This study investigated the effect of engineering acetyl-CoA metabolism on the membrane functionality and stress tolerance of yeast. Firstly, exogenous supplementation of acetyl-CoA improved the biomass and the ability of unsaturated fatty acid synthesis of Z. rouxii under salt stress. Q-PCR results suggested that the gene ACSS (coding acetyl-CoA synthetase) was significantly up-expressed. Subsequently, the gene ACSS from Z. rouxii was transformed and heterologously expressed in S. cerevisiae. The recombinant cells exhibited better multiple stress (salt, acid, heat, and cold) tolerance, higher fatty acid contents, membrane integrity, and fluidity. Our findings may provide a suitable means to enhance the stress tolerance and fermentation efficiency of yeast under harsh fermentation environments.
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Affiliation(s)
- Dingkang Wang
- College of Biomass Science and Engineering, Sichuan University, Chengdu, 610065, China
| | - Zixi He
- College of Biomass Science and Engineering, Sichuan University, Chengdu, 610065, China
| | - Huan Xia
- College of Biomass Science and Engineering, Sichuan University, Chengdu, 610065, China
| | - Jun Huang
- College of Biomass Science and Engineering, Sichuan University, Chengdu, 610065, China
| | - Yao Jin
- College of Biomass Science and Engineering, Sichuan University, Chengdu, 610065, China
| | - Rongqing Zhou
- College of Biomass Science and Engineering, Sichuan University, Chengdu, 610065, China
| | - Liying Hao
- State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, 610041, China.
| | - Chongde Wu
- College of Biomass Science and Engineering, Sichuan University, Chengdu, 610065, China.
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Oleaginous Heterotrophic Dinoflagellates—Crypthecodiniaceae. Mar Drugs 2023; 21:md21030162. [PMID: 36976211 PMCID: PMC10055936 DOI: 10.3390/md21030162] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2023] [Revised: 02/17/2023] [Accepted: 02/23/2023] [Indexed: 03/06/2023] Open
Abstract
The heterotrophic Crypthecodinium cohnii is a major model for dinoflagellate cell biology, and a major industrial producer of docosahexaenoic acid, a key nutraceutical and added pharmaceutical compound. Despite these factors, the family Crypthecodiniaceae is not fully described, which is partly attributable to their degenerative thecal plates, as well as the lack of ribotype-referred morphological description in many taxons. We report here significant genetic distances and phylogenetic cladding that support inter-specific variations within the Crypthecodiniaceae. We describe Crypthecodinium croucheri sp. nov. Kwok, Law and Wong, that have different genome sizes, ribotypes, and amplification fragment length polymorphism profiles when compared to the C. cohnii. The interspecific ribotypes were supported by distinctive truncation-insertion at the ITS regions that were conserved at intraspecific level. The long genetic distances between Crypthecodiniaceae and other dinoflagellate orders support the separation of the group, which includes related taxons with high oil content and degenerative thecal plates, to be ratified to the order level. The current study provides the basis for future specific demarcation-differentiation, which is an important facet in food safety, biosecurity, sustainable agriculture feeds, and biotechnology licensing of new oleaginous models.
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