1
|
Li J, Wang W, Li B, Xue Y, Wang X, Liu S, Hu S, Tang J, Yan B, Li T, Xue J. NADP +-dependent isocitrate dehydrogenase as a novel target for altering carbon flux to lipid accumulation and enhancing antioxidant capacity in Tetradesmus obliquus. BIORESOURCE TECHNOLOGY 2024; 395:130365. [PMID: 38266784 DOI: 10.1016/j.biortech.2024.130365] [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: 10/28/2023] [Revised: 01/18/2024] [Accepted: 01/20/2024] [Indexed: 01/26/2024]
Abstract
Regulatory complexities in lipogenesis hinder the harmonization of metabolic carbon precursors towards lipid synthesis. Exploring regulatory complexities in lipogenesis, this study identifies NADP+-dependent isocitrate dehydrogenase (IDH) in Tetradesmus obliquus as a key factor. Overexpression IDH in strains ToIDH-1 and ToIDH-2 resulted in a 1.69 and 1.64-fold increase in neutral lipids, respectively, compared to the wild type, with lipid yield reaching 234.56 and 227.17 mg/L. Notably, despite slower growth, the cellular biomass augmented to 790.67 mg/L. Metabolite analysis indicated a shift in carbon precursors from protein to lipid and carbohydrate synthesis. Morphological observations revealed increases in the volume and number of lipid droplets, alongside a change in the fatty acid profile favoring monounsaturated and saturated fatty acids. Furthermore, IDH overexpression enhanced NADPH production and antioxidant activity, thereby further boosting lipid accumulation when combined with salt stress. This study suggests a pathway for improved lipogenesis and algal growth via metabolic engineering.
Collapse
Affiliation(s)
- Jing Li
- Key Laboratory of Resource Biology and Biotechnology in Western China, Ministry of Education, Northwest University, Xi'an, Shaanxi 710069, China; Shaanxi Provincial Key Laboratory of Biotechnology, Northwest University, Xi'an 710069, China; Shaanxi Key Laboratory for Carbon Neutral Technology, China
| | - Wei Wang
- Key Laboratory of Resource Biology and Biotechnology in Western China, Ministry of Education, Northwest University, Xi'an, Shaanxi 710069, China; Shaanxi Provincial Key Laboratory of Biotechnology, Northwest University, Xi'an 710069, China
| | - Bingze Li
- Shaanxi Provincial Key Laboratory of Biotechnology, Northwest University, Xi'an 710069, China; Shaanxi Key Laboratory for Carbon Neutral Technology, China
| | - Yunzhuan Xue
- Key Laboratory of Resource Biology and Biotechnology in Western China, Ministry of Education, Northwest University, Xi'an, Shaanxi 710069, China; Shaanxi Key Laboratory for Carbon Neutral Technology, China
| | - Xinxin Wang
- Key Laboratory of Resource Biology and Biotechnology in Western China, Ministry of Education, Northwest University, Xi'an, Shaanxi 710069, China; Shaanxi Provincial Key Laboratory of Biotechnology, Northwest University, Xi'an 710069, China
| | - Shihui Liu
- Shaanxi Provincial Key Laboratory of Biotechnology, Northwest University, Xi'an 710069, China; Shaanxi Key Laboratory for Carbon Neutral Technology, China
| | - Shuwei Hu
- Key Laboratory of Resource Biology and Biotechnology in Western China, Ministry of Education, Northwest University, Xi'an, Shaanxi 710069, China; Shaanxi Key Laboratory for Carbon Neutral Technology, China
| | - Jiaxuan Tang
- Key Laboratory of Resource Biology and Biotechnology in Western China, Ministry of Education, Northwest University, Xi'an, Shaanxi 710069, China; Shaanxi Provincial Key Laboratory of Biotechnology, Northwest University, Xi'an 710069, China
| | - Bo Yan
- Shaanxi Provincial Key Laboratory of Biotechnology, Northwest University, Xi'an 710069, China; Shaanxi Key Laboratory for Carbon Neutral Technology, China
| | - Tong Li
- Key Laboratory of Resource Biology and Biotechnology in Western China, Ministry of Education, Northwest University, Xi'an, Shaanxi 710069, China; Shaanxi Provincial Key Laboratory of Biotechnology, Northwest University, Xi'an 710069, China; Shaanxi Key Laboratory for Carbon Neutral Technology, China
| | - Jiao Xue
- Key Laboratory of Resource Biology and Biotechnology in Western China, Ministry of Education, Northwest University, Xi'an, Shaanxi 710069, China; Shaanxi Provincial Key Laboratory of Biotechnology, Northwest University, Xi'an 710069, China; Shaanxi Key Laboratory for Carbon Neutral Technology, China.
| |
Collapse
|
2
|
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.
Collapse
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.
| |
Collapse
|
3
|
Shen XF, Xu YP, Tong XQ, Huang Q, Zhang S, Gong J, Chu FF, Zeng RJ. The mechanism of carbon source utilization by microalgae when co-cultivated with photosynthetic bacteria. BIORESOURCE TECHNOLOGY 2022; 365:128152. [PMID: 36265788 DOI: 10.1016/j.biortech.2022.128152] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/26/2022] [Revised: 10/11/2022] [Accepted: 10/12/2022] [Indexed: 06/16/2023]
Abstract
Microalgae-photosynthetic bacteria (PSB) co-culture, which is promising for wastewater treatment and lipid production, is lacking of study. In this work, the combinations of 3 microalgae and 3 PSB strains were firstly screened and then different inoculation ratios of the co-cultures were investigated. It was found the best promotion was Chlorella pyrenoidosa/Rhodobacter capsulatus co-culture (1:1), where the biomass productivity, acetate assimilation rate and lipid productivity were 1.64, 1.61 and 2.79 times than that of the sum of pure microalgae and PSB cultures, respectively. Meanwhile, the inoculation ratio significantly affected the growth rate and lipid productivity of co-culture systems. iTRAQ analysis showed that PSB played a positive effect on acetate assimilation, TCA cycle and glyoxylate cycle of microalgae, but decreased the carbon dioxide utilization and photosynthesis, indicating PSB promoted the microalgae metabolism of organic carbon utilization and weakened inorganic carbon utilization. These findings provide in-depth understanding of carbon utilization in microalgae-PSB co-culture.
Collapse
Affiliation(s)
- Xiao-Fei Shen
- School of Ecology and Environment, Anhui Normal University, Anhui 241000, PR China
| | - Ya-Ping Xu
- School of Ecology and Environment, Anhui Normal University, Anhui 241000, PR China
| | - Xiao-Qin Tong
- School of Ecology and Environment, Anhui Normal University, Anhui 241000, PR China
| | - Qi Huang
- School of Ecology and Environment, Anhui Normal University, Anhui 241000, PR China
| | - Shuai Zhang
- School of Ecology and Environment, Anhui Normal University, Anhui 241000, PR China
| | - Jing Gong
- School of Ecology and Environment, Anhui Normal University, Anhui 241000, PR China
| | - Fei-Fei Chu
- College of Standardization, China Jiliang University, Zhejiang 310018, PR China
| | - Raymond Jianxiong Zeng
- College of Resources and Environment, Fujian Agriculture and Forestry University, Fujian 350002, PR China.
| |
Collapse
|
4
|
Kang NK, Baek K, Koh HG, Atkinson CA, Ort DR, Jin YS. Microalgal metabolic engineering strategies for the production of fuels and chemicals. BIORESOURCE TECHNOLOGY 2022; 345:126529. [PMID: 34896527 DOI: 10.1016/j.biortech.2021.126529] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/29/2021] [Revised: 12/02/2021] [Accepted: 12/03/2021] [Indexed: 06/14/2023]
Abstract
Microalgae are promising sustainable resources because of their ability to convert CO2 into biofuels and chemicals directly. However, the industrial production and economic feasibility of microalgal bioproducts are still limited. As such, metabolic engineering approaches have been undertaken to enhance the productivities of microalgal bioproducts. In the last decade, impressive advances in microalgae metabolic engineering have been made by developing genetic engineering tools and multi-omics analysis. This review presents comprehensive microalgal metabolic pathways and metabolic engineering strategies for producing lipids, long chain-polyunsaturated fatty acids, terpenoids, and carotenoids. Additionally, promising metabolic engineering approaches specific to target products are summarized. Finally, this review discusses current challenges and provides future perspectives for the effective production of chemicals and fuels via microalgal metabolic engineering.
Collapse
Affiliation(s)
- Nam Kyu Kang
- Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL, USA; DOE Center for Advanced Bioenergy and Bioproducts Innovation, University of Illinois at Urbana-Champaign, Urbana, IL, USA
| | - Kwangryul Baek
- Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL, USA
| | - Hyun Gi Koh
- Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL, USA; DOE Center for Advanced Bioenergy and Bioproducts Innovation, University of Illinois at Urbana-Champaign, Urbana, IL, USA
| | - Christine Anne Atkinson
- Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL, USA; Department of Food Science and Human Nutrition, University of Illinois at Urbana-Champaign, Urbana, IL, USA
| | - Donald R Ort
- Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL, USA; DOE Center for Advanced Bioenergy and Bioproducts Innovation, University of Illinois at Urbana-Champaign, Urbana, IL, USA; Global Change and Photosynthesis Research Unit, Agricultural Research Service, United States Department of Agriculture, Urbana, IL, USA; Department of Crop Sciences, University of Illinois at Urbana-Champaign, Urbana, IL, USA; Department of Plant Biology, University of Illinois at Urbana-Champaign, Urbana, IL, USA
| | - Yong-Su Jin
- Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL, USA; DOE Center for Advanced Bioenergy and Bioproducts Innovation, University of Illinois at Urbana-Champaign, Urbana, IL, USA; Department of Food Science and Human Nutrition, University of Illinois at Urbana-Champaign, Urbana, IL, USA.
| |
Collapse
|