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Zhang MY, Xu XR, Zhao RP, Huang C, Song YD, Zhao ZT, Zhao YB, Ren XJ, Zhao XH. Mechanism of enhanced microalgal biomass and lipid accumulation through symbiosis between a highly succinic acid-producing strain of Escherichia coli SUC and Aurantiochytrium sp. SW1. BIORESOURCE TECHNOLOGY 2024; 394:130232. [PMID: 38141881 DOI: 10.1016/j.biortech.2023.130232] [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: 11/25/2023] [Revised: 12/19/2023] [Accepted: 12/19/2023] [Indexed: 12/25/2023]
Abstract
Microalgae, known for rapid growth and lipid richness, hold potential in biofuels and high-value biomolecules. The symbiotic link with bacteria is crucial in large-scale open cultures. This study explores algal-bacterial interactions using a symbiotic model, evaluating acid-resistant Lactic acid bacteria (LAB), stress-resilient Bacillus subtilis and Bacillus licheniformis, and various Escherichia coli strains in the Aurantiochytrium sp. SW1 system. It was observed that E. coli SUC significantly enhanced the growth and lipid production of Aurantiochytrium sp. SW1 by increasing enzyme activity (NAD-IDH, NAD-ME, G6PDH) while maintaining sustained succinic acid release. Optimal co-culture conditions included temperature 28 °C, a 1:10 algae-to-bacteria ratio, and pH 8. Under these conditions, Aurantiochytrium sp. SW1 biomass increased 3.17-fold to 27.83 g/L, and total lipid content increased 2.63-fold to 4.87 g/L. These findings have implications for more efficient microalgal lipid production and large-scale cultivation.
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Affiliation(s)
- Mei-Yu Zhang
- International Cooperative Joint Laboratory for Marine Microbial Cell Factories, Colin Ratledge Center for Microbial Lipids, College of Agricultural Engineering and Food Science, Shandong University of Technology, China; Shandong (Zibo) Prefabricated Food Research Center, College of Agricultural Engineering and Food Science, Shandong University of Technology, Shandong, China
| | - Xin-Ru Xu
- International Cooperative Joint Laboratory for Marine Microbial Cell Factories, Colin Ratledge Center for Microbial Lipids, College of Agricultural Engineering and Food Science, Shandong University of Technology, China
| | - Ru-Ping Zhao
- International Cooperative Joint Laboratory for Marine Microbial Cell Factories, Colin Ratledge Center for Microbial Lipids, College of Agricultural Engineering and Food Science, Shandong University of Technology, China
| | - Chao Huang
- International Cooperative Joint Laboratory for Marine Microbial Cell Factories, Colin Ratledge Center for Microbial Lipids, College of Agricultural Engineering and Food Science, Shandong University of Technology, China
| | - Yuan-Da Song
- International Cooperative Joint Laboratory for Marine Microbial Cell Factories, Colin Ratledge Center for Microbial Lipids, College of Agricultural Engineering and Food Science, Shandong University of Technology, China
| | - Zi-Tong Zhao
- Shandong (Zibo) Prefabricated Food Research Center, College of Agricultural Engineering and Food Science, Shandong University of Technology, Shandong, China
| | - Yu-Bin Zhao
- Luzhou Bio-Chem Technology Limited, Linyi, China
| | - Xiao-Jie Ren
- International Cooperative Joint Laboratory for Marine Microbial Cell Factories, Colin Ratledge Center for Microbial Lipids, College of Agricultural Engineering and Food Science, Shandong University of Technology, China; Shandong (Zibo) Prefabricated Food Research Center, College of Agricultural Engineering and Food Science, Shandong University of Technology, Shandong, China.
| | - Xin-He Zhao
- International Cooperative Joint Laboratory for Marine Microbial Cell Factories, Colin Ratledge Center for Microbial Lipids, College of Agricultural Engineering and Food Science, Shandong University of Technology, China; Shandong (Zibo) Prefabricated Food Research Center, College of Agricultural Engineering and Food Science, Shandong University of Technology, Shandong, China; Shanli Health Food Technology Co., LTD, Shandong, China.
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Tong CY, Honda K, Derek CJC. A review on microalgal-bacterial co-culture: The multifaceted role of beneficial bacteria towards enhancement of microalgal metabolite production. ENVIRONMENTAL RESEARCH 2023; 228:115872. [PMID: 37054838 DOI: 10.1016/j.envres.2023.115872] [Citation(s) in RCA: 12] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/07/2023] [Revised: 04/06/2023] [Accepted: 04/09/2023] [Indexed: 05/16/2023]
Abstract
Mass microalgal-bacterial co-cultures have come to the fore of applied physiological research, in particularly for the optimization of high-value metabolite from microalgae. These co-cultures rely on the existence of a phycosphere which harbors unique cross-kingdom associations that are a prerequisite for the cooperative interactions. However, detailed mechanisms underpinning the beneficial bacterial effects onto microalgal growth and metabolic production are rather limited at the moment. Hence, the main purpose of this review is to shed light on how bacteria fuels microalgal metabolism or vice versa during mutualistic interactions, building upon the phycosphere which is a hotspot for chemical exchange. Nutrients exchange and signal transduction between two not only increase the algal productivity, but also facilitate in the degradation of bio-products and elevate the host defense ability. Main chemical mediators such as photosynthetic oxygen, N-acyl-homoserine lactone, siderophore and vitamin B12 were identified to elucidate beneficial cascading effects from the bacteria towards microalgal metabolites. In terms of applications, the enhancement of soluble microalgal metabolites is often associated with bacteria-mediated cell autolysis while bacterial bio-flocculants can aid in microalgal biomass harvesting. In addition, this review goes in depth into the discussion on enzyme-based communication via metabolic engineering such as gene modification, cellular metabolic pathway fine-tuning, over expression of target enzymes, and diversion of flux toward key metabolites. Furthermore, possible challenges and recommendations aimed at stimulating microalgal metabolite production are outlined. As more evidence emerges regarding the multifaceted role of beneficial bacteria, it will be crucial to incorporate these findings into the development of algal biotechnology.
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Affiliation(s)
- C Y Tong
- School of Chemical Engineering, Engineering Campus, Universiti Sains Malaysia, 14300, Nibong Tebal, Penang, Malaysia
| | - Kohsuke Honda
- International Center for Biotechnology, Osaka University, 2-1 Yamada-oka, Suita, Osaka, 565-0871, Japan.
| | - C J C Derek
- School of Chemical Engineering, Engineering Campus, Universiti Sains Malaysia, 14300, Nibong Tebal, Penang, Malaysia.
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Metabolic Regulation of Sugar Assimilation for Lipid Production in Aspergillus oryzae BCC7051 through Comparative Transcriptome Perspective. BIOLOGY 2021; 10:biology10090885. [PMID: 34571762 PMCID: PMC8467706 DOI: 10.3390/biology10090885] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/13/2021] [Revised: 08/27/2021] [Accepted: 09/06/2021] [Indexed: 12/13/2022]
Abstract
Simple Summary Oleaginous fungi are a promising candidate to produce microbial lipids as alternative sources for industrial applications. As lipids are intracellular metabolites with dynamic traits, the fungal ability in utilizing carbon sources for biomass and lipid production is significant in terms of production yield and economic feasibility. This study aimed to explore the metabolic regulation in lipogenesis of oleaginous Aspergillus oryzae BCC7051 at the transcriptional level. Through comparative transcriptome analysis, a set of differentially expressed genes (DEGs) between the xylose- and glucose-grown cultures (C5 and C6 cultures) at fast-growing and lipid-accumulating stages were identified and functionally categorized into transporter proteins and cellular processes. Combining with the growth and lipid phenotypes, the transcriptome results pointed to a crucial link between sugar assimilation, energy, lipid, and other metabolisms in A. oryzae for leveraging the metabolic flux from xylose to fatty acid and lipid biosynthesis in render the oleaginous features. This study provides a remarkable insight in guiding strain optimization and bioprocess development using renewable feedstocks from agroindustrial residues. Abstract Microbial lipid production with cost effectiveness is a prerequisite for the oleochemical sector. In this work, genome-wide transcriptional responses on the utilization of xylose and glucose in oleaginous Aspergillus oryzae were studied with relation to growth and lipid phenotypic traits. Comparative analysis of the active growth (t1) and lipid-accumulating (t2) stages showed that the C5 cultures efficiently consumed carbon sources for biomass and lipid production comparable to the C6 cultures. By pairwise comparison, 599 and 917 differentially expressed genes (DEGs) were identified in the t1 and t2 groups, respectively, in which the consensus DEGs were categorized into polysaccharide-degrading enzymes, membrane transports, and cellular processes. A discrimination in transcriptional responses of DEGs set was also found in various metabolic genes, mostly in carbohydrate, amino acid, lipid, cofactors, and vitamin metabolisms. Although central carbohydrate metabolism was shared among the C5 and C6 cultures, the metabolic functions in acetyl-CoA and NADPH generation, and biosynthesis of terpenoid backbone, fatty acid, sterol, and amino acids were allocated for leveraging biomass and lipid production through at least transcriptional control. This study revealed robust metabolic networks in the oleaginicity of A. oryzae governing glucose/xylose flux toward lipid biosynthesis that provides meaningful hints for further process developments of microbial lipid production using cellulosic sugar feedstocks.
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Toward the Enhancement of Microalgal Metabolite Production through Microalgae-Bacteria Consortia. BIOLOGY 2021; 10:biology10040282. [PMID: 33915681 PMCID: PMC8065533 DOI: 10.3390/biology10040282] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/07/2021] [Revised: 03/19/2021] [Accepted: 03/25/2021] [Indexed: 12/13/2022]
Abstract
Engineered mutualistic consortia of microalgae and bacteria may be a means of assembling a novel combination of metabolic capabilities with potential biotechnological advantages. Microalgae are promising organisms for the sustainable production of metabolites of commercial interest, such as lipids, carbohydrates, pigments, and proteins. Several studies reveal that microalgae growth and cellular storage of these metabolites can be enhanced significantly by co-cultivation with growth-promoting bacteria. This review summarizes the state of the art of microalgae-bacteria consortia for the production of microalgal metabolites. We discuss the current knowledge on microalgae-bacteria mutualism and the mechanisms of bacteria to enhance microalgae metabolism. Furthermore, the potential routes for a microalgae-bacteria biorefinery are outlined in an attempt to overcome the economic failures and negative energy balances of the existing production processes.
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Su H, Feng J, Lv J, Liu Q, Nan F, Liu X, Xie S. Molecular Mechanism of Lipid Accumulation and Metabolism of Oleaginous Chlorococcum sphacosum GD from Soil under Salt Stress. Int J Mol Sci 2021; 22:ijms22031304. [PMID: 33525606 PMCID: PMC7865546 DOI: 10.3390/ijms22031304] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2020] [Revised: 01/25/2021] [Accepted: 01/26/2021] [Indexed: 01/05/2023] Open
Abstract
The oleaginous microalgae species Chlorococcum sphacosum GD is a promising feedstock for biodiesel production from soil. However, its metabolic mechanism of lipid production remains unclear. In this study, the lipid accumulation and metabolism mechanisms of Chlorococcum sphacosum GD were analyzed under salt stress based on transcriptome sequencing. The biomass and lipid content of the alga strain were determined under different NaCl concentrations, and total RNA from fresh cells were isolated and sequenced by HiSeq 2000 high throughput sequencing technology. As the salt concentration increased in culture medium, the algal lipid content increased but the biomass decreased. Following transcriptome sequencing by assembly and splicing, 24,128 unigenes were annotated, with read lengths mostly distributed in the 200-300 bp interval. Statistically significant differentially expressed unigenes were observed in different experimental groups, with 2051 up-regulated genes and 1835 down-regulated genes. The lipid metabolism pathway analysis showed that, under salt stress, gene-related fatty acid biosynthesis (ACCase, KASII, KAR, HAD, FATA) was significantly up-regulated, but some gene-related fatty acid degradation was significantly down-regulated. The comprehensive results showed that salt concentration can affect the lipid accumulation and metabolism of C. sphacosum GD, and the lipid accumulation is closely related to the fatty acid synthesis pathway.
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Fu L, Yan G, Li Y, Li Q, Zhou D. Phosphorus supply via a fed-batch strategy improves lipid heterotrophic production of Chlorella regularis. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2020; 27:31677-31685. [PMID: 32500492 DOI: 10.1007/s11356-020-09495-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/25/2020] [Accepted: 05/27/2020] [Indexed: 06/11/2023]
Abstract
Intracellular phosphorus (P) accumulation can improve microalgal growth and lipid synthesis. However, large excess of P causes cell poisoning. This study utilized a P-fed-batch strategy to investigate its potential to improve the utilization of the excessive P, while avoiding toxic side effects. This strategy contributed to a more complete utilization of the intracellularly stored P, which enhanced the microalgae biomass by 10-15% by upregulating the brassinosteroid growth hormone gene at a P-fed-batch frequency of 2-8. Furthermore, the lipid content increased by 4-16% via upregulation of lipid synthesis-related genes. As a result, the P-fed-batch strategy significantly increased the lipid production by 13-19%. The content of saturated fatty acid increased by ~ 100%, implying improved combustibility and oxidative stability. This is the first study of this P-fed-batch strategy and provides a new concept for the complete utilization of excessive P.
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Affiliation(s)
- Liang Fu
- Engineering Lab for Water Pollution Control and Resources Recovery, School of Environment, Northeast Normal University, Changchun, 130117, China
| | - Ge Yan
- Engineering Lab for Water Pollution Control and Resources Recovery, School of Environment, Northeast Normal University, Changchun, 130117, China
| | - Yunbao Li
- Key Laboratory of Groundwater Resources and Environment, Ministry of Education, Jilin University, Changchun, 130021, China
| | - Qingcheng Li
- Engineering Lab for Water Pollution Control and Resources Recovery, School of Environment, Northeast Normal University, Changchun, 130117, China
| | - Dandan Zhou
- Engineering Lab for Water Pollution Control and Resources Recovery, School of Environment, Northeast Normal University, Changchun, 130117, China.
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Xue LL, Chen HH, Jiang JG. Implications of glycerol metabolism for lipid production. Prog Lipid Res 2017; 68:12-25. [PMID: 28778473 DOI: 10.1016/j.plipres.2017.07.002] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2017] [Revised: 07/06/2017] [Accepted: 07/31/2017] [Indexed: 12/13/2022]
Abstract
Triacylglycerol (TAG) is an important product in oil-producing organisms. Biosynthesis of TAG can be completed through either esterification of fatty acids to glycerol backbone, or through esterification of 2-monoacylglycerol. This review will focus on the former pathway in which two precursors, fatty acid and glycerol-3-phosphate (G3P), are required for TAG formation. Tremendous progress has been made about the enzymes or genes that regulate the biosynthetic pathway of TAG. However, much attention has been paid to the fatty acid provision and the esterification process, while the possible role of G3P is largely neglected. Glycerol is extensively studied on its usage as carbon source for value-added products, but the modification of glycerol metabolism, which is directly associated with G3P synthesis, is seldom recognized in lipid investigations. The relevance among glycerol metabolism, G3P synthesis and lipid production is described, and the role of G3P in glycerol metabolism and lipid production are discussed in detail with an emphasis on how G3P affects lipid production through the modulation of glycerol metabolism. Observations of lipid metabolic changes due to glycerol related disruption in mammals, plants, and microorganisms are introduced. Altering glycerol metabolism results in the changes of final lipid content. Possible regulatory mechanisms concerning the relationship between glycerol metabolism and lipid production are summarized.
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Affiliation(s)
- Lu-Lu Xue
- (a)College of Food and Bioengineering, South China University of Technology, Guangzhou 510640, China; (b)Industrial Crops Research Institute, Henan Academy of Agricultural Sciences, Zhengzhou 450002, China
| | - Hao-Hong Chen
- (a)College of Food and Bioengineering, South China University of Technology, Guangzhou 510640, China
| | - Jian-Guo Jiang
- (a)College of Food and Bioengineering, South China University of Technology, Guangzhou 510640, China.
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Lopez BR, Hernandez JP, Bashan Y, de-Bashan LE. Immobilization of microalgae cells in alginate facilitates isolation of DNA and RNA. J Microbiol Methods 2017; 135:96-104. [DOI: 10.1016/j.mimet.2017.02.005] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2017] [Revised: 02/10/2017] [Accepted: 02/10/2017] [Indexed: 11/16/2022]
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Current advances in molecular, biochemical, and computational modeling analysis of microalgal triacylglycerol biosynthesis. Biotechnol Adv 2016; 34:1046-1063. [DOI: 10.1016/j.biotechadv.2016.06.004] [Citation(s) in RCA: 64] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2016] [Revised: 06/08/2016] [Accepted: 06/12/2016] [Indexed: 12/12/2022]
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Palacios OA, Choix FJ, Bashan Y, de-Bashan LE. Influence of tryptophan and indole-3-acetic acid on starch accumulation in the synthetic mutualistic Chlorella sorokiniana – Azospirillum brasilense system under heterotrophic conditions. Res Microbiol 2016; 167:367-79. [DOI: 10.1016/j.resmic.2016.02.005] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2015] [Revised: 09/07/2015] [Accepted: 02/15/2016] [Indexed: 01/08/2023]
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Palacios OA, Gomez-Anduro G, Bashan Y, de-Bashan LE. Tryptophan, thiamine and indole-3-acetic acid exchange betweenChlorella sorokinianaand the plant growth-promoting bacteriumAzospirillum brasilense. FEMS Microbiol Ecol 2016; 92:fiw077. [DOI: 10.1093/femsec/fiw077] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/12/2016] [Indexed: 11/14/2022] Open
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Shen XF, Chu FF, Lam PKS, Zeng RJ. Biosynthesis of high yield fatty acids from Chlorella vulgaris NIES-227 under nitrogen starvation stress during heterotrophic cultivation. WATER RESEARCH 2015; 81:294-300. [PMID: 26081436 DOI: 10.1016/j.watres.2015.06.003] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/26/2015] [Accepted: 06/02/2015] [Indexed: 06/04/2023]
Abstract
In this study the heterotrophic cultivation of Chlorella vulgaris NIES-227 fed with glucose was investigated systematically using six media types; combinations of nitrogen repletion/depletion and phosphorus repletion/limitation/depletion. It was found that a high yield of fatty acids (0.88 of fed glucose-COD) and a high content of fatty acid methyl esters (FAMEs) (89% of dry weight) were obtained under nitrogen starved conditions. To our knowledge it is the first report on such high COD conversion yield and FAME content in microalgae. The dominant fatty acid (>50%) was methyl oleate (C18:1), a desirable component for biodiesel synthesis. FAME content under nitrogen starved conditions was significantly higher than under nitrogen sufficient conditions, while phosphorus had no significant influence, indicating that nitrogen starvation was the real "fatty acids trigger" in heterotrophic cultivation. These findings could simplify the downstream extraction process, such as the extrusion of oil from soybeans, and could reduce operating costs by improving the fatty acid yield from waste COD.
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Affiliation(s)
- Xiao-Fei Shen
- Advanced Laboratory for Environmental Research and Technology, USTC-CityU, Suzhou, PR China
| | - Fei-Fei Chu
- Advanced Laboratory for Environmental Research and Technology, USTC-CityU, Suzhou, PR China
| | - Paul K S Lam
- Advanced Laboratory for Environmental Research and Technology, USTC-CityU, Suzhou, PR China; State Key Laboratory in Marine Pollution, Department of Biology and Chemistry, City University of Hong Kong, Kowloon, Hong Kong
| | - Raymond J Zeng
- Advanced Laboratory for Environmental Research and Technology, USTC-CityU, Suzhou, PR China; CAS Key Laboratory of Urban Pollutant Conversion, Department of Chemistry, University of Science and Technology of China, Hefei 230026, PR China.
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Meza B, de-Bashan LE, Hernandez JP, Bashan Y. Accumulation of intra-cellular polyphosphate in Chlorella vulgaris cells is related to indole-3-acetic acid produced by Azospirillum brasilense. Res Microbiol 2015; 166:399-407. [DOI: 10.1016/j.resmic.2015.03.001] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2014] [Revised: 03/10/2015] [Accepted: 03/11/2015] [Indexed: 10/23/2022]
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