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Sun H, Gao Z, Zhang L, Wang X, Gao M, Wang Q. A comprehensive review on microbial lipid production from wastes: research updates and tendencies. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2023; 30:79654-79675. [PMID: 37328718 DOI: 10.1007/s11356-023-28123-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/29/2022] [Accepted: 06/01/2023] [Indexed: 06/18/2023]
Abstract
Microbial lipids have recently attracted attention as an intriguing alternative for the biodiesel and oleochemical industries to achieve sustainable energy generation. However, large-scale lipid production remains limited due to the high processing costs. As multiple variables affect lipid synthesis, an up-to-date overview that will benefit researchers studying microbial lipids is necessary. In this review, the most studied keywords from bibliometric studies are first reviewed. Based on the results, the hot topics in the field were identified to be associated with microbiology studies that aim to enhance lipid synthesis and reduce production costs, focusing on the biological and metabolic engineering involved. The research updates and tendencies of microbial lipids were then analyzed in depth. In particular, feedstock and associated microbes, as well as feedstock and corresponding products, were analyzed in detail. Strategies for lipid biomass enhancement were also discussed, including feedstock adoption, value-added product synthesis, selection of oleaginous microbes, cultivation mode optimization, and metabolic engineering strategies. Finally, the environmental implications of microbial lipid production and possible research directions were presented.
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Affiliation(s)
- Haishu Sun
- School of Energy and Environmental Engineering, University of Science and Technology Beijing, Beijing, 100083, China
- Shunde Innovation School, University of Science and Technology Beijing, Foshan, 528399, China
| | - Zhen Gao
- School of Energy and Environmental Engineering, University of Science and Technology Beijing, Beijing, 100083, China
| | - Lirong Zhang
- Tianjin College, University of Science and Technology, Beijing, Tianjin, 301811, China
| | - Xiaona Wang
- School of Energy and Environmental Engineering, University of Science and Technology Beijing, Beijing, 100083, China.
- Shunde Innovation School, University of Science and Technology Beijing, Foshan, 528399, China.
| | - Ming Gao
- School of Energy and Environmental Engineering, University of Science and Technology Beijing, Beijing, 100083, China
| | - Qunhui Wang
- School of Energy and Environmental Engineering, University of Science and Technology Beijing, Beijing, 100083, China
- Tianjin College, University of Science and Technology, Beijing, Tianjin, 301811, China
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Triacyl Glycerols from Yeast-Catalyzed Batch and Fed-Batch Bioconversion of Hydrolyzed Lignocellulose from Cardoon Stalks. FERMENTATION 2021. [DOI: 10.3390/fermentation7040315] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
The lipogenic ability of the yeast Solicoccozyma terricola DBVPG 5870 grown on hydrolyzed lignocellulose obtained from cardoon stalks was evaluated. Data on cell biomass, lipid production, and fatty acid profiles of triacylglycerols obtained in batch and fed-batch experiments were carried out at the laboratory scale in a 5L fermenter, and at two different temperatures (20 and 25 °C) were reported. The higher production of total intracellular lipids (13.81 g/L) was found in the fed-batch experiments carried out at 20 °C. S. terricola exhibited the ability to produce high amounts of triacylglycerol (TAGs) with a characteristic fatty acids profile close to that of palm oil. The TAGs obtained from S. terricola grown on pre-treated lignocellulose could be proposed as a supplementary source of oleochemicals. Indeed, due to the rising prices of fossil fuels and because of the environmental-related issues linked to their employment, the use of TAGs produced by S. terricola grown on lignocellulose could represent a promising option as a supplementary oleochemical, especially for biodiesel production.
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Dornau A, Robson JF, Thomas GH, McQueen-Mason SJ. Robust microorganisms for biofuel and chemical production from municipal solid waste. Microb Cell Fact 2020; 19:68. [PMID: 32178677 PMCID: PMC7077162 DOI: 10.1186/s12934-020-01325-0] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2020] [Accepted: 03/06/2020] [Indexed: 01/30/2023] Open
Abstract
Background Worldwide 3.4 billion tonnes of municipal solid waste (MSW) will be produced annually by 2050, however, current approaches to MSW management predominantly involve unsustainable practices like landfilling and incineration. The organic fraction of MSW (OMSW) typically comprises ~ 50% lignocellulose-rich material but is underexplored as a biomanufacturing feedstock due to its highly inconsistent and heterogeneous composition. This study sought to overcome the limitations associated with studying MSW-derived feedstocks by using OMSW produced from a realistic and reproducible MSW mixture on a commercial autoclave system. The resulting OMSW fibre was enzymatically hydrolysed and used to screen diverse microorganisms of biotechnological interest to identify robust species capable of fermenting this complex feedstock. Results The autoclave pre-treated OMSW fibre contained a polysaccharide fraction comprising 38% cellulose and 4% hemicellulose. Enzymatic hydrolysate of OMSW fibre was high in d-glucose (5.5% w/v) and d-xylose (1.8%w/v) but deficient in nitrogen and phosphate. Although relatively low levels of levulinic acid (30 mM) and vanillin (2 mM) were detected and furfural and 5-hydroxymethylfurfural were absent, the hydrolysate contained an abundance of potentially toxic metals (0.6% w/v). Hydrolysate supplemented with 1% yeast extract to alleviate nutrient limitation was used in a substrate-oriented shake-flask screen with eight biotechnologically useful microorganisms (Clostridium saccharoperbutylacetonicum, Escherichia coli, Geobacillus thermoglucosidasius, Pseudomonas putida, Rhodococcus opacus, Saccharomyces cerevisiae, Schizosaccharomyces pombe and Zymomonas mobilis). Each species’ growth and productivity were characterised and three species were identified that robustly and efficiently fermented OMSW fibre hydrolysate without significant substrate inhibition: Z. mobilis, S. cerevisiae and R. opacus, respectively produced product to 69%, 70% and 72% of the maximum theoretical fermentation yield and could theoretically produce 136 kg and 139 kg of ethanol and 91 kg of triacylglycerol (TAG) per tonne of OMSW. Conclusions Developing an integrated biorefinery around MSW has the potential to significantly alleviate the environmental burden of current waste management practices. Substrate-oriented screening of a representative and reproducible OMSW-derived fibre identified microorganisms intrinsically suited to growth on OMSW hydrolysates. These species are promising candidates for developing an MSW biorefining platform and provide a foundation for future studies aiming to valorise this underexplored feedstock.
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Affiliation(s)
- Aritha Dornau
- Centre for Novel Agricultural Products (CNAP), Department of Biology, University of York, Heslington, YO10 5DD, York, UK
| | - James F Robson
- Department of Biology, University of York, Heslington, YO10 5DD, York, UK
| | - Gavin H Thomas
- Department of Biology, University of York, Heslington, YO10 5DD, York, UK
| | - Simon J McQueen-Mason
- Centre for Novel Agricultural Products (CNAP), Department of Biology, University of York, Heslington, YO10 5DD, York, UK.
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Chu M, Zhang L, Lou W, Zong M, Tang Y, Yang J. Preparation and Characterization of Oil Rich in Odd Chain Fatty Acids from Rhodococcus opacusPD630. J AM OIL CHEM SOC 2020. [DOI: 10.1002/aocs.12304] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Affiliation(s)
- Mei‐Yun Chu
- School of Food Science and EngineeringSouth China University of Technology, Wushan Road Guangzhou 510641 China
| | - Lin‐Shang Zhang
- School of Food Science and EngineeringSouth China University of Technology, Wushan Road Guangzhou 510641 China
| | - Wen‐Yong Lou
- School of Food Science and EngineeringSouth China University of Technology, Wushan Road Guangzhou 510641 China
| | - Min‐Hua Zong
- School of Food Science and EngineeringSouth China University of Technology, Wushan Road Guangzhou 510641 China
| | - Yu‐Qian Tang
- School of Food Science and EngineeringSouth China University of Technology, Wushan Road Guangzhou 510641 China
- South China Institute of Collaborative Innovation, Xincheng Road Dongguan 523808 China
| | - Ji‐Guo Yang
- School of Food Science and EngineeringSouth China University of Technology, Wushan Road Guangzhou 510641 China
- South China Institute of Collaborative Innovation, Xincheng Road Dongguan 523808 China
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Evaluation of various sulfides for enhanced photobiological H2 production by a dual-species co-culture system of Chlamydomonas reinhardtii and Thiomonas intermedia. Process Biochem 2019. [DOI: 10.1016/j.procbio.2019.03.028] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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Qian X, Gorte O, Chen L, Zhang W, Dong W, Ma J, Jiang M, Xin F, Ochsenreither K. Co-production of single cell oil and gluconic acid using oleaginous Cryptococcus podzolicus DSM 27192. BIOTECHNOLOGY FOR BIOFUELS 2019; 12:127. [PMID: 31139257 PMCID: PMC6528270 DOI: 10.1186/s13068-019-1469-9] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/30/2019] [Accepted: 05/15/2019] [Indexed: 06/01/2023]
Abstract
BACKGROUND The co-production of single cell oil (SCO) with value-added products could improve the economic viability of industrial SCO production. The newly isolated oleaginous yeast Cryptococcus podzolicus DSM 27192 was able to co-produce SCO intracellularly and gluconic acid (GA) extracellularly. In this study, the metabolic regulation of carbon distribution between SCO and GA through process optimization was comprehensively investigated. RESULTS The carbon flow distribution between SCO and GA was significantly influenced by the cultivation conditions, such as nitrogen sources, glucose concentration and dissolved oxygen concentration. It was found that organic nitrogen sources were beneficial for SCO accumulation, while GA production was decreased. Dissolved oxygen concentration (DOC) was found to enhance SCO accumulation, while high glucose concentration was more favorable for GA accumulation. Hence, a two-stage DOC or glucose concentration-controlled strategy was designed to improve cell growth and direct carbon distribution between SCO and GA. Moreover, C. podzolicus DSM 27192 could degrade its stored lipids to synthesize GA in the late stationary phase, although considerable amounts of glucose remained unconsumed in the culture medium, indicating the importance of fermentation time control in co-production systems. All these observations provide opportunity to favor either the production of SCO or GA or rather their simultaneous production. CONCLUSIONS Co-production of SCO and GA by C. podzolicus DSM 27192 can improve the economical value for microbial lipid-derived biodiesel production. Moreover, the results of the proposed co-production strategy might give guidance for other co-production systems.
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Affiliation(s)
- Xiujuan Qian
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Puzhu South Road 30#, Nanjing, 211816 People’s Republic of China
| | - Olga Gorte
- Institute of Process Engineering in Life Sciences, Section II: Technical Biology, Karlsruhe Institute of Technology, Fritz-Haber-Weg 4, 76131 Karlsruhe, Germany
| | - Lin Chen
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Puzhu South Road 30#, Nanjing, 211816 People’s Republic of China
| | - Wenming Zhang
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Puzhu South Road 30#, Nanjing, 211816 People’s Republic of China
- Jiangsu National Synergetic Innovation Center for Advanced Materials (SICAM), Nanjing Tech University, Nanjing, 211816 People’s Republic of China
| | - Weiliang Dong
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Puzhu South Road 30#, Nanjing, 211816 People’s Republic of China
- Jiangsu National Synergetic Innovation Center for Advanced Materials (SICAM), Nanjing Tech University, Nanjing, 211816 People’s Republic of China
| | - Jiangfeng Ma
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Puzhu South Road 30#, Nanjing, 211816 People’s Republic of China
- Jiangsu National Synergetic Innovation Center for Advanced Materials (SICAM), Nanjing Tech University, Nanjing, 211816 People’s Republic of China
| | - Min Jiang
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Puzhu South Road 30#, Nanjing, 211816 People’s Republic of China
- Jiangsu National Synergetic Innovation Center for Advanced Materials (SICAM), Nanjing Tech University, Nanjing, 211816 People’s Republic of China
| | - Fengxue Xin
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Puzhu South Road 30#, Nanjing, 211816 People’s Republic of China
- Jiangsu National Synergetic Innovation Center for Advanced Materials (SICAM), Nanjing Tech University, Nanjing, 211816 People’s Republic of China
| | - Katrin Ochsenreither
- Institute of Process Engineering in Life Sciences, Section II: Technical Biology, Karlsruhe Institute of Technology, Fritz-Haber-Weg 4, 76131 Karlsruhe, Germany
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Fei Q, Puri AW, Smith H, Dowe N, Pienkos PT. Enhanced biological fixation of methane for microbial lipid production by recombinant Methylomicrobium buryatense. BIOTECHNOLOGY FOR BIOFUELS 2018; 11:129. [PMID: 29755588 PMCID: PMC5934843 DOI: 10.1186/s13068-018-1128-6] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/22/2017] [Accepted: 04/23/2018] [Indexed: 05/24/2023]
Abstract
BACKGROUND Due to the success of shale gas development in the US, the production cost of natural gas has been reduced significantly, which in turn has made methane (CH4), the major component of natural gas, a potential alternative substrate for bioconversion processes compared with other high-price raw material sources or edible feedstocks. Therefore, exploring effective ways to use CH4 for the production of biofuels is attractive. Biological fixation of CH4 by methanotrophic bacteria capable of using CH4 as their sole carbon and energy source has obtained great attention for biofuel production from this resource. RESULTS In this study, a fast-growing and lipid-rich methanotroph, Methylomicrobium buryatense 5GB1 and its glycogen-knock-out mutant (AP18) were investigated for the production of lipids derived from intracellular membranes, which are key precursors for the production of green diesel. The effects of culture conditions on cell growth and lipid production were investigated in high cell density cultivation with continuous feeding of CH4 and O2. The highest dry cell weight observed was 21.4 g/L and the maximum lipid productivity observed was 45.4 mg/L/h obtained in batch cultures, which corresponds to a 2-fold enhancement in cell density and 3-fold improvement in lipid production, compared with previous reported data from cultures of 5GB1. A 90% enhancement of lipid content was achieved by limiting the biosynthesis of glycogen in strain AP18. Increased CH4/O2 uptake and CO2 evaluation rates were observed in AP18 cultures suggesting that more carbon substrate and energy are needed for AP18 growth while producing lipids. The lipid produced by M. buryatense was estimated to have a cetane number of 75, which is 50% higher than biofuel standards requested by US and EU. CONCLUSIONS Cell growth and lipid production were significantly influenced by culture conditions for both 5GB1 and AP18. Enhanced lipid production in terms of titer, productivity, and content was achieved under high cell density culture conditions by blocking glycogen accumulation as a carbon sink in the strain AP18. Differences observed in CH4/O2 gas uptake and CO2 evolution rates as well as cell growth and glycogen accumulation between 5GB1 and AP18 suggest changes in the metabolic network between these strains. This bioconversion process provides a promising opportunity to transform CH4 into biofuel molecules and encourages further investigation to elucidate the remarkable CH4 biofixation mechanism used by these bacteria.
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Affiliation(s)
- Qiang Fei
- School of Chemical Engineering and Technology, Xi’an Jiaotong University, Xi’an, China
- National Bioenergy Center, National Renewable Energy Laboratory, Golden, CO USA
| | - Aaron W. Puri
- Department of Chemical Engineering, University of Washington, Seattle, WA USA
| | - Holly Smith
- National Bioenergy Center, National Renewable Energy Laboratory, Golden, CO USA
| | - Nancy Dowe
- National Bioenergy Center, National Renewable Energy Laboratory, Golden, CO USA
| | - Philip. T. Pienkos
- National Bioenergy Center, National Renewable Energy Laboratory, Golden, CO USA
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Chen Z, Wan C. Co-fermentation of lignocellulose-based glucose and inhibitory compounds for lipid synthesis by Rhodococcus jostii RHA1. Process Biochem 2017. [DOI: 10.1016/j.procbio.2017.03.023] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
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Hapeta P, Rakicka M, Dulermo R, Gamboa-Meléndez H, Cruz-Le Coq AM, Nicaud JM, Lazar Z. Transforming sugars into fat - lipid biosynthesis using different sugars inYarrowia lipolytica. Yeast 2017; 34:293-304. [DOI: 10.1002/yea.3232] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2017] [Revised: 03/09/2017] [Accepted: 03/10/2017] [Indexed: 11/09/2022] Open
Affiliation(s)
- Piotr Hapeta
- Department of Biotechnology and Food Microbiology; Wroclaw University of Environmental and Life Sciences; Chelmonskiego 37 51-630 Wroclaw Poland
| | - Magdalena Rakicka
- Department of Biotechnology and Food Microbiology; Wroclaw University of Environmental and Life Sciences; Chelmonskiego 37 51-630 Wroclaw Poland
| | - Remi Dulermo
- Micalis Institute, INRA, AgroParisTech; Université Paris-Sud; F-78350 Jouy-en-Josas France
| | - Heber Gamboa-Meléndez
- Micalis Institute, INRA, AgroParisTech; Université Paris-Sud; F-78350 Jouy-en-Josas France
| | - Anne-Marie Cruz-Le Coq
- Micalis Institute, INRA, AgroParisTech; Université Paris-Sud; F-78350 Jouy-en-Josas France
| | - Jean-Marc Nicaud
- Micalis Institute, INRA, AgroParisTech; Université Paris-Sud; F-78350 Jouy-en-Josas France
| | - Zbigniew Lazar
- Department of Biotechnology and Food Microbiology; Wroclaw University of Environmental and Life Sciences; Chelmonskiego 37 51-630 Wroclaw Poland
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Forde GM, Rainey TJ, Speight R, Batchelor W, Pattenden LK. Matching the biomass to the bioproduct. PHYSICAL SCIENCES REVIEWS 2016. [DOI: 10.1515/psr-2016-0046] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
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Xiong X, Lian J, Yu X, Garcia-Perez M, Chen S. Engineering levoglucosan metabolic pathway in Rhodococcus jostii RHA1 for lipid production. J Ind Microbiol Biotechnol 2016; 43:1551-1560. [PMID: 27558782 DOI: 10.1007/s10295-016-1832-9] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2016] [Accepted: 08/15/2016] [Indexed: 11/28/2022]
Abstract
Oleaginous strains of Rhodococcus including R. jostii RHA1 have attracted considerable attention due to their ability to accumulate triacylglycerols (TAGs), robust growth properties and genetic tractability. In this study, a novel metabolic pathway was introduced into R. jostii by heterogenous expression of the well-characterized gene, lgk encoding levoglucosan kinase from Lipomyces starkeyi YZ-215. This enables the recombinant R. jostii RHA1 to produce TAGs from the anhydrous sugar, levoglucosan, which can be generated efficiently as the major molecule from the pyrolysis of cellulose. The recombinant R. jostii RHA1 could grow on levoglucosan as the sole carbon source, and the consumption rate of levoglucosan was determined. Furthermore, expression of one more copy of lgk increased the enzymatic activity of LGK in the recombinant. However, the growth performance of the recombinant bearing two copies of lgk on levoglucosan was not improved. Although expression of lgk in the recombinants was not repressed by the glucose present in the media, glucose in the sugar mixture still affected consumption of levoglucosan. Under nitrogen limiting conditions, lipid produced from levoglucosan by the recombinant bearing lgk was up to 43.54 % of the cell dry weight, which was comparable to the content of lipid accumulated from glucose. This work demonstrated the technical feasibility of producing lipid from levoglucosan, an anhydrosugar derived from the pyrolysis of lignocellulosic materials, by the genetically modified rhodococci strains.
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Affiliation(s)
- Xiaochao Xiong
- Department of Biological Systems Engineering, Washington State University, L. J. Smith Hall, P.O. Box 646120, Pullman, WA, 99164-6120, USA
| | - Jieni Lian
- Department of Biological Systems Engineering, Washington State University, L. J. Smith Hall, P.O. Box 646120, Pullman, WA, 99164-6120, USA.,Department of Chemical and Biological Engineering, Iowa State University, Ames, IA, 50011, USA
| | - Xiaochen Yu
- Department of Biological Systems Engineering, Washington State University, L. J. Smith Hall, P.O. Box 646120, Pullman, WA, 99164-6120, USA.,Department of Biochemistry, Biophysics, and Molecular Biology, Iowa State University, Ames, IA, 50011, USA
| | - Manuel Garcia-Perez
- Department of Biological Systems Engineering, Washington State University, L. J. Smith Hall, P.O. Box 646120, Pullman, WA, 99164-6120, USA
| | - Shulin Chen
- Department of Biological Systems Engineering, Washington State University, L. J. Smith Hall, P.O. Box 646120, Pullman, WA, 99164-6120, USA.
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Fei Q, O’Brien M, Nelson R, Chen X, Lowell A, Dowe N. Enhanced lipid production by Rhodosporidium toruloides using different fed-batch feeding strategies with lignocellulosic hydrolysate as the sole carbon source. BIOTECHNOLOGY FOR BIOFUELS 2016; 9:130. [PMID: 27340432 PMCID: PMC4918137 DOI: 10.1186/s13068-016-0542-x] [Citation(s) in RCA: 75] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/25/2016] [Accepted: 06/02/2016] [Indexed: 05/15/2023]
Abstract
BACKGROUND Industrial biotechnology that is able to provide environmentally friendly bio-based products has attracted more attention in replacing petroleum-based industries. Currently, most of the carbon sources used for fermentation-based bioprocesses are obtained from agricultural commodities that are used as foodstuff for human beings. Lignocellulose-derived sugars as the non-food, green, and sustainable alternative carbon sources have great potential to avoid this dilemma for producing the renewable, bio-based hydrocarbon fuel precursors, such as microbial lipid. Efficient bioconversion of lignocellulose-based sugars into lipids is one of the critical parameters for industrial application. Therefore, the fed-batch cultivation, which is a common method used in industrial applications, was investigated to achieve a high cell density culture along with high lipid yield and productivity. RESULTS In this study, several fed-batch strategies were explored to improve lipid production using lignocellulosic hydrolysates derived from corn stover. Compared to the batch culture giving a lipid yield of 0.19 g/g, the dissolved-oxygen-stat feeding mode increased the lipid yield to 0.23 g/g and the lipid productivity to 0.33 g/L/h. The pulse feeding mode further improved lipid productivity to 0.35 g/L/h and the yield to 0.24 g/g. However, the highest lipid yield (0.29 g/g) and productivity (0.4 g/L/h) were achieved using an automated online sugar control feeding mode, which gave a dry cell weight of 54 g/L and lipid content of 59 % (w/w). The major fatty acids of the lipid derived from lignocellulosic hydrolysates were predominately palmitic acid and oleic acid, which are similar to those of conventional oilseed plants. CONCLUSIONS Our results suggest that the fed-batch feeding strategy can strongly influence the lipid production. The online sugar control feeding mode was the most appealing strategy for high cell density, lipid yield, and lipid productivity using lignocellulosic hydrolysates as the sole carbon source.
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Affiliation(s)
- Qiang Fei
- />School of Chemical Engineering and Technology, Xi’an Jiaotong University, Xi’an, 710049 China
- />National Bioenergy Center, National Renewable Energy Laboratory, 15013 Denver West Parkway, Golden, CO 80401 USA
| | - Marykate O’Brien
- />National Bioenergy Center, National Renewable Energy Laboratory, 15013 Denver West Parkway, Golden, CO 80401 USA
| | - Robert Nelson
- />National Bioenergy Center, National Renewable Energy Laboratory, 15013 Denver West Parkway, Golden, CO 80401 USA
| | - Xiaowen Chen
- />National Bioenergy Center, National Renewable Energy Laboratory, 15013 Denver West Parkway, Golden, CO 80401 USA
| | - Andrew Lowell
- />National Bioenergy Center, National Renewable Energy Laboratory, 15013 Denver West Parkway, Golden, CO 80401 USA
- />KBI Biopharma, 2500 Central Ave, Boulder, CO 80301 USA
| | - Nancy Dowe
- />National Bioenergy Center, National Renewable Energy Laboratory, 15013 Denver West Parkway, Golden, CO 80401 USA
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Metabolic engineering Corynebacterium glutamicum to produce triacylglycerols. Metab Eng 2015; 33:86-97. [PMID: 26645801 DOI: 10.1016/j.ymben.2015.11.002] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2015] [Revised: 10/04/2015] [Accepted: 11/17/2015] [Indexed: 01/09/2023]
Abstract
In this study, we metabolically engineered Corynebacterium glutamicum to produce triacylglycerols (TAGs) by completing and constraining a de novo TAG biosynthesis pathway. First, the plasmid pZ8_TAG4 was constructed which allows the heterologous expression of four genes: three (atf1 and atf2, encoding the diacylglycerol acyltransferase; pgpB, encoding the phosphatidic acid phosphatase) to complete the TAG biosynthesis pathway, and one gene (tadA) for lipid body assembly. Second, we applied four metabolic strategies to increase TAGs accumulation: (i) boosting precursor supply by heterologous expression of tesA (encoding thioesterase to form free fatty acid to reduce the feedback inhibition by acyl-ACP) and fadD (encoding acyl-CoA synthetase to enhance acyl-CoA supply), (ii) reduction of TAG degradation and precursor consumption by deleting four cellular lipases (cg0109, cg0110, cg1676 and cg1320) and the diacylglycerol kinase (cg2849), (iii) enhancement of fatty acid biosynthesis by deletion of fasR (cg2737, TetR-type transcriptional regulator of genes for the fatty acid biosynthesis), and (iv) elimination of the observed by-product formation of organic acids by blocking the acetic acid (pqo) and lactic acid production (ldh) pathways. The final strain (CgTesRtcEfasEbp/pZ8_TAG4) achieved a 7.5% yield of total fatty acids (2.38 ± 0.05 g/L intracellular fatty acids and 0.64 ± 0.09 g/L extracellular fatty acids) from 4% glucose in shake flasks after process optimization. This corresponds to maximum intracellular fatty acids content of 17.8 ± 0.5% of the dry cell.
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Kurosawa K, Anthony Debono C, Sinskey AJ. Lignocellulose-derived inhibitors improve lipid extraction from wet Rhodococcus opacus cells. BIORESOURCE TECHNOLOGY 2015; 193:206-212. [PMID: 26141279 DOI: 10.1016/j.biortech.2015.05.103] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/07/2015] [Revised: 05/27/2015] [Accepted: 05/28/2015] [Indexed: 06/04/2023]
Abstract
Extracting lipids from oleaginous microbial cells in a cost effective and environmentally compatible manner remains a critical challenge in developing manufacturing paradigms for advanced liquid biofuels. In this study, a new approach using microbial growth inhibitors from lignocellulose-derived feedstocks was used to extract lipids efficiently from wet cell mass of the oleaginous bacterium Rhodococcus opacus MITXM-61. Nine common lignocellulose-derived inhibitors for treatment of cells prior to solvent extraction were used and evaluated for their efficiency of lipid extraction from the cells. When the inhibitors were individually examined, formic acid and furfural showed the highest extraction efficiency of lipids from wet cell mass. Multiple extractions of lipids with methanol from wet cell mass pretreated with combined common inhibitors or hardwood hydrolysate comprising lignocellulose-derived inhibitors resulted in lipid recovery of greater than 85% of total lipids, a 1.7-fold increase of lipid extraction as compared to those in the absence of the inhibitors.
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Affiliation(s)
- Kazuhiko Kurosawa
- Department of Biology, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA 02139, USA.
| | - C Anthony Debono
- Department of Biology, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA 02139, USA.
| | - Anthony J Sinskey
- Department of Biology, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA 02139, USA; Engineering Systems Division, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA 02139, USA.
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Liang YJ, Jiang JG. Characterization of malic enzyme and the regulation of its activity and metabolic engineering on lipid production. RSC Adv 2015. [DOI: 10.1039/c5ra04635a] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Nowadays, microbial lipids are employed as the feedstock for biodiesel production, which has attracted great attention across the whole world.
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Affiliation(s)
- Ying-Jie Liang
- School of Biological Science & Engineering
- South China University of Technology
- Guangzhou
- China
| | - Jian-Guo Jiang
- School of Biological Science & Engineering
- South China University of Technology
- Guangzhou
- China
- College of Food Science and Engineering
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