1
|
Jiang B, Liu J, Wang J, Zhao G, Zhao Z. Adaptive Evolution for the Efficient Production of High-Quality d-Lactic Acid Using Engineered Klebsiella pneumoniae. Microorganisms 2024; 12:1167. [PMID: 38930549 PMCID: PMC11205318 DOI: 10.3390/microorganisms12061167] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2024] [Revised: 05/31/2024] [Accepted: 06/06/2024] [Indexed: 06/28/2024] Open
Abstract
d-Lactic acid serves as a pivotal platform chemical in the production of poly d-lactic acid (PDLA) and other value-added products. This compound can be synthesized by certain bacteria, including Klebsiella pneumoniae. However, industrial-scale lactic acid production in Klebsiella pneumoniae faces challenges due to growth inhibition caused by lactic acid stress, which acts as a bottleneck in commercial microbial fermentation processes. To address this, we employed a combination of evolutionary and genetic engineering approaches to create an improved Klebsiella pneumoniae strain with enhanced lactic acid tolerance and production. In flask fermentation experiments, the engineered strain achieved an impressive accumulation of 19.56 g/L d-lactic acid, representing the highest production yield observed in Klebsiella pneumoniae to date. Consequently, this strain holds significant promise for applications in industrial bioprocessing. Notably, our genome sequencing and experimental analyses revealed a novel correlation between UTP-glucose-1-phosphate uridylyltransferase GalU and lactic acid resistance in Klebsiella pneumoniae. Further research is warranted to explore the potential of targeting GalU for enhancing d-lactic acid production.
Collapse
Affiliation(s)
- Bo Jiang
- State Key Laboratory of Microbial Technology and Institute of Microbial Technology, Shandong University, Qingdao 266237, China; (B.J.); (J.L.); (J.W.)
| | - Jiezheng Liu
- State Key Laboratory of Microbial Technology and Institute of Microbial Technology, Shandong University, Qingdao 266237, China; (B.J.); (J.L.); (J.W.)
- CAS Key Laboratory of Biobased Materials, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao 266101, China
- Shandong Energy Institute, Qingdao 266101, China
- Qingdao New Energy Shandong Laboratory, Qingdao 266101, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Jingnan Wang
- State Key Laboratory of Microbial Technology and Institute of Microbial Technology, Shandong University, Qingdao 266237, China; (B.J.); (J.L.); (J.W.)
| | - Guang Zhao
- State Key Laboratory of Microbial Technology and Institute of Microbial Technology, Shandong University, Qingdao 266237, China; (B.J.); (J.L.); (J.W.)
| | - Zhe Zhao
- State Key Laboratory of Microbial Technology and Institute of Microbial Technology, Shandong University, Qingdao 266237, China; (B.J.); (J.L.); (J.W.)
| |
Collapse
|
2
|
Raimondi S, Foca G, Ulrici A, Destro L, Leonardi A, Buzzi R, Candeliere F, Rossi M, Amaretti A. Improved fed-batch processes with Wickerhamomyces anomalus WC 1501 for the production of D-arabitol from pure glycerol. Microb Cell Fact 2022; 21:179. [PMID: 36058916 PMCID: PMC9442996 DOI: 10.1186/s12934-022-01898-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2022] [Accepted: 08/11/2022] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND D-Arabitol, a five-carbon sugar alcohol, represents a main target of microbial biorefineries aiming to valorize cheap substrates. The yeast Wickerhamomyces anomalus WC 1501 is known to produce arabitol in a glycerol-based nitrogen-limited medium and preliminary fed-batch processes with this yeast were reported to yield 18.0 g/L arabitol. RESULTS Fed-batch fermentations with W. anomalus WC 1501 were optimized using central composite design (CCD). Dissolved oxygen had not a significant effect, while optimum values were found for glycerol concentration (114.5 g/L), pH (5.9), and temperature (32.5 °C), yielding 29 g/L D-arabitol in 160 h, a conversion yield of 0.25 g of arabitol per g of consumed glycerol, and a volumetric productivity of 0.18 g/L/h. CCD optimal conditions were the basis for further improvement, consisting in increasing the cellular density (3✕), applying a constant feeding of glycerol, and increasing temperature during production. The best performing fed-batch fermentations achieved 265 g/L D-arabitol after 325 h, a conversion yield of 0.74 g/g, and a volumetric productivity of 0.82 g/L/h. CONCLUSION W. anomalus WC 1501 confirmed as an excellent producer of D-arabitol, exhibiting a remarkable capability of transforming pure glycerol. The study reports among the highest values ever reported for microbial transformation of glycerol into D-arabitol, in terms of arabitol titer, conversion yield, and productivity.
Collapse
Affiliation(s)
- Stefano Raimondi
- Department of Life Sciences, University of Modena and Reggio Emilia, 41125, Modena, Italy.,Biogest-Siteia, University of Modena and Reggio Emilia, 42124, Reggio Emilia, Italy
| | - Giorgia Foca
- Department of Life Sciences, University of Modena and Reggio Emilia, 41125, Modena, Italy.,Biogest-Siteia, University of Modena and Reggio Emilia, 42124, Reggio Emilia, Italy
| | - Alessandro Ulrici
- Department of Life Sciences, University of Modena and Reggio Emilia, 41125, Modena, Italy.,Biogest-Siteia, University of Modena and Reggio Emilia, 42124, Reggio Emilia, Italy
| | - Lorenza Destro
- Department of Chemical and Geological Sciences, University of Modena and Reggio Emilia, 41125, Modena, Italy
| | - Alan Leonardi
- Department of Life Sciences, University of Modena and Reggio Emilia, 41125, Modena, Italy
| | - Raissa Buzzi
- Department of Chemical, Pharmaceutical and Agricultural Sciences, University of Ferrara, 44121, Ferrara, Italy
| | - Francesco Candeliere
- Department of Life Sciences, University of Modena and Reggio Emilia, 41125, Modena, Italy
| | - Maddalena Rossi
- Department of Life Sciences, University of Modena and Reggio Emilia, 41125, Modena, Italy.,Biogest-Siteia, University of Modena and Reggio Emilia, 42124, Reggio Emilia, Italy
| | - Alberto Amaretti
- Department of Life Sciences, University of Modena and Reggio Emilia, 41125, Modena, Italy. .,Biogest-Siteia, University of Modena and Reggio Emilia, 42124, Reggio Emilia, Italy.
| |
Collapse
|
3
|
Liu M, Huo M, Liu C, Guo L, Ding Y, Ma Q, Qi Q, Xian M, Zhao G. Lysine acetylation of Escherichia coli lactate dehydrogenase regulates enzyme activity and lactate synthesis. Front Bioeng Biotechnol 2022; 10:966062. [PMID: 36051589 PMCID: PMC9424733 DOI: 10.3389/fbioe.2022.966062] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2022] [Accepted: 07/27/2022] [Indexed: 11/17/2022] Open
Abstract
As an evolutionarily conserved posttranslational modification, protein lysine acetylation plays important roles in many physiological and metabolic processes. However, there are few reports about the applications of lysine acetylation in metabolic regulations. Lactate is a main byproduct in microbial fermentation, and itself also an important bulk chemical with considerable commercial values in many fields. Lactate dehydrogenase (LdhA) is the key enzyme catalyzing lactate synthesis from pyruvate. Here, we reported that Escherichia coli LdhA can be acetylated and the acetylated lysine sites were identified by mass spectrometry. The effects and regulatory mechanisms of acetylated sites on LdhA activity were characterized. Finally, lysine acetylation was successfully used to regulate the lactate synthesis. LdhA (K9R) mutant overexpressed strain improved the lactate titer and glucose conversion efficiency by 1.74 folds than that of wild-type LdhA overexpressed strain. LdhA (K154Q-K248Q) mutant can inhibit lactate accumulation and improve 3HP production. Our study established a paradigm for lysine acetylation in lactate synthesis regulation and suggested that lysine acetylation may be a promising strategy to improve the target production and conversion efficiency in microbial synthesis. The application of lysine acetylation in regulating lactate synthesis also provides a reference for the treatment of lactate-related diseases.
Collapse
Affiliation(s)
- Min Liu
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao, China
| | - Meitong Huo
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao, China
| | - Changshui Liu
- Institute of Oceanology, Chinese Academy of Sciences, Qingdao, China
| | - Likun Guo
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao, China
| | - Yamei Ding
- Institute of Oceanology, Chinese Academy of Sciences, Qingdao, China
| | - Qingjun Ma
- Institute of Oceanology, Chinese Academy of Sciences, Qingdao, China
| | - Qingsheng Qi
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao, China
| | - Mo Xian
- CAS Key Laboratory of Biobased Materials, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, China
- *Correspondence: Mo Xian, ; Guang Zhao,
| | - Guang Zhao
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao, China
- CAS Key Laboratory of Biobased Materials, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, China
- *Correspondence: Mo Xian, ; Guang Zhao,
| |
Collapse
|
4
|
Son J, Baritugo KA, Lim SH, Lim HJ, Jeong S, Lee JY, Choi JI, Joo JC, Na JG, Park SJ. Microbial cell factories for the production of three-carbon backbone organic acids from agro-industrial wastes. BIORESOURCE TECHNOLOGY 2022; 349:126797. [PMID: 35122981 DOI: 10.1016/j.biortech.2022.126797] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/12/2021] [Revised: 01/26/2022] [Accepted: 01/28/2022] [Indexed: 06/14/2023]
Abstract
At present, mass production of basic and valuable commodities is dependent on linear petroleum-based industries, which ultimately makes the depletion of finite natural reserves and accumulation of non-biodegradable and hazardous wastes. Therefore, an ecofriendly and sustainable solution should be established for a circular economy where infinite resources, such as agro-industrial wastes, are fully utilized as substrates in the production of target value-added chemicals. Hereby, recent advances in metabolic engineering strategies and techniques used in the development of microbial cell factories for enhanced production of three-carbon platform chemicals such as lactic acid, propionic acid, and 3-hydroxypropionic acid are discussed. Further developments and future perspectives in the production of these organic acids from agro-industrial wastes from the dairy, sugar, and biodiesel industries are also highlighted to demonstrate the importance of waste-based biorefineries for organic acid production.
Collapse
Affiliation(s)
- Jina Son
- Department of Chemical Engineering and Materials Science, Graduate Program in System Health Science and Engineering, Ewha Womans University, Seoul 03760, Republic of Korea
| | - Kei-Anne Baritugo
- Department of Chemical Engineering and Materials Science, Graduate Program in System Health Science and Engineering, Ewha Womans University, Seoul 03760, Republic of Korea
| | - Seo Hyun Lim
- Department of Chemical Engineering and Materials Science, Graduate Program in System Health Science and Engineering, Ewha Womans University, Seoul 03760, Republic of Korea
| | - Hye Jin Lim
- Department of Chemical Engineering and Materials Science, Graduate Program in System Health Science and Engineering, Ewha Womans University, Seoul 03760, Republic of Korea
| | - Seona Jeong
- Department of Chemical Engineering and Materials Science, Graduate Program in System Health Science and Engineering, Ewha Womans University, Seoul 03760, Republic of Korea
| | - Ji Yeon Lee
- Department of Chemical Engineering and Materials Science, Graduate Program in System Health Science and Engineering, Ewha Womans University, Seoul 03760, Republic of Korea
| | - Jong-Il Choi
- Department of Biotechnology and Bioengineering, Chonnam National University, Gwangju 61186, Korea
| | - Jeong Chan Joo
- Department of Biotechnology, The Catholic University of Korea, Bucheon-si, Gyeonggi-do 14662, Republic of Korea
| | - Jeong-Geol Na
- Department of Chemical and Biomolecular Engineering, Sogang University, Seoul 04107, Republic of Korea
| | - Si Jae Park
- Department of Chemical Engineering and Materials Science, Graduate Program in System Health Science and Engineering, Ewha Womans University, Seoul 03760, Republic of Korea.
| |
Collapse
|
5
|
Co-Production of Isoprene and Lactate by Engineered Escherichia coli in Microaerobic Conditions. Molecules 2021; 26:molecules26237173. [PMID: 34885764 PMCID: PMC8659262 DOI: 10.3390/molecules26237173] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2021] [Revised: 11/23/2021] [Accepted: 11/25/2021] [Indexed: 11/21/2022] Open
Abstract
Lactate and isoprene are two common monomers for the industrial production of polyesters and synthetic rubbers. The present study tested the co-production of D-lactate and isoprene by engineered Escherichia coli in microaerobic conditions. The deletion of alcohol dehydrogenase (adhE) and acetate kinase (ackA) genes, along with the supplementation with betaine, improved the co-production of lactate and isoprene from the substrates of glucose and mevalonate. In fed-batch studies, microaerobic fermentation significantly improved the isoprene concentration in fermentation outlet gas (average 0.021 g/L), compared with fermentation under aerobic conditions (average 0.0009 g/L). The final production of D-lactate and isoprene can reach 44.0 g/L and 3.2 g/L, respectively, through fed-batch microaerobic fermentation. Our study demonstrated a dual-phase production strategy in the co-production of isoprene (gas phase) and lactate (liquid phase). The increased concentration of gas-phase isoprene could benefit the downstream process and decrease the production cost to collect and purify the bio-isoprene from the fermentation outlet gas. The proposed microaerobic process can potentially be applied in the production of other volatile bioproducts to benefit the downstream purification process.
Collapse
|
6
|
A Focus on the Transformation Processes for the Valorization of Glycerol Derived from the Production Cycle of Biofuels. Catalysts 2021. [DOI: 10.3390/catal11020280] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Glycerol is a valuable by-product in the biodiesel industries. However, the increase in biodiesel production resulted in an excess production of glycerol, with a limited market compared to its availability. Precisely because glycerol became a waste to be disposed of, the costs of biodiesel production have reduced. From an environmental point of view, identifying reactions that can convert glycerol into new products that can be reused in different applications has become a real necessity. According to the unique structural characteristics of glycerol, transformation processes can lead to different chemical functionalities through redox reactions, dehydration, esterification, and etherification, with the formation of products that can be applied both at the finest chemical level and to bulk chemistry.
Collapse
|
7
|
Wang J, Sui X, Ding Y, Fu Y, Feng X, Liu M, Zhang Y, Xian M, Zhao G. A fast and robust iterative genome-editing method based on a Rock-Paper-Scissors strategy. Nucleic Acids Res 2021; 49:e12. [PMID: 33270888 PMCID: PMC7826264 DOI: 10.1093/nar/gkaa1141] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2020] [Revised: 10/28/2020] [Accepted: 11/07/2020] [Indexed: 01/22/2023] Open
Abstract
The production of optimized strains of a specific phenotype requires the construction and testing of a large number of genome modifications and combinations thereof. Most bacterial iterative genome-editing methods include essential steps to eliminate selection markers, or to cure plasmids. Additionally, the presence of escapers leads to time-consuming separate single clone picking and subsequent cultivation steps. Herein, we report a genome-editing method based on a Rock-Paper-Scissors (RPS) strategy. Each of three constructed sgRNA plasmids can cure, or be cured by, the other two plasmids in the system; plasmids from a previous round of editing can be cured while the current round of editing takes place. Due to the enhanced curing efficiency and embedded double check mechanism, separate steps for plasmid curing or confirmation are not necessary, and only two times of cultivation are needed per genome-editing round. This method was successfully demonstrated in Escherichia coli and Klebsiella pneumoniae with both gene deletions and replacements. To the best of our knowledge, this is the fastest and most robust iterative genome-editing method, with the least times of cultivation decreasing the possibilities of spontaneous genome mutations.
Collapse
Affiliation(s)
- Jichao Wang
- CAS Key Lab of Biobased Materials, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, 266101 Qingdao, China
| | - Xinyue Sui
- CAS Key Lab of Biobased Materials, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, 266101 Qingdao, China
- University of Chinese Academy of Sciences, 100049 Beijing, China
| | - Yamei Ding
- Institute of Oceanology, Chinese Academy of Sciences, 266071 Qingdao, China
| | - Yingxin Fu
- CAS Key Lab of Biobased Materials, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, 266101 Qingdao, China
| | - Xinjun Feng
- CAS Key Lab of Biobased Materials, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, 266101 Qingdao, China
| | - Min Liu
- CAS Key Lab of Biobased Materials, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, 266101 Qingdao, China
- State Key Laboratory of Microbial Technology, Shandong University, 266237 Qingdao, China
| | - Youming Zhang
- State Key Laboratory of Microbial Technology, Shandong University, 266237 Qingdao, China
| | - Mo Xian
- CAS Key Lab of Biobased Materials, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, 266101 Qingdao, China
| | - Guang Zhao
- CAS Key Lab of Biobased Materials, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, 266101 Qingdao, China
- State Key Laboratory of Microbial Technology, Shandong University, 266237 Qingdao, China
| |
Collapse
|
8
|
Li Y, Yang S, Ma D, Song W, Gao C, Liu L, Chen X. Microbial engineering for the production of C 2-C 6 organic acids. Nat Prod Rep 2021; 38:1518-1546. [PMID: 33410446 DOI: 10.1039/d0np00062k] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Covering: up to the end of 2020Organic acids, as building block compounds, have been widely used in food, pharmaceutical, plastic, and chemical industries. Until now, chemical synthesis is still the primary method for industrial-scale organic acid production. However, this process encounters some inevitable challenges, such as depletable petroleum resources, harsh reaction conditions and complex downstream processes. To solve these problems, microbial cell factories provide a promising approach for achieving the sustainable production of organic acids. However, some key metabolites in central carbon metabolism are strictly regulated by the network of cellular metabolism, resulting in the low productivity of organic acids. Thus, multiple metabolic engineering strategies have been developed to reprogram microbial cell factories to produce organic acids, including monocarboxylic acids, hydroxy carboxylic acids, amino carboxylic acids, dicarboxylic acids and monomeric units for polymers. These strategies mainly center on improving the catalytic efficiency of the enzymes to increase the conversion rate, balancing the multi-gene biosynthetic pathways to reduce the byproduct formation, strengthening the metabolic flux to promote the product biosynthesis, optimizing the metabolic network to adapt the environmental conditions and enhancing substrate utilization to broaden the substrate spectrum. Here, we describe the recent advances in producing C2-C6 organic acids by metabolic engineering strategies. In addition, we provide new insights as to when, what and how these strategies should be taken. Future challenges are also discussed in further advancing microbial engineering and establishing efficient biorefineries.
Collapse
Affiliation(s)
- Yang Li
- State Key Laboratory of Food Science and Technology, Jiangnan University, 1800 Lihu Road, Wuxi 214122, China.
| | | | | | | | | | | | | |
Collapse
|
9
|
Wang YD, Liao JY, Chiang CJ, Chao YP. A simple strategy to effectively produce d-lactate in crude glycerol-utilizing Escherichia coli. BIOTECHNOLOGY FOR BIOFUELS 2019; 12:273. [PMID: 31832096 PMCID: PMC6864932 DOI: 10.1186/s13068-019-1615-4] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/13/2019] [Accepted: 11/13/2019] [Indexed: 06/10/2023]
Abstract
BACKGROUND Fed-batch fermentation has been conventionally implemented for the production of lactic acid with a high titer and high productivity. However, its operation needs a complicated control which increases the production cost. RESULTS This issue was addressed by simplifying the production scheme. Escherichia coli was manipulated for its glycerol dissimilation and d-lactate synthesis pathways and then subjected to adaptive evolution under high crude glycerol. Batch fermentation in the two-stage mode was performed by controlling the dissolved oxygen (DO), and the evolved strain deprived of poxB enabled production of 100 g/L d-lactate with productivity of 1.85 g/L/h. To increase productivity, the producer strain was further evolved to improve its growth rate on crude glycerol. The fermentation was performed to undergo the aerobic growth with low substrate, followed by the anaerobic production with high substrate. Moreover, the intracellular redox of the strain was balanced by fulfillment of the anaerobic respiratory chain with nitrate reduction. Without controlling the DO, the microbial fermentation resulted in the homofermentative production of d-lactate (ca. 0.97 g/g) with a titer of 115 g/L and productivity of 3.29 g/L/h. CONCLUSIONS The proposed fermentation strategy achieves the highest yield based on crude glycerol and a comparable titer and productivity as compared to the approach by fed-batch fermentation. It holds a promise to sustain the continued development of the crude glycerol-based biorefinery.
Collapse
Affiliation(s)
- Yao-De Wang
- Department of Chemical Engineering, Feng Chia University, 100 Wenhwa Road, Taichung, 40724 Taiwan
| | - Jin-Yi Liao
- Department of Chemical Engineering, Feng Chia University, 100 Wenhwa Road, Taichung, 40724 Taiwan
| | - Chung-Jen Chiang
- Department of Medical Laboratory Science and Biotechnology, China Medical University, No. 91, Hsueh-Shih Road, Taichung, 40402 Taiwan
| | - Yun-Peng Chao
- Department of Chemical Engineering, Feng Chia University, 100 Wenhwa Road, Taichung, 40724 Taiwan
- Department of Medical Research, China Medical University Hospital, Taichung, 40447 Taiwan
- Department of Health and Nutrition Biotechnology, Asia University, Taichung, 41354 Taiwan
| |
Collapse
|
10
|
Westbrook AW, Miscevic D, Kilpatrick S, Bruder MR, Moo-Young M, Chou CP. Strain engineering for microbial production of value-added chemicals and fuels from glycerol. Biotechnol Adv 2019; 37:538-568. [DOI: 10.1016/j.biotechadv.2018.10.006] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2017] [Revised: 10/03/2018] [Accepted: 10/10/2018] [Indexed: 12/22/2022]
|
11
|
Li F, An X, Wu D, Xu J, Chen Y, Li W, Cao Y, Guo X, Lin X, Li C, Liu S, Song H. Engineering Microbial Consortia for High-Performance Cellulosic Hydrolyzates-Fed Microbial Fuel Cells. Front Microbiol 2019; 10:409. [PMID: 30936852 PMCID: PMC6432859 DOI: 10.3389/fmicb.2019.00409] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2018] [Accepted: 02/18/2019] [Indexed: 11/13/2022] Open
Abstract
Microbial fuel cells (MFCs) are eco-friendly bio-electrochemical reactors that use exoelectrogens as biocatalyst for electricity harvest from organic biomass, which could also be used as biosensors for long-term environmental monitoring. Glucose and xylose, as the primary ingredients from cellulose hydrolyzates, is an appealing substrate for MFC. Nevertheless, neither xylose nor glucose can be utilized as carbon source by well-studied exoelectrogens such as Shewanella oneidensis. In this study, to harvest the electricity by rapidly harnessing xylose and glucose from corn stalk hydrolysate, we herein firstly designed glucose and xylose co-fed engineered Klebsiella pneumoniae-S. oneidensis microbial consortium, in which K. pneumoniae as the fermenter converted glucose and xylose into lactate to feed the exoelectrogens (S. oneidensis). To produce more lactate in K. pneumoniae, we eliminated the ethanol and acetate pathway via deleting pta (phosphotransacetylase gene) and adhE (alcohol dehydrogenase gene) and further constructed a synthesis and delivery system through expressing ldhD (lactate dehydrogenase gene) and lldP (lactate transporter gene). To facilitate extracellular electron transfer (EET) of S. oneidensis, a biosynthetic flavins pathway from Bacillus subtilis was expressed in a highly hydrophobic S. oneidensis CP-S1, which not only improved direct-contacted EET via enhancing S. oneidensis adhesion to the carbon electrode but also accelerated the flavins-mediated EET via increasing flavins synthesis. Furthermore, we optimized the ratio of glucose and xylose concentration to provide a stable carbon source supply in MFCs for higher power density. The glucose and xylose co-fed MFC inoculated with the recombinant consortium generated a maximum power density of 104.7 ± 10.0 mW/m2, which was 7.2-folds higher than that of the wild-type consortium (12.7 ± 8.0 mW/m2). Lastly, we used this synthetic microbial consortium in the corn straw hydrolyzates-fed MFC, obtaining a power density 23.5 ± 6.0 mW/m2.
Collapse
Affiliation(s)
- Feng Li
- Key Laboratory of Systems Bioengineering (MOE), Frontier Science Center for Synthetic Biology, School of Chemical Engineering and Technology, Tianjin University, Tianjin, China
| | - Xingjuan An
- Key Laboratory of Systems Bioengineering (MOE), Frontier Science Center for Synthetic Biology, School of Chemical Engineering and Technology, Tianjin University, Tianjin, China
| | - Deguang Wu
- Department of Brewing Engineering, Moutai Institute, Renhuai, China.,Tianjin Engineering Research Center of Microbial Metabolism and Fermentation Process Control, Tianjin University of Science and Technology, Tianjin, China
| | - Jing Xu
- Key Laboratory of Systems Bioengineering (MOE), Frontier Science Center for Synthetic Biology, School of Chemical Engineering and Technology, Tianjin University, Tianjin, China
| | - Yuanyuan Chen
- Key Laboratory of Systems Bioengineering (MOE), Frontier Science Center for Synthetic Biology, School of Chemical Engineering and Technology, Tianjin University, Tianjin, China
| | - Wenchao Li
- Key Laboratory of Systems Bioengineering (MOE), Frontier Science Center for Synthetic Biology, School of Chemical Engineering and Technology, Tianjin University, Tianjin, China
| | - Yingxiu Cao
- Key Laboratory of Systems Bioengineering (MOE), Frontier Science Center for Synthetic Biology, School of Chemical Engineering and Technology, Tianjin University, Tianjin, China
| | - Xuewu Guo
- Tianjin Engineering Research Center of Microbial Metabolism and Fermentation Process Control, Tianjin University of Science and Technology, Tianjin, China
| | - Xue Lin
- College of Food Science and Technology, Hainan University, Haikou, China
| | - Congfa Li
- College of Food Science and Technology, Hainan University, Haikou, China
| | - Sixin Liu
- College of Food Science and Technology, Hainan University, Haikou, China
| | - Hao Song
- Key Laboratory of Systems Bioengineering (MOE), Frontier Science Center for Synthetic Biology, School of Chemical Engineering and Technology, Tianjin University, Tianjin, China
| |
Collapse
|
12
|
Recent Advances in the Metabolic Engineering of Klebsiella pneumoniae: A Potential Platform Microorganism for Biorefineries. BIOTECHNOL BIOPROC E 2019. [DOI: 10.1007/s12257-018-0346-x] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
|
13
|
Wang B, Zhang X, Yu X, Cui Z, Wang Z, Chen T, Zhao X. Evolutionary engineering of Escherichia coli for improved anaerobic growth in minimal medium accelerated lactate production. Appl Microbiol Biotechnol 2019; 103:2155-2170. [PMID: 30623201 DOI: 10.1007/s00253-018-09588-9] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2018] [Revised: 10/24/2018] [Accepted: 12/16/2018] [Indexed: 01/28/2023]
Abstract
Anaerobic fermentation is a favorable process for microbial production of bulk chemicals like ethanol and organic acids. Low productivity is the bottleneck of several anaerobic processes which has significant impact on the technique competitiveness of production strain. Improving growth rate of production strain can speed up the total production cycle and may finally increase productivity of anaerobic processes. In this work, evolutionary engineering of wild-type strain Escherichia coli W3110 was adopted to improve anaerobic growth in mineral medium. Significant increases in exponential growth rate and stationary cell density were achieved in evolved strain WE269, and a 96.5% increase in lactate productivity has also been observed in batch fermentation of this strain with M9 minimal medium. Then, an engineered strain for lactate production (BW100) was constructed by using WE269 as a platform and 98.3 g/L lactate (with an optical purity of D-lactate above 95%) was produced in a 5-L bioreactor after 48 h with a productivity of 2.05 g/(L·h). Finally, preliminary investigation demonstrated that mutation in sucD (sucD M245I) (encoding succinyl-CoA synthetase); ilvG (ilvG Δ1bp) (encoding acetolactate synthase 2 catalytic subunit), and rpoB (rpoB T1037P) (encoding RNA polymerase β subunit) significantly improved anaerobic growth of E. coli. Double-gene mutation in ilvG and sucD resumed most of the growth potential of evolved strain WE269. This work suggested that improving anaerobic growth of production host can increase productivity of organic acids like lactate, and specific mutation-enabled improved growth may also be applied to metabolic engineering for production of other bulk chemicals.
Collapse
Affiliation(s)
- Baowei Wang
- Department of Biochemical Engineering, School of Chemical Engineering and Technology, Tianjin University, Tianjin, People's Republic of China
- SynBio Research Platform, Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), Tianjin, People's Republic of China
- Frontier Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering (MOE), School of Chemical Engineering and Technology, Tianjin University, Tianjin, People's Republic of China
| | - Xiaoxia Zhang
- Department of Biochemical Engineering, School of Chemical Engineering and Technology, Tianjin University, Tianjin, People's Republic of China
- SynBio Research Platform, Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), Tianjin, People's Republic of China
- Frontier Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering (MOE), School of Chemical Engineering and Technology, Tianjin University, Tianjin, People's Republic of China
| | - Xinlei Yu
- Department of Biochemical Engineering, School of Chemical Engineering and Technology, Tianjin University, Tianjin, People's Republic of China
- SynBio Research Platform, Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), Tianjin, People's Republic of China
- Frontier Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering (MOE), School of Chemical Engineering and Technology, Tianjin University, Tianjin, People's Republic of China
| | - Zhenzhen Cui
- Department of Biochemical Engineering, School of Chemical Engineering and Technology, Tianjin University, Tianjin, People's Republic of China
- SynBio Research Platform, Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), Tianjin, People's Republic of China
- Frontier Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering (MOE), School of Chemical Engineering and Technology, Tianjin University, Tianjin, People's Republic of China
| | - Zhiwen Wang
- Department of Biochemical Engineering, School of Chemical Engineering and Technology, Tianjin University, Tianjin, People's Republic of China
- SynBio Research Platform, Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), Tianjin, People's Republic of China
- Frontier Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering (MOE), School of Chemical Engineering and Technology, Tianjin University, Tianjin, People's Republic of China
| | - Tao Chen
- Department of Biochemical Engineering, School of Chemical Engineering and Technology, Tianjin University, Tianjin, People's Republic of China.
- SynBio Research Platform, Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), Tianjin, People's Republic of China.
- Frontier Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering (MOE), School of Chemical Engineering and Technology, Tianjin University, Tianjin, People's Republic of China.
| | - Xueming Zhao
- Department of Biochemical Engineering, School of Chemical Engineering and Technology, Tianjin University, Tianjin, People's Republic of China
- SynBio Research Platform, Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), Tianjin, People's Republic of China
- Frontier Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering (MOE), School of Chemical Engineering and Technology, Tianjin University, Tianjin, People's Republic of China
| |
Collapse
|
14
|
Kumar V, Park S. Potential and limitations of Klebsiella pneumoniae as a microbial cell factory utilizing glycerol as the carbon source. Biotechnol Adv 2018; 36:150-167. [DOI: 10.1016/j.biotechadv.2017.10.004] [Citation(s) in RCA: 53] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2017] [Revised: 10/15/2017] [Accepted: 10/16/2017] [Indexed: 12/16/2022]
|
15
|
Pradima J, Kulkarni MR, Archna. Review on enzymatic synthesis of value added products of glycerol, a by-product derived from biodiesel production. RESOURCE-EFFICIENT TECHNOLOGIES 2017. [DOI: 10.1016/j.reffit.2017.02.009] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
|
16
|
Production of D-lactate from glucose using Klebsiella pneumoniae mutants. Microb Cell Fact 2017; 16:209. [PMID: 29162110 PMCID: PMC5697408 DOI: 10.1186/s12934-017-0822-6] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2017] [Accepted: 11/12/2017] [Indexed: 11/10/2022] Open
Abstract
Background d-Lactate is a valued chemical which can be produced by some bacteria including Klebsiella pneumoniae. However, only a few studies have focused on K. pneumoniae for d-lactate production with a significant amount of by-products, which complicated the purification process and decreased the yield of d-lactate. Results Based on the redirection of carbon towards by-product formation, the effects of single-gene and multiple-gene deletions in K. pneumoniae on d-lactate production from glucose via acetolactate synthase (budB), acetate kinase (ackA), and alcohol dehydrogenase (adhE) were tested. Klebsiella pneumoniae mutants had different production behaviours. The accumulation of the main by-products was decreased in the mutants. The triple mutant strain had the most powerful ability to produce optically pure d-lactate from glucose, and was tested with xylose and arabinose as carbon sources. Fed-batch fermentation was also carried out under various aeration rates, and the strain accumulated 125.1 g/L d-lactate with a yield of 0.91 g/g glucose at 2.5 vvm. Conclusions Knocking out by-product synthesis genes had a remarkable influence on the production and yield of d-lactate. This study demonstrated, for the first time, that K. pneumoniae has great potential to convert monosaccharides into d-lactate. The results provide new insights for industrial production of d-lactate by K. pneumoniae.
Collapse
|
17
|
Prasirtsak B, Thitiprasert S, Tolieng V, Assabumrungrat S, Tanasupawat S, Thongchul N. Characterization of D-lactic acid, spore-forming bacteria and Terrilactibacillus laevilacticus SK5-6 as potential industrial strains. ANN MICROBIOL 2017. [DOI: 10.1007/s13213-017-1306-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022] Open
|
18
|
Coordination of metabolic pathways: Enhanced carbon conservation in 1,3-propanediol production by coupling with optically pure lactate biosynthesis. Metab Eng 2017; 41:102-114. [PMID: 28396036 DOI: 10.1016/j.ymben.2017.03.009] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2016] [Revised: 01/09/2017] [Accepted: 03/31/2017] [Indexed: 11/23/2022]
Abstract
Metabolic engineering has emerged as a powerful tool for bioproduction of both fine and bulk chemicals. The natural coordination among different metabolic pathways contributes to the complexity of metabolic modification, which hampers the development of biorefineries. Herein, the coordination between the oxidative and reductive branches of glycerol metabolism was rearranged in Klebsiella oxytoca to improve the 1,3-propanediol production. After deliberating on the product value, carbon conservation, redox balance, biological compatibility and downstream processing, the lactate-producing pathway was chosen for coupling with the 1,3-propanediol-producing pathway. Then, the other pathways of 2,3-butanediol, ethanol, acetate, and succinate were blocked in sequence, leading to improved d-lactate biosynthesis, which as return drove the 1,3-propanediol production. Meanwhile, efficient co-production of 1,3-propanediol and l-lactate was also achieved by replacing ldhD with ldhL from Bacillus coagulans. The engineered strains PDL-5 and PLL co-produced over 70g/L 1,3-propanediol and over 100g/L optically pure d-lactate and l-lactate, respectively, with high conversion yields of over 0.95mol/mol from glycerol.
Collapse
|
19
|
High production of 2,3-butanediol from glycerol without 1,3-propanediol formation by Raoultella ornithinolytica B6. Appl Microbiol Biotechnol 2017; 101:2821-2830. [DOI: 10.1007/s00253-017-8094-y] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2016] [Revised: 12/20/2016] [Accepted: 12/25/2016] [Indexed: 01/07/2023]
|
20
|
Strategies for manipulation of oxygen utilization by the electron transfer chain in microbes for metabolic engineering purposes. J Ind Microbiol Biotechnol 2016; 44:647-658. [PMID: 27800562 DOI: 10.1007/s10295-016-1851-6] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2016] [Accepted: 10/06/2016] [Indexed: 12/14/2022]
Abstract
Microaerobic growth is of importance in ecological niches, pathogenic infections and industrial production of chemicals. The use of low levels of oxygen enables the cell to gain energy and grow more robustly in the presence of a carbon source that can be oxidized and provide electrons to the respiratory chain in the membrane. A considerable amount of information is available on the genes and proteins involved in respiratory growth and the regulation of genes involved in aerobic and anaerobic metabolism. The dependence of regulation on sensing systems that respond to reduced quinones (e.g. ArcB) or oxygen levels that affect labile redox components of transcription regulators (Fnr) are key in understanding the regulation. Manipulation of the amount of respiration can be difficult to control in dense cultures or inadequately mixed reactors leading to inhomogeneous cultures that may have lower than optimal performance. Efforts to control respiration through genetic means have been reported and address mutations affecting components of the electron transport chain. In a recent report completion for intermediates of the ubiquinone biosynthetic pathway was used to dial the level of respiration vs lactate formation in an aerobically grown E. coli culture.
Collapse
|
21
|
Biotechnological production of enantiomerically pure d-lactic acid. Appl Microbiol Biotechnol 2016; 100:9423-9437. [DOI: 10.1007/s00253-016-7843-7] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2016] [Revised: 09/04/2016] [Accepted: 09/07/2016] [Indexed: 12/13/2022]
|
22
|
Feng X, Xian M, Liu W, Xu C, Zhang H, Zhao G. Biosynthesis of poly(3-hydroxypropionate) from glycerol using engineered Klebsiella pneumoniae strain without vitamin B12. Bioengineered 2016; 6:77-81. [PMID: 25621933 DOI: 10.1080/21655979.2015.1011027] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
Poly(3-hydroxypropionate) (P3HP) is a biodegradable and biocompatible thermoplastic. Previous studies demonstrated that engineered Escherichia coli strains can produce P3HP with supplementation of expensive vitamin B12. The present study examined the production of P3HP from glycerol in the recombinant Klebsiella pneumoniae strain, which naturally synthesizes vitamin B12. The genes glycerol dehydratase and its reactivation factor (dhaB123, gdrA, and gdrB from K. pneumoniae), aldehyde dehydrogenase (aldH from E. coli) were cloned and expressed in K. pneumoniae to produce 3-hydroxypropionate (3HP), with 2 genes (dhaT and yqhD) for biosynthesis of 1,3-propanediol were deleted. To obtain P3HP production, propionyl-CoA synthetase (prpE from E. coli) and polyhydroxyalkanoate synthase (phaC from Ralstonia eutropha) were introduced. Under the appropriate aeration condition, the cell yield and P3HP content were 0.24 g/L and 12.7% (wt/wt [cell dry weight]) respectively along with 2.03 g/L 3HP after 48 h cultivation. Although the yield is relatively low, this study shows the feasibility of producing P3HP in K. pneumoniae from glycerol without vitamin B12 for the first time. The results also suggest that the aeration conditions should be optimized carefully for the efficient production of P3HP.
Collapse
Affiliation(s)
- Xinjun Feng
- a CAS Key Laboratory of Biobased Materials; Qingdao Institute of Bioenergy and Bioprocess Technology ; Chinese Academy of Sciences ; Qingdao , China
| | | | | | | | | | | |
Collapse
|
23
|
Tong W, Xu Y, Xian M, Niu W, Guo J, Liu H, Zhao G. Biosynthetic pathway for acrylic acid from glycerol in recombinant Escherichia coli. Appl Microbiol Biotechnol 2016; 100:4901-7. [PMID: 26782744 DOI: 10.1007/s00253-015-7272-z] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2015] [Revised: 12/13/2015] [Accepted: 12/23/2015] [Indexed: 10/22/2022]
Abstract
Acrylic acid is an important industrial feedstock. In this study, a de novo acrylate biosynthetic pathway from inexpensive carbon source glycerol was constructed in Escherichia coli. The acrylic acid was produced from glycerol via 3-hydroxypropionaldehyde, 3-hydroxypropionyl-CoA, and acrylyl-CoA. The acrylate production was improved by screening and site-directed mutagenesis of key enzyme enoyl-CoA hydratase and chromosomal integration of some exogenous genes. Finally, our recombinant strain produced 37.7 mg/L acrylic acid under shaking flask conditions. Although the acrylate production is low, our study shows feasibility of engineering an acrylate biosynthetic pathway from inexpensive carbon source. Furthermore, the reasons for limited acrylate production and further strain optimization that should be performed in the future were also discussed.
Collapse
Affiliation(s)
- Wenhua Tong
- CAS Key Lab of Biobased Materials, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, 266101, China.,University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Ying Xu
- CAS Key Lab of Biobased Materials, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, 266101, China.,University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Mo Xian
- CAS Key Lab of Biobased Materials, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, 266101, China
| | - Wei Niu
- Department of Chemistry, University of Nebraska-Lincoln, Lincoln, NE, 68588, USA
| | - Jiantao Guo
- Department of Chemistry, University of Nebraska-Lincoln, Lincoln, NE, 68588, USA
| | - Huizhou Liu
- CAS Key Lab of Biobased Materials, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, 266101, China.
| | - Guang Zhao
- CAS Key Lab of Biobased Materials, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, 266101, China.
| |
Collapse
|
24
|
Murakami N, Oba M, Iwamoto M, Tashiro Y, Noguchi T, Bonkohara K, Abdel-Rahman MA, Zendo T, Shimoda M, Sakai K, Sonomoto K. l-Lactic acid production from glycerol coupled with acetic acid metabolism by Enterococcus faecalis without carbon loss. J Biosci Bioeng 2016; 121:89-95. [DOI: 10.1016/j.jbiosc.2015.05.009] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2015] [Revised: 04/27/2015] [Accepted: 05/17/2015] [Indexed: 11/27/2022]
|
25
|
Chen Z, Liu D. Toward glycerol biorefinery: metabolic engineering for the production of biofuels and chemicals from glycerol. BIOTECHNOLOGY FOR BIOFUELS 2016; 9:205. [PMID: 27729943 PMCID: PMC5048440 DOI: 10.1186/s13068-016-0625-8] [Citation(s) in RCA: 51] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/12/2016] [Accepted: 09/24/2016] [Indexed: 05/03/2023]
Abstract
As an inevitable by-product of the biofuel industry, glycerol is becoming an attractive feedstock for biorefinery due to its abundance, low price and high degree of reduction. Converting crude glycerol into value-added products is important to increase the economic viability of the biofuel industry. Metabolic engineering of industrial strains to improve its performance and to enlarge the product spectrum of glycerol biotransformation process is highly important toward glycerol biorefinery. This review focuses on recent metabolic engineering efforts as well as challenges involved in the utilization of glycerol as feedstock for the production of fuels and chemicals, especially for the production of diols, organic acids and biofuels.
Collapse
Affiliation(s)
- Zhen Chen
- Department of Chemical Engineering, Tsinghua University, Beijing, 100084 China
- Tsinghua Innovation Center in Dongguan, Dongguan, 523808 China
| | - Dehua Liu
- Department of Chemical Engineering, Tsinghua University, Beijing, 100084 China
- Tsinghua Innovation Center in Dongguan, Dongguan, 523808 China
| |
Collapse
|
26
|
Eiteman MA, Ramalingam S. Microbial production of lactic acid. Biotechnol Lett 2015; 37:955-72. [PMID: 25604523 DOI: 10.1007/s10529-015-1769-5] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2014] [Accepted: 01/07/2015] [Indexed: 10/24/2022]
Abstract
Lactic acid is an important commodity chemical having a wide range of applications. Microbial production effectively competes with chemical synthesis methods because biochemical synthesis permits the generation of either one of the two enantiomers with high optical purity at high yield and titer, a result which is particularly beneficial for the production of poly(lactic acid) polymers having specific properties. The commercial viability of microbial lactic acid production relies on utilization of inexpensive carbon substrates derived from agricultural or waste resources. Therefore, optimal lactic acid formation requires an understanding and engineering of both the competing pathways involved in carbohydrate metabolism, as well as pathways leading to potential by-products which both affect product yield. Recent research leverages those biochemical pathways, while researchers also continue to seek strains with improved tolerance and ability to perform under desirable industrial conditions, for example, of pH and temperature.
Collapse
Affiliation(s)
- Mark A Eiteman
- BioChemical Engineering Program, College of Engineering, University of Georgia, Athens, GA, 30602, USA,
| | | |
Collapse
|