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Guo X, Ding Y, Chen Y, Fu H, Wang J. Microbial cell factory for butyl butyrate production: Knowledges and perspectives. Microb Biotechnol 2024; 17:e14502. [PMID: 38888486 PMCID: PMC11184938 DOI: 10.1111/1751-7915.14502] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2024] [Revised: 05/08/2024] [Accepted: 05/12/2024] [Indexed: 06/20/2024] Open
Abstract
Butyl butyrate is a short-chain fatty acid ester (C8) with a fruity aroma. It has broad prospects in the fields of foods, cosmetics and biofuels. At present, butyl butyrate is produced by chemical synthesis in the industry, but it is highly dependent on petroleum-based products. The growing concerns regarding the future scarcity of fossil fuels have been strongly promoted the transition from traditional fossil fuels and products to renewable bioenergy and biochemicals. Therefore, it is necessary to develop a green biochemical technology to replace traditional petroleum-based materials. In recent years, microorganisms such as Escherichia coli and Clostridium have been engineered to serve as cell factories for the sustainable one-pot production of short-chain fatty acid esters, including butyl butyrate. This opinion highlights the recent development in the use of lipases and alcohol acyltransferases (AATs) for butyl butyrate production in microbial fermentation, as well as future perspectives.
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Affiliation(s)
- Xiaolong Guo
- School of Biology and Biological EngineeringSouth China University of TechnologyGuangzhouChina
| | - Yuqing Ding
- School of Biology and Biological EngineeringSouth China University of TechnologyGuangzhouChina
| | - Yufan Chen
- School of Biology and Biological EngineeringSouth China University of TechnologyGuangzhouChina
| | - Hongxin Fu
- School of Biology and Biological EngineeringSouth China University of TechnologyGuangzhouChina
- Guangdong Provincial Key Laboratory of Fermentation and Enzyme EngineeringSouth China University of TechnologyGuangzhouChina
- State Key Laboratory of Pulp and Paper EngineeringSouth China University of TechnologyGuangzhouChina
| | - Jufang Wang
- School of Biology and Biological EngineeringSouth China University of TechnologyGuangzhouChina
- Guangdong Provincial Key Laboratory of Fermentation and Enzyme EngineeringSouth China University of TechnologyGuangzhouChina
- State Key Laboratory of Pulp and Paper EngineeringSouth China University of TechnologyGuangzhouChina
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Seo H, Castro G, Trinh CT. Engineering a Synthetic Escherichia coli Coculture for Compartmentalized de novo Biosynthesis of Isobutyl Butyrate from Mixed Sugars. ACS Synth Biol 2024; 13:259-268. [PMID: 38091519 PMCID: PMC10804408 DOI: 10.1021/acssynbio.3c00493] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2023] [Revised: 11/21/2023] [Accepted: 11/22/2023] [Indexed: 01/23/2024]
Abstract
Short-chain esters are versatile chemicals that can be used as flavors, fragrances, solvents, and fuels. The de novo ester biosynthesis consists of diverging and converging pathway submodules, which is challenging to engineer to achieve optimal metabolic fluxes and selective product synthesis. Compartmentalizing the pathway submodules into specialist cells that facilitate pathway modularization and labor division is a promising solution. Here, we engineered a synthetic Escherichia coli coculture with the compartmentalized sugar utilization and ester biosynthesis pathways to produce isobutyl butyrate from a mixture of glucose and xylose. To compartmentalize the sugar-utilizing pathway submodules, we engineered a xylose-utilizing E. coli specialist that selectively consumes xylose over glucose and bypasses carbon catabolite repression (CCR) while leveraging the native CCR machinery to activate a glucose-utilizing E. coli specialist. We found that the compartmentalization of sugar catabolism enabled simultaneous co-utilization of glucose and xylose by a coculture of the two E. coli specialists, improving the stability of the coculture population. Next, we modularized the isobutyl butyrate pathway into the isobutanol, butyl-CoA, and ester condensation submodules, where we distributed the isobutanol submodule to the glucose-utilizing specialist and the other submodules to the xylose-utilizing specialist. Upon compartmentalization of the isobutyl butyrate pathway submodules into these sugar-utilizing specialist cells, a robust synthetic coculture was engineered to selectively produce isobutyl butyrate, reduce the biosynthesis of unwanted ester byproducts, and improve the production titer as compared to the monoculture.
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Affiliation(s)
- Hyeongmin Seo
- Department
of Chemical and Biomolecular Engineering, The University of Tennessee, Knoxville, Tennessee 37996, United States
- Center
of Bioenergy Innovation, Oak Ridge National
Laboratory, Oak Ridge, Tennessee 37830, United States
| | - Gillian Castro
- Department
of Chemical and Biomolecular Engineering, The University of Tennessee, Knoxville, Tennessee 37996, United States
| | - Cong T. Trinh
- Department
of Chemical and Biomolecular Engineering, The University of Tennessee, Knoxville, Tennessee 37996, United States
- Center
of Bioenergy Innovation, Oak Ridge National
Laboratory, Oak Ridge, Tennessee 37830, United States
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Guo X, Li X, Feng J, Yue Z, Fu H, Wang J. Engineering of Clostridium tyrobutyricum for butyric acid and butyl butyrate production from cassava starch. BIORESOURCE TECHNOLOGY 2024; 391:129914. [PMID: 37923229 DOI: 10.1016/j.biortech.2023.129914] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/22/2023] [Revised: 10/22/2023] [Accepted: 10/23/2023] [Indexed: 11/07/2023]
Abstract
Clostridium tyrobutyricum has been successfully engineered to produce butyrate, butanol, butyl butyrate, and γ-aminobutyric acid. It would be interesting to produce bio-chemicals and bio-fuels directly using starch from non-food crop, e.g., cassava, by engineered C. tyrobutyricum. In this study, heterologous α-amylases were screened and expressed in C. tyrobutyricum, resulting in successfully starch hydrolyzation. Furthermore, α-glucosidase (AgluI) was co-expressed with α-amylases, resulting in enhancement in the capacity of starch hydrolyzation and butyrate production. When increasing the cassava starch concentration to 100 g/L, the engineered strain CTAA05 produced 27.0 g/L butyrate. In addition, when introducing butyl butyrate synthetic pathway, strain MU3-AAV produced 26.8 g/L butyl butyrate with 100 g/L cassava starch as substrate. This study showed a generalizable framework to engineered anaerobes for anaerobic production of bio-chemicals and bio-fuels from starchy biomass.
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Affiliation(s)
- Xiaolong Guo
- School of Biology and Biological Engineering, South China University of Technology, Guangzhou 510006, China
| | - Xin Li
- School of Biology and Biological Engineering, South China University of Technology, Guangzhou 510006, China
| | - Jun Feng
- School of Biology and Biological Engineering, South China University of Technology, Guangzhou 510006, China
| | - Zhi Yue
- School of Biology and Biological Engineering, South China University of Technology, Guangzhou 510006, China
| | - Hongxin Fu
- School of Biology and Biological Engineering, South China University of Technology, Guangzhou 510006, China; Guangdong Provincial Key Laboratory of Fermentation and Enzyme Engineering, South China University of Technology, Guangzhou 510006, China.
| | - Jufang Wang
- School of Biology and Biological Engineering, South China University of Technology, Guangzhou 510006, China; Guangdong Provincial Key Laboratory of Fermentation and Enzyme Engineering, South China University of Technology, Guangzhou 510006, China.
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Liu G, Huang L, Lian J. Alcohol acyltransferases for the biosynthesis of esters. BIOTECHNOLOGY FOR BIOFUELS AND BIOPRODUCTS 2023; 16:93. [PMID: 37264424 DOI: 10.1186/s13068-023-02343-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/05/2023] [Accepted: 05/18/2023] [Indexed: 06/03/2023]
Abstract
Esters are widely used in food, energy, spices, chemical industry, etc., becoming an indispensable part of life. However, their production heavily relies on the fossil energy industry, which presents significant challenges associated with energy shortages and environmental pollution. Consequently, there is an urgent need to identify alternative green methods for ester production. One promising solution is biosynthesis, which offers sustainable and environmentally friendly processes. In ester biosynthesis, alcohol acyltransferases (AATs) catalyze the condensation of acyl-CoAs and alcohols to form esters, enabling the biosynthesis of nearly 100 different kinds of esters, such as ethyl acetate, hexyl acetate, ethyl crotonate, isoamyl acetate, and butyl butyrate. However, low catalytic efficiency and low selectivity of AATs represent the major bottlenecks for the biosynthesis of certain specific esters, which should be addressed with protein molecular engineering approaches before practical biotechnological applications. This review provides an overview of AAT enzymes, including their sequences, structures, active sites, catalytic mechanisms, and metabolic engineering applications. Furthermore, considering the critical role of AATs in determining the final ester products, the current research progresses of AAT modification using protein molecular engineering are also discussed. This review summarized the major challenges and prospects of AAT enzymes in ester biosynthesis.
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Affiliation(s)
- Gaofei Liu
- Key Laboratory of Biomass Chemical Engineering of Ministry of Education, College of Chemical and Biological Engineering, Zhejiang University, Hangzhou, 310027, China
- ZJU-Hangzhou Global Scientific and Technological Innovation Center, Zhejiang University, Hangzhou, 311215, China
| | - Lei Huang
- Key Laboratory of Biomass Chemical Engineering of Ministry of Education, College of Chemical and Biological Engineering, Zhejiang University, Hangzhou, 310027, China
- ZJU-Hangzhou Global Scientific and Technological Innovation Center, Zhejiang University, Hangzhou, 311215, China
| | - Jiazhang Lian
- Key Laboratory of Biomass Chemical Engineering of Ministry of Education, College of Chemical and Biological Engineering, Zhejiang University, Hangzhou, 310027, China.
- ZJU-Hangzhou Global Scientific and Technological Innovation Center, Zhejiang University, Hangzhou, 311215, China.
- Zhejiang Key Laboratory of Smart Biomaterials, Zhejiang University, Hangzhou, 310027, China.
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Wang R, Liu X, Lv B, Sun W, Li C. Designing Intracellular Compartments for Efficient Engineered Microbial Cell Factories. ACS Synth Biol 2023; 12:1378-1395. [PMID: 37083286 DOI: 10.1021/acssynbio.2c00671] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/22/2023]
Abstract
With the rapid development of synthetic biology, various kinds of microbial cell factories (MCFs) have been successfully constructed to produce high-value-added compounds. However, the complexity of metabolic regulation and pathway crosstalk always cause issues such as intermediate metabolite accumulation, byproduct generation, and metabolic burden in MCFs, resulting in low efficiencies and low yields of industrial biomanufacturing. Such issues could be solved by spatially rearranging the pathways using intracellular compartments. In this review, design strategies are summarized and discussed based on the types and characteristics of natural and artificial subcellular compartments. This review systematically presents information for the construction of efficient MCFs with intracellular compartments in terms of four aspects of design strategy goals: (1) improving local reactant concentration; (2) intercepting and isolating competing pathways; (3) providing specific reaction substances and environments; and (4) storing and accumulating products.
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Affiliation(s)
- Ruwen Wang
- Key Laboratory of Medical Molecule Science and Pharmaceutical Engineering, Ministry of Industry and Information Technology, Institute of Biochemical Engineering, School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing, 100081, PR China
| | - Xin Liu
- Key Lab for Industrial Biocatalysis, Ministry of Education, Department of Chemical Engineering, Tsinghua University, Beijing, 100084, PR China
| | - Bo Lv
- Key Laboratory of Medical Molecule Science and Pharmaceutical Engineering, Ministry of Industry and Information Technology, Institute of Biochemical Engineering, School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing, 100081, PR China
| | - Wentao Sun
- Key Lab for Industrial Biocatalysis, Ministry of Education, Department of Chemical Engineering, Tsinghua University, Beijing, 100084, PR China
| | - Chun Li
- Key Laboratory of Medical Molecule Science and Pharmaceutical Engineering, Ministry of Industry and Information Technology, Institute of Biochemical Engineering, School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing, 100081, PR China
- Key Lab for Industrial Biocatalysis, Ministry of Education, Department of Chemical Engineering, Tsinghua University, Beijing, 100084, PR China
- Center for Synthetic and System Biology, Tsinghua University, Beijing, 100084, PR China
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Carruthers DN, Kim J, Mendez-Perez D, Monroe E, Myllenbeck N, Liu Y, Davis RW, Sundstrom E, Lee TS. Microbial production of high octane and high sensitivity olefinic ester biofuels. BIOTECHNOLOGY FOR BIOFUELS AND BIOPRODUCTS 2023; 16:60. [PMID: 37016410 PMCID: PMC10071710 DOI: 10.1186/s13068-023-02301-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/12/2022] [Accepted: 03/08/2023] [Indexed: 04/06/2023]
Abstract
BACKGROUND Advanced spark ignition engines require high performance fuels with improved resistance to autoignition. Biologically derived olefinic alcohols have arisen as promising blendstock candidates due to favorable octane numbers and synergistic blending characteristics. However, production and downstream separation of these alcohols are limited by their intrinsic toxicity and high aqueous solubility, respectively. Bioproduction of carboxylate esters of alcohols can improve partitioning and reduce toxicity, but in practice has been limited to saturated esters with characteristically low octane sensitivity. If olefinic esters retain the synergistic blending characteristics of their alcohol counterparts, they could improve the bioblendstock combustion performance while also retaining the production advantages of the ester moiety. RESULTS Optimization of Escherichia coli isoprenoid pathways has led to high titers of isoprenol and prenol, which are not only excellent standalone biofuel and blend candidates, but also novel targets for esterification. Here, a selection of olefinic esters enhanced blendstock performance according to their degree of unsaturation and branching. E. coli strains harboring optimized mevalonate pathways, thioester pathways, and heterologous alcohol acyltransferases (ATF1, ATF2, and SAAT) were engineered for the bioproduction of four novel olefinic esters. Although prenyl and isoprenyl lactate titers were limited to 1.48 ± 0.41 mg/L and 5.57 ± 1.36 mg/L, strains engineered for prenyl and isoprenyl acetate attained titers of 176.3 ± 16.0 mg/L and 3.08 ± 0.27 g/L, respectively. Furthermore, prenyl acetate (20% bRON = 125.8) and isoprenyl acetate (20% bRON = 108.4) exhibited blend properties comparable to ethanol and significantly better than any saturated ester. By further scaling cultures to a 2-L bioreactor under fed-batch conditions, 15.0 ± 0.9 g/L isoprenyl acetate was achieved on minimal medium. Metabolic engineering of acetate pathway flux further improved titer to attain an unprecedented 28.0 ± 1.0 g/L isoprenyl acetate, accounting for 75.7% theoretical yield from glucose. CONCLUSION Our study demonstrated novel bioproduction of four isoprenoid oxygenates for fuel blending. Our optimized E. coli production strain generated an unprecedented titer of isoprenyl acetate and when paired with its favorable blend properties, may enable rapid scale-up of olefinic alcohol esters for use as a fuel blend additive or as a precursor for longer-chain biofuels and biochemicals.
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Affiliation(s)
- David N Carruthers
- Biological Systems and Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
- Joint BioEnergy Institute, 5885 Hollis Street, Emeryville, CA, 94608, USA
| | - Jinho Kim
- Biological Systems and Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
- Joint BioEnergy Institute, 5885 Hollis Street, Emeryville, CA, 94608, USA
| | - Daniel Mendez-Perez
- Biological Systems and Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
- Joint BioEnergy Institute, 5885 Hollis Street, Emeryville, CA, 94608, USA
| | - Eric Monroe
- Sandia National Laboratories, Livermore, CA, 94551, USA
| | | | - Yuzhong Liu
- Biological Systems and Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
- Joint BioEnergy Institute, 5885 Hollis Street, Emeryville, CA, 94608, USA
| | - Ryan W Davis
- Sandia National Laboratories, Livermore, CA, 94551, USA
| | - Eric Sundstrom
- Biological Systems and Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
- Advanced Biofuels and Bioproducts Process Development Unit, Emeryville, CA, 94608, USA
| | - Taek Soon Lee
- Biological Systems and Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA.
- Joint BioEnergy Institute, 5885 Hollis Street, Emeryville, CA, 94608, USA.
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Guo X, Zhang H, Feng J, Yang L, Luo K, Fu H, Wang J. De novo biosynthesis of butyl butyrate in engineered Clostridium tyrobutyricum. Metab Eng 2023; 77:64-75. [PMID: 36948242 DOI: 10.1016/j.ymben.2023.03.009] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2022] [Revised: 03/07/2023] [Accepted: 03/20/2023] [Indexed: 03/24/2023]
Abstract
Butyl butyrate has broad applications in foods, cosmetics, solvents, and biofuels. Microbial synthesis of bio-based butyl butyrate has been regarded as a promising approach recently. Herein, we engineered Clostridium tyrobutyricum ATCC 25755 to achieve de novo biosynthesis of butyl butyrate from fermentable sugars. Through introducing the butanol synthetic pathway (enzyme AdhE2), screening alcohol acyltransferases (AATs), adjusting transcription of VAAT and adhE2 (i.e., optimizing promoter), and efficient supplying butyryl-CoA, an excellent engineered strain, named MUV3, was obtained with ability to produce 4.58 g/L butyl butyrate at 25 °C with glucose in serum bottles. More NADH is needed for butyl butyrate synthesis, thus mannitol (the more reduced substrate) was employed to produce butyl butyrate. Ultimately, 62.59 g/L butyl butyrate with a selectivity of 95.97%, and a yield of 0.21 mol/mol was obtained under mannitol with fed-batch fermentation in a 5 L bioreactor, which is the highest butyl butyrate titer reported so far. Altogether, this study presents an anaerobic fermentative platform for de novo biosynthesis of butyl butyrate in one step, which lays the foundation for butyl butyrate biosynthesis from renewable biomass feedstocks.
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Affiliation(s)
- Xiaolong Guo
- School of Biology and Biological Engineering, South China University of Technology, Guangzhou, 510006, China
| | - Huihui Zhang
- School of Biology and Biological Engineering, South China University of Technology, Guangzhou, 510006, China
| | - Jun Feng
- School of Biology and Biological Engineering, South China University of Technology, Guangzhou, 510006, China
| | - Lu Yang
- School of Biology and Biological Engineering, South China University of Technology, Guangzhou, 510006, China
| | - Kui Luo
- School of Biology and Biological Engineering, South China University of Technology, Guangzhou, 510006, China
| | - Hongxin Fu
- School of Biology and Biological Engineering, South China University of Technology, Guangzhou, 510006, China; Guangdong Provincial Key Laboratory of Fermentation and Enzyme Engineering, South China University of Technology, Guangzhou, 510006, China.
| | - Jufang Wang
- School of Biology and Biological Engineering, South China University of Technology, Guangzhou, 510006, China; Guangdong Provincial Key Laboratory of Fermentation and Enzyme Engineering, South China University of Technology, Guangzhou, 510006, China.
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