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Shipmon JC, Rathinasabapathi P, Broich ML, Hemansi, Eiteman MA. Production of Esters in Escherichia coli Using Citrate Synthase Variants. Microorganisms 2024; 12:1338. [PMID: 39065106 PMCID: PMC11278746 DOI: 10.3390/microorganisms12071338] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2024] [Revised: 06/24/2024] [Accepted: 06/27/2024] [Indexed: 07/28/2024] Open
Abstract
Acetate esters comprise a wide range of products including fragrances and industrial solvents. Biosynthesis of esters offers a promising alternative to chemical synthesis because such routes use renewable carbohydrate resources and minimize the generation of waste. One biochemical method for ester formation relies on the ATF1 gene from Saccharomyces cerevisiae, which encodes alcohol-O-acyltransferase (AAT) which converts acetyl-CoA and an exogenously supplied alcohol into the ester. In this study, the formation of several acetate esters via AAT was examined in Escherichia coli chromosomally expressing citrate synthase variants, which create a metabolic bottleneck at acetyl-CoA. In shake flask cultures, variant strains generated more acetate esters than the strains expressing the wild-type citrate synthase. In a controlled bioreactor, E. coli GltA[A267T] generated 3.9 g propyl acetate in 13 h, corresponding to a yield of 0.155 g propyl acetate/g glucose, which is 18% greater than that obtained by the wild-type GltA control. These results demonstrate the ability of citrate synthase variants to redistribute carbon from central metabolism into acetyl-CoA-derived biochemicals.
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Affiliation(s)
- Jacoby C. Shipmon
- School of Chemical, Materials and Biomedical Engineering, University of Georgia, Athens, GA 30602, USA; (J.C.S.)
| | - Pasupathi Rathinasabapathi
- School of Chemical, Materials and Biomedical Engineering, University of Georgia, Athens, GA 30602, USA; (J.C.S.)
- Department of Genetic Engineering, SRM Institute of Science and Technology, Chengalpattu District, Kattankulathur 603202, Tamil Nadu, India
| | - Michael L. Broich
- School of Chemical, Materials and Biomedical Engineering, University of Georgia, Athens, GA 30602, USA; (J.C.S.)
| | - Hemansi
- School of Chemical, Materials and Biomedical Engineering, University of Georgia, Athens, GA 30602, USA; (J.C.S.)
- Department of Microbiology, Central University of Haryana, Mahendergarh 123029, Haryana, India
| | - Mark A. Eiteman
- School of Chemical, Materials and Biomedical Engineering, University of Georgia, Athens, GA 30602, USA; (J.C.S.)
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2
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Dickey RM, Gopal MR, Nain P, Kunjapur AM. Recent developments in enzymatic and microbial biosynthesis of flavor and fragrance molecules. J Biotechnol 2024; 389:43-60. [PMID: 38616038 DOI: 10.1016/j.jbiotec.2024.04.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2024] [Revised: 04/08/2024] [Accepted: 04/08/2024] [Indexed: 04/16/2024]
Abstract
Flavors and fragrances are an important class of specialty chemicals for which interest in biomanufacturing has risen during recent years. These naturally occurring compounds are often amenable to biosynthesis using purified enzyme catalysts or metabolically engineered microbial cells in fermentation processes. In this review, we provide a brief overview of the categories of molecules that have received the greatest interest, both academically and industrially, by examining scholarly publications as well as patent literature. Overall, we seek to highlight innovations in the key reaction steps and microbial hosts used in flavor and fragrance manufacturing.
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Affiliation(s)
- Roman M Dickey
- Department of Chemical and Biomolecular Engineering, University of Delaware, Newark, DE 19711, USA
| | - Madan R Gopal
- Department of Chemical and Biomolecular Engineering, University of Delaware, Newark, DE 19711, USA
| | - Priyanka Nain
- Department of Chemical and Biomolecular Engineering, University of Delaware, Newark, DE 19711, USA
| | - Aditya M Kunjapur
- Department of Chemical and Biomolecular Engineering, University of Delaware, Newark, DE 19711, USA.
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3
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Lu C, Ramalho TP, Bisschops MMM, Wijffels RH, Martins Dos Santos VAP, Weusthuis RA. Crossing bacterial boundaries: The carbon catabolite repression system Crc-Hfq of Pseudomonas putida KT2440 as a tool to control translation in E. coli. N Biotechnol 2023; 77:20-29. [PMID: 37348756 DOI: 10.1016/j.nbt.2023.06.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2023] [Revised: 06/05/2023] [Accepted: 06/19/2023] [Indexed: 06/24/2023]
Abstract
As a global regulatory mechanism, carbon catabolite repression allows bacteria and eukaryal microbes to preferentially utilize certain substrates from a mixture of carbon sources. The mechanism varies among different species. In Pseudomonas spp., it is mainly mediated by the Crc-Hfq complex which binds to the 5' region of the target mRNAs, thereby inhibiting their translation. This molecular mechanism enables P. putida to rapidly adjust and fine-tune gene expression in changing environments. Hfq is an RNA-binding protein that is ubiquitous and highly conserved in bacterial species. Considering the characteristics of Hfq, and the widespread use and rapid response of Crc-Hfq in P. putida, this complex has the potential to become a general toolbox for post-transcriptional multiplex regulation. In this study, we demonstrate for the first time that transplanting the pseudomonal catabolite repression protein, Crc, into E. coli causes multiplex gene repression. Under the control of Crc, the production of a diester and its precursors was significantly reduced. The effects of Crc introduction on cell growth in both minimal and rich media were evaluated. Two potential factors - off-target effects and Hfq-sequestration - could explain negative effects on cell growth. Simultaneous reduction of off-targeting and increased sequestration of Hfq by the introduction of the small RNA CrcZ, indicated that Hfq sequestration plays a more prominent role in the negative side-effects. This suggests that the negative growth effect can be mitigated by well-controlled expression of Hfq. This study reveals the feasibility of controlling gene expression using heterologous regulation systems.
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Affiliation(s)
- Chunzhe Lu
- Bioprocess Engineering, Wageningen University and Research, 6700AA Wageningen, The Netherlands.
| | - Tiago P Ramalho
- Bioprocess Engineering, Wageningen University and Research, 6700AA Wageningen, The Netherlands
| | - Markus M M Bisschops
- Bioprocess Engineering, Wageningen University and Research, 6700AA Wageningen, The Netherlands
| | - Rene H Wijffels
- Bioprocess Engineering, Wageningen University and Research, 6700AA Wageningen, The Netherlands; Faculty of Biosciences and Aquaculture, Nord University, N-8049 Bodø, Norway
| | - Vitor A P Martins Dos Santos
- Bioprocess Engineering, Wageningen University and Research, 6700AA Wageningen, The Netherlands; Lifeglimmer GmbH, Berlin, Germany
| | - Ruud A Weusthuis
- Bioprocess Engineering, Wageningen University and Research, 6700AA Wageningen, The Netherlands
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4
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Hoffmann A, Franz A, Walther T, Löser C. Utilization of delactosed whey permeate for the synthesis of ethyl acetate with Kluyveromyces marxianus. Appl Microbiol Biotechnol 2023; 107:1635-1648. [PMID: 36786916 PMCID: PMC10006051 DOI: 10.1007/s00253-023-12419-1] [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: 11/07/2022] [Revised: 12/21/2022] [Accepted: 01/30/2023] [Indexed: 02/15/2023]
Abstract
Ethyl acetate is an important organic solvent and currently produced from fossil carbon resources. Microbial synthesis of this ester from sugar-rich waste could be an interesting alternative. Therefore, synthesis of ethyl acetate by Kluyveromyces marxinanus DSM 5422 from delactosed whey permeate (DWP) was studied in an aerated stirred bioreactor at 40 °C. DWP is mainly composed of residual lactose and minerals. The minerals inhibited yeast growth, as witnessed by an increased lag period, a reduced growth rate, and an extended process duration. All experiments were therefore carried out with diluted DWP. In a series of batch experiments, the pH of iron-deficient DWP medium varied between 4.8 and 5.9. The pH of the cultivation medium significantly influenced cell growth and product syntheses, with the highest ethyl acetate yield of 0.347 g g-1 and lowest by-product formation achieved at pH 5.1. It is likely that this effect is due to pH-dependent iron chelation, which affects the iron bioavailability and the intracellular iron content, thus affecting growth and metabolite synthesis. The viability of yeast cells was always high despite the harsh conditions in DWP medium, which enabled extended usage of the biomass in repeated-batch and fed-batch cultivations. These two culture techniques increased the volume of DWP processed per time by 32 and 84% for the repeated-batch and the fed-batch cultivation, respectively, without a drop of the ester yield. KEY POINTS: • Delactosed whey permeate was converted to ethyl acetate with a high rate and yield. • The formation of ethyl acetate in DWP medium at iron limitation is pH-dependent. • Highly active yeasts from batch processes enabled extension as fed and repeated batch.
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Affiliation(s)
- Andreas Hoffmann
- Bioprocess Engineering, Institute of Natural Materials Technology, Technische Universität Dresden, 01062, Dresden, Germany
| | - Alexander Franz
- Bioprocess Engineering, Institute of Natural Materials Technology, Technische Universität Dresden, 01062, Dresden, Germany
- Biophysical Chemistry, Institute of Biochemistry, University of Leipzig, 04103, Leipzig, Germany
| | - Thomas Walther
- Bioprocess Engineering, Institute of Natural Materials Technology, Technische Universität Dresden, 01062, Dresden, Germany
| | - Christian Löser
- Bioprocess Engineering, Institute of Natural Materials Technology, Technische Universität Dresden, 01062, Dresden, Germany.
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5
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Dykstra JC, van Oort J, Yazdi AT, Vossen E, Patinios C, van der Oost J, Sousa DZ, Kengen SWM. Metabolic engineering of Clostridium autoethanogenum for ethyl acetate production from CO. Microb Cell Fact 2022; 21:243. [DOI: 10.1186/s12934-022-01964-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2022] [Accepted: 10/18/2022] [Indexed: 11/25/2022] Open
Abstract
Abstract
Background
Ethyl acetate is a bulk chemical traditionally produced via energy intensive chemical esterification. Microbial production of this compound offers promise as a more sustainable alternative process. So far, efforts have focused on using sugar-based feedstocks for microbial ester production, but extension to one-carbon substrates, such as CO and CO2/H2, is desirable. Acetogens present a promising microbial platform for the production of ethyl esters from these one-carbon substrates.
Results
We engineered the acetogen C. autoethanogenum to produce ethyl acetate from CO by heterologous expression of an alcohol acetyltransferase (AAT), which catalyzes the formation of ethyl acetate from acetyl-CoA and ethanol. Two AATs, Eat1 from Kluyveromyces marxianus and Atf1 from Saccharomyces cerevisiae, were expressed in C. autoethanogenum. Strains expressing Atf1 produced up to 0.2 mM ethyl acetate. Ethyl acetate production was barely detectable (< 0.01 mM) for strains expressing Eat1. Supplementation of ethanol was investigated as potential boost for ethyl acetate production but resulted only in a 1.5-fold increase (0.3 mM ethyl acetate). Besides ethyl acetate, C. autoethanogenum expressing Atf1 could produce 4.5 mM of butyl acetate when 20 mM butanol was supplemented to the growth medium.
Conclusions
This work offers for the first time a proof-of-principle that autotrophic short chain ester production from C1-carbon feedstocks is possible and offers leads on how this approach can be optimized in the future.
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6
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Ku JT, Chen AY, Lan EI. Metabolic engineering of Escherichia coli for efficient biosynthesis of butyl acetate. Microb Cell Fact 2022; 21:28. [PMID: 35193559 PMCID: PMC8864926 DOI: 10.1186/s12934-022-01755-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2021] [Accepted: 02/07/2022] [Indexed: 11/30/2022] Open
Abstract
Background Butyl acetate is a versatile compound that is widely used in the chemical and food industry. The conventional butyl acetate synthesis via Fischer esterification of butanol and acetic acid using catalytic strong acids under high temperature is not environmentally benign. Alternative lipase-catalyzed ester formation requires a significant amount of organic solvent which also presents another environmental challenge. Therefore, a microbial cell factory capable of producing butyl acetate through fermentation of renewable resources would provide a greener approach to butyl acetate production. Result Here, we developed a metabolically engineered strain of Escherichia coli that efficiently converts glucose to butyl acetate. A modified Clostridium CoA-dependent butanol production pathway was used to synthesize butanol which was then condensed with acetyl-CoA through an alcohol acetyltransferase. Optimization of alcohol acetyltransferase expression and redox balance with auto-inducible fermentative controlled gene expression led to an effective titer of 22.8 ± 1.8 g/L butyl acetate produced in a bench-top bioreactor. Conclusion Building on the well-developed Clostridium CoA-dependent butanol biosynthetic pathway, expression of an alcohol acetyltransferase converts the butanol produced into butyl acetate. The results from this study provided a strain of E. coli capable of directly producing butyl acetate from renewable resources at ambient conditions. Supplementary Information The online version contains supplementary material available at 10.1186/s12934-022-01755-y.
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Affiliation(s)
- Jason T Ku
- Institute of Molecular Medicine and Bioengineering, National Chiao Tung University, 1001 Daxue Road, Hsinchu City, 300, Taiwan.,Institute of Molecular Medicine and Bioengineering, National Yang Ming Chiao Tung University, 1001 Daxue Road, Hsinchu City, 300, Taiwan
| | - Arvin Y Chen
- Institute of Molecular Medicine and Bioengineering, National Chiao Tung University, 1001 Daxue Road, Hsinchu City, 300, Taiwan.,Institute of Molecular Medicine and Bioengineering, National Yang Ming Chiao Tung University, 1001 Daxue Road, Hsinchu City, 300, Taiwan
| | - Ethan I Lan
- Department of Biological Science and Technology, National Chiao Tung University, 1001 Daxue Road, Hsinchu City, 300, Taiwan. .,Department of Biological Science and Technology, National Yang Ming Chiao Tung University, 1001 Daxue Road, Hsinchu City, 300, Taiwan.
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7
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Bohnenkamp AC, Wijffels RH, Kengen SWM, Weusthuis RA. Co-production of hydrogen and ethyl acetate in Escherichia coli. BIOTECHNOLOGY FOR BIOFUELS 2021; 14:192. [PMID: 34598726 PMCID: PMC8487115 DOI: 10.1186/s13068-021-02036-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/16/2021] [Accepted: 09/07/2021] [Indexed: 06/13/2023]
Abstract
BACKGROUND Ethyl acetate (C4H8O2) and hydrogen (H2) are industrially relevant compounds that preferably are produced via sustainable, non-petrochemical production processes. Both compounds are volatile and can be produced by Escherichia coli before. However, relatively low yields for hydrogen are obtained and a mix of by-products renders the sole production of hydrogen by micro-organisms unfeasible. High yields for ethyl acetate have been achieved, but accumulation of formate remained an undesired but inevitable obstacle. Coupling ethyl acetate production to the conversion of formate into H2 may offer an interesting solution to both drawbacks. Ethyl acetate production requires equimolar amounts of ethanol and acetyl-CoA, which enables a redox neutral fermentation, without the need for production of by-products, other than hydrogen and CO2. RESULTS We engineered Escherichia coli towards improved conversion of formate into H2 and CO2 by inactivating the formate hydrogen lyase repressor (hycA), both uptake hydrogenases (hyaAB, hybBC) and/or overexpressing the hydrogen formate lyase activator (fhlA), in an acetate kinase (ackA) and lactate dehydrogenase (ldhA)-deficient background strain. Initially 10 strains, with increasing number of modifications were evaluated in anaerobic serum bottles with respect to growth. Four reference strains ΔldhAΔackA, ΔldhAΔackA p3-fhlA, ΔldhAΔackAΔhycAΔhyaABΔhybBC and ΔldhAΔackAΔhycAΔhyaABΔhybBC p3-fhlA were further equipped with a plasmid carrying the heterologous ethanol acyltransferase (Eat1) from Wickerhamomyces anomalus and analyzed with respect to their ethyl acetate and hydrogen co-production capacity. Anaerobic co-production of hydrogen and ethyl acetate via Eat1 was achieved in 1.5-L pH-controlled bioreactors. The cultivation was performed at 30 °C in modified M9 medium with glucose as the sole carbon source. Anaerobic conditions and gas stripping were established by supplying N2 gas. CONCLUSIONS We showed that the engineered strains co-produced ethyl acetate and hydrogen to yields exceeding 70% of the pathway maximum for ethyl acetate and hydrogen, and propose in situ product removal via gas stripping as efficient technique to isolate the products of interest.
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Affiliation(s)
- Anna C Bohnenkamp
- Bioprocess Engineering, Wageningen University and Research, Droevendaalsesteeg 1, 6708 PB, Wageningen, The Netherlands.
| | - René H Wijffels
- Bioprocess Engineering, Wageningen University and Research, Droevendaalsesteeg 1, 6708 PB, Wageningen, The Netherlands
- Faculty of Biosciences and Aquaculture, Nord University, 8049, Bodø, Norway
| | - Servé W M Kengen
- Laboratory of Microbiology, Wageningen University and Research, Stippeneng 4, 6708 WE, Wageningen, The Netherlands
| | - Ruud A Weusthuis
- Bioprocess Engineering, Wageningen University and Research, Droevendaalsesteeg 1, 6708 PB, Wageningen, The Netherlands.
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8
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De novo biosynthesis of tyrosol acetate and hydroxytyrosol acetate from glucose in engineered Escherichia coli. Enzyme Microb Technol 2021; 150:109886. [PMID: 34489039 DOI: 10.1016/j.enzmictec.2021.109886] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2021] [Revised: 07/25/2021] [Accepted: 07/28/2021] [Indexed: 11/21/2022]
Abstract
Tyrosol and hydroxytyrosol derived from virgin olive oil and olives extract, have wide applications both as functional food components and as nutraceuticals. However, they have low bioavailability due to their low absorption and high metabolism in human liver and small intestine. Acetylation of tyrosol and hydroxytyrosol can effectively improve their bioavailability and thus increase their potential use in the food and cosmeceutical industries. There is no report on the bioproductin of tyrosol acetate and hydroxytyrosol acetate so far. Thus, it is of great significance to develop microbial cell factories for achieving tyrosol acetate or hydroxytyrosol acetate biosynthesis. In this study, a de novo biosynthetic pathway for the production of tyrosol acetate and hydroxytyrosol acetate was constructed in Escherichia coli. First, an engineered E. coli that allows production of tyrosol from simple carbon sources was established. Four aldehyde reductases were compared, and it was found that yeaE is the best aldehyde reductase for tyrosol accumulation. Subsequently, the pathway was extended for tyrosol acetate production by further overexpression of alcohol acetyltransferase ATF1 for the conversion of tyrosol to tyrosol acetate. Finally, the pathway was further extended for hydroxytyrosol acetate production by overexpression of 4-hydroxyphenylacetate 3-hydroxylase HpaBC.
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9
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Feng J, Zhang J, Ma Y, Feng Y, Wang S, Guo N, Wang H, Wang P, Jiménez-Bonilla P, Gu Y, Zhou J, Zhang ZT, Cao M, Jiang D, Wang S, Liu XW, Shao Z, Borovok I, Huang H, Wang Y. Renewable fatty acid ester production in Clostridium. Nat Commun 2021; 12:4368. [PMID: 34272383 PMCID: PMC8285483 DOI: 10.1038/s41467-021-24038-3] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2020] [Accepted: 05/26/2021] [Indexed: 11/25/2022] Open
Abstract
Bioproduction of renewable chemicals is considered as an urgent solution for fossil energy crisis. However, despite tremendous efforts, it is still challenging to generate microbial strains that can produce target biochemical to high levels. Here, we report an example of biosynthesis of high-value and easy-recoverable derivatives built upon natural microbial pathways, leading to improvement in bioproduction efficiency. By leveraging pathways in solventogenic clostridia for co-producing acyl-CoAs, acids and alcohols as precursors, through rational screening for host strains and enzymes, systematic metabolic engineering-including elimination of putative prophages, we develop strains that can produce 20.3 g/L butyl acetate and 1.6 g/L butyl butyrate. Techno-economic analysis results suggest the economic competitiveness of our developed bioprocess. Our principles of selecting the most appropriate host for specific bioproduction and engineering microbial chassis to produce high-value and easy-separable end products may be applicable to other bioprocesses. Esters can be used as fuels and specialty chemicals for food flavoring, cosmetic and pharmaceutical industries. Here, the authors systematically engineer clostridia, including discovery and deletion of prophages to increase strain stability, for the production of butyl acetate and butyl butyrate from corn stover at low cost.
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Affiliation(s)
- Jun Feng
- Department of Biosystems Engineering, Auburn University, Auburn, AL, USA.,Center for Bioenergy and Bioproducts, Auburn University, Auburn, AL, USA
| | - Jie Zhang
- Department of Biosystems Engineering, Auburn University, Auburn, AL, USA.,Center for Bioenergy and Bioproducts, Auburn University, Auburn, AL, USA
| | - Yuechao Ma
- Department of Biosystems Engineering, Auburn University, Auburn, AL, USA.,Center for Bioenergy and Bioproducts, Auburn University, Auburn, AL, USA
| | - Yiming Feng
- Department of Food Science and Technology, Virginia Tech, Blacksburg, VA, USA
| | - Shangjun Wang
- Department of Biosystems Engineering, Auburn University, Auburn, AL, USA.,Center for Bioenergy and Bioproducts, Auburn University, Auburn, AL, USA
| | - Na Guo
- Department of Biosystems Engineering, Auburn University, Auburn, AL, USA.,Center for Bioenergy and Bioproducts, Auburn University, Auburn, AL, USA
| | - Haijiao Wang
- Department of Biosystems Engineering, Auburn University, Auburn, AL, USA.,Center for Bioenergy and Bioproducts, Auburn University, Auburn, AL, USA
| | - Pixiang Wang
- Department of Biosystems Engineering, Auburn University, Auburn, AL, USA.,Center for Bioenergy and Bioproducts, Auburn University, Auburn, AL, USA
| | - Pablo Jiménez-Bonilla
- Department of Biosystems Engineering, Auburn University, Auburn, AL, USA.,Center for Bioenergy and Bioproducts, Auburn University, Auburn, AL, USA.,School of Chemistry, National University (UNA), Heredia, Costa Rica
| | - Yanyan Gu
- Department of Biosystems Engineering, Auburn University, Auburn, AL, USA.,Center for Bioenergy and Bioproducts, Auburn University, Auburn, AL, USA
| | - Junping Zhou
- Department of Biosystems Engineering, Auburn University, Auburn, AL, USA.,Center for Bioenergy and Bioproducts, Auburn University, Auburn, AL, USA
| | - Zhong-Tian Zhang
- Department of Biosystems Engineering, Auburn University, Auburn, AL, USA.,Center for Bioenergy and Bioproducts, Auburn University, Auburn, AL, USA
| | - Mingfeng Cao
- Department of Chemical and Biological Engineering, Iowa State University, Ames, IA, USA.,NSF Engineering Research Center for Biorenewable Chemicals, Iowa State University, Ames, IA, USA
| | - Di Jiang
- Department of Applied Chemistry, University of Science and Technology of China, Hefei, China
| | - Shuning Wang
- State Key Laboratory of Microbial Technology, Microbial Technology Institute, Shandong University, Qingdao, China
| | - Xian-Wei Liu
- Department of Applied Chemistry, University of Science and Technology of China, Hefei, China
| | - Zengyi Shao
- Department of Chemical and Biological Engineering, Iowa State University, Ames, IA, USA.,NSF Engineering Research Center for Biorenewable Chemicals, Iowa State University, Ames, IA, USA
| | - Ilya Borovok
- The Shmunis School of Biomedicine and Cancer Research, Faculty of Life Sciences, Tel Aviv University, Ramat Aviv, Tel Aviv, Israel
| | - Haibo Huang
- Department of Food Science and Technology, Virginia Tech, Blacksburg, VA, USA.
| | - Yi Wang
- Department of Biosystems Engineering, Auburn University, Auburn, AL, USA. .,Center for Bioenergy and Bioproducts, Auburn University, Auburn, AL, USA.
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10
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Wang Q, Al Makishah NH, Li Q, Li Y, Liu W, Sun X, Wen Z, Yang S. Developing Clostridia as Cell Factories for Short- and Medium-Chain Ester Production. Front Bioeng Biotechnol 2021; 9:661694. [PMID: 34164382 PMCID: PMC8215697 DOI: 10.3389/fbioe.2021.661694] [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: 01/31/2021] [Accepted: 04/19/2021] [Indexed: 11/21/2022] Open
Abstract
Short- and medium-chain volatile esters with flavors and fruity fragrances, such as ethyl acetate, butyl acetate, and butyl butyrate, are usually value-added in brewing, food, and pharmacy. The esters can be naturally produced by some microorganisms. As ester-forming reactions are increasingly deeply understood, it is possible to produce esters in non-natural but more potential hosts. Clostridia are a group of important industrial microorganisms since they can produce a variety of volatile organic acids and alcohols with high titers, especially butanol and butyric acid through the CoA-dependent carbon chain elongation pathway. This implies sufficient supplies of acyl-CoA, organic acids, and alcohols in cells, which are precursors for ester production. Besides, some Clostridia could utilize lignocellulosic biomass, industrial off-gas, or crude glycerol to produce other branched or straight-chain alcohols and acids. Therefore, Clostridia offer great potential to be engineered to produce short- and medium-chain volatile esters. In the review, the efforts to produce esters from Clostridia via in vitro lipase-mediated catalysis and in vivo alcohol acyltransferase (AAT)-mediated reaction are comprehensively revisited. Besides, the advantageous characteristics of several Clostridia and clostridial consortia for bio-ester production and the driving force of synthetic biology to clostridial chassis development are also discussed. It is believed that synthetic biotechnology should enable the future development of more effective Clostridia for ester production.
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Affiliation(s)
- Qingzhuo Wang
- School of Food Science and Pharmaceutical Engineering, Nanjing Normal University, Nanjing, China
| | - Naief H Al Makishah
- Department of Environmental Sciences, Faculty of Meteorology, Environment and Arid Land Agriculture, King Abdulaziz University, Jeddah, Saudi Arabia
| | - Qi Li
- College of Life Sciences, Sichuan Normal University, Chengdu, China
| | - Yanan Li
- School of Food Science and Pharmaceutical Engineering, Nanjing Normal University, Nanjing, China
| | - Wenzheng Liu
- School of Food Science and Pharmaceutical Engineering, Nanjing Normal University, Nanjing, China
| | - Xiaoman Sun
- School of Food Science and Pharmaceutical Engineering, Nanjing Normal University, Nanjing, China
| | - Zhiqiang Wen
- School of Food Science and Pharmaceutical Engineering, Nanjing Normal University, Nanjing, China
| | - Sheng Yang
- Huzhou Center of Industrial Biotechnology, Shanghai Institutes of Biological Sciences, Chinese Academy of Sciences, Shanghai, China.,Key Laboratory of Synthetic Biology, CAS Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, China
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11
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Zhu L, Zhang J, Yang J, Jiang Y, Yang S. Strategies for optimizing acetyl-CoA formation from glucose in bacteria. Trends Biotechnol 2021; 40:149-165. [PMID: 33965247 DOI: 10.1016/j.tibtech.2021.04.004] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2020] [Revised: 04/02/2021] [Accepted: 04/02/2021] [Indexed: 12/17/2022]
Abstract
Acetyl CoA is an important precursor for various chemicals. We provide a metabolic engineering guideline for the production of acetyl-CoA and other end products from a bacterial chassis. Among 13 pathways that produce acetyl-CoA from glucose, 11 lose carbon in the process, and two do not. The first 11 use the Embden-Meyerhof-Parnas (EMP) pathway to produce redox cofactors and gain or lose ATP. The other two pathways function via phosphoketolase with net consumption of ATP, so they must therefore be combined with one of the 11 glycolytic pathways or auxiliary pathways. Optimization of these pathways can maximize the theoretical acetyl-CoA yield, thereby minimizing the overall cost of subsequent acetyl-CoA-derived molecules. Other strategies for generating hyper-producer strains are also addressed.
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Affiliation(s)
- Li Zhu
- Shanghai Laiyi Center for Biopharmaceutical R&D, Shanghai 200240, China
| | - Jieze Zhang
- Department of Chemistry, University of Southern California, Los Angeles, CA 90089, USA
| | - Jiawei Yang
- College of Life Science, University of Chinese Academy of Sciences, Beijing 100049, China; Key Laboratory of Synthetic Biology, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200032, China
| | - Yu Jiang
- Huzhou Center of Industrial Biotechnology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Huzhou 313000, China; Shanghai Taoyusheng Biotechnology Company Ltd, Shanghai 200032, China
| | - Sheng Yang
- Key Laboratory of Synthetic Biology, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200032, China; Huzhou Center of Industrial Biotechnology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Huzhou 313000, China.
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12
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Shi W, Li J, Chen Y, Liu X, Chen Y, Guo X, Xiao D. Metabolic Engineering of Saccharomyces cerevisiae for Ethyl Acetate Biosynthesis. ACS Synth Biol 2021; 10:495-504. [PMID: 33576609 DOI: 10.1021/acssynbio.0c00446] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Ethyl acetate can be synthesized from acetyl-CoA and ethanol via a reaction by alcohol acetyltransferases (AATase) in yeast. In order to increase the yield of acetyl-CoA, different terminators were used to optimize the expressions of acetyl-CoA synthetase (ACS1/2) and aldehyde dehydrogenase (ALD6) to increase the contents of acetyl-CoA in Saccharomyces cerevisiae. ATF1 coding AATase was coexpressed in expression cassettes of ACS1/ACS2 and ALD6 to promote the carbon flux toward ethyl acetate from acetyl-CoA. Further to improve ethyl acetate production, four heterologous AATase including HuvEAT1 (Hanseniaspora uvarum), KamEAT1 (Kluyveromyces marxianus), VAAT (wild strawberry), and AeAT9 (kiwifruit) were introduced. Subsequently mitochondrial transport and utilization of pyruvate and acetyl-CoA were impeded to increase the ethyl acetate accumulation in cytoplasm. Under the optimal fermentation conditions, the engineered strain of PGAeΔPOR2 produced 1.69 g/L ethyl acetate, which was the highest value reported to date by metabolic engineering methods.
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Affiliation(s)
- Wenqi Shi
- Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education, Tianjin Industrial Microbiology Key Laboratory, College of Biotechnology, Tianjin University of Science and Technology, Tianjin 300457, China
| | - Jie Li
- Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education, Tianjin Industrial Microbiology Key Laboratory, College of Biotechnology, Tianjin University of Science and Technology, Tianjin 300457, China
| | - Yanfang Chen
- Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education, Tianjin Industrial Microbiology Key Laboratory, College of Biotechnology, Tianjin University of Science and Technology, Tianjin 300457, China
| | - Xiaohang Liu
- Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education, Tianjin Industrial Microbiology Key Laboratory, College of Biotechnology, Tianjin University of Science and Technology, Tianjin 300457, China
| | - Yefu Chen
- Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education, Tianjin Industrial Microbiology Key Laboratory, College of Biotechnology, Tianjin University of Science and Technology, Tianjin 300457, China
| | - Xuewu Guo
- Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education, Tianjin Industrial Microbiology Key Laboratory, College of Biotechnology, Tianjin University of Science and Technology, Tianjin 300457, China
| | - Dongguang Xiao
- Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education, Tianjin Industrial Microbiology Key Laboratory, College of Biotechnology, Tianjin University of Science and Technology, Tianjin 300457, China
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13
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Löser C, Kupsch C, Walther T, Hoffmann A. A new approach for balancing the microbial synthesis of ethyl acetate and other volatile metabolites during aerobic bioreactor cultivations. Eng Life Sci 2021; 21:137-153. [PMID: 33716613 PMCID: PMC7923609 DOI: 10.1002/elsc.202000047] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2020] [Accepted: 10/23/2020] [Indexed: 01/05/2023] Open
Abstract
Ethyl acetate is an organic solvent with many industrial applications, currently produced by energy-intensive chemical processes based on fossil carbon resources. Ethyl acetate can be synthesized from renewable sugars by yeasts like Kluyveromyces marxianus in aerobic processes. However, ethyl acetate is highly volatile and thus stripped from aerated cultivation systems which complicate the quantification of the produced ester. Synthesis of volatile metabolites is commonly monitored by repeated analysis of metabolite concentrations in both the gas and liquid phase. In this study, a model-based method for quantifying the synthesis and degradation of volatile metabolites was developed. This quantification of volatiles is solely based on repeatedly measured gas-phase concentrations and allows calculation of reaction rates and yields in high temporal resolution. Parameters required for these calculations were determined in abiotic stripping tests. The developed method was validated for ethyl acetate, ethanol and acetaldehyde which were synthesized by K. marxianus DSM 5422 during an iron-limited batch cultivation; it was shown that the presented method is more precise and less time-consuming than the conventional method. The biomass-specific synthesis rate and the yield of ethyl acetate varied over time and exhibited distinct momentary maxima of 0.50 g g‒1h‒1 and 0.38 g g‒1 at moderate iron limitation.
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Affiliation(s)
- Christian Löser
- Chair of Bioprocess Engineering, Institute of Natural Materials TechnologyTechnische Universität DresdenDresdenGermany
| | - Christian Kupsch
- Chair of Bioprocess Engineering, Institute of Natural Materials TechnologyTechnische Universität DresdenDresdenGermany
| | - Thomas Walther
- Chair of Bioprocess Engineering, Institute of Natural Materials TechnologyTechnische Universität DresdenDresdenGermany
| | - Andreas Hoffmann
- Chair of Bioprocess Engineering, Institute of Natural Materials TechnologyTechnische Universität DresdenDresdenGermany
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14
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Hoffmann A, Kupsch C, Walther T, Löser C. Synthesis of ethyl acetate from glucose by Kluyveromyces marxianus, Cyberlindnera jadinii and Wickerhamomyces anomalus depending on the induction mode. Eng Life Sci 2021; 21:154-168. [PMID: 33716614 PMCID: PMC7923572 DOI: 10.1002/elsc.202000048] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2020] [Revised: 10/28/2020] [Accepted: 11/12/2020] [Indexed: 11/17/2022] Open
Abstract
Ethyl acetate is currently produced from fossil carbon resources. This ester could also be microbially synthesized from sugar-rich wastes of the food industry. Wild-type strains with GRAS status are preferred for such applications. Production of ethyl acetate by wild-type yeasts has been repeatedly reported, but comparative studies with several strains at various induction modes are largely missing. Here, synthesis of ethyl acetate by three yeasts with GRAS status, Kluyveromyces marxianus DSM 5422, Cyberlindnera jadinii DSM 2361 and Wickerhamomyces anomalus DSM 6766, was studied under identical and well-defined conditions in an aerated bioreactor, by inducing the ester synthesis via iron or oxygen limitation. Balancing the ester synthesis was based on measured concentrations of ethyl acetate in the exhaust gas, delivering masses of synthesized ester and synthesis rates in a high temporal resolution. All tested yeasts synthesized ethyl acetate under these conditions, but the intensity varied with the strain and induction mode. The highest yields were achieved under iron limitation with K. marxianus (0.182 g g-1) and under oxygen limitation with W. anomalus (0.053 g g-1). Iron limitation proved to be the better inducer for ester synthesis while oxygen limitation favored ethanol formation. K. marxianus DSM 5422 was the most potent producer of ethyl acetate exhibiting the highest biomass-specific synthesis rate of 0.5 g g-1h-1 under moderate iron limitation.
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Affiliation(s)
- Andreas Hoffmann
- Chair of Bioprocess EngineeringInstitute of Natural Materials TechnologyTechnische Universität DresdenDresdenGermany
| | - Christian Kupsch
- Chair of Bioprocess EngineeringInstitute of Natural Materials TechnologyTechnische Universität DresdenDresdenGermany
| | - Thomas Walther
- Chair of Bioprocess EngineeringInstitute of Natural Materials TechnologyTechnische Universität DresdenDresdenGermany
| | - Christian Löser
- Chair of Bioprocess EngineeringInstitute of Natural Materials TechnologyTechnische Universität DresdenDresdenGermany
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15
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Patinios C, Lanza L, Corino I, Franssen MCR, Van der Oost J, Weusthuis RA, Kengen SWM. Eat1-Like Alcohol Acyl Transferases From Yeasts Have High Alcoholysis and Thiolysis Activity. Front Microbiol 2020; 11:579844. [PMID: 33193208 PMCID: PMC7658179 DOI: 10.3389/fmicb.2020.579844] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2020] [Accepted: 10/09/2020] [Indexed: 11/13/2022] Open
Abstract
Esters are important flavor and fragrance compounds that are present in many food and beverage products. Many of these esters are produced by yeasts and bacteria during fermentation. While ester production in yeasts through the alcohol acyl transferase reaction has been thoroughly investigated, ester production through alcoholysis has been completely neglected. Here, we further analyze the catalytic capacity of the yeast Eat1 enzyme and demonstrate that it also has alcoholysis and thiolysis activities. Eat1 can perform alcoholysis in an aqueous environment in vitro, accepting a wide range of alcohols (C2-C10) but only a small range of acyl donors (C2-C4). We show that alcoholysis occurs in vivo in several Crabtree negative yeast species but also in engineered Saccharomyces cerevisiae strains that overexpress Eat1 homologs. The alcoholysis activity of Eat1 was also used to upgrade ethyl esters to butyl esters in vivo by overexpressing Eat1 in Clostridium beijerinckii. Approximately 17 mM of butyl acetate and 0.3 mM of butyl butyrate could be produced following our approach. Remarkably, the in vitro alcoholysis activity is 445 times higher than the previously described alcohol acyl transferase activity. Thus, alcoholysis is likely to affect the ester generation, both quantitatively and qualitatively, in food and beverage production processes. Moreover, mastering the alcoholysis activity of Eat1 may give rise to the production of novel food and beverage products.
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Affiliation(s)
- Constantinos Patinios
- Laboratory of Microbiology, Department of Agrotechnology and Food Sciences, Wageningen University and Research, Wageningen, Netherlands
- Laboratory of Bioprocess Engineering, Department of Agrotechnology and Food Sciences, Wageningen University and Research, Wageningen, Netherlands
| | - Lucrezia Lanza
- Laboratory of Microbiology, Department of Agrotechnology and Food Sciences, Wageningen University and Research, Wageningen, Netherlands
| | - Inge Corino
- Laboratory of Microbiology, Department of Agrotechnology and Food Sciences, Wageningen University and Research, Wageningen, Netherlands
| | - Maurice C. R. Franssen
- Laboratory of Organic Chemistry, Department of Agrotechnology and Food Sciences, Wageningen University and Research, Wageningen, Netherlands
| | - John Van der Oost
- Laboratory of Microbiology, Department of Agrotechnology and Food Sciences, Wageningen University and Research, Wageningen, Netherlands
| | - Ruud A. Weusthuis
- Laboratory of Bioprocess Engineering, Department of Agrotechnology and Food Sciences, Wageningen University and Research, Wageningen, Netherlands
| | - Servé W. M. Kengen
- Laboratory of Microbiology, Department of Agrotechnology and Food Sciences, Wageningen University and Research, Wageningen, Netherlands
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16
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Zhang S, Guo F, Yan W, Dong W, Zhou J, Zhang W, Xin F, Jiang M. Perspectives for the microbial production of ethyl acetate. Appl Microbiol Biotechnol 2020; 104:7239-7245. [PMID: 32656615 DOI: 10.1007/s00253-020-10756-z] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2020] [Revised: 06/13/2020] [Accepted: 06/24/2020] [Indexed: 12/21/2022]
Abstract
Ethyl acetate is one of the short-chain esters and widely used in the food, beverage, and solvent areas. The ethyl acetate production currently proceeds through unsustainable and energy intensive processes, which are based on natural gas and crude oil. Microbial conversion of biomass-derived sugars into ethyl acetate may provide a sustainable alternative. In this review, the perspectives of bio-catalyzing ethanol and acetic acid to ethyl acetate using lipases in vitro was introduced. Besides, the crucial elements for high yield of ethyl acetate in fermentation was expounded. Also, metabolic engineering in yeasts to product ethyl acetate in vivo using alcohol acyl transferases (AAT) was discussed. KEY POINTS: •The accumulation of acetyl-CoA is crucial for synthesizing ethyl acetate in vivo; AAT-mediated metabolic engineering could efficiently improve ethyl acetate production.
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Affiliation(s)
- Shangjie Zhang
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Puzhu South Road 30#, Nanjing, 211800, People's Republic of China
| | - Feng Guo
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Puzhu South Road 30#, Nanjing, 211800, People's Republic of China
| | - Wei Yan
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Puzhu South Road 30#, Nanjing, 211800, 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, 211800, People's Republic of China.,Jiangsu National Synergetic Innovation Center for Advanced Materials (SICAM), Nanjing Tech University, Nanjing, 211800, People's Republic of China
| | - Jie Zhou
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Puzhu South Road 30#, Nanjing, 211800, People's Republic of China.,Jiangsu National Synergetic Innovation Center for Advanced Materials (SICAM), Nanjing Tech University, Nanjing, 211800, 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, 211800, People's Republic of China. .,Jiangsu National Synergetic Innovation Center for Advanced Materials (SICAM), Nanjing Tech University, Nanjing, 211800, 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, 211800, People's Republic of China. .,Jiangsu National Synergetic Innovation Center for Advanced Materials (SICAM), Nanjing Tech University, Nanjing, 211800, 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, 211800, People's Republic of China.,Jiangsu National Synergetic Innovation Center for Advanced Materials (SICAM), Nanjing Tech University, Nanjing, 211800, People's Republic of China
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