101
|
Hoff B, Plassmeier J, Blankschien M, Letzel A, Kourtz L, Schröder H, Koch W, Zelder O. Unlocking Nature's Biosynthetic Power—Metabolic Engineering for the Fermentative Production of Chemicals. Angew Chem Int Ed Engl 2020. [DOI: 10.1002/ange.202004248] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Affiliation(s)
- Birgit Hoff
- RBW, White Biotechnology Research BASF SE building: A30, Carl-Bosch-Strasse 38 67056 Ludwigshafen am Rhein Germany
| | - Jens Plassmeier
- Biomaterials Conagen, Inc. 15 DeAngelo Drive 01730 Bedford, MA USA
| | - Matthew Blankschien
- James R. Randall Research Center ADM 1001 North Brush College Road 62521 Decatur, Il USA
| | - Anne‐Catrin Letzel
- RBW, White Biotechnology Research BASF SE building: A30, Carl-Bosch-Strasse 38 67056 Ludwigshafen am Rhein Germany
| | - Lauralynn Kourtz
- R&D Allied Microbiota 1345 Ave of Americas 10105 New York, NY USA
| | - Hartwig Schröder
- RBW, White Biotechnology Research BASF SE building: A30, Carl-Bosch-Strasse 38 67056 Ludwigshafen am Rhein Germany
| | - Walter Koch
- RBW, White Biotechnology Research BASF SE building: A30, Carl-Bosch-Strasse 38 67056 Ludwigshafen am Rhein Germany
| | - Oskar Zelder
- RBW, White Biotechnology Research BASF SE building: A30, Carl-Bosch-Strasse 38 67056 Ludwigshafen am Rhein Germany
| |
Collapse
|
102
|
Cascaded valorization of seaweed using microbial cell factories. Curr Opin Biotechnol 2020; 65:102-113. [DOI: 10.1016/j.copbio.2020.02.008] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2020] [Revised: 02/14/2020] [Accepted: 02/17/2020] [Indexed: 11/17/2022]
|
103
|
Sun L, Gong M, Lv X, Huang Z, Gu Y, Li J, Du G, Liu L. Current advance in biological production of short-chain organic acid. Appl Microbiol Biotechnol 2020; 104:9109-9124. [DOI: 10.1007/s00253-020-10917-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2020] [Revised: 09/14/2020] [Accepted: 09/17/2020] [Indexed: 12/31/2022]
|
104
|
Filipowicz N, Momotko M, Boczkaj G, Cieśliński H. Determination of phenol biodegradation pathways in three psychrotolerant yeasts, Candida subhashii A01 1, Candida oregonensis B02 1 and Schizoblastosporion starkeyi-henricii L01 2, isolated from Rucianka peatland. Enzyme Microb Technol 2020; 141:109663. [PMID: 33051016 PMCID: PMC7474889 DOI: 10.1016/j.enzmictec.2020.109663] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2020] [Revised: 08/21/2020] [Accepted: 09/02/2020] [Indexed: 02/02/2023]
Abstract
In this study, three psychrotolerant phenol-degrading yeast strains Candida subhashii (strain A011), Candida oregonenis (strain B021) and Schizoblastosporion starkeyi-henricii (strain L012) isolated from Rucianka peatland were examined to determine which alternative metabolic pathway for phenol biodegradation is used by these microorganisms. All yeast strains were cultivated in minimal salt medium supplemented with phenol at 500, 750 and 1000 mg l-1 concentration with two ways of conducting phenol biodegradation experiments: with and without the starving step of yeast cells. For studied yeast strains, no catechol 2,3-dioxygenase activities were detected by enzymatic assay and no products of catechol meta-cleavage in yeast cultures supernatants (GC-MS analysis), were detected. The detection of catechol 1,2-dioxygenase activity and the presence of cis,cis-muconic acid in the analyzed samples revealed that all studied psychrotolerant yeast strains were able to metabolize phenol via the ortho-cleavage pathway. Therefore, they may be tested in terms of their use to develop biotechnology for the production of cis,cis-muconic acid, a substrate used in the production of plastics (PET) and other valuable goods.
Collapse
Affiliation(s)
- Natalia Filipowicz
- Department of Molecular Biotechnology and Microbiology, Gdańsk University of Technology, Narutowicza 11/12, 80-233 Gdańsk, Poland.
| | - Malwina Momotko
- Department of Process Engineering and Chemical Technology, Gdańsk University of Technology, Narutowicza 11/12, 80-233 Gdańsk, Poland.
| | - Grzegorz Boczkaj
- Department of Process Engineering and Chemical Technology, Gdańsk University of Technology, Narutowicza 11/12, 80-233 Gdańsk, Poland.
| | - Hubert Cieśliński
- Department of Molecular Biotechnology and Microbiology, Gdańsk University of Technology, Narutowicza 11/12, 80-233 Gdańsk, Poland.
| |
Collapse
|
105
|
Weimer A, Kohlstedt M, Volke DC, Nikel PI, Wittmann C. Industrial biotechnology of Pseudomonas putida: advances and prospects. Appl Microbiol Biotechnol 2020; 104:7745-7766. [PMID: 32789744 PMCID: PMC7447670 DOI: 10.1007/s00253-020-10811-9] [Citation(s) in RCA: 91] [Impact Index Per Article: 22.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2020] [Revised: 07/23/2020] [Accepted: 08/02/2020] [Indexed: 11/17/2022]
Abstract
Pseudomonas putida is a Gram-negative, rod-shaped bacterium that can be encountered in diverse ecological habitats. This ubiquity is traced to its remarkably versatile metabolism, adapted to withstand physicochemical stress, and the capacity to thrive in harsh environments. Owing to these characteristics, there is a growing interest in this microbe for industrial use, and the corresponding research has made rapid progress in recent years. Hereby, strong drivers are the exploitation of cheap renewable feedstocks and waste streams to produce value-added chemicals and the steady progress in genetic strain engineering and systems biology understanding of this bacterium. Here, we summarize the recent advances and prospects in genetic engineering, systems and synthetic biology, and applications of P. putida as a cell factory. KEY POINTS: • Pseudomonas putida advances to a global industrial cell factory. • Novel tools enable system-wide understanding and streamlined genomic engineering. • Applications of P. putida range from bioeconomy chemicals to biosynthetic drugs.
Collapse
Affiliation(s)
- Anna Weimer
- Institute of Systems Biotechnology, Saarland University, Campus A1.5, 66123, Saarbrücken, Germany
| | - Michael Kohlstedt
- Institute of Systems Biotechnology, Saarland University, Campus A1.5, 66123, Saarbrücken, Germany
| | - Daniel C Volke
- The Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, Lyngby, Denmark
| | - Pablo I Nikel
- The Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, Lyngby, Denmark
| | - Christoph Wittmann
- Institute of Systems Biotechnology, Saarland University, Campus A1.5, 66123, Saarbrücken, Germany.
| |
Collapse
|
106
|
Mohamed ET, Werner AZ, Salvachúa D, Singer CA, Szostkiewicz K, Rafael Jiménez-Díaz M, Eng T, Radi MS, Simmons BA, Mukhopadhyay A, Herrgård MJ, Singer SW, Beckham GT, Feist AM. Adaptive laboratory evolution of Pseudomonas putida KT2440 improves p-coumaric and ferulic acid catabolism and tolerance. Metab Eng Commun 2020; 11:e00143. [PMID: 32963959 PMCID: PMC7490845 DOI: 10.1016/j.mec.2020.e00143] [Citation(s) in RCA: 50] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2020] [Revised: 08/05/2020] [Accepted: 08/20/2020] [Indexed: 01/27/2023] Open
Abstract
Pseudomonas putida KT2440 is a promising bacterial chassis for the conversion of lignin-derived aromatic compound mixtures to biofuels and bioproducts. Despite the inherent robustness of this strain, further improvements to aromatic catabolism and toxicity tolerance of P. putida will be required to achieve industrial relevance. Here, tolerance adaptive laboratory evolution (TALE) was employed with increasing concentrations of the hydroxycinnamic acids p-coumaric acid (pCA) and ferulic acid (FA) individually and in combination (pCA + FA). The TALE experiments led to evolved P. putida strains with increased tolerance to the targeted acids as compared to wild type. Specifically, a 37 h decrease in lag phase in 20 g/L pCA and a 2.4-fold increase in growth rate in 30 g/L FA was observed. Whole genome sequencing of intermediate and endpoint evolved P. putida populations revealed several expected and non-intuitive genetic targets underlying these aromatic catabolic and toxicity tolerance enhancements. PP_3350 and ttgB were among the most frequently mutated genes, and the beneficial contributions of these mutations were verified via gene knockouts. Deletion of PP_3350, encoding a hypothetical protein, recapitulated improved toxicity tolerance to high concentrations of pCA, but not an improved growth rate in high concentrations of FA. Deletion of ttgB, part of the TtgABC efflux pump, severely inhibited growth in pCA + FA TALE-derived strains but did not affect growth in pCA + FA in a wild type background, suggesting epistatic interactions. Genes involved in flagellar movement and transcriptional regulation were often mutated in the TALE experiments on multiple substrates, reinforcing ideas of a minimal and deregulated cell as optimal for domesticated growth. Overall, this work demonstrates increased tolerance towards and growth rate at the expense of hydroxycinnamic acids and presents new targets for improving P. putida for microbial lignin valorization. Pseudomonas putida was evolved in increasing hydroxycinnamic acid concentrations. The lag phase in high p-coumaric acid concentration was reduced. The growth rate and tolerance to high ferulic acid concentration was increased. PP_3350 and ttgB contribute to the observed phenotypes.
Collapse
Affiliation(s)
- Elsayed T Mohamed
- Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, Lyngby, Denmark
| | - Allison Z Werner
- Renewable Resources and Enabling Sciences Center, National Renewable Energy Laboratory, Golden, CO, USA.,Center for Bioenergy Innovation, Oak Ridge, TN, USA
| | - Davinia Salvachúa
- Renewable Resources and Enabling Sciences Center, National Renewable Energy Laboratory, Golden, CO, USA
| | - Christine A Singer
- Renewable Resources and Enabling Sciences Center, National Renewable Energy Laboratory, Golden, CO, USA
| | - Kiki Szostkiewicz
- Renewable Resources and Enabling Sciences Center, National Renewable Energy Laboratory, Golden, CO, USA
| | - Manuel Rafael Jiménez-Díaz
- Joint BioEnergy Institute, Emeryville, CA, USA.,Biological Systems and Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Thomas Eng
- Joint BioEnergy Institute, Emeryville, CA, USA.,Biological Systems and Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Mohammad S Radi
- Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, Lyngby, Denmark
| | - Blake A Simmons
- Joint BioEnergy Institute, Emeryville, CA, USA.,Biological Systems and Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Aindrila Mukhopadhyay
- Joint BioEnergy Institute, Emeryville, CA, USA.,Biological Systems and Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Markus J Herrgård
- Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, Lyngby, Denmark
| | - Steven W Singer
- Joint BioEnergy Institute, Emeryville, CA, USA.,Biological Systems and Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Gregg T Beckham
- Renewable Resources and Enabling Sciences Center, National Renewable Energy Laboratory, Golden, CO, USA.,Center for Bioenergy Innovation, Oak Ridge, TN, USA
| | - Adam M Feist
- Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, Lyngby, Denmark.,Joint BioEnergy Institute, Emeryville, CA, USA.,Department of Bioengineering, University of California, San Diego, CA, USA
| |
Collapse
|
107
|
Choi S, Lee HN, Park E, Lee SJ, Kim ES. Recent Advances in Microbial Production of cis,cis-Muconic Acid. Biomolecules 2020; 10:biom10091238. [PMID: 32854378 PMCID: PMC7564838 DOI: 10.3390/biom10091238] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2020] [Revised: 08/20/2020] [Accepted: 08/20/2020] [Indexed: 02/06/2023] Open
Abstract
cis,cis-Muconic acid (MA) is a valuable C6 dicarboxylic acid platform chemical that is used as a starting material for the production of various valuable polymers and drugs, including adipic acid and terephthalic acid. As an alternative to traditional chemical processes, bio-based MA production has progressed to the establishment of de novo MA pathways in several microorganisms, such as Escherichia coli, Corynebacterium glutamicum, Pseudomonas putida, and Saccharomyces cerevisiae. Redesign of the metabolic pathway, intermediate flux control, and culture process optimization were all pursued to maximize the microbial MA production yield. Recently, MA production from biomass, such as the aromatic polymer lignin, has also attracted attention from researchers focusing on microbes that are tolerant to aromatic compounds. This paper summarizes recent microbial MA production strategies that involve engineering the metabolic pathway genes as well as the heterologous expression of some foreign genes involved in MA biosynthesis. Microbial MA production will continue to play a vital role in the field of bio-refineries and a feasible way to complement various petrochemical-based chemical processes.
Collapse
Affiliation(s)
- Sisun Choi
- Department of Biological Engineering, Inha University, Incheon 22212, Korea; (S.C.); (H.-N.L.); (E.P.)
| | - Han-Na Lee
- Department of Biological Engineering, Inha University, Incheon 22212, Korea; (S.C.); (H.-N.L.); (E.P.)
- STR Biotech Co., Ltd., Chuncheon-si, Gangwon-do 24232, Korea;
| | - Eunhwi Park
- Department of Biological Engineering, Inha University, Incheon 22212, Korea; (S.C.); (H.-N.L.); (E.P.)
| | - Sang-Jong Lee
- STR Biotech Co., Ltd., Chuncheon-si, Gangwon-do 24232, Korea;
| | - Eung-Soo Kim
- Department of Biological Engineering, Inha University, Incheon 22212, Korea; (S.C.); (H.-N.L.); (E.P.)
- Correspondence: ; Tel.: +82-32-860-8318; Fax: +82-32-872-4046
| |
Collapse
|
108
|
Otto M, Wynands B, Marienhagen J, Blank LM, Wierckx N. Benzoate Synthesis from Glucose or Glycerol Using Engineered
Pseudomonas taiwanensis. Biotechnol J 2020; 15:e2000211. [DOI: 10.1002/biot.202000211] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2020] [Revised: 06/25/2020] [Indexed: 12/27/2022]
Affiliation(s)
- Maike Otto
- Institute of Bio‐ and Geosciences (IBG‐1: Biotechnology) Forschungszentrum Jülich GmbH Jülich 52425 Germany
| | - Benedikt Wynands
- Institute of Bio‐ and Geosciences (IBG‐1: Biotechnology) Forschungszentrum Jülich GmbH Jülich 52425 Germany
| | - Jan Marienhagen
- Institute of Bio‐ and Geosciences (IBG‐1: Biotechnology) Forschungszentrum Jülich GmbH Jülich 52425 Germany
- Institute of Biotechnology RWTH Aachen University Aachen 52074 Germany
| | - Lars M. Blank
- Institute of Applied Microbiology RWTH Aachen University Aachen 52074 Germany
| | - Nick Wierckx
- Institute of Bio‐ and Geosciences (IBG‐1: Biotechnology) Forschungszentrum Jülich GmbH Jülich 52425 Germany
| |
Collapse
|
109
|
Singhvi M, Kim BS. Lignin valorization using biological approach. Biotechnol Appl Biochem 2020; 68:459-468. [PMID: 32725827 DOI: 10.1002/bab.1995] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Accepted: 07/27/2020] [Indexed: 11/06/2022]
Abstract
Due to the structural complexity and recalcitrance nature of lignin, its depolymerization into monomeric units becomes one of the biggest challenges in the bioconversion of lignin into value-added products. Depolymerization of lignin produces a blend of many compounds that are problematic for isolating components in a cost-effective way. Lignin valorization using a biological approach facilitates sustainable and commercially viable biorefineries. The use of microbes for the conversion of depolymerized lignin compounds into target products can be a solution to the heterogeneity issue. Several studies have been carried out to develop robust strains that can utilize all relevant lignin-derived compounds, but constructing these strains is difficult. As an alternative, designing multiple microbes to convert a mixture of various compounds into the desired product seems realistic. This review provides an overview of lignin bioconversion using various approaches such as metabolic engineering and synthetic biology. Ligninolytic strains have a broad enzymatic machine for depolymerization of lignin and its conversion into intermediates such as catechol or protocatechuate. These intermediates can be further converted to metabolite products such as polyhydroxyalkanoates and triacylglycerol. Synthetic biology offers encouraging methodologies to construct pathways for lignin conversion and to engineer ligninolytic microbes as prospective strains for lignin bioconversion.
Collapse
Affiliation(s)
- Mamata Singhvi
- Department of Chemical Engineering, Chungbuk National University, Cheongju, Chungbuk, Republic of Korea
| | - Beom Soo Kim
- Department of Chemical Engineering, Chungbuk National University, Cheongju, Chungbuk, Republic of Korea
| |
Collapse
|
110
|
Fully biological production of adipic acid analogs from branched catechols. Sci Rep 2020; 10:13367. [PMID: 32770001 PMCID: PMC7414886 DOI: 10.1038/s41598-020-70158-z] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2020] [Accepted: 07/20/2020] [Indexed: 01/02/2023] Open
Abstract
Microbial production of adipic acid from lignin-derived monomers, such as catechol, is a greener alternative to the petrochemical-based process. Here, we produced adipic acid from catechol using catechol 1,2-dioxygenase (CatA) and a muconic acid reductase (MAR) in Escherichia coli. As the reaction progressed, the pH of the media dropped from 7 to 4-5 and the muconic acid isomerized from the cis,cis (ccMA) to the cis,trans (ctMA) isomer. Feeding experiments suggested that cells preferentially uptook ctMA and that MAR efficiently reduced all muconic isomers to adipic acid. Intrigued by the substrate promiscuity of MAR, we probed its utility to produce branched chiral diacids. Using branched catechols likely found in pretreated lignin, we found that while MAR fully reduced 2-methyl-muconic acid to 2-methyl-adipic acid, MAR reduced only one double bond in 3-substituted muconic acids. In the future, MAR's substrate promiscuity could be leveraged to produce chiral-branched adipic acid analogs to generate branched, nylon-like polymers with reduced crystallinity.
Collapse
|
111
|
Mendonca CM, Wilkes RA, Aristilde L. Advancements in 13C isotope tracking of synergistic substrate co-utilization in Pseudomonas species and implications for biotechnology applications. Curr Opin Biotechnol 2020; 64:124-133. [DOI: 10.1016/j.copbio.2020.02.004] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2020] [Revised: 02/07/2020] [Accepted: 02/07/2020] [Indexed: 12/16/2022]
|
112
|
Wang Y, Liu Y, Zheng P, Sun J, Wang M. Microbial Base Editing: A Powerful Emerging Technology for Microbial Genome Engineering. Trends Biotechnol 2020; 39:165-180. [PMID: 32680590 DOI: 10.1016/j.tibtech.2020.06.010] [Citation(s) in RCA: 37] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2020] [Revised: 06/16/2020] [Accepted: 06/17/2020] [Indexed: 02/08/2023]
Abstract
Genome engineering is crucial for answering fundamental questions about, and exploring practical applications of, microorganisms. Various microbial genome-engineering tools, including CRISPR/Cas-enhanced homologous recombination (HR), have been developed, with ever-improving simplicity, efficiency, and applicability. Recently, a powerful emerging technology based on CRISPR/Cas-nucleobase deaminase fusions, known as base editing, opened new avenues for microbial genome engineering. Base editing enables nucleotide transition without inducing lethal double-stranded (ds)DNA cleavage, adding foreign donor DNA, or depending on inefficient HR. Here, we review ongoing efforts to develop and apply base editing to engineer industrially and clinically relevant microorganisms. We also summarize bioinformatics tools that would greatly facilitate guide (g)RNA design and sequencing data analysis and discuss the future challenges and prospects associated with this technology.
Collapse
Affiliation(s)
- Yu Wang
- Key Laboratory of Systems Microbial Biotechnology, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, China.
| | - Ye Liu
- Key Laboratory of Systems Microbial Biotechnology, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, China
| | - Ping Zheng
- Key Laboratory of Systems Microbial Biotechnology, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, China
| | - Jibin Sun
- Key Laboratory of Systems Microbial Biotechnology, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, China
| | - Meng Wang
- Key Laboratory of Systems Microbial Biotechnology, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, China.
| |
Collapse
|
113
|
Common problems associated with the microbial productions of aromatic compounds and corresponding metabolic engineering strategies. Biotechnol Adv 2020; 41:107548. [DOI: 10.1016/j.biotechadv.2020.107548] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2019] [Revised: 04/06/2020] [Accepted: 04/08/2020] [Indexed: 01/06/2023]
|
114
|
Morales GM, Ali SS, Si H, Zhang W, Zhang R, Hosseini K, Sun J, Zhu D. Acidic Versus Alkaline Bacterial Degradation of Lignin Through Engineered Strain E. coli BL21(Lacc): Exploring the Differences in Chemical Structure, Morphology, and Degradation Products. Front Bioeng Biotechnol 2020; 8:671. [PMID: 32714907 PMCID: PMC7344149 DOI: 10.3389/fbioe.2020.00671] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2020] [Accepted: 05/29/2020] [Indexed: 11/30/2022] Open
Abstract
There is increasing interest in research on lignin biodegradation compounds as potential building blocks in applications related to renewable products. More attention is necessary to evaluate the effects of the initial pH conditions during the bacterial degradation of lignin. In this study we performed experiments on lignin biodegradation under acidic and mild alkaline conditions. For acidic biodegradation, lignin was chemically pretreated with hydrogen peroxide. Alkaline biodegradation was achieved by developing the bacterial growth on Luria and Bertani medium with alkali lignin as the sole carbon source. The mutant strain Escherichia coli BL21(Lacc) was used to carry out lignin biodegradation over 10 days of incubation. Results demonstrated that under acidic conditions there was a predominance of aliphatic compounds of the C3–C4 type. Alkaline biodegradation was produced in the context of oxidative stress, with a greater abundance of aryl compounds. The final pH values of acidic and alkaline biodegradation of lignin were 2.53 and 7.90, respectively. The results of the gas chromatography mass spectrometry analysis detected compounds such as crotonic acid, lactic acid and 3-hydroxybutanoic acid for acidic conditions, with potential applications for adhesives and polymer precursors. Under alkaline conditions, detected compounds included 2-phenylethanol and dehydroabietic acid, with potential applications for perfumery and anti tumor/anti-inflammatory medications. Size-exclusion chromatography analysis showed that the weight-average molecular weight of the alkaline biodegraded lignin increased by 6.75-fold compared to the acidic method, resulting in a repolymerization of its molecular structure. Lignin repolymerization coincided with an increase in the relative abundance of dehydroabietic acid and isovanillyl alcohol, from 2.70 and 3.96% on day zero to 13.43 and 10.26% on 10th day. The results of the Fourier-transformed Infrared spectroscopy detected the presence of C = O bond and OH functional group associated with carboxylic acids in the acidic method. In the alkaline method there was a greater preponderance of signals related to skeletal aromatic structures, the amine functional group and the C – O – bond. Lignin biodegradation products from E. coli BL21(Lacc), under different initial pH conditions, demonstrated a promising potential to enlarge the spectrum of renewable products for biorefinery activities.
Collapse
Affiliation(s)
- Gabriel Murillo Morales
- Biofuels Institute, School of Environmental Science and Safety Engineering, Jiangsu University, Zhenjiang, China
| | - Sameh S Ali
- Biofuels Institute, School of Environmental Science and Safety Engineering, Jiangsu University, Zhenjiang, China.,State Key Laboratory of Applied Microbiology Southern China, Guangdong Provincial Key Laboratory of Microbial Culture Collection and Application, Guangdong Open Laboratory of Applied Microbiology, Guangdong Institute of Microbiology, Guangdong Academy of Sciences, Guangzhou, China
| | - Haibing Si
- Biofuels Institute, School of Environmental Science and Safety Engineering, Jiangsu University, Zhenjiang, China
| | - Weimin Zhang
- Botany Department, Faculty of Science, Tanta University, Tanta, Egypt
| | - Rongxian Zhang
- School of Chemistry and Chemical Engineering, Jiangsu University, Zhenjiang, China
| | - Keyvan Hosseini
- School of Public Affairs, University of Science and Technology of China, Hefei, China
| | - Jianzhong Sun
- Biofuels Institute, School of Environmental Science and Safety Engineering, Jiangsu University, Zhenjiang, China
| | - Daochen Zhu
- Biofuels Institute, School of Environmental Science and Safety Engineering, Jiangsu University, Zhenjiang, China.,Botany Department, Faculty of Science, Tanta University, Tanta, Egypt
| |
Collapse
|
115
|
Zhu D, Adebisi WA, Ahmad F, Sethupathy S, Danso B, Sun J. Recent Development of Extremophilic Bacteria and Their Application in Biorefinery. Front Bioeng Biotechnol 2020; 8:483. [PMID: 32596215 PMCID: PMC7303364 DOI: 10.3389/fbioe.2020.00483] [Citation(s) in RCA: 46] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2020] [Accepted: 04/27/2020] [Indexed: 12/22/2022] Open
Abstract
The biorefining technology for biofuels and chemicals from lignocellulosic biomass has made great progress in the world. However, mobilization of laboratory research toward industrial setup needs to meet a series of criteria, including the selection of appropriate pretreatment technology, breakthrough in enzyme screening, pathway optimization, and production technology, etc. Extremophiles play an important role in biorefinery by providing novel metabolic pathways and catalytically stable/robust enzymes that are able to act as biocatalysts under harsh industrial conditions on their own. This review summarizes the potential application of thermophilic, psychrophilic alkaliphilic, acidophilic, and halophilic bacteria and extremozymes in the pretreatment, saccharification, fermentation, and lignin valorization process. Besides, the latest studies on the engineering bacteria of extremophiles using metabolic engineering and synthetic biology technologies for high-efficiency biofuel production are also introduced. Furthermore, this review explores the comprehensive application potential of extremophiles and extremozymes in biorefinery, which is partly due to their specificity and efficiency, and points out the necessity of accelerating the commercialization of extremozymes.
Collapse
Affiliation(s)
- Daochen Zhu
- Biofuels Institute, School of the Environment and Safety Engineering, Jiangsu University, Zhenjiang, China
- State Key Laboratory of Applied Microbiology Southern China, Guangdong Provincial Key Laboratory of Microbial Culture Collection and Application, Guangdong Open Laboratory of Applied Microbiology, Guangdong Institute of Microbiology, Guangzhou, China
| | - Wasiu Adewale Adebisi
- Biofuels Institute, School of the Environment and Safety Engineering, Jiangsu University, Zhenjiang, China
| | - Fiaz Ahmad
- Biofuels Institute, School of the Environment and Safety Engineering, Jiangsu University, Zhenjiang, China
| | - Sivasamy Sethupathy
- Biofuels Institute, School of the Environment and Safety Engineering, Jiangsu University, Zhenjiang, China
| | - Blessing Danso
- Biofuels Institute, School of the Environment and Safety Engineering, Jiangsu University, Zhenjiang, China
| | - Jianzhong Sun
- Biofuels Institute, School of the Environment and Safety Engineering, Jiangsu University, Zhenjiang, China
| |
Collapse
|
116
|
Gonçalves CC, Bruce T, Silva CDOG, Fillho EXF, Noronha EF, Carlquist M, Parachin NS. Bioprospecting Microbial Diversity for Lignin Valorization: Dry and Wet Screening Methods. Front Microbiol 2020; 11:1081. [PMID: 32582068 PMCID: PMC7295907 DOI: 10.3389/fmicb.2020.01081] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2020] [Accepted: 04/30/2020] [Indexed: 01/02/2023] Open
Abstract
Lignin is an abundant cell wall component, and it has been used mainly for generating steam and electricity. Nevertheless, lignin valorization, i.e. the conversion of lignin into high value-added fuels, chemicals, or materials, is crucial for the full implementation of cost-effective lignocellulosic biorefineries. From this perspective, rapid screening methods are crucial for time- and resource-efficient development of novel microbial strains and enzymes with applications in the lignin biorefinery. The present review gives an overview of recent developments and applications of a vast arsenal of activity and sequence-based methodologies for uncovering novel microbial strains with ligninolytic potential, novel enzymes for lignin depolymerization and for unraveling the main metabolic routes during growth on lignin. Finally, perspectives on the use of each of the presented methods and their respective advantages and disadvantages are discussed.
Collapse
Affiliation(s)
- Carolyne Caetano Gonçalves
- Department of Genomic Science and Biotechnology, Universidade Católica de Brasília - UCB, Brasília, Brazil
| | - Thiago Bruce
- Department of Genomic Science and Biotechnology, Universidade Católica de Brasília - UCB, Brasília, Brazil
| | | | | | - Eliane Ferreira Noronha
- Laboratory of Enzymology, Department of Cellular Biology, University of Brasília, Brasília, Brazil
| | - Magnus Carlquist
- Division of Applied Microbiology, Department of Chemistry, Faculty of Engineering, Lund University, Lund, Sweden
| | - Nádia Skorupa Parachin
- Department of Genomic Science and Biotechnology, Universidade Católica de Brasília - UCB, Brasília, Brazil
| |
Collapse
|
117
|
Loeschcke A, Thies S. Engineering of natural product biosynthesis in Pseudomonas putida. Curr Opin Biotechnol 2020; 65:213-224. [PMID: 32498036 DOI: 10.1016/j.copbio.2020.03.007] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2020] [Revised: 03/01/2020] [Accepted: 03/30/2020] [Indexed: 01/03/2023]
Affiliation(s)
- Anita Loeschcke
- Institute of Molecular Enzyme Technology, Heinrich-Heine-University Düsseldorf, Germany.
| | - Stephan Thies
- Institute of Molecular Enzyme Technology, Heinrich-Heine-University Düsseldorf, Germany.
| |
Collapse
|
118
|
Weiss R, Guebitz GM, Pellis A, Nyanhongo GS. Harnessing the Power of Enzymes for Tailoring and Valorizing Lignin. Trends Biotechnol 2020; 38:1215-1231. [PMID: 32423726 DOI: 10.1016/j.tibtech.2020.03.010] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2019] [Revised: 03/17/2020] [Accepted: 03/19/2020] [Indexed: 02/07/2023]
Abstract
Lignin, a structural component of lignocellulosic plants, is an alternative raw material with enormous potential to replace diminishing fossil-based resources for the sustainable production of many chemicals and materials. Unfortunately, lignin's heterogeneity, low reactivity, and strong intra- and intermolecular hydrogen interactions and modifications introduced during the pulping process present significant technical challenges. However, the increasing ability to tailor lignin biosynthesis pathways by targeting enzymes and the continued discovery of more robust biocatalysts are enabling the synthesis of novel valuable products. This review summarizes how enzymes involved in lignin biosynthesis pathways and microbial enzymes are being harnessed to produce chemicals and materials and to upgrade lignin properties for the synthesis of a variety of value-added lignin industrial products.
Collapse
Affiliation(s)
- Renate Weiss
- University of Natural Resources and Life Sciences, Vienna, Institute of Environmental Biotechnology, Konrad Lorenz Straße 20, 3430, Tulln an der Donau, Austria
| | - Georg M Guebitz
- University of Natural Resources and Life Sciences, Vienna, Institute of Environmental Biotechnology, Konrad Lorenz Straße 20, 3430, Tulln an der Donau, Austria; Austrian Centre for Industrial Biotechnology (ACIB), Konrad Lorenz Strasse 20, 3430, Tulln an der Donau, Austria
| | - Alessandro Pellis
- University of Natural Resources and Life Sciences, Vienna, Institute of Environmental Biotechnology, Konrad Lorenz Straße 20, 3430, Tulln an der Donau, Austria
| | - Gibson S Nyanhongo
- University of Natural Resources and Life Sciences, Vienna, Institute of Environmental Biotechnology, Konrad Lorenz Straße 20, 3430, Tulln an der Donau, Austria; Austrian Centre for Industrial Biotechnology (ACIB), Konrad Lorenz Strasse 20, 3430, Tulln an der Donau, Austria.
| |
Collapse
|
119
|
Tailoring microbes to upgrade lignin. Curr Opin Chem Biol 2020; 59:23-29. [PMID: 32388219 DOI: 10.1016/j.cbpa.2020.04.001] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2020] [Revised: 03/31/2020] [Accepted: 04/01/2020] [Indexed: 12/16/2022]
Abstract
Lignin depolymerization generates a mixture of numerous compounds that are difficult to separate cost-effectively. To address this heterogeneity issue, microbes have been employed to 'biologically funnel' a broad range of compounds present in depolymerized lignin into common central metabolites that can be converted into a single desirable product. Because the composition of depolymerized lignin varies significantly with the type of biomass and the depolymerization method, microbes should be selected and engineered by considering this compositional variation. An ideal microbe must efficiently metabolize all relevant lignin-derived compounds regardless of the compositional variation of feedstocks, but discovering or developing such a perfect microbe is very challenging. Instead, developing multiple tailored microbes to tolerate a given mixture of lignin-derived compounds and to convert most of these into a target product is more practical. This review summarizes recent progress toward the development of such microbes for lignin valorization and offers future directions.
Collapse
|
120
|
Niu W, Willett H, Mueller J, He X, Kramer L, Ma B, Guo J. Direct biosynthesis of adipic acid from lignin-derived aromatics using engineered Pseudomonas putida KT2440. Metab Eng 2020; 59:151-161. [DOI: 10.1016/j.ymben.2020.02.006] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2019] [Revised: 02/24/2020] [Accepted: 02/25/2020] [Indexed: 11/28/2022]
|
121
|
Sun L, Alper HS. Non-conventional hosts for the production of fuels and chemicals. Curr Opin Chem Biol 2020; 59:15-22. [PMID: 32348879 DOI: 10.1016/j.cbpa.2020.03.004] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2020] [Revised: 03/18/2020] [Accepted: 03/25/2020] [Indexed: 12/16/2022]
Abstract
Biotechnology offers a green alternative for the production of fuels and chemicals using microbes. Although traditional model hosts such as Escherichia coli and Saccharomyces cerevisiae have been widely studied and used, they may not be the best hosts for industrial application. In this review, we explore recent advances in the use of nonconventional hosts for the production of a variety of fuel, cosmetics, perfumes, food, and pharmaceuticals. Specifically, we highlight twenty-seven popular molecules with a special focus on recent progress and metabolic engineering strategies to enable improved production of fuels and chemicals. These examples demonstrate the promise of nonconventional host engineering.
Collapse
Affiliation(s)
- Lichao Sun
- Institute of Food Science and Technology, Chinese Academy of Agricultural Sciences, Beijing, 100193, People's Republic of China
| | - Hal S Alper
- Institute for Cellular and Molecular Biology, The University of Texas at Austin, 2500 Speedway Avenue, Austin, TX, 78712, United States; McKetta Department of Chemical Engineering, The University of Texas at Austin, 200 E Dean Keeton St. Stop C0400, Austin, TX, 78712, United States.
| |
Collapse
|
122
|
Nitschel R, Ankenbauer A, Welsch I, Wirth NT, Massner C, Ahmad N, McColm S, Borges F, Fotheringham I, Takors R, Blombach B. Engineering Pseudomonas putida KT2440 for the production of isobutanol. Eng Life Sci 2020; 20:148-159. [PMID: 32874178 PMCID: PMC7447888 DOI: 10.1002/elsc.201900151] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2019] [Revised: 12/08/2019] [Accepted: 12/10/2019] [Indexed: 11/06/2022] Open
Abstract
We engineered P. putida for the production of isobutanol from glucose by preventing product and precursor degradation, inactivation of the soluble transhydrogenase SthA, overexpression of the native ilvC and ilvD genes, and implementation of the feedback-resistant acetolactate synthase AlsS from Bacillus subtilis, ketoacid decarboxylase KivD from Lactococcus lactis, and aldehyde dehydrogenase YqhD from Escherichia coli. The resulting strain P. putida Iso2 produced isobutanol with a substrate specific product yield (Y Iso/S) of 22 ± 2 mg per gram of glucose under aerobic conditions. Furthermore, we identified the ketoacid decarboxylase from Carnobacterium maltaromaticum to be a suitable alternative for isobutanol production, since replacement of kivD from L. lactis in P. putida Iso2 by the variant from C. maltaromaticum yielded an identical YIso/S. Although P. putida is regarded as obligate aerobic, we show that under oxygen deprivation conditions this bacterium does not grow, remains metabolically active, and that engineered producer strains secreted isobutanol also under the non-growing conditions.
Collapse
Affiliation(s)
- Robert Nitschel
- Institute of Biochemical EngineeringUniversity of StuttgartStuttgartGermany
| | - Andreas Ankenbauer
- Institute of Biochemical EngineeringUniversity of StuttgartStuttgartGermany
| | - Ilona Welsch
- Institute of Biochemical EngineeringUniversity of StuttgartStuttgartGermany
| | - Nicolas T. Wirth
- Institute of Biochemical EngineeringUniversity of StuttgartStuttgartGermany
| | - Christoph Massner
- Institute of Biochemical EngineeringUniversity of StuttgartStuttgartGermany
| | - Naveed Ahmad
- Ingenza Ltd., Roslin Innovation CentreCharnock Bradley Building, Easter Bush CampusRoslinUK
| | - Stephen McColm
- Ingenza Ltd., Roslin Innovation CentreCharnock Bradley Building, Easter Bush CampusRoslinUK
| | - Frédéric Borges
- Laboratoire d'Ingénierie des Biomolécules (LIBio)Université de LorraineNancyFrance
| | - Ian Fotheringham
- Ingenza Ltd., Roslin Innovation CentreCharnock Bradley Building, Easter Bush CampusRoslinUK
| | - Ralf Takors
- Institute of Biochemical EngineeringUniversity of StuttgartStuttgartGermany
| | - Bastian Blombach
- Institute of Biochemical EngineeringUniversity of StuttgartStuttgartGermany
- Microbial Biotechnology, Campus Straubing for Biotechnology and SustainabilityTechnical University of MunichStraubingGermany
| |
Collapse
|
123
|
Wang G, Øzmerih S, Guerreiro R, Meireles AC, Carolas A, Milne N, Jensen MK, Ferreira BS, Borodina I. Improvement of cis, cis-Muconic Acid Production in Saccharomyces cerevisiae through Biosensor-Aided Genome Engineering. ACS Synth Biol 2020; 9:634-646. [PMID: 32058699 PMCID: PMC8457548 DOI: 10.1021/acssynbio.9b00477] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Muconic acid is a potential platform chemical for the production of nylon, polyurethanes, and terephthalic acid. It is also an attractive functional copolymer in plastics due to its two double bonds. At this time, no economically viable process for the production of muconic acid exists. To harness novel genetic targets for improved production of cis,cis-muconic acid (CCM) in the yeast Saccharomyces cerevisiae, we employed a CCM-biosensor coupled to GFP expression with a broad dynamic response to screen UV-mutagenesis libraries of CCM-producing yeast. Via fluorescence activated cell sorting we identified a clone Mut131 with a 49.7% higher CCM titer and 164% higher titer of biosynthetic intermediate-protocatechuic acid (PCA). Genome resequencing of the Mut131 and reverse engineering identified seven causal missense mutations of the native genes (PWP2, EST2, ATG1, DIT1, CDC15, CTS2, and MNE1) and a duplication of two CCM biosynthetic genes, encoding dehydroshikimate dehydratase and catechol 1,2-dioxygenase, which were not recognized as flux controlling before. The Mut131 strain was further rationally engineered by overexpression of the genes encoding for PCA decarboxylase and AROM protein without shikimate dehydrogenase domain (Aro1pΔE), and by restoring URA3 prototrophy. The resulting engineered strain produced 20.8 g/L CCM in controlled fed-batch fermentation, with a yield of 66.2 mg/g glucose and a productivity of 139 mg/L/h, representing the highest reported performance metrics in a yeast for de novo CCM production to date and the highest production of an aromatic compound in yeast. The study illustrates the benefit of biosensor-based selection and brings closer the prospect of biobased muconic acid.
Collapse
Affiliation(s)
- Guokun Wang
- The Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, Lyngby, DK-2800 Kgs, Denmark
| | - Süleyman Øzmerih
- The Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, Lyngby, DK-2800 Kgs, Denmark
| | - Rogério Guerreiro
- Biotrend-Inovação e Engenharia em Biotecnologia SA, Cantanhede, 3060-197, Portugal
| | - Ana C. Meireles
- Biotrend-Inovação e Engenharia em Biotecnologia SA, Cantanhede, 3060-197, Portugal
| | - Ana Carolas
- Biotrend-Inovação e Engenharia em Biotecnologia SA, Cantanhede, 3060-197, Portugal
| | - Nicholas Milne
- The Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, Lyngby, DK-2800 Kgs, Denmark
| | - Michael K. Jensen
- The Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, Lyngby, DK-2800 Kgs, Denmark
| | - Bruno S. Ferreira
- Biotrend-Inovação e Engenharia em Biotecnologia SA, Cantanhede, 3060-197, Portugal
| | - Irina Borodina
- The Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, Lyngby, DK-2800 Kgs, Denmark
| |
Collapse
|
124
|
Development of a CRISPR/Cas9n-based tool for metabolic engineering of Pseudomonas putida for ferulic acid-to-polyhydroxyalkanoate bioconversion. Commun Biol 2020; 3:98. [PMID: 32139868 PMCID: PMC7058019 DOI: 10.1038/s42003-020-0824-5] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2019] [Accepted: 02/12/2020] [Indexed: 12/18/2022] Open
Abstract
Ferulic acid is a ubiquitous phenolic compound in lignocellulose, which is recognized for its role in the microbial carbon catabolism and industrial value. However, its recalcitrance and toxicity poses a challenge for ferulic acid-to-bioproducts bioconversion. Here, we develop a genome editing strategy for Pseudomonas putida KT2440 using an integrated CRISPR/Cas9n-λ-Red system with pyrF as a selection marker, which maintains cell viability and genetic stability, increases mutation efficiency, and simplifies genetic manipulation. Via this method, four functional modules, comprised of nine genes involved in ferulic acid catabolism and polyhydroxyalkanoate biosynthesis, were integrated into the genome, generating the KTc9n20 strain. After metabolic engineering and optimization of C/N ratio, polyhydroxyalkanoate production was increased to ~270 mg/L, coupled with ~20 mM ferulic acid consumption. This study not only establishes a simple and efficient genome editing strategy, but also offers an encouraging example of how to apply this method to improve microbial aromatic compound bioconversion. Yueyue Zhou et al. develop a genetic engineering method that increases the production of polyhydroxyalkanoate from ferulic acid, which is toxic at high concentrations. This study provides insight into the bioconversion of the aromatic compound in Pseudomonas.
Collapse
|
125
|
Poblete-Castro I, Aravena-Carrasco C, Orellana-Saez M, Pacheco N, Cabrera A, Borrero-de Acuña JM. Engineering the Osmotic State of Pseudomonas putida KT2440 for Efficient Cell Disruption and Downstream Processing of Poly(3-Hydroxyalkanoates). Front Bioeng Biotechnol 2020; 8:161. [PMID: 32211393 PMCID: PMC7066983 DOI: 10.3389/fbioe.2020.00161] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2019] [Accepted: 02/17/2020] [Indexed: 11/17/2022] Open
Abstract
In the last decade, the development of novel programmable cell lytic systems based on different inducible genetic constructs like the holin–endolysin and lysozyme appears as a promising alternative to circumvent the use of costly enzymes and mechanical disrupters for downstream processing of intracellular microbial products. Despite the advances, upon activation of these systems the cellular disruption of the biocatalyst occurs in an extended period, thus delaying the recovery of poly(3-hydroxyalkanoate) (PHA). Herein the osmotic state of Pseudomonas putida KT2440 was engineered by inactivating the inner-membrane residing rescue valve MscL, which is responsible mainly for circumventing low-osmolarity challenges. Then the major outer membrane porin OprF and the specific porin OprE were overproduced during PHA producing conditions on decanoate-grown cells. The engineered P. putida strains carrying each porin showed no impairment on growth rate and final biomass and PHA yield after 48 h cultivation. Expression of both porins in tandem in the mutant strain KTΔmscL-oprFE led to a slight reduction of the biomass synthesis (∼10%) but higher PHA accumulation (%wt) relative to the cell dry mass. Each strain was then challenged to an osmotic upshift for 1 h and subsequently to a rapid passage to a hypotonic condition where the membrane stability of the KTΔmscL-oprFE suffered damage, resulting in a rapid reduction of cell viability. Cell disruption accounted for >95% of the cell population within 3 h as reported by colony forming units (CFU), FACS analyses, and transmission electron microscopy. PHA recovery yielded 94.2% of the biosynthesized biopolymer displaying no significant alterations on the final monomer composition. This study can serve as an efficient genetic platform for the recovery of any microbial intracellular compound allowing less unit operation steps for cellular disruption.
Collapse
Affiliation(s)
- Ignacio Poblete-Castro
- Biosystems Engineering Laboratory, Center for Bioinformatics and Integrative Biology, Faculty of Life Sciences, Universidad Andres Bello, Santiago, Chile
| | - Carla Aravena-Carrasco
- Biosystems Engineering Laboratory, Center for Bioinformatics and Integrative Biology, Faculty of Life Sciences, Universidad Andres Bello, Santiago, Chile
| | - Matias Orellana-Saez
- Biosystems Engineering Laboratory, Center for Bioinformatics and Integrative Biology, Faculty of Life Sciences, Universidad Andres Bello, Santiago, Chile
| | - Nicolás Pacheco
- Biosystems Engineering Laboratory, Center for Bioinformatics and Integrative Biology, Faculty of Life Sciences, Universidad Andres Bello, Santiago, Chile
| | - Alex Cabrera
- Unidad de Citometría de Flujo, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - José Manuel Borrero-de Acuña
- Institute of Microbiology, Technische Universität Braunschweig, Braunschweig, Germany.,Braunschweig Integrated Centre of Systems Biology, Technische Universität Braunschweig, Braunschweig, Germany
| |
Collapse
|
126
|
|
127
|
Abstract
Pseudomonas putidais a fast-growing bacterium found mostly in temperate soil and water habitats. The metabolic versatility ofP. putidamakes this organism attractive for biotechnological applications such as biodegradation of environmental pollutants and synthesis of added-value chemicals (biocatalysis). This organism has been extensively studied in respect to various stress responses, mechanisms of genetic plasticity and transcriptional regulation of catabolic genes.P. putidais able to colonize the surface of living organisms, but is generally considered to be of low virulence. A number ofP. putidastrains are able to promote plant growth. The aim of this review is to give historical overview of the discovery of the speciesP. putidaand isolation and characterization ofP. putidastrains displaying potential for biotechnological applications. This review also discusses some major findings inP. putidaresearch encompassing regulation of catabolic operons, stress-tolerance mechanisms and mechanisms affecting evolvability of bacteria under conditions of environmental stress.
Collapse
|
128
|
Li M, Wilkins M. Fed-batch cultivation and adding supplements to increase yields of polyhydroxybutyrate production by Cupriavidus necator from corn stover alkaline pretreatment liquor. BIORESOURCE TECHNOLOGY 2020; 299:122676. [PMID: 31924491 DOI: 10.1016/j.biortech.2019.122676] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/10/2019] [Revised: 12/19/2019] [Accepted: 12/21/2019] [Indexed: 06/10/2023]
Abstract
The aim of this study was to evaluate polyhydroxybutyrate (PHB) production and productivity with supplements under fed-batch cultivation at bioreactor scale (1.3 L). In this study, multiple supplements including oxidative enzyme, mediators, surfactants and silicon nanoparticles were added to Cupriavidus necator culture growing on alkaline pretreatment liquor (APL). At 1.3 L bioreactor scale, PHB production reached 3.3 g/L. To further enhance PHB production, fed-batch cultivation with two different feeding strategies were applied. Under single pulse feeding of 300 mL medium, PHB production reached 4.0 g/L. Under 4 pulses feeding of 75 mL medium each time, PHB production reached 4.5 g/L. This is the highest PHB production from lignin that the authors are aware of in literature.
Collapse
Affiliation(s)
- Mengxing Li
- Department of Biological Systems Engineering, The University of Nebraska-Lincoln, Lincoln 68583 USA; Department of Statistics, The University of Nebraska-Lincoln, Lincoln 68583 USA
| | - Mark Wilkins
- Department of Biological Systems Engineering, The University of Nebraska-Lincoln, Lincoln 68583 USA; Department of Food Science and Technology, University of Nebraska-Lincoln, Lincoln 68588 USA; Industrial Agricultural Products Center, University of Nebraska-Lincoln, Lincoln 68583 USA.
| |
Collapse
|
129
|
Duuren JBJH, Wild PJ, Starck S, Bradtmöller C, Selzer M, Mehlmann K, Schneider R, Kohlstedt M, Poblete‐Castro I, Stolzenberger J, Barton N, Fritz M, Scholl S, Venus J, Wittmann C. Limited life cycle and cost assessment for the bioconversion of lignin‐derived aromatics into adipic acid. Biotechnol Bioeng 2020; 117:1381-1393. [DOI: 10.1002/bit.27299] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2019] [Accepted: 02/03/2020] [Indexed: 01/20/2023]
Affiliation(s)
| | - Paul J. Wild
- Biomass & Energy Efficiency, TNOPetten The Netherlands
| | - Sören Starck
- Institute of Systems BiotechnologySaarland UniversitySaarbrücken Germany
| | - Christian Bradtmöller
- Institute for Chemical and Thermal Process EngineeringTechnische Universität BraunschweigBraunschweig Germany
| | - Mirjam Selzer
- Institute of Systems BiotechnologySaarland UniversitySaarbrücken Germany
| | - Kerstin Mehlmann
- Department of BioengineeringLeibniz Institute for Agricultural Engineering and Bioeconomy (ATB)Potsdam Germany
| | - Roland Schneider
- Department of BioengineeringLeibniz Institute for Agricultural Engineering and Bioeconomy (ATB)Potsdam Germany
| | - Michael Kohlstedt
- Institute of Systems BiotechnologySaarland UniversitySaarbrücken Germany
| | - Ignacio Poblete‐Castro
- Biosystems Engineering Laboratory, Center for Bioinformatics and Integrative Biology, Faculty of Natural SciencesUniversidad Andres BelloSantiago de Chile Chile
| | | | - Nadja Barton
- Institute of Systems BiotechnologySaarland UniversitySaarbrücken Germany
| | - Michel Fritz
- Institute of Systems BiotechnologySaarland UniversitySaarbrücken Germany
| | - Stephan Scholl
- Institute for Chemical and Thermal Process EngineeringTechnische Universität BraunschweigBraunschweig Germany
| | - Joachim Venus
- Department of BioengineeringLeibniz Institute for Agricultural Engineering and Bioeconomy (ATB)Potsdam Germany
| | - Christoph Wittmann
- Institute of Systems BiotechnologySaarland UniversitySaarbrücken Germany
| |
Collapse
|
130
|
Engineering glucose metabolism for enhanced muconic acid production in Pseudomonas putida KT2440. Metab Eng 2020; 59:64-75. [PMID: 31931111 DOI: 10.1016/j.ymben.2020.01.001] [Citation(s) in RCA: 62] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2019] [Revised: 01/01/2020] [Accepted: 01/04/2020] [Indexed: 12/24/2022]
Abstract
Pseudomonas putida KT2440 has received increasing attention as an important biocatalyst for the conversion of diverse carbon sources to multiple products, including the olefinic diacid, cis,cis-muconic acid (muconate). P. putida has been previously engineered to produce muconate from glucose; however, periplasmic oxidation of glucose causes substantial 2-ketogluconate accumulation, reducing product yield and selectivity. Deletion of the glucose dehydrogenase gene (gcd) prevents 2-ketogluconate accumulation, but dramatically slows growth and muconate production. In this work, we employed adaptive laboratory evolution to improve muconate production in strains incapable of producing 2-ketogluconate. Growth-based selection improved growth, but reduced muconate titer. A new muconate-responsive biosensor was therefore developed to enable muconate-based screening using fluorescence activated cell sorting. Sorted clones demonstrated both improved growth and muconate production. Mutations identified by whole genome resequencing of these isolates indicated that glucose metabolism may be dysregulated in strains lacking gcd. Using this information, we used targeted engineering to recapitulate improvements achieved by evolution. Deletion of the transcriptional repressor gene hexR improved strain growth and increased the muconate production rate, and the impact of this deletion was investigated using transcriptomics. The genes gntZ and gacS were also disrupted in several evolved clones, and deletion of these genes further improved strain growth and muconate production. Together, these targets provide a suite of modifications that improve glucose conversion to muconate by P. putida in the context of gcd deletion. Prior to this work, our engineered strain lacking gcd generated 7.0 g/L muconate at a productivity of 0.07 g/L/h and a 38% yield (mol/mol) in a fed-batch bioreactor. Here, the resulting strain with the deletion of hexR, gntZ, and gacS achieved 22.0 g/L at 0.21 g/L/h and a 35.6% yield (mol/mol) from glucose in similar conditions. These strategies enabled enhanced muconic acid production and may also improve production of other target molecules from glucose in P. putida.
Collapse
|
131
|
Chauhan PS. Role of various bacterial enzymes in complete depolymerization of lignin: A review. BIOCATALYSIS AND AGRICULTURAL BIOTECHNOLOGY 2020. [DOI: 10.1016/j.bcab.2020.101498] [Citation(s) in RCA: 37] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
|
132
|
Thompson MG, Valencia LE, Blake-Hedges JM, Cruz-Morales P, Velasquez AE, Pearson AN, Sermeno LN, Sharpless WA, Benites VT, Chen Y, Baidoo EE, Petzold CJ, Deutschbauer AM, Keasling JD. Omics-driven identification and elimination of valerolactam catabolism in Pseudomonas putida KT2440 for increased product titer. Metab Eng Commun 2019; 9:e00098. [PMID: 31720214 PMCID: PMC6838509 DOI: 10.1016/j.mec.2019.e00098] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2019] [Revised: 07/13/2019] [Accepted: 08/08/2019] [Indexed: 12/25/2022] Open
Abstract
Pseudomonas putida is a promising bacterial chassis for metabolic engineering given its ability to metabolize a wide array of carbon sources, especially aromatic compounds derived from lignin. However, this omnivorous metabolism can also be a hindrance when it can naturally metabolize products produced from engineered pathways. Herein we show that P. putida is able to use valerolactam as a sole carbon source, as well as degrade caprolactam. Lactams represent important nylon precursors, and are produced in quantities exceeding one million tons per year (Zhang et al., 2017). To better understand this metabolism we use a combination of Random Barcode Transposon Sequencing (RB-TnSeq) and shotgun proteomics to identify the oplBA locus as the likely responsible amide hydrolase that initiates valerolactam catabolism. Deletion of the oplBA genes prevented P. putida from growing on valerolactam, prevented the degradation of valerolactam in rich media, and dramatically reduced caprolactam degradation under the same conditions. Deletion of oplBA, as well as pathways that compete for precursors L-lysine or 5-aminovalerate, increased the titer of valerolactam from undetectable after 48 h of production to ~90 mg/L. This work may serve as a template to rapidly eliminate undesirable metabolism in non-model hosts in future metabolic engineering efforts.
Collapse
Affiliation(s)
- Mitchell G. Thompson
- Joint BioEnergy Institute, 5885 Hollis Street, Emeryville, CA, 94608, USA
- Biological Systems & Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
- Department of Plant and Microbial Biology, University of California, Berkeley, CA, 94720, USA
| | - Luis E. Valencia
- Joint BioEnergy Institute, 5885 Hollis Street, Emeryville, CA, 94608, USA
- Biological Systems & Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
- Joint Program in Bioengineering, University of California, Berkeley/San Francisco, CA, 94720, USA
| | - Jacquelyn M. Blake-Hedges
- Joint BioEnergy Institute, 5885 Hollis Street, Emeryville, CA, 94608, USA
- Biological Systems & Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
- Department of Chemistry, University of California, Berkeley, CA, 94720, USA
| | - Pablo Cruz-Morales
- Joint BioEnergy Institute, 5885 Hollis Street, Emeryville, CA, 94608, USA
- Biological Systems & Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
- Centro de Biotecnologia FEMSA, Instituto Tecnologico y de Estudios Superiores de Monterrey, Mexico
| | - Alexandria E. Velasquez
- Joint BioEnergy Institute, 5885 Hollis Street, Emeryville, CA, 94608, USA
- Biological Systems & Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | - Allison N. Pearson
- Joint BioEnergy Institute, 5885 Hollis Street, Emeryville, CA, 94608, USA
- Biological Systems & Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | - Lauren N. Sermeno
- Joint BioEnergy Institute, 5885 Hollis Street, Emeryville, CA, 94608, USA
- Biological Systems & Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | - William A. Sharpless
- Joint BioEnergy Institute, 5885 Hollis Street, Emeryville, CA, 94608, USA
- Biological Systems & Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | - Veronica T. Benites
- Joint BioEnergy Institute, 5885 Hollis Street, Emeryville, CA, 94608, USA
- Biological Systems & Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | - Yan Chen
- Joint BioEnergy Institute, 5885 Hollis Street, Emeryville, CA, 94608, USA
- Biological Systems & Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | - Edward E.K. Baidoo
- Joint BioEnergy Institute, 5885 Hollis Street, Emeryville, CA, 94608, USA
- Biological Systems & Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | - Christopher J. Petzold
- Joint BioEnergy Institute, 5885 Hollis Street, Emeryville, CA, 94608, USA
- Biological Systems & Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | - Adam M. Deutschbauer
- Department of Plant and Microbial Biology, University of California, Berkeley, CA, 94720, USA
- Environmental Genomics and Systems Biology Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Jay D. Keasling
- Joint BioEnergy Institute, 5885 Hollis Street, Emeryville, CA, 94608, USA
- Biological Systems & Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
- Joint Program in Bioengineering, University of California, Berkeley/San Francisco, CA, 94720, USA
- Department of Chemical and Biomolecular Engineering, University of California, Berkeley, CA, 94720, USA
- The Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, Denmark
- Center for Synthetic Biochemistry, Institute for Synthetic Biology, Shenzhen Institutes for Advanced Technologies, Shenzhen, China
| |
Collapse
|
133
|
Otto M, Wynands B, Lenzen C, Filbig M, Blank LM, Wierckx N. Rational Engineering of Phenylalanine Accumulation in Pseudomonas taiwanensis to Enable High-Yield Production of Trans-Cinnamate. Front Bioeng Biotechnol 2019; 7:312. [PMID: 31824929 PMCID: PMC6882275 DOI: 10.3389/fbioe.2019.00312] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2019] [Accepted: 10/23/2019] [Indexed: 12/31/2022] Open
Abstract
Microbial biocatalysis represents a promising alternative for the production of a variety of aromatic chemicals, where microorganisms are engineered to convert a renewable feedstock under mild production conditions into a valuable chemical building block. This study describes the rational engineering of the solvent-tolerant bacterium Pseudomonas taiwanensis VLB120 toward accumulation of L-phenylalanine and its conversion into the chemical building block t-cinnamate. We recently reported rational engineering of Pseudomonas toward L-tyrosine accumulation by the insertion of genetic modifications that allow both enhanced flux and prevent aromatics degradation. Building on this knowledge, three genes encoding for enzymes involved in the degradation of L-phenylalanine were deleted to allow accumulation of 2.6 mM of L-phenylalanine from 20 mM glucose. The amino acid was subsequently converted into the aromatic model compound t-cinnamate by the expression of a phenylalanine ammonia-lyase (PAL) from Arabidopsis thaliana. The engineered strains produced t-cinnamate with yields of 23 and 39% Cmol Cmol−1 from glucose and glycerol, respectively. Yields were improved up to 48% Cmol Cmol−1 from glycerol when two enzymes involved in the shikimate pathway were additionally overexpressed, however with negative impact on strain performance and reproducibility. Production titers were increased in fed-batch fermentations, in which 33.5 mM t-cinnamate were produced solely from glycerol, in a mineral medium without additional complex supplements. The aspect of product toxicity was targeted by the utilization of a streamlined, genome-reduced strain, which improves upon the already high tolerance of P. taiwanensis VLB120 toward t-cinnamate.
Collapse
Affiliation(s)
- Maike Otto
- Institute of Bio- and Geosciences (IBG-1: Biotechnology), Forschungszentrum Jülich GmbH, Jülich, Germany
| | - Benedikt Wynands
- Institute of Bio- and Geosciences (IBG-1: Biotechnology), Forschungszentrum Jülich GmbH, Jülich, Germany
| | - Christoph Lenzen
- Institute of Applied Microbiology, Rheinisch-Westfälische Technische Hochschule (RWTH) Aachen University, Aachen, Germany
| | - Melanie Filbig
- Institute of Applied Microbiology, Rheinisch-Westfälische Technische Hochschule (RWTH) Aachen University, Aachen, Germany
| | - Lars M Blank
- Institute of Applied Microbiology, Rheinisch-Westfälische Technische Hochschule (RWTH) Aachen University, Aachen, Germany
| | - Nick Wierckx
- Institute of Bio- and Geosciences (IBG-1: Biotechnology), Forschungszentrum Jülich GmbH, Jülich, Germany
| |
Collapse
|
134
|
Nogales J, Mueller J, Gudmundsson S, Canalejo FJ, Duque E, Monk J, Feist AM, Ramos JL, Niu W, Palsson BO. High-quality genome-scale metabolic modelling of Pseudomonas putida highlights its broad metabolic capabilities. Environ Microbiol 2019; 22:255-269. [PMID: 31657101 PMCID: PMC7078882 DOI: 10.1111/1462-2920.14843] [Citation(s) in RCA: 86] [Impact Index Per Article: 17.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2019] [Revised: 09/27/2019] [Accepted: 10/23/2019] [Indexed: 12/19/2022]
Abstract
Genome-scale reconstructions of metabolism are computational species-specific knowledge bases able to compute systemic metabolic properties. We present a comprehensive and validated reconstruction of the biotechnologically relevant bacterium Pseudomonas putida KT2440 that greatly expands computable predictions of its metabolic states. The reconstruction represents a significant reactome expansion over available reconstructed bacterial metabolic networks. Specifically, iJN1462 (i) incorporates several hundred additional genes and associated reactions resulting in new predictive capabilities, including new nutrients supporting growth; (ii) was validated by in vivo growth screens that included previously untested carbon (48) and nitrogen (41) sources; (iii) yielded gene essentiality predictions showing large accuracy when compared with a knock-out library and Bar-seq data; and (iv) allowed mapping of its network to 82 P. putida sequenced strains revealing functional core that reflect the large metabolic versatility of this species, including aromatic compounds derived from lignin. Thus, this study provides a thoroughly updated metabolic reconstruction and new computable phenotypes for P. putida, which can be leveraged as a first step toward understanding the pan metabolic capabilities of Pseudomonas.
Collapse
Affiliation(s)
- Juan Nogales
- Department of Systems Biology, Centro Nacional de Biotecnología (CNB-CSIC), Madrid, Spain.,Department of Bioengineering, University of California, San Diego, La Jolla, CA, USA
| | - Joshua Mueller
- Department of Bioengineering, University of California, San Diego, La Jolla, CA, USA.,Department of Chemical and Biomolecular Engineering, University of Nebraska-Lincoln, Lincoln, NE, USA
| | | | - Francisco J Canalejo
- Department of Systems Biology, Centro Nacional de Biotecnología (CNB-CSIC), Madrid, Spain
| | - Estrella Duque
- Department of Environmental Protection, Estación Experimental del Zaidín (CSIC), Granada, Spain
| | - Jonathan Monk
- Department of Bioengineering, University of California, San Diego, La Jolla, CA, USA
| | - Adam M Feist
- Department of Bioengineering, University of California, San Diego, La Jolla, CA, USA
| | - Juan Luis Ramos
- Department of Environmental Protection, Estación Experimental del Zaidín (CSIC), Granada, Spain
| | - Wei Niu
- Department of Chemical and Biomolecular Engineering, University of Nebraska-Lincoln, Lincoln, NE, USA
| | - Bernhard O Palsson
- Department of Bioengineering, University of California, San Diego, La Jolla, CA, USA
| |
Collapse
|
135
|
Becker J, Wittmann C. A field of dreams: Lignin valorization into chemicals, materials, fuels, and health-care products. Biotechnol Adv 2019; 37:107360. [DOI: 10.1016/j.biotechadv.2019.02.016] [Citation(s) in RCA: 207] [Impact Index Per Article: 41.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2018] [Revised: 02/18/2019] [Accepted: 02/22/2019] [Indexed: 02/07/2023]
|
136
|
Promoting microbial utilization of phenolic substrates from bio-oil. ACTA ACUST UNITED AC 2019; 46:1531-1545. [DOI: 10.1007/s10295-019-02208-z] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2019] [Accepted: 06/21/2019] [Indexed: 10/26/2022]
Abstract
Abstract
The economic viability of the biorefinery concept is limited by the valorization of lignin. One possible method of lignin valorization is biological upgrading with aromatic-catabolic microbes. In conjunction, lignin monomers can be produced by fast pyrolysis and fractionation. However, biological upgrading of these lignin monomers is limited by low water solubility. Here, we address the problem of low water solubility with an emulsifier blend containing approximately 70 wt% Tween® 20 and 30 wt% Span® 80. Pseudomonas putida KT2440 grew to an optical density (OD600) of 1.0 ± 0.2 when supplied with 1.6 wt% emulsified phenolic monomer-rich product produced by fast pyrolysis of red oak using an emulsifier dose of 0.076 ± 0.002 g emulsifier blend per g of phenolic monomer-rich product. This approach partially mitigated the toxicity of the model phenolic monomer p-coumarate to the microbe, but not benzoate or vanillin. This study provides a proof of concept that processing of biomass-derived phenolics to increase aqueous availability can enhance microbial utilization.
Collapse
|
137
|
Systems biology based metabolic engineering for non-natural chemicals. Biotechnol Adv 2019; 37:107379. [DOI: 10.1016/j.biotechadv.2019.04.001] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2018] [Revised: 02/23/2019] [Accepted: 04/01/2019] [Indexed: 12/17/2022]
|
138
|
Li X, Zheng Y. Biotransformation of lignin: Mechanisms, applications and future work. Biotechnol Prog 2019; 36:e2922. [PMID: 31587530 DOI: 10.1002/btpr.2922] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2019] [Revised: 09/19/2019] [Accepted: 09/24/2019] [Indexed: 01/04/2023]
Abstract
As one of the most abundant polymers in biosphere, lignin has attracted extensive attention as a kind of promising feedstock for biofuel and bio-based products. However, the utilization of lignin presents various challenges in that its complex composition and structure and high resistance to degradation. Lignin conversion through biological platform harnesses the catalytic power of microorganisms to decompose complex lignin molecules and obtain value-added products through biosynthesis. Given the heterogeneity of lignin, various microbial metabolic pathways are involved in lignin bioconversion processes, which has been characterized in extensive research work. With different types of lignin substrates (e.g., model compounds, technical lignin, and lignocellulosic biomass), several bacterial and fungal species have been proved to own lignin-degrading abilities and accumulate microbial products (e.g., lipid and polyhydroxyalkanoates), while the lignin conversion efficiencies are still relatively low. Genetic and metabolic strategies have been developed to enhance lignin biodegradation by reprogramming microbial metabolism, and diverse products, such as vanillin and dicarboxylic acids were also produced from lignin. This article aims at presenting a comprehensive review on lignin bioconversion including lignin degradation mechanisms, metabolic pathways, and applications for the production of value-added bioproducts. Advanced techniques on genetic and metabolic engineering are also covered in the recent development of biological platforms for lignin utilization. To conclude this article, the existing challenges for efficient lignin bioprocessing are analyzed and possible directions for future work are proposed.
Collapse
Affiliation(s)
- Xiang Li
- Department of Grain Science and Industry, Kansas State University, Manhattan, Kansas
| | - Yi Zheng
- Department of Grain Science and Industry, Kansas State University, Manhattan, Kansas
| |
Collapse
|
139
|
Kowalczyk JE, Peng M, Pawlowski M, Lipzen A, Ng V, Singan V, Wang M, Grigoriev IV, Mäkelä MR. The White-Rot Basidiomycete Dichomitus squalens Shows Highly Specific Transcriptional Response to Lignocellulose-Related Aromatic Compounds. Front Bioeng Biotechnol 2019; 7:229. [PMID: 31616664 PMCID: PMC6763618 DOI: 10.3389/fbioe.2019.00229] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2019] [Accepted: 09/05/2019] [Indexed: 11/13/2022] Open
Abstract
Lignocellulosic plant biomass is an important feedstock for bio-based economy. In particular, it is an abundant renewable source of aromatic compounds, which are present as part of lignin, as side-groups of xylan and pectin, and in other forms, such as tannins. As filamentous fungi are the main organisms that modify and degrade lignocellulose, they have developed a versatile metabolism to convert the aromatic compounds that are toxic at relatively low concentrations to less toxic ones. During this process, fungi form metabolites some of which represent high-value platform chemicals or important chemical building blocks, such as benzoic, vanillic, and protocatechuic acid. Especially basidiomycete white-rot fungi with unique ability to degrade the recalcitrant lignin polymer are expected to perform highly efficient enzymatic conversions of aromatic compounds, thus having huge potential for biotechnological exploitation. However, the aromatic metabolism of basidiomycete fungi is poorly studied and knowledge on them is based on the combined results of studies in variety of species, leaving the overall picture in each organism unclear. Dichomitus squalens is an efficiently wood-degrading white-rot basidiomycete that produces a diverse set of extracellular enzymes targeted for lignocellulose degradation, including oxidative enzymes that act on lignin. Our recent study showed that several intra- and extracellular aromatic compounds were produced when D. squalens was cultivated on spruce wood, indicating also versatile aromatic metabolic abilities for this species. In order to provide the first molecular level systematic insight into the conversion of plant biomass derived aromatic compounds by basidiomycete fungi, we analyzed the transcriptomes of D. squalens when grown with 10 different lignocellulose-related aromatic monomers. Significant differences for example with respect to the expression of lignocellulose degradation related genes, but also putative genes encoding transporters and catabolic pathway genes were observed between the cultivations supplemented with the different aromatic compounds. The results demonstrate that the transcriptional response of D. squalens is highly dependent on the specific aromatic compounds present suggesting that instead of a common regulatory system, fine-tuned regulation is needed for aromatic metabolism.
Collapse
Affiliation(s)
| | - Mao Peng
- Fungal Physiology, Westerdijk Fungal Biodiversity Institute and Fungal Molecular Physiology, Utrecht University, Utrecht, Netherlands
| | - Megan Pawlowski
- U.S. Department of Energy Joint Genome Institute, Walnut Creek, CA, United States
| | - Anna Lipzen
- U.S. Department of Energy Joint Genome Institute, Walnut Creek, CA, United States
| | - Vivian Ng
- U.S. Department of Energy Joint Genome Institute, Walnut Creek, CA, United States
| | - Vasanth Singan
- U.S. Department of Energy Joint Genome Institute, Walnut Creek, CA, United States
| | - Mei Wang
- U.S. Department of Energy Joint Genome Institute, Walnut Creek, CA, United States
| | - Igor V Grigoriev
- U.S. Department of Energy Joint Genome Institute, Walnut Creek, CA, United States
| | - Miia R Mäkelä
- Department of Microbiology, University of Helsinki, Helsinki, Finland
| |
Collapse
|
140
|
Lee S, Kang M, Bae JH, Sohn JH, Sung BH. Bacterial Valorization of Lignin: Strains, Enzymes, Conversion Pathways, Biosensors, and Perspectives. Front Bioeng Biotechnol 2019; 7:209. [PMID: 31552235 PMCID: PMC6733911 DOI: 10.3389/fbioe.2019.00209] [Citation(s) in RCA: 64] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2019] [Accepted: 08/19/2019] [Indexed: 12/17/2022] Open
Abstract
Lignin, an aromatic polymer found in plants, has been studied for years in many biological fields. Initially, when biofuel was produced from lignocellulosic biomass, lignin was regarded as waste generated by the biorefinery and had to be removed, because of its inhibitory effects on fermentative bacteria. Although it has since proven to be a natural resource for bio-products with considerable potential, its utilization is confined by its complex structure. Hence, the microbial degradation of lignin has attracted researchers' interest to overcome this problem. From this perspective, the studies have primarily focused on fungal systems, such as extracellular peroxidase and laccase from white- and brown-rot fungi. However, recent reports have suggested that bacteria play an increasing role in breaking down lignin. This paper, therefore, reviews the role of bacteria in lignin and lignin-related research. Several reports on bacterial species in soil that can degrade lignin and their enzymes are included. In addition, a cellulolytic anaerobic bacterium capable of solubilizing lignin and carbohydrate simultaneously has recently been identified, even though the enzyme involved has not been discovered yet. The assimilation of lignin-derived small molecules and their conversion to renewable chemicals by bacteria, such as muconic acid and polyhydroxyalkanoates, including genetic modification to enhance their capability was discussed. This review also covers the indirect use of bacteria for lignin degradation, which is concerned with whole-cell biosensors designed to detect the aromatic chemicals released from lignin transformation.
Collapse
Affiliation(s)
- Siseon Lee
- Synthetic Biology and Bioengineering Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon, South Korea
| | - Minsik Kang
- Synthetic Biology and Bioengineering Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon, South Korea
- Department of Biosystems and Bioengineering, Korea University of Science and Technology, Daejeon, South Korea
| | - Jung-Hoon Bae
- Synthetic Biology and Bioengineering Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon, South Korea
| | - Jung-Hoon Sohn
- Synthetic Biology and Bioengineering Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon, South Korea
- Department of Biosystems and Bioengineering, Korea University of Science and Technology, Daejeon, South Korea
| | - Bong Hyun Sung
- Synthetic Biology and Bioengineering Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon, South Korea
- Department of Biosystems and Bioengineering, Korea University of Science and Technology, Daejeon, South Korea
| |
Collapse
|
141
|
GC-MS-based 13C metabolic flux analysis resolves the parallel and cyclic glucose metabolism of Pseudomonas putida KT2440 and Pseudomonas aeruginosa PAO1. Metab Eng 2019; 54:35-53. [DOI: 10.1016/j.ymben.2019.01.008] [Citation(s) in RCA: 74] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2018] [Revised: 01/16/2019] [Accepted: 01/16/2019] [Indexed: 01/05/2023]
|
142
|
Salmela M, Lehtinen T, Efimova E, Santala S, Santala V. Alkane and wax ester production from lignin‐related aromatic compounds. Biotechnol Bioeng 2019; 116:1934-1945. [DOI: 10.1002/bit.27005] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2018] [Revised: 03/29/2019] [Accepted: 04/18/2019] [Indexed: 12/24/2022]
Affiliation(s)
- Milla Salmela
- Faculty of Engineering and Natural Sciences, Hervanta CampusTampere UniversityTampere Finland
| | - Tapio Lehtinen
- Faculty of Engineering and Natural Sciences, Hervanta CampusTampere UniversityTampere Finland
| | - Elena Efimova
- Faculty of Engineering and Natural Sciences, Hervanta CampusTampere UniversityTampere Finland
| | - Suvi Santala
- Faculty of Engineering and Natural Sciences, Hervanta CampusTampere UniversityTampere Finland
| | - Ville Santala
- Faculty of Engineering and Natural Sciences, Hervanta CampusTampere UniversityTampere Finland
| |
Collapse
|
143
|
Abstract
Production of fuels and chemicals from renewable lignocellulosic feedstocks is a promising alternative to petroleum-derived compounds. Due to the complexity of lignocellulosic feedstocks, microbial conversion of all potential substrates will require substantial metabolic engineering. Non-model microbes offer desirable physiological traits, but also increase the difficulty of heterologous pathway engineering and optimization. The development of modular design principles that allow metabolic pathways to be used in a variety of novel microbes with minimal strain-specific optimization will enable the rapid construction of microbes for commercial production of biofuels and bioproducts. In this review, we discuss variability of lignocellulosic feedstocks, pathways for catabolism of lignocellulose-derived compounds, challenges to heterologous engineering of catabolic pathways, and opportunities to apply modular pathway design. Implementation of these approaches will simplify the process of modifying non-model microbes to convert diverse lignocellulosic feedstocks.
Collapse
|
144
|
Advances in microbial lignin degradation and its applications. Curr Opin Biotechnol 2019; 56:179-186. [DOI: 10.1016/j.copbio.2018.11.011] [Citation(s) in RCA: 87] [Impact Index Per Article: 17.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2018] [Revised: 11/14/2018] [Accepted: 11/14/2018] [Indexed: 12/29/2022]
|
145
|
Zhang R, Zhao CH, Chang HC, Chai MZ, Li BZ, Yuan YJ. Lignin valorization meets synthetic biology. Eng Life Sci 2019; 19:463-470. [PMID: 32625023 DOI: 10.1002/elsc.201800133] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2018] [Revised: 02/20/2019] [Accepted: 03/16/2019] [Indexed: 12/23/2022] Open
Abstract
Lignin, an abundant renewable resource in nature, is a highly heterogeneous biopolymer consisting of phenylpropanoid units. It is essential for sustainable utilization of biomass to convert lignin to value-added products. However, there are technical obstacles for lignin valorization due to intrinsic heterogeneity. The emerging of synthetic biology technologies brings new opportunities for lignin breakdown and utilization. In this review, we discussed the applications of synthetic biology on lignin conversion, especially the production of value-added products, such as aromatic chemicals, ring-cleaved chemicals from lignin-derived aromatics and bio-active substances. Synthetic biology will offer new potential strategies for lignin valorization by optimizing lignin degradation enzymes, building novel artificial converting pathways, and improving the chassis of model microorganisms.
Collapse
Affiliation(s)
- Renkuan Zhang
- Frontier Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering (Ministry of Education) School of Chemical Engineering and Technology Tianjin University Tianjin P. R. China.,Collaborative Innovation Center of Chemical Science and Engineering (Tianjin) Tianjin University Tianjin P. R. China
| | - Chen-Hui Zhao
- Frontier Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering (Ministry of Education) School of Chemical Engineering and Technology Tianjin University Tianjin P. R. China.,Collaborative Innovation Center of Chemical Science and Engineering (Tianjin) Tianjin University Tianjin P. R. China
| | - Han-Chen Chang
- Frontier Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering (Ministry of Education) School of Chemical Engineering and Technology Tianjin University Tianjin P. R. China.,Collaborative Innovation Center of Chemical Science and Engineering (Tianjin) Tianjin University Tianjin P. R. China
| | - Meng-Zhe Chai
- Frontier Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering (Ministry of Education) School of Chemical Engineering and Technology Tianjin University Tianjin P. R. China.,Collaborative Innovation Center of Chemical Science and Engineering (Tianjin) Tianjin University Tianjin P. R. China
| | - Bing-Zhi Li
- Frontier Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering (Ministry of Education) School of Chemical Engineering and Technology Tianjin University Tianjin P. R. China.,Collaborative Innovation Center of Chemical Science and Engineering (Tianjin) Tianjin University Tianjin P. R. China
| | - Ying-Jin Yuan
- Frontier Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering (Ministry of Education) School of Chemical Engineering and Technology Tianjin University Tianjin P. R. China.,Collaborative Innovation Center of Chemical Science and Engineering (Tianjin) Tianjin University Tianjin P. R. China
| |
Collapse
|
146
|
Poblete-Castro I, Wittmann C, Nikel PI. Biochemistry, genetics and biotechnology of glycerol utilization in Pseudomonas species. Microb Biotechnol 2019; 13:32-53. [PMID: 30883020 PMCID: PMC6922529 DOI: 10.1111/1751-7915.13400] [Citation(s) in RCA: 49] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2019] [Revised: 02/17/2019] [Accepted: 02/23/2019] [Indexed: 11/30/2022] Open
Abstract
The use of renewable waste feedstocks is an environment‐friendly choice contributing to the reduction of waste treatment costs and increasing the economic value of industrial by‐products. Glycerol (1,2,3‐propanetriol), a simple polyol compound widely distributed in biological systems, constitutes a prime example of a relatively cheap and readily available substrate to be used in bioprocesses. Extensively exploited as an ingredient in the food and pharmaceutical industries, glycerol is also the main by‐product of biodiesel production, which has resulted in a progressive drop in substrate price over the years. Consequently, glycerol has become an attractive substrate in biotechnology, and several chemical commodities currently produced from petroleum have been shown to be obtained from this polyol using whole‐cell biocatalysts with both wild‐type and engineered bacterial strains. Pseudomonas species, endowed with a versatile and rich metabolism, have been adopted for the conversion of glycerol into value‐added products (ranging from simple molecules to structurally complex biopolymers, e.g. polyhydroxyalkanoates), and a number of metabolic engineering strategies have been deployed to increase the number of applications of glycerol as a cost‐effective substrate. The unique genetic and metabolic features of glycerol‐grown Pseudomonas are presented in this review, along with relevant examples of bioprocesses based on this substrate – and the synthetic biology and metabolic engineering strategies implemented in bacteria of this genus aimed at glycerol valorization.
Collapse
Affiliation(s)
- Ignacio Poblete-Castro
- Biosystems Engineering Laboratory, Center for Bioinformatics and Integrative Biology, Faculty of Natural Sciences, Universidad Andrés Bello, Santiago de Chile, Chile
| | - Christoph Wittmann
- Institute of Systems Biotechnology, Universität des Saarlandes, Saarbrücken, Germany
| | - Pablo I Nikel
- The Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, Kgs Lyngby, Denmark
| |
Collapse
|
147
|
Xu Z, Lei P, Zhai R, Wen Z, Jin M. Recent advances in lignin valorization with bacterial cultures: microorganisms, metabolic pathways, and bio-products. BIOTECHNOLOGY FOR BIOFUELS 2019; 12:32. [PMID: 30815030 PMCID: PMC6376720 DOI: 10.1186/s13068-019-1376-0] [Citation(s) in RCA: 102] [Impact Index Per Article: 20.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/08/2018] [Accepted: 02/08/2019] [Indexed: 05/09/2023]
Abstract
Lignin is the most abundant aromatic substrate on Earth and its valorization technologies are still under developed. Depolymerization and fragmentation are the predominant preparatory strategies for valorization of lignin to chemicals and fuels. However, due to the structural heterogeneity of lignin, depolymerization and fragmentation typically result in diverse product species, which require extensive separation and purification procedures to obtain target products. For lignin valorization, bacterial-based systems have attracted increasing attention because of their diverse metabolisms, which can be used to funnel multiple lignin-based compounds into specific target products. Here, recent advances in lignin valorization using bacteria are critically reviewed, including lignin-degrading bacteria that are able to degrade lignin and use lignin-associated aromatics, various associated metabolic pathways, and application of bacterial cultures for lignin valorization. This review will provide insight into the recent breakthroughs and future trends of lignin valorization based on bacterial systems.
Collapse
Affiliation(s)
- Zhaoxian Xu
- School of Environmental and Biological Engineering, Nanjing University of Science and Technology, Nanjing, 210094 China
| | - Peng Lei
- Nanjing Institute for Comprehensive Utilization of Wild Plants, Nanjing, 211111 China
| | - Rui Zhai
- School of Environmental and Biological Engineering, Nanjing University of Science and Technology, Nanjing, 210094 China
| | - Zhiqiang Wen
- School of Environmental and Biological Engineering, Nanjing University of Science and Technology, Nanjing, 210094 China
| | - Mingjie Jin
- School of Environmental and Biological Engineering, Nanjing University of Science and Technology, Nanjing, 210094 China
| |
Collapse
|
148
|
Nikel PI, de Lorenzo V. Pseudomonas putida as a functional chassis for industrial biocatalysis: From native biochemistry to trans-metabolism. Metab Eng 2018; 50:142-155. [DOI: 10.1016/j.ymben.2018.05.005] [Citation(s) in RCA: 245] [Impact Index Per Article: 40.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2018] [Revised: 05/07/2018] [Accepted: 05/10/2018] [Indexed: 12/12/2022]
|
149
|
Metabolically engineered Corynebacterium glutamicum for bio-based production of chemicals, fuels, materials, and healthcare products. Metab Eng 2018; 50:122-141. [DOI: 10.1016/j.ymben.2018.07.008] [Citation(s) in RCA: 138] [Impact Index Per Article: 23.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2018] [Revised: 07/17/2018] [Accepted: 07/18/2018] [Indexed: 01/15/2023]
|
150
|
Becker J, Kuhl M, Kohlstedt M, Starck S, Wittmann C. Metabolic engineering of Corynebacterium glutamicum for the production of cis, cis-muconic acid from lignin. Microb Cell Fact 2018; 17:115. [PMID: 30029656 PMCID: PMC6054733 DOI: 10.1186/s12934-018-0963-2] [Citation(s) in RCA: 101] [Impact Index Per Article: 16.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2018] [Accepted: 07/13/2018] [Indexed: 11/25/2022] Open
Abstract
Background Cis, cis-muconic acid (MA) is a dicarboxylic acid of recognized industrial value. It provides direct access to adipic acid and terephthalic acid, prominent monomers of commercial plastics. Results In the present work, we engineered the soil bacterium Corynebacterium glutamicum into a stable genome-based cell factory for high-level production of bio-based MA from aromatics and lignin hydrolysates. The elimination of muconate cycloisomerase (catB) in the catechol branch of the β-ketoadipate pathway provided a mutant, which accumulated MA at 100% molar yield from catechol, phenol, and benzoic acid, using glucose as additional growth substrate. The production of MA was optimized by constitutive overexpression of catA, which increased the activity of the encoded catechol 1,2-dioxygenase, forming MA from catechol, tenfold. Intracellular levels of catechol were more than 30-fold lower than extracellular levels, minimizing toxicity, but still saturating the high affinity CatA enzyme. In a fed-batch process, the created strain C. glutamicum MA-2 accumulated 85 g L−1 MA from catechol in 60 h and achieved a maximum volumetric productivity of 2.4 g L−1 h−1. The strain was furthermore used to demonstrate the production of MA from lignin in a cascade process. Following hydrothermal depolymerization of softwood lignin into small aromatics, the MA-2 strain accumulated 1.8 g L−1 MA from the obtained hydrolysate. Conclusions Our findings open the door to valorize lignin, the second most abundant polymer on earth, by metabolically engineered C. glutamicum for industrial production of MA and potentially other chemicals. Electronic supplementary material The online version of this article (10.1186/s12934-018-0963-2) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Judith Becker
- Institute of Systems Biotechnology, Saarland University, Campus A1.5, Saarbrücken, Germany
| | - Martin Kuhl
- Institute of Systems Biotechnology, Saarland University, Campus A1.5, Saarbrücken, Germany
| | - Michael Kohlstedt
- Institute of Systems Biotechnology, Saarland University, Campus A1.5, Saarbrücken, Germany
| | - Sören Starck
- Institute of Systems Biotechnology, Saarland University, Campus A1.5, Saarbrücken, Germany
| | - Christoph Wittmann
- Institute of Systems Biotechnology, Saarland University, Campus A1.5, Saarbrücken, Germany.
| |
Collapse
|