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Zhu P, Luo R, Li Y, Chen X. Metabolic Engineering and Adaptive Evolution for Efficient Production of l-Lactic Acid in Saccharomyces cerevisiae. Microbiol Spectr 2022; 10:e0227722. [PMID: 36354322 PMCID: PMC9769770 DOI: 10.1128/spectrum.02277-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2022] [Accepted: 10/15/2022] [Indexed: 11/12/2022] Open
Abstract
l-Lactic acid (LA) is a three-carbon hydroxycarboxylic acid with extensive applications in food, cosmetic, agricultural, pharmaceutical, and bioplastic industries. However, microbial LA production is limited by its intrinsic inefficiency of cellular metabolism. Here, pathway engineering was used to rewire the biosynthetic pathway for LA production in Saccharomyces cerevisiae by screening heterologous l-lactate dehydrogenase, reducing ethanol accumulation, and introducing a bacterial acetyl coenzyme A (acetyl-CoA) synthesis pathway. To improve its intrinsic efficiency of LA export, transporter engineering was conducted by screening the monocarboxylate transporters and then strengthening the capacity of LA export, leading to LA production up to 51.4 g/L. To further enhance its intrinsic efficiency of acid tolerance, adaptive evolution was adopted by cultivating yeast cells with a gradual increase in LA levels during 12 serial subcultures, resulting in a 17.5% increase in LA production to 60.4 g/L. Finally, the engineered strain S.c-NO.2-100 was able to produce 121.5 g/L LA, with a yield of up to 0.81 g/g in a 5-L batch bioreactor. The strategy described here provides a guide for developing efficient cell factories for the production of the other industrially useful organic acids. IMPORTANCE Saccharomyces cerevisiae is one of the most widely engineered cell factories for the production of organic acids. However, microbial production of l-lactic acid is limited by its intrinsic inefficiency of cellular metabolism in S. cerevisiae. Here, the transmission efficiency of the biosynthetic pathway was improved by pathway optimization to increase l-lactic acid production. Then, the synthetic ability for l-lactic acid was further enhanced by adaptive evolution to improve acid tolerance of S. cerevisiae. Based on these strategies, the final engineered S. cerevisiae strain achieved high efficiency of l-lactic acid production. These findings provide new insight into improving the intrinsic efficiency of cellular metabolism and will help to construct superior industrial yeast strains for high-level production of other organic acids.
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Affiliation(s)
- Pan Zhu
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, China
- State Key Laboratory of Membrane Biology, School of Life Sciences, Tsinghua University, Beijing, China
| | - Rui Luo
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, China
- Key Laboratory of Industrial Biotechnology, Ministry of Education, Jiangnan University, Wuxi, China
| | - Yize Li
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, China
- Key Laboratory of Industrial Biotechnology, Ministry of Education, Jiangnan University, Wuxi, China
| | - Xiulai Chen
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, China
- Key Laboratory of Industrial Biotechnology, Ministry of Education, Jiangnan University, Wuxi, China
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Mao Q, Jiang J, Wu X, Ma Y, Zhang Y, Zhao Y, Zhang Y, Wang Q. Bifunctional alcohol/aldehyde dehydrogenase AdhE controls phospho-transferase system sugar utilization and virulence gene expression by interacting PtsH in Edwardsiella piscicida. Microbiol Res 2022; 260:127018. [DOI: 10.1016/j.micres.2022.127018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2021] [Revised: 03/26/2022] [Accepted: 03/29/2022] [Indexed: 10/18/2022]
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3
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Hirayama S, Nakao R. Glycine significantly enhances bacterial membrane vesicle production: a powerful approach for isolation of LPS-reduced membrane vesicles of probiotic Escherichia coli. Microb Biotechnol 2020; 13:1162-1178. [PMID: 32348028 PMCID: PMC7264892 DOI: 10.1111/1751-7915.13572] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2019] [Revised: 03/21/2020] [Accepted: 03/22/2020] [Indexed: 01/05/2023] Open
Abstract
Bacterial membrane vesicles (MVs) have attracted strong interest in recent years as novel nanoparticle delivery platforms. Glycine is known to induce morphological changes in the outer layer of bacteria. We report here that glycine dramatically facilitates MV production in a flagella-deficient mutant of the non-pathogenic probiotic Escherichia coli strain Nissle 1917. Supplementation of culture medium with 1.0% glycine induced cell deformation at the early exponential phase, eventually followed by quasi-lysis during the late exponential to stationary phase. Glycine supplementation also significantly increased the number of MVs with enlarged particle size and altered the protein profile with an increase in the inner membrane and cytoplasmic protein contents as compared to non-induced MVs. Of note, the endotoxin activity of glycine-induced MVs was approximately eightfold or sixfold lower than that of non-induced MVs when compared at equal protein or lipid concentrations respectively. Nevertheless, glycine-induced MVs efficiently induced both immune responses in a mouse macrophage-like cell line and adjuvanticity in an intranasal vaccine mouse model, comparable to those of non-induced MVs. We propose that the present method of inducing MV production with glycine can be used for emerging biotechnological applications of MVs that have immunomodulatory activities, while dramatically reducing the presence of endotoxins.
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Affiliation(s)
- Satoru Hirayama
- Department of Bacteriology INational Institute of Infectious Diseases1‐23‐1 ToyamaShinjuku, Tokyo162‐8640Japan
- Japan Agency for Medical Research and Development20F Yomiuri Shimbun Bldg. 1‐7‐1 OtemachiChiyoda, Tokyo100‐0004Japan
| | - Ryoma Nakao
- Department of Bacteriology INational Institute of Infectious Diseases1‐23‐1 ToyamaShinjuku, Tokyo162‐8640Japan
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Guerrero-Torres V, Rios-Lozano M, Badillo-Corona JA, Chairez I, Garibay-Orijel C. Robust Parameter Identification to Perform the Modeling of pta and poxB Genes Deletion Effect on Escherichia Coli. Appl Biochem Biotechnol 2016; 179:1418-34. [PMID: 27093969 DOI: 10.1007/s12010-016-2074-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2015] [Accepted: 04/03/2016] [Indexed: 11/27/2022]
Abstract
The aim of this study was to design a robust parameter identification algorithm to characterize the effect of gene deletion on Escherichia coli (E. coli) MG1655. Two genes (pta and poxB) in the competitive pathways were deleted from this microorganism to inhibit pyruvate consumption. This condition deviated the E. coli metabolism toward the Krebs cycle. As a consequence, the biomass, substrate (glucose), lactic, and acetate acids as well as ethanol concentrations were modified. A hybrid model was proposed to consider the effect of gene deletion on the metabolism of E. coli. The model parameters were estimated by the application of a least mean square method based on the instrument variable technique. To evaluate the parametric identifier method, a set of robust exact differentiators, based on the super-twisting algorithm, was implemented. The hybrid model was successfully characterized by the parameters obtained from experimental information of E. coli MG1655. The significant difference between parameters obtained with wild-type strain and the modified (with deleted genes) justifies the application of the parametric identification algorithm. This characterization can be used to optimize the production of different byproducts of commercial interest.
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Affiliation(s)
| | - M Rios-Lozano
- SEPI-UPIBI, Instituto Politécnico Nacional, Mexico City, Mexico
| | | | - I Chairez
- Department of Bioprocesses-UPIBI, Instituto Politécnico Nacional, Mexico City, Mexico.
| | - C Garibay-Orijel
- Department of Bioprocesses-UPIBI, Instituto Politécnico Nacional, Mexico City, Mexico
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Abstract
Pyruvate and acetyl-CoA form the backbone of central metabolism. The nonoxidative cleavage of pyruvate to acetyl-CoA and formate by the glycyl radical enzyme pyruvate formate lyase is one of the signature reactions of mixed-acid fermentation in enterobacteria. Under these conditions, formic acid accounts for up to one-third of the carbon derived from glucose. The further metabolism of acetyl-CoA to acetate via acetyl-phosphate catalyzed by phosphotransacetylase and acetate kinase is an exemplar of substrate-level phosphorylation. Acetyl-CoA can also be used as an acceptor of the reducing equivalents generated during glycolysis, whereby ethanol is formed by the polymeric acetaldehyde/alcohol dehydrogenase (AdhE) enzyme. The metabolism of acetyl-CoA via either the acetate or the ethanol branches is governed by the cellular demand for ATP and the necessity to reoxidize NADH. Consequently, in the absence of an electron acceptor mutants lacking either branch of acetyl-CoA metabolism fail to cleave pyruvate, despite the presence of PFL, and instead reduce it to D-lactate by the D-lactate dehydrogenase. The conversion of PFL to the active, radical-bearing species is controlled by a radical-SAM enzyme, PFL-activase. All of these reactions are regulated in response to the prevalent cellular NADH:NAD+ ratio. In contrast to Escherichia coli and Salmonella species, some genera of enterobacteria, e.g., Klebsiella and Enterobacter, produce the more neutral product 2,3-butanediol and considerable amounts of CO2 as fermentation products. In these bacteria, two molecules of pyruvate are converted to α-acetolactate (AL) by α-acetolactate synthase (ALS). AL is then decarboxylated and subsequently reduced to the product 2,3-butandiol.
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Metabolic response of Clostridium ljungdahlii to oxygen exposure. Appl Environ Microbiol 2015; 81:8379-91. [PMID: 26431975 DOI: 10.1128/aem.02491-15] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2015] [Accepted: 09/23/2015] [Indexed: 12/31/2022] Open
Abstract
Clostridium ljungdahlii is an important synthesis gas-fermenting bacterium used in the biofuels industry, and a preliminary investigation showed that it has some tolerance to oxygen when cultured in rich mixotrophic medium. Batch cultures not only continue to grow and consume H2, CO, and fructose after 8% O2 exposure, but fermentation product analysis revealed an increase in ethanol concentration and decreased acetate concentration compared to non-oxygen-exposed cultures. In this study, the mechanisms for higher ethanol production and oxygen/reactive oxygen species (ROS) detoxification were identified using a combination of fermentation, transcriptome sequencing (RNA-seq) differential expression, and enzyme activity analyses. The results indicate that the higher ethanol and lower acetate concentrations were due to the carboxylic acid reductase activity of a more highly expressed predicted aldehyde oxidoreductase (CLJU_c24130) and that C. ljungdahlii's primary defense upon oxygen exposure is a predicted rubrerythrin (CLJU_c39340). The metabolic responses of higher ethanol production and oxygen/ROS detoxification were found to be linked by cofactor management and substrate and energy metabolism. This study contributes new insights into the physiology and metabolism of C. ljungdahlii and provides new genetic targets to generate C. ljungdahlii strains that produce more ethanol and are more tolerant to syngas contaminants.
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Song JY, Park JS, Kang CD, Cho HY, Yang D, Lee S, Cho KM. Introduction of a bacterial acetyl-CoA synthesis pathway improves lactic acid production in Saccharomyces cerevisiae. Metab Eng 2015; 35:38-45. [PMID: 26384570 DOI: 10.1016/j.ymben.2015.09.006] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2014] [Revised: 08/06/2015] [Accepted: 09/08/2015] [Indexed: 11/19/2022]
Abstract
Acid-tolerant Saccharomyces cerevisiae was engineered to produce lactic acid by expressing heterologous lactate dehydrogenase (LDH) genes, while attenuating several key pathway genes, including glycerol-3-phosphate dehydrogenase1 (GPD1) and cytochrome-c oxidoreductase2 (CYB2). In order to increase the yield of lactic acid further, the ethanol production pathway was attenuated by disrupting the pyruvate decarboxylase1 (PDC1) and alcohol dehydrogenase1 (ADH1) genes. Despite an increase in lactic acid yield, severe reduction of the growth rate and glucose consumption rate owing to the absence of ADH1 caused a considerable decrease in the overall productivity. In Δadh1 cells, the levels of acetyl-CoA, a key precursor for biologically applicable components, could be insufficient for normal cell growth. To increase the cellular supply of acetyl-CoA, we introduced bacterial acetylating acetaldehyde dehydrogenase (A-ALD) enzyme (EC 1.2.1.10) genes into the lactic acid-producing S. cerevisiae. Escherichia coli-derived A-ALD genes, mhpF and eutE, were expressed and effectively complemented the attenuated acetaldehyde dehydrogenase (ALD)/acetyl-CoA synthetase (ACS) pathway in the yeast. The engineered strain, possessing a heterologous acetyl-CoA synthetic pathway, showed an increased glucose consumption rate and higher productivity of lactic acid fermentation. The production of lactic acid was reached at 142g/L with production yield of 0.89g/g and productivity of 3.55gL(-1)h(-1) under fed-batch fermentation in bioreactor. This study demonstrates a novel approach that improves productivity of lactic acid by metabolic engineering of the acetyl-CoA biosynthetic pathway in yeast.
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Affiliation(s)
- Ji-Yoon Song
- Biomaterials Laboratory, Material Research Center, Samsung Advanced Institute of Technology, Gyeonggi-do, Republic of Korea
| | - Joon-Song Park
- Biomaterials Laboratory, Material Research Center, Samsung Advanced Institute of Technology, Gyeonggi-do, Republic of Korea
| | - Chang Duk Kang
- Biomaterials Laboratory, Material Research Center, Samsung Advanced Institute of Technology, Gyeonggi-do, Republic of Korea
| | - Hwa-Young Cho
- Biomaterials Laboratory, Material Research Center, Samsung Advanced Institute of Technology, Gyeonggi-do, Republic of Korea
| | - Dongsik Yang
- Biomaterials Laboratory, Material Research Center, Samsung Advanced Institute of Technology, Gyeonggi-do, Republic of Korea
| | - Seunghyun Lee
- Biomaterials Laboratory, Material Research Center, Samsung Advanced Institute of Technology, Gyeonggi-do, Republic of Korea
| | - Kwang Myung Cho
- Biomaterials Laboratory, Material Research Center, Samsung Advanced Institute of Technology, Gyeonggi-do, Republic of Korea.
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8
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Computational protein design enables a novel one-carbon assimilation pathway. Proc Natl Acad Sci U S A 2015; 112:3704-9. [PMID: 25775555 DOI: 10.1073/pnas.1500545112] [Citation(s) in RCA: 212] [Impact Index Per Article: 23.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
We describe a computationally designed enzyme, formolase (FLS), which catalyzes the carboligation of three one-carbon formaldehyde molecules into one three-carbon dihydroxyacetone molecule. The existence of FLS enables the design of a new carbon fixation pathway, the formolase pathway, consisting of a small number of thermodynamically favorable chemical transformations that convert formate into a three-carbon sugar in central metabolism. The formolase pathway is predicted to use carbon more efficiently and with less backward flux than any naturally occurring one-carbon assimilation pathway. When supplemented with enzymes carrying out the other steps in the pathway, FLS converts formate into dihydroxyacetone phosphate and other central metabolites in vitro. These results demonstrate how modern protein engineering and design tools can facilitate the construction of a completely new biosynthetic pathway.
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Khan I, Chen Y, Dong T, Hong X, Takeuchi R, Mori H, Kihara D. Genome-scale identification and characterization of moonlighting proteins. Biol Direct 2014; 9:30. [PMID: 25497125 PMCID: PMC4307903 DOI: 10.1186/s13062-014-0030-9] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2014] [Accepted: 12/02/2014] [Indexed: 01/19/2023] Open
Abstract
BACKGROUND Moonlighting proteins perform two or more cellular functions, which are selected based on various contexts including the cell type they are expressed, their oligomerization status, and the binding of different ligands at different sites. To understand overall landscape of their functional diversity, it is important to establish methods that can identify moonlighting proteins in a systematic fashion. Here, we have developed a computational framework to find moonlighting proteins on a genome scale and identified multiple proteomic characteristics of these proteins. RESULTS First, we analyzed Gene Ontology (GO) annotations of known moonlighting proteins. We found that the GO annotations of moonlighting proteins can be clustered into multiple groups reflecting their diverse functions. Then, by considering the observed GO term separations, we identified 33 novel moonlighting proteins in Escherichia coli and confirmed them by literature review. Next, we analyzed moonlighting proteins in terms of protein-protein interaction, gene expression, phylogenetic profile, and genetic interaction networks. We found that moonlighting proteins physically interact with a higher number of distinct functional classes of proteins than non-moonlighting ones and also found that most of the physically interacting partners of moonlighting proteins share the latter's primary functions. Interestingly, we also found that moonlighting proteins tend to interact with other moonlighting proteins. In terms of gene expression and phylogenetically related proteins, a weak trend was observed that moonlighting proteins interact with more functionally diverse proteins. Structural characteristics of moonlighting proteins, i.e. intrinsic disordered regions and ligand binding sites were also investigated. CONCLUSION Additional functions of moonlighting proteins are difficult to identify by experiments and these proteins also pose a significant challenge for computational function annotation. Our method enables identification of novel moonlighting proteins from current functional annotations in public databases. Moreover, we showed that potential moonlighting proteins without sufficient functional annotations can be identified by analyzing available omics-scale data. Our findings open up new possibilities for investigating the multi-functional nature of proteins at the systems level and for exploring the complex functional interplay of proteins in a cell. REVIEWERS This article was reviewed by Michael Galperin, Eugine Koonin, and Nick Grishin.
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Affiliation(s)
- Ishita Khan
- />Department of Computer Science, Purdue University, 305 North University Street, West Lafayette, IN 47907 USA
| | - Yuqian Chen
- />Department of Biological Sciences, Purdue University, 240 Martin Jischke Drive, West Lafayette, IN 47907 USA
| | - Tiange Dong
- />Department of Biological Sciences, Purdue University, 240 Martin Jischke Drive, West Lafayette, IN 47907 USA
| | - Xioawei Hong
- />Department of Biological Sciences, Purdue University, 240 Martin Jischke Drive, West Lafayette, IN 47907 USA
| | - Rikiya Takeuchi
- />Graduate School of Biological Sciences, Nara Institute of Science and Technology, 8916-5, Takayama, Ikoma, Nara, 630-0192 Japan
| | - Hirotada Mori
- />Graduate School of Biological Sciences, Nara Institute of Science and Technology, 8916-5, Takayama, Ikoma, Nara, 630-0192 Japan
| | - Daisuke Kihara
- />Department of Computer Science, Purdue University, 305 North University Street, West Lafayette, IN 47907 USA
- />Department of Biological Sciences, Purdue University, 240 Martin Jischke Drive, West Lafayette, IN 47907 USA
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Morshedi D, Aliakbari F, Nouri HR, Lotfinia M, Fallahi J. Using small molecules as a new challenge to redirect metabolic pathway. 3 Biotech 2014; 4:513-522. [PMID: 28324386 PMCID: PMC4162896 DOI: 10.1007/s13205-013-0185-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2013] [Accepted: 11/09/2013] [Indexed: 11/26/2022] Open
Abstract
The presence of acetate in the bacterial medium leads to a reduction in the growth rate of cells and recombinant protein production. In this study, three compounds including propionic acid, lithium chloride and butyric acid were added to the medium which decreased acetate levels and enhanced recombinant protein production (alpha-synuclein). In fact, propionic acid and lithium chloride are both known as acetate kinase inhibitors. The results obtained in the case of butyric acid were similar to those of the two other compounds indicating that butyric acid may act through a mechanism similar to propionic acid and lithium chloride. Consequently, it was shown that the presence of each of these supplements (5–200 μM) increased recombinant alpha-synuclein production and cell density by approximately 10–15 %. HPLC analysis showed that the levels of acetate in the media containing the supplements were considerably less than those of the control. Furthermore, pH values remained almost constant in the supplemented cultures. Growing the bacteria at lower temperatures (25 °C) indicated that the positive effects of these supplements were not as effective as at higher temperatures (37 °C), presumably due to the adequate balance between oxygen and carbon consumption. This study can confirm the viewpoint regarding the harmful effects of acetate on the recombinant protein production and cell density. Besides, such methods represent easy and complementary ways to increase target recombinant protein production without negatively affecting host cell density, and requiring complex genetic manipulation.
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Affiliation(s)
- Dina Morshedi
- Department of Industrial and Environmental Biotechnology, National Institute of Genetic Engineering and Biotechnology, Shahrak-e Pajoohesh, km 15, Tehran-Karaj Highway, P. O. Box: 14965/161, Tehran, Iran.
| | - Farhang Aliakbari
- Department of Industrial and Environmental Biotechnology, National Institute of Genetic Engineering and Biotechnology, Shahrak-e Pajoohesh, km 15, Tehran-Karaj Highway, P. O. Box: 14965/161, Tehran, Iran
- Department of Biotechnology, Semnan University of Medical Sciences, Semnan, Iran
| | - Hamid Reza Nouri
- Department of Industrial and Environmental Biotechnology, National Institute of Genetic Engineering and Biotechnology, Shahrak-e Pajoohesh, km 15, Tehran-Karaj Highway, P. O. Box: 14965/161, Tehran, Iran
| | - Majid Lotfinia
- Department of Stem Cells and Developmental Biology, Cell Science Research Center, Royan Institute for Stem Cell Biology and Technology, ACECR, Tehran, Iran
- Department of Biochemistry, Pasteur Institute of Iran, Tehran, Iran
| | - Jafar Fallahi
- Department of Industrial and Environmental Biotechnology, National Institute of Genetic Engineering and Biotechnology, Shahrak-e Pajoohesh, km 15, Tehran-Karaj Highway, P. O. Box: 14965/161, Tehran, Iran
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Gulevich AY, Skorokhodova AY, Sukhozhenko AV, Shakulov RS, Debabov VG. Metabolic engineering of Escherichia coli for 1-butanol biosynthesis through the inverted aerobic fatty acid β-oxidation pathway. Biotechnol Lett 2011; 34:463-9. [PMID: 22105550 DOI: 10.1007/s10529-011-0797-z] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2011] [Accepted: 11/09/2011] [Indexed: 11/30/2022]
Abstract
The basic reactions of the clostridial 1-butanol biosynthesis pathway can be regarded to be the inverted reactions of the fatty acid β-oxidation pathway. A pathway for the biosynthesis of fuels and chemicals was recently engineered by combining enzymes from both aerobic and anaerobic fatty acid β-oxidation as well as enzymes from other metabolic pathways. In the current study, we demonstrate the inversion of the entire aerobic fatty acid β-oxidation cycle for 1-butanol biosynthesis. The constructed markerless and plasmidless Escherichia coli strain BOX-3 (MG1655 lacI(Q) attB-P(trc-ideal-4)-SD(φ10)-adhE(Glu568Lys) attB-P(trc-ideal-4)-SD(φ10)-atoB attB-P(trc-ideal-4)-SD(φ10)-fadB attB-P(trc-ideal-4)-SD(φ10)-fadE) synthesises 0.3-1 mg 1-butanol/l in the presence of the specific inducer. No 1-butanol production was detected in the absence of the inducer.
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Affiliation(s)
- Andrey Yu Gulevich
- Research Institute for Genetics and Selection of Industrial Microorganisms, 1-st Dorozhniy Pr., 1, Moscow, Russia 117545.
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Buschhorn H, Dürre P, Gottschalk G. Production and Utilization of Ethanol by the Homoacetogen Acetobacterium woodii. Appl Environ Microbiol 2010; 55:1835-40. [PMID: 16347978 PMCID: PMC202959 DOI: 10.1128/aem.55.7.1835-1840.1989] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Acetobacterium woodii formed ethanol as a fermentation product in addition to acetate when the phosphate concentration of the medium was between 0.2 and 8.4 mM. Considerable amounts of alanine were also found (2 to 11 mM). Supplementation with phosphate caused a shift to acetate as the only end product. Ethanol could also serve as a substrate for A. woodii. The fermentation yielded predominantly acetate and was strictly dependent on high bicarbonate concentrations. 1-Propanol, 1-butanol, and 1-pentanol were converted to the corresponding fatty acids but allowed only marginal growth. A. wieringae and A. carbinolicum grown under identical conditions were also able to form ethanol, and A. wieringae could use ethanol as a substrate, too. Alcohol dehydrogenase and acetaldehyde dehydrogenase activities were determined in A. woodii. Activity stains of polyacrylamide gels with crude extracts allowed the detection of acetaldehyde dehydrogenase but not of alcohol dehydrogenase. Trace amounts of methane were detected during growth of A. woodii on glucose and ethanol.
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Affiliation(s)
- H Buschhorn
- Institut für Mikrobiologie, Universität Göttingen, Grisebachstrasse 8, D-3400 Göttingen, Federal Republic of Germany
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Atteia A, van Lis R, Mendoza-Hernández G, Henze K, Martin W, Riveros-Rosas H, González-Halphen D. Bifunctional aldehyde/alcohol dehydrogenase (ADHE) in chlorophyte algal mitochondria. PLANT MOLECULAR BIOLOGY 2003; 53:175-188. [PMID: 14756315 DOI: 10.1023/b:plan.0000009274.19340.36] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Protein profiles of mitochondria isolated from the heterotrophic chlorophyte Polytomella sp. grown on ethanol at pH 6.0 and pH 3.7 were analyzed by Blue Native and denaturing polyacrylamide gel electrophoresis. Steady-state levels of oxidative phosphorylation complexes were influenced by external pH. Levels of an abundant, soluble, mitochondrial protein of 85 kDa and its corresponding mRNA increased at pH 6.0 relative to pH 3.7. N-terminal and internal sequencing of the 85 kDa mitochondrial protein together with the corresponding cDNA identified it as a bifunctional aldehyde/alcohol dehydrogenase (ADHE) with strong similarity to homologues from eubacteria and amitochondriate protists. A mitochondrial targeting sequence of 27 amino acids precedes the N-terminus of the mature mitochondrial protein. A gene encoding an ADHE homologue was also identified in the genome of Chlamydomonas reinhardtii, a photosynthetic relative of Polytomella. ADHE reveals a complex picture of sequence similarity among homologues. The lack of ADHE from archaebacteria indicates a eubacterial origin for the eukaryotic enzyme. Among eukaryotes, ADHE has hitherto been characteristic of anaerobes since it is essential to cytosolic energy metabolism of amitochondriate protists such as Giardia intestinalis and Entamoeba histolytica. Its abundance and expression pattern suggest an important role for ADHE in mitochondrial metabolism of Polytomella under the conditions studied. The current data are compatible with the view that Polytomella ADHE could be involved either in ethanol production or assimilation, or both, depending upon environmental conditions. Presence of ADHE in an oxygen-respiring algal mitochondrion and co-expression at ambient oxygen levels with respiratory chain components is unexpected with respect to the view that eukaryotes acquired ADHE genes specifically as an adaptation to an anaerobic lifestyle.
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Affiliation(s)
- Ariane Atteia
- Departamento de Genética Molecular, Instituto de Fisiología Celular, Universidad Nacional Autáonoma de México, México D.F. 04510, México.
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Mahishi LH, Tripathi G, Rawal SK. Poly(3-hydroxybutyrate) (PHB) synthesis by recombinant Escherichia coli harbouring Streptomyces aureofaciens PHB biosynthesis genes: effect of various carbon and nitrogen sources. Microbiol Res 2003; 158:19-27. [PMID: 12608576 DOI: 10.1078/0944-5013-00161] [Citation(s) in RCA: 58] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Recombinant Escherichia coli (ATCC:PTA-1579) harbouring poly(3-hydroxybutyrate) (PHB) synthesising genes from Streptomyces aureofaciens NRRL 2209 accumulates PHB. Effects of different carbon and nitrogen sources on PHB accumulation by recombinant E. coli were studied. Among the carbon sources used glycerol, glucose, palm oil and ethanol supported PHB accumulation. No PHB accumulated in recombinant cells when sucrose or molasses were used as carbon source. Yeast extract, peptone, a combination of yeast extract and peptone, and corn steep liquor were used as nitrogen sources. The maximum PHB accumulation (60% of cell dry weight) was measured after 48 h of cell growth at 37 degrees C in a medium with glycerol as the sole carbon source, and yeast extract and peptone as nitrogen sources. Scanning electron microscopy of the PHB granules isolated from recombinant E. coli revealed these to be spherical in shape with a diameter ranging from 0.11 to 0.35 pm with the mean value of 0.23 +/- 0.06 pm.
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Affiliation(s)
- L H Mahishi
- Plant Tissue Culture Division, National Chemical Laboratory, Pune 411008, India
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Echave P, Esparza-Cerón MA, Cabiscol E, Tamarit J, Ros J, Membrillo-Hernández J, Lin ECC. DnaK dependence of mutant ethanol oxidoreductases evolved for aerobic function and protective role of the chaperone against protein oxidative damage in Escherichia coli. Proc Natl Acad Sci U S A 2002; 99:4626-31. [PMID: 11917132 PMCID: PMC123698 DOI: 10.1073/pnas.072504199] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2001] [Indexed: 11/18/2022] Open
Abstract
The adhE gene of Escherichia coli encodes a multifunctional ethanol oxidoreductase (AdhE) that catalyzes successive reductions of acetyl-CoA to acetaldehyde and then to ethanol reversibly at the expense of NADH. Mutant JE52, serially selected for acquired and improved ability to grow aerobically on ethanol, synthesized an AdhE(A267T/E568K) with two amino acid substitutions that sequentially conferred improved catalytic properties and stability. Here we show that the aerobic growth ability on ethanol depends also on protection of the mutant AdhE against metal-catalyzed oxidation by the chaperone DnaK (a member of the Hsp70 family). No DnaK protection of the enzyme is evident during anaerobic growth on glucose. Synthesis of DnaK also protected E. coli from H2O2 killing under conditions when functional AdhE is not required. Our results therefore suggest that, in addition to the known role of protecting cells against heat stress, DnaK also protects numerous kinds of proteins from oxidative damage.
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Affiliation(s)
- Pedro Echave
- Departamento de Biologia Molecular y Biotecnologia, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, P.O. Box 70-228, 04510 Mexico City, Mexico
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16
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Dailly Y, Mat-Jan F, Clark DP. Novel alcohol dehydrogenase activity in a mutant of Salmonella able to use ethanol as sole carbon source. FEMS Microbiol Lett 2001; 201:41-5. [PMID: 11445165 DOI: 10.1111/j.1574-6968.2001.tb10730.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022] Open
Abstract
We selected a mutant of Salmonella enterica serovar Typhimurium that is capable of growing in air on ethanol as sole carbon and energy source. This adhI mutant expressed high levels of a novel alcohol dehydrogenase (AdhI) that uses ethanol, 1-propanol and 2-propanol as substrates. The fermentative AdhE alcohol dehydrogenase was not expressed aerobically in the adhI mutant. Anaerobically, both the novel AdhI enzyme and the AdhE were expressed simultaneously in the adhI mutant. However, the adhI mutant showed no alteration in the composition of the fermentation products. In addition we found that both the parental Salmonella and its alcohol using adhI mutant expressed substantial levels of a dye-linked aldehyde dehydrogenase that is presumably responsible for conversion of acetaldehyde to acetate. This contrasts with the situation in Escherichia coli where mutants able to grow on ethanol express high aerobic levels of the AdhE enzyme, which performs both the alcohol dehydrogenase and aldehyde dehydrogenase reactions.
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Affiliation(s)
- Y Dailly
- Department of Microbiology, Southern Illinois University, Carbondale, IL 62901, USA
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17
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Holland-Staley CA, Lee K, Clark DP, Cunningham PR. Aerobic activity of Escherichia coli alcohol dehydrogenase is determined by a single amino acid. J Bacteriol 2000; 182:6049-54. [PMID: 11029424 PMCID: PMC94738 DOI: 10.1128/jb.182.21.6049-6054.2000] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Expression of the alcohol dehydrogenase gene, adhE, in Escherichia coli is anaerobically regulated at both the transcriptional and the translational levels. To study the AdhE protein, the adhE(+) structural gene was cloned into expression vectors under the control of the lacZ and trp(c) promoters. Wild-type AdhE protein produced under aerobic conditions from these constructs was inactive. Constitutive mutants (adhC) that produced high levels of AdhE under both aerobic and anaerobic conditions were previously isolated. When only the adhE structural gene from one of the adhC mutants was cloned into expression vectors, highly functional AdhE protein was isolated under both aerobic and anaerobic conditions. Sequence analysis revealed that the adhE gene from the adhC mutant contained two mutations resulting in two amino acid substitutions, Ala267Thr and Glu568Lys. Thus, adhC strains contain a promoter mutation and two mutations in the structural gene. The mutant structural gene from adhC strains was designated adhE*. Fragment exchange experiments revealed that the substitution responsible for aerobic expression in the adhE* clones is Glu568Lys. Genetic selection and site-directed mutagenesis experiments showed that virtually any amino acid substitution for Glu568 produced AdhE that was active under both aerobic and anaerobic conditions. These findings suggest that adhE expression is also regulated posttranslationally and that strict regulation of alcohol dehydrogenase activity in E. coli is physiologically significant.
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Affiliation(s)
- C A Holland-Staley
- Infectious Disease Research, Henry Ford Hospital, Detroit, Michigan 48202, USA
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18
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Membrillo-Hernandez J, Echave P, Cabiscol E, Tamarit J, Ros J, Lin EC. Evolution of the adhE gene product of Escherichia coli from a functional reductase to a dehydrogenase. Genetic and biochemical studies of the mutant proteins. J Biol Chem 2000; 275:33869-75. [PMID: 10922373 DOI: 10.1074/jbc.m005464200] [Citation(s) in RCA: 68] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The multifunctional AdhE protein of Escherichia coli (encoded by the adhE gene) physiologically catalyzes the sequential reduction of acetyl-CoA to acetaldehyde and then to ethanol under fermentative conditions. The NH(2)-terminal region of the AdhE protein is highly homologous to aldehyde:NAD(+) oxidoreductases, whereas the COOH-terminal region is homologous to a family of Fe(2+)-dependent ethanol:NAD(+) oxidoreductases. This fusion protein also functions as a pyruvate formate lyase deactivase. E. coli cannot grow aerobically on ethanol as the sole carbon and energy source because of inadequate rate of adhE transcription and the vulnerability of the AdhE protein to metal-catalyzed oxidation. In this study, we characterized 16 independent two-step mutants with acquired and improved aerobic growth ability on ethanol. The AdhE proteins in these mutants catalyzed the sequential oxidation of ethanol to acetaldehyde and to acetyl-CoA. All first stage mutants grew on ethanol with a doubling time of about 240 min. Sequence analysis of a randomly chosen mutant revealed an Ala-267 --> Thr substitution in the acetaldehyde:NAD(+) oxidoreductase domain of AdhE. All second stage mutants grew on ethanol with a doubling time of about 90 min, and all of them produced an AdhE(A267T/E568K). Purified AdhE(A267T) and AdhE(A267T/E568K) showed highly elevated acetaldehyde dehydrogenase activities. It therefore appears that when AdhE catalyzes the two sequential reactions in the counter-physiological direction, acetaldehyde dehydrogenation is the rate-limiting step. Both mutant proteins were more thermosensitive than the wild-type protein, but AdhE(A267T/E568K) was more thermal stable than AdhE(A267T). Since both mutant enzymes exhibited similar kinetic properties, the second mutation probably conferred an increased growth rate on ethanol by stabilizing AdhE(A267T).
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Affiliation(s)
- J Membrillo-Hernandez
- Department of Microbiology and Molecular Genetics, Harvard Medical School, Boston, Massachusetts 02115, USA
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19
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Abstract
This map is an update of the edition 9 map by Berlyn et al. (M. K. B. Berlyn, K. B. Low, and K. E. Rudd, p. 1715-1902, in F. C. Neidhardt et al., ed., Escherichia coli and Salmonella: cellular and molecular biology, 2nd ed., vol. 2, 1996). It uses coordinates established by the completed sequence, expressed as 100 minutes for the entire circular map, and adds new genes discovered and established since 1996 and eliminates those shown to correspond to other known genes. The latter are included as synonyms. An alphabetical list of genes showing map location, synonyms, the protein or RNA product of the gene, phenotypes of mutants, and reference citations is provided. In addition to genes known to correspond to gene sequences, other genes, often older, that are described by phenotype and older mapping techniques and that have not been correlated with sequences are included.
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Affiliation(s)
- M K Berlyn
- Department of Biology and School of Forestry and Environmental Studies, Yale University, New Haven, Connecticut 06520-8104, USA.
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20
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Rachman MA, Furutani Y, Nakashimada Y, Kakizono T, Nishio N. Enhanced hydrogen production in altered mixed acid fermentation of glucose by Enterobacter aerogenes. ACTA ACUST UNITED AC 1997. [DOI: 10.1016/s0922-338x(97)80142-0] [Citation(s) in RCA: 108] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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21
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Abstract
There is an astonishing array of microbial alcohol oxidoreductases. They display a wide variety of substrate specificities and they fulfill several vital but quite different physiological functions. Some of these enzymes are involved in the production of alcoholic beverages and of industrial solvents, others are important in the production of vinegar, and still others participate in the degradation of naturally occurring and xenobiotic aromatic compounds as well as in the growth of bacteria and yeasts on methanol. They can be divided into three major categories. (1) The NAD- or NADP-dependent dehydrogenases. These can in turn be divided into the group I long-chain (approximately 350 amino acid residues) zinc-dependent enzymes such as alcohol dehydrogenases I, II, and III of Saccharomyces cerevisiae or the plasmid-encoded benzyl alcohol dehydrogenase of Pseudomonas putida; the group II short-chain (approximately 250 residues) zinc-independent enzymes such as ribitol dehydrogenase of Klebsiella aerogenes; the group III "iron-activated" enzymes that generally contain approximately 385 amino acid residues, such as alcohol dehydrogenase II of Zymomonas mobilis and alcohol dehydrogenase IV of Saccharomyces cerevisiae, but may contain almost 900 residues in the case of the multifunctional alcohol dehydrogenases of Escherichia coli and Clostridium acetobutylicum. The aldehyde/alcohol oxidoreductase of Amycolatopsis methanolica and the methanol dehydrogenases of A. methanolica and Mycobacterium gasti are 4-nitroso-N,N-dimethylaniline-dependent nicotinoproteins. (2) NAD(P)-independent enzymes that use pyrroloquinoline quinone, haem or cofactor F420 as cofactor, exemplified by methanol dehydrogenase of Paracoccus denitrificans, ethanol dehydrogenase of Acetobacter and Gluconobacter spp. and the alcohol dehydrogenases of certain archaebacteria. (3) Oxidases that catalyze an essentially irreversible oxidation of alcohols, such as methanol oxidase of Hansenula polymorpha and probably the veratryl alcohol oxidases of certain fungi involved in lignin degradation. This review deals mainly with those enzymes for which complete amino acid sequences are available. The discussion focuses on a comparison of their primary, secondary, tertiary, and quaternary structures and their catalytic mechanisms. The physiological roles of the enzymes and isoenzymes are also considered, as are their probable evolutionary relationships.
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Affiliation(s)
- M F Reid
- Department of Biochemistry, University of Glasgow, Scotland, U.K
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22
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Abstract
A list of currently identified gene products of Escherichia coli is given, together with a bibliography that provides pointers to the literature on each gene product. A scheme to categorize cellular functions is used to classify the gene products of E. coli so far identified. A count shows that the numbers of genes concerned with small-molecule metabolism are on the same order as the numbers concerned with macromolecule biosynthesis and degradation. One large category is the category of tRNAs and their synthetases. Another is the category of transport elements. The categories of cell structure and cellular processes other than metabolism are smaller. Other subjects discussed are the occurrence in the E. coli genome of redundant pairs and groups of genes of identical or closely similar function, as well as variation in the degree of density of genetic information in different parts of the genome.
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Affiliation(s)
- M Riley
- Marine Biological Laboratory, Woods Hole, Massachusetts 02543
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23
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Oppermann FB, Schmidt B, Steinbüchel A. Purification and characterization of acetoin:2,6-dichlorophenolindophenol oxidoreductase, dihydrolipoamide dehydrogenase, and dihydrolipoamide acetyltransferase of the Pelobacter carbinolicus acetoin dehydrogenase enzyme system. J Bacteriol 1991; 173:757-67. [PMID: 1898934 PMCID: PMC207069 DOI: 10.1128/jb.173.2.757-767.1991] [Citation(s) in RCA: 61] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Dihydrolipoamide dehydrogenase (DHLDH), dihydrolipoamide acetyltransferase (DHLTA), and acetoin: 2,6-dichlorophenolindophenol oxidoreductase (Ao:DCPIP OR) were purified from acetoin-grown cells of Pelobacter carbinolicus. DHLDH had a native Mr of 110,000, consisted of two identical subunits of Mr 54,000, and reacted only with NAD(H) as a coenzyme. The N-terminal amino acid sequence included the flavin adenine dinucleotide-binding site and exhibited a high degree of homology to other DHLDHs. DHLTA had a native Mr of greater than 500,000 and consisted of subunits identical in size (Mr 60,000). The enzyme was highly sensitive to proteolytic attack. During limited tryptic digestion, two major fragments of Mr 32,500 and 25,500 were formed. Ao:DCPIP OR consisted of two different subunits of Mr 37,500 and 38,500 and had a native Mr in the range of 143,000 to 177,000. In vitro in the presence of DCPIP, it catalyzed a thiamine pyrophosphate-dependent oxidative-hydrolytic cleavage of acetoin, methylacetoin, and diacetyl. The combination of purified Ao:DCPIP OR, DHLTA, and DHLDH in the presence of thiamine pyrophosphate and the substrate acetoin or methylacetoin resulted in a coenzyme A-dependent reduction of NAD. In the strictly anaerobic acetoin-utilizing bacteria P. carbinolicus, Pelobacter venetianus, Pelobacter acetylenicus, Pelobacter propionicus, Acetobacterium carbinolicum, and Clostridium magnum, the enzymes Ao:DCPIP OR, DHLTA, and DHLDH were induced during growth on acetoin, whereas they were absent or scarcely present in cells grown on a nonacetoinogenic substrate.
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Affiliation(s)
- F B Oppermann
- Institut für Mikrobiologie der Georg-August-Universität, Göttingen, Federal Republic of Germany
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24
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Goodlove PE, Cunningham PR, Parker J, Clark DP. Cloning and sequence analysis of the fermentative alcohol-dehydrogenase-encoding gene of Escherichia coli. Gene X 1989; 85:209-14. [PMID: 2695398 DOI: 10.1016/0378-1119(89)90483-6] [Citation(s) in RCA: 100] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
A 6-kb fragment of DNA, which complemented defects in the alcohol dehydrogenase (ADH)-encoding gene (adhE) of Escherichia coli, was cloned into a multicopy vector. Both ADH and coenzyme-A-linked acetaldehyde dehydrogenase (ACDH) activities were encoded by the plasmid, pHIL8. The adhE gene was identified as an open reading frame of 891 codons encoding an Mr 96,008 protein (minus the initiating methionine). Codon usage analysis indicates that adhE should be highly expressed. This gene shows no significant homology to any previously sequenced ADH-encoding gene.
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Affiliation(s)
- P E Goodlove
- Department of Microbiology, Southern Illinois University, Carbondale 62901
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25
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26
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Mat-Jan F, Alam KY, Clark DP. Mutants of Escherichia coli deficient in the fermentative lactate dehydrogenase. J Bacteriol 1989; 171:342-8. [PMID: 2644194 PMCID: PMC209593 DOI: 10.1128/jb.171.1.342-348.1989] [Citation(s) in RCA: 127] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Mutants of Escherichia coli deficient in the fermentative NAD-linked lactate dehydrogenase (ldh) have been isolated. These mutants showed no growth defects under anaerobic conditions unless present together with a defect in pyruvate formate lyase (pfl). Double mutants (pfl ldh) were unable to grow anaerobically on glucose or other sugars even when supplemented with acetate, whereas pfl mutants can do so. The ldh mutation was found to map at 30.5 min on the E. coli chromosome. The ldh mutant FMJ39 showed no detectable lactate dehydrogenase activity and produced no lactic acid from glucose under anaerobic conditions as estimated by in vivo nuclear magnetic resonance measurements. We also found that in wild-type strains the fermentative lactate dehydrogenase was conjointly induced by anaerobic conditions and an acidic pH. Despite previous findings that phosphate concentrations affect the proportion of lactic acid produced during fermentation, we were unable to find any intrinsic effect of phosphate on lactate dehydrogenase activity, apart from the buffering effect of this ion.
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Affiliation(s)
- F Mat-Jan
- Department of Microbiology, Southern Illinois University, Carbondale 62901
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27
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Reams SG, Clark DP. Glucose repression of anaerobic genes ofEscherichia coliis independent of cyclic AMP. FEMS Microbiol Lett 1988. [DOI: 10.1111/j.1574-6968.1988.tb03183.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
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28
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Palosaari NR, Rogers P. Purification and properties of the inducible coenzyme A-linked butyraldehyde dehydrogenase from Clostridium acetobutylicum. J Bacteriol 1988; 170:2971-6. [PMID: 3384801 PMCID: PMC211236 DOI: 10.1128/jb.170.7.2971-2976.1988] [Citation(s) in RCA: 48] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
The coenzyme A (CoA)-linked butyraldehyde dehydrogenase (BAD) from Clostridium acetobutylicum was characterized and purified to homogeneity. The enzyme was induced over 200-fold, coincident with a shift from an acidogenic to a solventogenic fermentation, during batch culture growth. The increase in enzyme activity was found to require new protein synthesis since induction was blocked by the addition of rifampin and antibody against the purified enzyme showed the appearance of enzyme antigen beginning at the shift of the fermentation and increasing coordinately with the increase in enzyme specific activity. The CoA-linked acetaldehyde dehydrogenase was copurified with BAD during an 89-fold purification, indicating that one enzyme accounts for the synthesis of the two aldehyde intermediates for both butanol and ethanol production. Butanol dehydrogenase activity was clearly separate from the BAD enzyme activity on TEAE cellulose. A molecular weight of 115,000 was determined for the native enzyme, and the enzyme subunit had a molecular weight of 56,000 indicating that the active form is a homodimer. Kinetic constants were determined in both the forward and reverse directions. In the reverse direction both the Vmax and the apparent affinity for butyraldehyde and caproaldehyde were significantly greater than they were for acetaldehyde, while in the forward direction, the Vmax for butyryl-CoA was fivefold that for acetyl-CoA. These and other properties of BAD indicate that this enzyme is distinctly different from other reported CoA-dependent aldehyde dehydrogenases.
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Affiliation(s)
- N R Palosaari
- Department of Microbiology, University of Minnesota, Minneapolis 55455
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29
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Conway T, Sewell GW, Osman YA, Ingram LO. Cloning and sequencing of the alcohol dehydrogenase II gene from Zymomonas mobilis. J Bacteriol 1987; 169:2591-7. [PMID: 3584063 PMCID: PMC212129 DOI: 10.1128/jb.169.6.2591-2597.1987] [Citation(s) in RCA: 172] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
The gene which encodes alcohol dehydrogenase II (adhB) from Zymomonas mobilis was cloned in Escherichia coli as a 1.4-kilobase DNA fragment by using a novel indicator plate which directly detects the expression of this activity by recombinant colonies. The DNA sequence for this clone contained an open reading frame encoding a polypeptide of 383 amino acids, with a molecular weight of 40,141. Although this protein exhibited very little homology with other known alcohol dehydrogenases, the predicted amino acid composition was in excellent agreement with that reported for the purified alcohol dehydrogenase II protein from Z. mobilis. In Z. mobilis, the adhB gene was transcribed from tandem promoters which were separated by 100 base pairs and ended with a transcriptional terminator (13-base-pair palindrome). In Escherichia coli, only one of the Z. mobilis promoters was used, despite apparent similarity to the enteric consensus promoter. The adhB gene was transcribed at low levels in E. coli from the P2 promoter of Z. mobilis but was expressed well in E. coli under control of the lac promoter (approximately 0.25% of the total cell protein).
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30
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Clark DP, Rod ML. Regulatory mutations that allow the growth of Escherichia coli on butanol as carbon source. J Mol Evol 1987; 25:151-8. [PMID: 3116274 DOI: 10.1007/bf02101757] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Starting with adhC mutants of Escherichia coli in which alcohol dehydrogenase (ADH) and acetaldehyde CoA dehydrogenase (ACDH) are expressed constitutively at high levels, we selected mutants with still higher levels of both enzymes. Selection for growth on ethanol in the presence of inhibitors of ADH gave several mutants that had from 2- to 10-fold increases in the levels of both enzymes. These mutations were found to map far from the adhC locus at around 90 min. Such adhR mutants were unable to grow on acetate or ethanol in certain media unless supplemented with extra manganese. This growth disability was suppressed by secondary mutations, one of which, aceX, increased sensitivity to several toxic metals and may perhaps derepress Mn transport. When the adhR mutation expressing the highest ADH and ACDH levels was present together with fadR and atoC mutations (allowing efficient catabolism of acetoacetyl-CoA) and with an aceX mutation, the resulting strains became capable of using n-butanol as sole carbon and energy source. The use of butanol by E. coli illustrates the artificial evolution of a new catabolic pathway, in this case by the selection of four successive regulatory mutations (fadR, adhC, atoC, and adhR) together with the poorly defined aceX mutation. Each stage in the acquisition of this novel pathway confers the ability to use a new growth substrate: decanoic acid (fadR), ethanol (adhC), butyric acid (atoC), and butanol (adhR, when present with aceX).
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Affiliation(s)
- D P Clark
- Department of Microbiology, Southern Illinois University, Carbondale 62901
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31
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Cooper CL, Jackowski S, Rock CO. Fatty acid metabolism in sn-glycerol-3-phosphate acyltransferase (plsB) mutants. J Bacteriol 1987; 169:605-11. [PMID: 3542964 PMCID: PMC211821 DOI: 10.1128/jb.169.2.605-611.1987] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Fatty acid metabolism was examined in Escherichia coli plsB mutants that were conditionally defective in sn-glycerol-3-phosphate acyltransferase activity. The fatty acids synthesized when acyl transfer to glycerol-3-phosphate was inhibited were preferentially transferred to phosphatidylglycerol. A comparison of the ratio of phospholipid species labeled with 32Pi and [3H]acetate in the presence and absence of glycerol-3-phosphate indicated that [3H]acetate incorporation into phosphatidylglycerol was due to fatty acid turnover. A significant contraction of the acetyl coenzyme A pool after glycerol-3-phosphate starvation of the plsB mutant precluded the quantitative assessment of the rate of phosphatidylglycerol fatty acid labeling. Fatty acid chain length in membrane phospholipids increased as the concentration of the glycerol-3-phosphate growth supplement decreased, and after the abrupt cessation of phospholipid biosynthesis abnormally long chain fatty acids were excreted into the growth medium. These data suggest that the acyl moieties of phosphatidylglycerol are metabolically active, and that competition between fatty acid elongation and acyl transfer is an important determinant of the acyl chain length in membrane phospholipids.
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32
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Cunningham PR, Clark DP. The use of suicide substrates to select mutants of Escherichia coli lacking enzymes of alcohol fermentation. MOLECULAR & GENERAL GENETICS : MGG 1986; 205:487-93. [PMID: 3550385 DOI: 10.1007/bf00338087] [Citation(s) in RCA: 36] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Mutants of Escherichia coli resistant to chloroethanol or to chloroacetaldehyde were selected. Such mutants were found to lack the fermentative coenzyme A (CoA) linked acetaldehyde dehydrogenase activity. Most also lacked the associated fermentative enzyme alcohol dehydrogenase. Both types of mutants, those lacking acetaldehyde dehydrogenase alone or lacking both enzymes, mapped close to the regulatory adhC gene at 27 min on the E. coli genetic map. The previously described acd mutants which lack acetaldehyde dehydrogenase and which map at 63 min were shown to be pleiotropic, affecting respiration and growth on a variety of substrates. It therefore seems likely that the structural genes for both the acetaldehyde and alcohol dehydrogenases lie in the adhCE operon. This interpretation was confirmed by the isolation of temperature sensitive chloracetaldehyde-resistant mutants, some of which produced thermolabile acetaldehyde dehydrogenase and alcohol dehydrogenase and were also found to map at the adh locus. Reversion analysis indicated that mutants lacking one or both enzymes carried single mutations. The gene order in the adh region was determined by three point crosses to be trp-zch::Tn10-adh-galU-bglY-tyrT-chlC.
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33
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Abstract
A collection of anaerobically induced gene fusions were isolated, and representative isolates were characterized with respect to their regulatory properties, phenotypes, and approximate map locations. Four fusion strains that had defects in the anaerobic metabolism of asparagine or aspartate were found. These fusions were all repressed by alternate electron acceptors, ammonia, and glucose but were induced by other sugars. Several other fusion strains which demonstrated no observable phenotype showed diverse regulatory responses. The anaerobically induced fusions were scattered around the Escherichia coli chromosome more or less at random, suggesting that all the isolates examined were in separate genes.
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34
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Singer ME, Finnerty WR. Alcohol dehydrogenases in Acinetobacter sp. strain HO1-N: role in hexadecane and hexadecanol metabolism. J Bacteriol 1985; 164:1017-24. [PMID: 2933391 PMCID: PMC219292 DOI: 10.1128/jb.164.3.1017-1024.1985] [Citation(s) in RCA: 33] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Multiple alcohol dehydrogenases (ADH) were demonstrated in Acinetobacter sp. strain HO1-N. ADH-A and ADH-B were distinguished on the basis of electrophoretic mobility, pyridine nucleotide cofactor requirement, and substrate specificity. ADH-A is a soluble, NAD-linked, inducible ethanol dehydrogenase (EDH) exhibiting an apparent Km for ethanol of 512 microM and a Vmax of 138 nmol/min. An ethanol-negative mutant (Eth1) was isolated which contained 6.5% of wild-type EDH activity and was deficient in ADH-A. Eth1 exhibited normal growth on hexadecane and hexadecanol. A second ethanol-negative mutant (Eth3) was acetaldehyde dehydrogenase (ALDH) deficient, having 12.5% of wild-type ALDH activity. Eth3 had threefold-higher EDH activity than the wild-type strain. ALDH is a soluble, NAD-linked, ethanol-inducible enzyme which exhibited an apparent Km for acetaldehyde of 50 microM and a Vmax of 183 nmol/min. Eth3 exhibited normal growth on hexadecane, hexadecanol, and fatty aldehyde. ADH-B is a soluble, constitutive, NADP-linked ADH which was active with medium-chain-length alcohols. Hexadecanol dehydrogenase (HDH), a soluble and membrane-bound, NAD-linked ADH, was induced 5- to 11-fold by growth on hexadecane or hexadecanol. HDH exhibited apparent Kms for hexadecanol of 1.6 and 2.8 microM in crude extracts derived from hexadecane- and hexadecanol-grown cells, respectively. HDH was distinct from ADH-A and ADH-B, since HDH and ADH-A were not coinduced; Eth1 had wild-type levels of HDH; and HDH requires NAD, while ADH-B requires NADP. NAD- and NADP-independent HDH activity was not detected in the soluble or membrane fraction of extracts derived from hexadecane- or hexadecanol-grown cells. NAD-linked HDH appears to possess a functional role in hexadecane and hexadecanol dissimilation.
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35
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36
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37
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Abstract
Anaerobically,
Brochothrix thermosphacta
fermented glucose primarily to
l
-lactate, acetate, formate, and ethanol. The ratio of these end products varied with growth conditions. Both the presence of acetate and formate and a pH below about 6 increased
l
-lactate production from glucose. Small amounts of butane-2,3-diol were also produced when the pH of the culture was low (≤5.5) or when acetate was added to the growth medium. Radioactive label from [1-
14
C]acetate was incorporated into ethanol and
l
-lactate, implying reversibility of pyruvate-formate lyase. In crude extracts, the following enzymes involved in pyruvate metabolism were demonstrated: lactate dehydrogenase, phosphotransacetylase, acetate kinase, acetaldehyde dehydrogenase (coenzyme A acetylating), ethanol dehydrogenase, pH 6 acetolactate-forming enzyme, and diacetyl (acetoin) reductase. The lactate dehydrogenase did not require fructose-1,6-disphosphate or Mn
2+
for activity.
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Affiliation(s)
- F H Grau
- Meat Research Laboratory, Division of Food Research, Commonwealth Scientific and Industrial Research Organization, Cannon Hill, Queenland 4170, Australia
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Abstract
Mutants of Escherichia coli resistant to allyl alcohol were selected. Such mutants were found to lack alcohol dehydrogenase. In addition, mutants with temperature-sensitive alcohol dehydrogenase activity were obtained. These mutations, designated adhE, are all located at the previously described adh regulatory locus. Most adhE mutants were also defective in acetaldehyde dehydrogenase activity.
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Chang YY, Cronan JE. Mapping nonselectable genes of Escherichia coli by using transposon Tn10: location of a gene affecting pyruvate oxidase. J Bacteriol 1982; 151:1279-89. [PMID: 6286595 PMCID: PMC220406 DOI: 10.1128/jb.151.3.1279-1289.1982] [Citation(s) in RCA: 60] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
Mutants of Escherichia coli K-12 deficient in pyruvate oxidase were isolated by screening for the production of 14CO2 from [1-14C]pyruvate by the method of Tabor et al. (J. Bacteriol. 128:485-486, 1976). One of these lesions (designated poxA) decreased the pyruvate oxidase activity to 10 to 15% of the normal level but grew well. To map this nonselectable mutation, we isolated strains having transposon Tn10 inserted into the chromosome close to the poxA locus and mapped the transposon. These insertions were isolated by the following procedure: (i) pools of Tn10 insertions into the chromosomes of two different Hfr strains were prepared by transposition from a lambda::Tn10 vector; (ii) these Tn10-carrying strains were then mated with a poxA recipient strain, and tetracycline-resistant (Tetr) recombinants were selected; (iii) the Tetr recombinants were then screened for 14CO2 production from [1-14C]pyruvate. This method was shown to give a greater than 40-fold enrichment of insertions of Tn10 near the poxA gene as compared with transduction. Calculations indicate that a similar enrichment should be expected for other genes. The enrichment is due to the much greater map interval over which strong linkage between selected and unselected markers is found in conjugational crosses as compared with transductional crosses. The use of Hfr conjugative transfer allows isolation of transposon insertions closely linked to a nonselectable gene by scoring hundreds rather than thousands of colonies. Using a Tn10 insertion greater than 98% cotransduced with the poxA locus, we mapped the poxA gene on the E. coli genetic map. The poxA locus is located at 94 min, close to the psd locus. The clockwise gene order is ampA, poxA, psd, purA. The poxA mutation is recessive and appears to be a regulatory gene.
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Cronan JE, Littel KJ, Jackowski S. Genetic and biochemical analyses of pantothenate biosynthesis in Escherichia coli and Salmonella typhimurium. J Bacteriol 1982; 149:916-22. [PMID: 7037743 PMCID: PMC216478 DOI: 10.1128/jb.149.3.916-922.1982] [Citation(s) in RCA: 71] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
Pantothenate (pan) auxotrophs of Escherichia coli K-12 and Salmonella typhimurium LT2 were characterized by enzymatic and genetic analyses. The panB mutants of both organisms and the pan-6 ("panA") mutant of S. typhimurium are deficient in ketopantoate hydroxymethyltransferase, whereas the panC mutants lack pantothenate synthetase. panD mutants of E. coli K-12 were previously shown to be deficient in aspartate 1-decarboxylase. All mutants showed only a single enzyme defect. The finding that the pan-6 mutant was deficient in ketopantoate hydroxymethyltransferase indicates that the genetic lesion is a panB allele. The pan-6 mutant therefore is deficient in the utilization of alpha-ketoisovalerate rather than the synthesis of alpha-ketoisovalerate, as originally proposed. The order of the pan genes of E. coli K-12 was determined by phage P1-mediated three-factor crosses. The clockwise order was found to be aceF panB panD panC tonA on the genetic map of E. coli K-12. The three-factor crosses were greatly facilitated by use of a closely linked Tn10 transposon as the outside marker. We also found that supplementation of E. coli K-12 auxotrophs with a high concentration of pantothenate or beta-alanine increased the intracellular coenzyme A level two- to threefold above the normal level. Supplementation with pantoate or ketopantoate resulted in smaller increases.
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Clark DP, Lorowitz W, Cronan JE. Genetic deregulation of ethanol-related genes. BASIC LIFE SCIENCES 1982; 19:363-9. [PMID: 7039601 DOI: 10.1007/978-1-4684-4142-0_27] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
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42
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Abstract
Coenzyme A (CoA) and acyl carrier protein are two cofactors in fatty acid metabolism, and both possess a 4'-phosphopantetheine moiety that is metabolically derived from the vitamin pantothenate. We studied the regulation of the metabolic pathway that gives rise to these two cofactors in an Escherichia coli beta-alanine auxotroph, strain SJ16. Identification and quantitation of the intracellular and extracellular beta-alanine-derived metabolites from cells grown on increasing beta-alanine concentrations were performed. The intracellular content of acyl carrier protein was relatively insensitive to beta-alanine input, whereas the CoA content increased as a function of external beta-alanine concentration, reaching a maximum at 8 microM beta-alanine. Further increase in the beta-alanine concentration led to the excretion of pantothenate into the medium. Comparing the amount of pantothenate found outside the cell to the level of intracellular metabolites demonstrates that E. coli is capable of producing 15-fold more pantoic acid than is required to maintain the intracellular CoA content. Therefore, the supply of pantoic acid is not a limiting factor in CoA biosynthesis. Wild-type cells also excreted pantothenate into the medium, showing that the beta-alanine supply is also not rate limiting in CoA biogenesis. Taken together, the results point to pantothenate kinase as the primary enzymatic step that regulates the CoA content of E. coli.
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Abstract
Fusion of the lacZ gene coding for beta-galactosidase to the fadA,B and fadE operons was accomplished by using the phage Mu d (Apr lac). In such fusion strains, beta-galactosidase was induced by long-chain fatty acids and repressed by glucose, as is the normal pattern of control for the enzymes of the fad regulon. The level of induction seen was approximately 10-fold for both the fadA and fadE operons. These results demonstrate that the previously observed regulation of both the fadA and fadE operons is at the transcriptional level. When an insertion mutation in the fadR (repressor) gene was introduced into the fusion strains, beta-galactosidase was produced constitutively. A series of fatty acids of different chain lengths were tested as inducers. Acids of chain lengths of 10 carbon atoms or less failed to induce, those of 12 carbon atoms induced partly, and those of 14 or more carbon atoms induced fully. Imidazole was found to counteract the glucose repression of the fadA operon as recently demonstrated for the ara operon.
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Structural, enzymatic, and genetic studies of beta-ketoacyl-acyl carrier protein synthases I and II of Escherichia coli. J Biol Chem 1980. [DOI: 10.1016/s0021-9258(19)70226-9] [Citation(s) in RCA: 160] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
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