DOCSLIB.ORG

Engineering the Bioconversion of Methane and Methanol to Fuels And

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Engineering the Bioconversion of Methane and Methanol to Fuels And Available online at www.sciencedirect.com ScienceDirect Engineering the bioconversion of methane and methanol to fuels and chemicals in native and synthetic methylotrophs 1,2 1,2 1 R Kyle Bennett , Lisa M Steinberg , Wilfred Chen and 1,2 Eleftherios T Papoutsakis 3 3 Methylotrophy describes the ability of organisms to utilize 2 Â 10 trillion ft . At current energy usage rates, this is reduced one-carbon compounds, notably methane and enough natural gas to supply the US for 100 years. Meth- methanol, as growth and energy sources. Abundant natural gas ane is also a potent greenhouse gas, having a warming supplies, composed primarily of methane, have prompted potential 21 times that of CO2. As a result, along with the interest in using these compounds, which are more reduced food versus fuel debate, biological gas-to-liquid (GTL) than sugars, as substrates to improve product titers and yields conversion technologies are promising alternatives for of bioprocesses. Engineering native methylotophs or fuel and chemical production. This review discusses developing synthetic methylotrophs are emerging fields to recent progress made toward understanding and convert methane and methanol into fuels and chemicals under engineering native methanotrophs and synthetic methy- aerobic and anaerobic conditions. This review discusses lotrophs for production of fuels and chemicals. Advance- recent progress made toward engineering native ments in aerobic and anaerobic methane utilization will methanotrophs for aerobic and anaerobic methane utilization first be discussed, followed by those made toward engi- and synthetic methylotrophs for methanol utilization. Finally, neering synthetic methylotrophs for methanol utilization. strategies to overcome the limitations involved with synthetic Finally, difficulties with engineering synthetic methanol methanol utilization, notably methanol dehydrogenase kinetics utilization and strategies to overcome them will be and ribulose 5-phosphate regeneration, are discussed. detailed. Addresses 1 Aerobic methane utilization to produce fuels Department of Chemical and Biomolecular Engineering, University of and chemicals Delaware, 150 Academy St., Newark, DE 19716, USA 2 The Delaware Biotechnology Institute, Molecular Biotechnology The physiology and biochemistry of aerobic methano- Laboratory, University of Delaware, 15 Innovation Way, Newark, DE trophs, which utilize methane as their sole carbon and 19711, USA energy source, have been extensively reviewed [3,4]. The first step in methane assimilation is oxidation to methanol Corresponding author: Papoutsakis, Eleftherios T ([email protected]) by methane monooxygenase (MMO) [5], followed by oxidation to formaldehyde by pyrroloquinoline quinone Current Opinion in Biotechnology 50 2018, :81–93 (PQQ)-containing methanol dehydrogenase (MDH) This review comes from a themed issue on Energy biotechnology [3,4]. Type I methanotrophs are gammaproteobacteria, which assimilate formaldehyde via the ribulose monopho- Edited by Akihiko Kondo and Hal Alper sphate (RuMP) pathway. Type II methanotrophs, which assimilate formaldehyde via the serine cycle, are alpha- proteobacteria [4]. A third group of aerobic methanotrophs, https://doi.org/10.1016/j.copbio.2017.11.010 Type X, utilize the RuMP pathway for formaldehyde 0958-1669/ã 2017 Elsevier Ltd. All rights reserved. assimilation but express low levels of serine cycle enzymes and grow at higher temperatures [3]. Two types of MMOs have been identified [5,6]. Nearly all methanotrophs express a membrane-bound particulate MMO (pMMO), and a few also express a soluble MMO Introduction (sMMO). pMMO is an integral membrane hydroxylase Abundant natural gas supplies have made methane and with three subunits arranged as an a3b3g3 trimer, encoded methanol promising substrates for biological production by the pmoCAB operon, and contains two Cu-containing of fuels and chemicals [1 ]. These one-carbon (C1) active sites in the N-termini and C-termini of pmoB compounds are at least 50% more reduced than traditional [6]. sMMO contains three components: a hydroxylase, sugars, for example, glucose, allowing for improved prod- encoded by mmoX, mmoY and mmoZ, a reductase, uct titers and yields [2 ]. Worldwide, the amount of encoded by mmoC, and a regulatory protein, encoded 3 recoverable natural gas is estimated to be 7.2 Â 10 tril- by mmoB [5,6]. The hydroxylase is an a2b2g2 dimer with 3 lion ft [1 ]. In the US alone, estimates approach a diiron active site in the alpha subunit [5]. pMMO has a www.sciencedirect.com Current Opinion in Biotechnology 2018, 50:81–93 82 Energy biotechnology narrow substrate specificity and oxidizes shorter alkanes into lactic and acetic acid with increased ATP and up to five carbons [6] whereas sMMO has a broader decreased CO2 production [19]. Overexpression of phos- substrate range that includes aromatic and heterocyclic phoketolase in M. buryatense led to a 2.6-fold improve- compounds [6]. ment in biomass and lipid yield from methane [20 ]. In addition to oxygen, some methanotrophs use alternate Methylomonas sp. 16a is an interesting methanotroph due electron acceptors for methane activation. A methane- to high-level production of C30 carotenoids [21], but the oxidizing, nitrite-reducing enrichment culture from fresh- production of larger carotenoids remains challenging due water sediment was dominated by one bacterial species to lack of genetic tools. Episomal gene expression for [7], and metagenomic sequencing led to the construction synthesis of C40 carotenoids, astaxanthin and canthaxan- À1 of the full draft genome of a proposed new species, thin, resulted in yields of 2.4 g gDW [22]. Increased Methylomirabilis oxyfera [8], which possesses a pMMO yields were obtained by optimizing chromosomal inte- and an incomplete denitrification pathway. Methane is gration location [23] and co-expression of bacterial oxidized with nitrite and a pathway was proposed in hemoglobins [24]. which two molecules of NO could be used to produce N2 and O2 for methane oxidation [8]. Methane oxidation Efforts have also been made to engineer methanotrophs coupled to nitrate reduction was described for Methylomonas for high-volume chemicals, for example, lactic and suc- denitrificans under hypoxia [9]. cinic acids. Overexpression of lactate dehydrogenase (LDH) from Lactobacillus helveticus in M. buryatense There is increased interest in engineering methanotrophs improved lactate production by 70-fold over the wild- for converting methane into fuels and chemicals. Improv- type strain, resulting in 0.8 g/L [25 ]. Expression of the ing methane oxidation, either by MMO overexpression or succinate synthesis pathway in M. capsulatus Bath enhanced activity via protein engineering, could increase resulted in 70 mg/L [26 ]. Trace-level production of efficiency. However, MMO expression in heterologous 1,4-butanediol [27 ] and isobutanol [28 ] has also been hosts has largely failed [10]. A number of genetic tools reported. have been developed for methanotrophs [10], including conjugation for introducing genetic material from E. coli. Although aerobic methane conversion to fuels and che- Methylomicrobium buryatense 5G is emerging as a tractable micals has been demonstrated, only low yields were host for metabolic engineering with advances including achieved at small scale. During the oxidation of methane engineering of a strain capable of IncP-based vector repli- to methanol via MMO, two electrons are required to cation for episomal gene expression [11], development of simultaneously reduce O2 to H2O. Recovery of these selection/counter-selection markers for allelic exchange electrons is achieved in the subsequent step of methanol [11] and transformation using electroporation [10]. oxidation to formaldehyde. Therefore, the result is the redox-neutral conversion of methane to formaldehyde, Currently, Methylosinus trichosporium is the preferred spe- which results in a 36% energy loss [1 ]. Since formalde- cies for methanol production, which requires a co-sub- hyde possesses the same degree of reduction as traditional strate and inhibition of MDH [12]. Another strategy for sugars, for example, glucose, product yields achieved methanol production is co-feeding methane and ammonia from aerobic methane conversion are expected to be to a nitrifying culture where the methanol produced by comparable to those of aerobic sugar metabolism. Fur- action of ammonia monooxygenase cannot be used by the thermore, yields of reduced fuels and chemicals will be nitrifiers [13]. A third strategy uses an engineered BM-3 limited under aerobic conditions as oxidative phosphor- cytochrome P450 monooxygenase from Bacillus megaterium ylation competes for reducing equivalents in the form of for methane oxidation [14]. NAD(P)H. Scale-up of aerobic methane conversion also presents a challenge, as methane and oxygen gas transfer One product from methane is polyhydroxybutyrate limitations result in poor kinetics. Although these chal- (PHB), a biopolymer and plastic substitute [15,16]. lenges can be addressed by enhancing the volumetric Methanotrophs synthesize intracellular PHB as a source mass transfer coefficient (kLa), either from increased gas of reducing equivalents for growth under nutrient-limit- flow rate, agitation or improved reactor design, these ing conditions albeit yields are modest and of low molec- improvements result in larger operating and capital ular weight [15,16]. Methylobacterium organophilum CZ-2 expenses [1 ]. was reported to accumulate up to 57% PHB under nitro-
Load more

Recommended publications
  • Identification of Active Methylotroph Populations in an Acidic Forest Soil
    Microbiology (2002), 148, 2331–2342 Printed in Great Britain Identification of active methylotroph populations in an acidic forest soil by stable- isotope probing Stefan Radajewski,1 Gordon Webster,2† David S. Reay,3‡ Samantha A. Morris,1 Philip Ineson,4 David B. Nedwell,3 James I. Prosser2 and J. Colin Murrell1 Author for correspondence: J. Colin Murrell. Tel: j44 24 7652 2553. Fax: j44 24 7652 3568. e-mail: cmurrell!bio.warwick.ac.uk 1 Department of Biological Stable-isotope probing (SIP) is a culture-independent technique that enables Sciences, University of the isolation of DNA from micro-organisms that are actively involved in a Warwick, Coventry CV4 7AL, UK specific metabolic process. In this study, SIP was used to characterize the active methylotroph populations in forest soil (pH 35) microcosms that were exposed 2 Department of Molecular 13 13 13 13 and Cell Biology, to CH3OH or CH4. Distinct C-labelled DNA ( C-DNA) fractions were resolved University of Aberdeen, from total community DNA by CsCl density-gradient centrifugation. Analysis of Institute of Medical 16S rDNA sequences amplified from the 13C-DNA revealed that bacteria related Sciences, Foresterhill, Aberdeen AB25 2ZD, UK to the genera Methylocella, Methylocapsa, Methylocystis and Rhodoblastus had assimilated the 13C-labelled substrates, which suggested that moderately 3 Department of Biological Sciences, University of acidophilic methylotroph populations were active in the microcosms. Essex, Wivenhoe Park, Enrichments targeted towards the active proteobacterial CH3OH utilizers were Colchester, Essex CO4 3SQ, successful, although none of these bacteria were isolated into pure culture. A UK parallel analysis of genes encoding the key enzymes methanol dehydrogenase 4 Department of Biology, and particulate methane monooxygenase reflected the 16S rDNA analysis, but University of York, PO Box 373, YO10 5YW, UK unexpectedly revealed sequences related to the ammonia monooxygenase of ammonia-oxidizing bacteria (AOB) from the β-subclass of the Proteobacteria.
    [Show full text]
  • Adaptive Laboratory Evolution Enhances Methanol Tolerance and Conversion in Engineered Corynebacterium Glutamicum
    ARTICLE https://doi.org/10.1038/s42003-020-0954-9 OPEN Adaptive laboratory evolution enhances methanol tolerance and conversion in engineered Corynebacterium glutamicum Yu Wang 1, Liwen Fan1,2, Philibert Tuyishime1, Jiao Liu1, Kun Zhang1,3, Ning Gao1,3, Zhihui Zhang1,3, ✉ ✉ 1234567890():,; Xiaomeng Ni1, Jinhui Feng1, Qianqian Yuan1, Hongwu Ma1, Ping Zheng1,2,3 , Jibin Sun1,3 & Yanhe Ma1 Synthetic methylotrophy has recently been intensively studied to achieve methanol-based biomanufacturing of fuels and chemicals. However, attempts to engineer platform micro- organisms to utilize methanol mainly focus on enzyme and pathway engineering. Herein, we enhanced methanol bioconversion of synthetic methylotrophs by improving cellular tolerance to methanol. A previously engineered methanol-dependent Corynebacterium glutamicum is subjected to adaptive laboratory evolution with elevated methanol content. Unexpectedly, the evolved strain not only tolerates higher concentrations of methanol but also shows improved growth and methanol utilization. Transcriptome analysis suggests increased methanol con- centrations rebalance methylotrophic metabolism by down-regulating glycolysis and up- regulating amino acid biosynthesis, oxidative phosphorylation, ribosome biosynthesis, and parts of TCA cycle. Mutations in the O-acetyl-L-homoserine sulfhydrylase Cgl0653 catalyzing formation of L-methionine analog from methanol and methanol-induced membrane-bound transporter Cgl0833 are proven crucial for methanol tolerance. This study demonstrates the importance of
    [Show full text]
  • Isolation, Characterization and Substrate-Transport Studies of a New, Unique Methylotroph
    RICE UNIVERSITY ISOLATION, CHARACTERIZATION AND SUBSTRATE-TRANSPORT STUDIES OF A NEW, UNIQUE METHYLOTROPH by Thomas Alan Keuer A THESIS SUBMITTED IN PARTIAL FULFULLMENT OF THE REQUIREMENTS FOR THE DEGREE Master of Science APPROVED, THESIS COMMITTEE: E. Terry Papoutsakis, Assistant Professor of Chemical Engineering LarryOf. Mclntire, Professor and Chairman of Chemical Engineering <03^ ' Roger Storck, Professor of Biology Houston, Texas April, 1984 3 1272 00289 0232 ABSTRACT Keuer, Thomas A. M.S. Rice University, April 1984. Isolation, Characterization and Substrate-Transport Studies of a New, Unique Methylotroph. Major Professor: E. T. Papoutsakis. Methylotrophic bacteria which assimilate carbon via the Ribulose Monophosphate Pathway are bioenergetically superior to other methylotrophs. The dehydrogenases which catalyze the oxidation of formaldehyde to formate and formate to CO2 in RMP bacteria produce much of the ATP required for biosynthesis. A strain, designated T15, has been isolated on the basis of high In vitro activities of the above two key enzymes, and has been biochemically characterized. The new strain exhibits high yields (up to 0.63 g cells/g MeOH) and growth rates (up to 0.46 hr“^) in batch culture? however, the yields and growth rates in continuous culture are significantly lower. Study of the transport mechanisms has provided valuable insight into the relationship between substrate uptake and the growth characteristics of T15. Experi¬ ments with radiolabelled substrates have indicated that methanol enters the cells primarily by diffusion? consequently, the bacteria are not able to accumulate methanol internally in order to support efficient Ill continuous growth. Formaldehyde, on the other hand, is accumulated by an active transport system which depends on the A pH component of the membrane proton-motive force.
    [Show full text]
  • Bacterial Metabolism of Methylated Amines and Identification of Novel Methylotrophs in Movile Cave
    The ISME Journal (2015) 9, 195–206 & 2015 International Society for Microbial Ecology All rights reserved 1751-7362/15 www.nature.com/ismej ORIGINAL ARTICLE Bacterial metabolism of methylated amines and identification of novel methylotrophs in Movile Cave Daniela Wischer1, Deepak Kumaresan1,4, Antonia Johnston1, Myriam El Khawand1, Jason Stephenson2, Alexandra M Hillebrand-Voiculescu3, Yin Chen2 and J Colin Murrell1 1School of Environmental Sciences, University of East Anglia, Norwich, UK; 2School of Life Sciences, University of Warwick, Coventry, UK and 3Department of Biospeleology and Karst Edaphobiology, Emil Racovit¸a˘ Institute of Speleology, Bucharest, Romania Movile Cave, Romania, is an unusual underground ecosystem that has been sealed off from the outside world for several million years and is sustained by non-phototrophic carbon fixation. Methane and sulfur-oxidising bacteria are the main primary producers, supporting a complex food web that includes bacteria, fungi and cave-adapted invertebrates. A range of methylotrophic bacteria in Movile Cave grow on one-carbon compounds including methylated amines, which are produced via decomposition of organic-rich microbial mats. The role of methylated amines as a carbon and nitrogen source for bacteria in Movile Cave was investigated using a combination of cultivation studies and DNA stable isotope probing (DNA-SIP) using 13C-monomethylamine (MMA). Two newly developed primer sets targeting the gene for gamma-glutamylmethylamide synthetase (gmaS), the first enzyme of the recently-discovered indirect MMA-oxidation pathway, were applied in functional gene probing. SIP experiments revealed that the obligate methylotroph Methylotenera mobilis is one of the dominant MMA utilisers in the cave. DNA-SIP experiments also showed that a new facultative methylotroph isolated in this study, Catellibacterium sp.
    [Show full text]
  • Adverse Effect of the Methanotroph Methylocystis Sp. M6 on the Non-Methylotroph Microbacterium Sp
    J. Microbiol. Biotechnol. (2018), 28(10), 1706–1715 https://doi.org/10.4014/jmb.1804.04015 Research Article Review jmb Adverse Effect of the Methanotroph Methylocystis sp. M6 on the Non-Methylotroph Microbacterium sp. NM2 So-Yeon Jeong1, Kyung-Suk Cho2, and Tae Gwan Kim1* 1Department of Microbiology, Pusan National University, Pusan 46241, Republic of Korea 2Department of Environmental Science and Engineering, Ewha Womans University, Seoul 03760, Republic of Korea Received: April 12, 2018 Revised: July 19, 2018 Several non-methylotrophic bacteria have been reported to improve the growth and activity of Accepted: August 23, 2018 methanotrophs; however, their interactions remain to be elucidated. We investigated the First published online interaction between Methylocystis sp. M6 and Microbacterium sp. NM2. A batch co-culture August 24, 2018 experiment showed that NM2 markedly increased the biomass and methane removal of M6. *Corresponding author qPCR analysis revealed that NM2 enhanced both the growth and methane-monooxygenase Phone: +82-515102268; gene expression of M6. A fed-batch experiment showed that co-culture was more efficient in Fax: +82-515141778; -1 -1 E-mail: [email protected] removing methane than M6 alone (28.4 vs. 18.8 µmol·l ·d ), although the biomass levels were similar. A starvation experiment for 21 days showed that M6 population remained stable while NM2 population decreased by 66% in co-culture, but the results were opposite in pure cultures, indicating that M6 may cross-feed growth substrates from NM2. These results indicate that M6 apparently had no negative effect on NM2 when M6 actively proliferated with methane. Interestingly, a batch experiment involving a dialysis membrane indicates that physical proximity between NM2 and M6 is required for such biomass and methane removal enhancement.
    [Show full text]
  • Methylotrophs and Methylotroph Communities
    caister.com/meth Methylotrophs and Methylotroph Communities https://doi.org/10.21775/9781912530045 Edited by Ludmila Chistoserdova Department of Chemical Engineering University of Washington Seattle WA USA Caister Academic Press Date: 15:45 Thursday 21 March 2019 UNCORRECTED PROOF File: Methylotrophs 3P caister.com/meth Copyright © 2019 Caister Academic Press Norfolk, UK www.caister.com British Library Cataloguing-in-Publication Data A catalogue record for this book is available from the British Library ISBN: 978-1-912530-04-5 (hardback) ISBN: 978-1-912530-05-2 (ebook) Description or mention of instrumentation, software, or other products in this book does not imply endorsement by the author or publisher. The author and publisher do not assume responsibility for the validity of any products or procedures mentioned or described in this book or for the consequences of their use. All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means, electronic, mechanical, photocopying, recording or otherwise, without the prior permission of the publisher. No claim to original U.S. Government works. Cover design adapted with permission from Dr Kelly C. Wrighton, Fort Collins, CO, USA Ebooks Ebooks supplied to individuals are single-user only and must not be reproduced, copied, stored in a retrieval system, or distributed by any means, electronic, mechanical, photocopying, email, internet or otherwise. Ebooks supplied to academic libraries, corporations, government organizations, public libraries, and school libraries are subject to the terms and conditions specified by the supplier. Date: 15:45 Thursday 21 March 2019 UNCORRECTED PROOF File: Methylotrophs 3P caister.com/meth Contents Preface v 1 Methanotrophy – Environmental, Industrial and Medical Applications 1 Jeremy D.
    [Show full text]
  • Specialized Metabolites from Methylotrophic Proteobacteria Aaron W
    Specialized Metabolites from Methylotrophic Proteobacteria Aaron W. Puri* Department of Chemistry and the Henry Eyring Center for Cell and Genome Science, University of Utah, Salt Lake City, UT, USA. *Correspondence: [email protected] htps://doi.org/10.21775/cimb.033.211 Abstract these compounds and strategies for determining Biosynthesized small molecules known as special- their biological functions. ized metabolites ofen have valuable applications Te explosion in bacterial genome sequences in felds such as medicine and agriculture. Con- available in public databases as well as the availabil- sequently, there is always a demand for novel ity of bioinformatics tools for analysing them has specialized metabolites and an understanding of revealed that many bacterial species are potentially their bioactivity. Methylotrophs are an underex- untapped sources for new molecules (Cimerman- plored metabolic group of bacteria that have several cic et al., 2014). Tis includes organisms beyond growth features that make them enticing in terms those traditionally relied upon for natural product of specialized metabolite discovery, characteriza- discovery, and recent studies have shown that tion, and production from cheap feedstocks such examining the biosynthetic potential of new spe- as methanol and methane gas. Tis chapter will cies indeed reveals new classes of compounds examine the predicted biosynthetic potential of (Pidot et al., 2014; Pye et al., 2017). Tis strategy these organisms and review some of the specialized is complementary to synthetic biology approaches metabolites they produce that have been character- focused on activating BGCs that are not normally ized so far. expressed under laboratory conditions in strains traditionally used for natural product discovery, such as Streptomyces (Rutledge and Challis, 2015).
    [Show full text]
  • Difference Between Chemoorganotrophic and Obligate Autotroph
    Difference Between Chemoorganotrophic And Obligate Autotroph Cary underbidding misanthropically. Ulric often demise parlous when conjugated Ford mollycoddles indistinctly and domes her cyma. Lew often descants unfeignedly when isocheimic Tedie turn-offs designedly and Judaizing her accentors. No mechanism for anaerobic metabolism in conjunction with a common when algae, along the catabolism ofaromatic compounds provide evidence was a difference between trees inferred with the four genera have a consensus approach to The physiological characteristics of use different types of bacteria and their interactions. CO2 stimulates the chemoorganotrophic growth of both ammonia oxidizers and the. Chemoorganotrophic Definition of Chemoorganotrophic by. While Acidithiobacillus ferrooxidans growing on FeSO4 would depict an obligate aerobe. A fundamental metabolic distinction is between autotrophs and heterotrophs. Cthe intermediate steps of autotroph and only select multiple curvature and to safely place in each student need to a membrane that can be essentially the deep. The facultative autotroph also oxidizes a ridicule of organic compounds such. Bacterial Metabolism Medical Microbiology NCBI Bookshelf. Interestingly the amount cure the carboxylase in M capsulatus in chemostat culture. Facultative autotroph Can reproduce as autotroph if they must first better as. Learning Objectives Differentiate photoautotrophs from photoheterotrophs. Electron Transport Chain. Ecology of Cyanobacteria II Their Diversity in Space faculty Time. A Photographic Atlas for the Microbiology Laboratory. 5 Algae Biology LibreTexts. MB302 Oregon State University. Autotroph t-trf An organism that manufactures its own value from inorganic substances such high carbon dioxide and ammonia Most autotrophs such clean green plants certain algae and photosynthetic bacteria use ticket for energy. Ment was achieved by comparison by the labour count helpless the pervert of Thiobacillus A2 obtained on.
    [Show full text]
  • Evolution of Methanotrophy in the Beijerinckiaceae&Mdash
    The ISME Journal (2014) 8, 369–382 & 2014 International Society for Microbial Ecology All rights reserved 1751-7362/14 www.nature.com/ismej ORIGINAL ARTICLE The (d)evolution of methanotrophy in the Beijerinckiaceae—a comparative genomics analysis Ivica Tamas1, Angela V Smirnova1, Zhiguo He1,2 and Peter F Dunfield1 1Department of Biological Sciences, University of Calgary, Calgary, Alberta, Canada and 2Department of Bioengineering, School of Minerals Processing and Bioengineering, Central South University, Changsha, Hunan, China The alphaproteobacterial family Beijerinckiaceae contains generalists that grow on a wide range of substrates, and specialists that grow only on methane and methanol. We investigated the evolution of this family by comparing the genomes of the generalist organotroph Beijerinckia indica, the facultative methanotroph Methylocella silvestris and the obligate methanotroph Methylocapsa acidiphila. Highly resolved phylogenetic construction based on universally conserved genes demonstrated that the Beijerinckiaceae forms a monophyletic cluster with the Methylocystaceae, the only other family of alphaproteobacterial methanotrophs. Phylogenetic analyses also demonstrated a vertical inheritance pattern of methanotrophy and methylotrophy genes within these families. Conversely, many lateral gene transfer (LGT) events were detected for genes encoding carbohydrate transport and metabolism, energy production and conversion, and transcriptional regulation in the genome of B. indica, suggesting that it has recently acquired these genes. A key difference between the generalist B. indica and its specialist methanotrophic relatives was an abundance of transporter elements, particularly periplasmic-binding proteins and major facilitator transporters. The most parsimonious scenario for the evolution of methanotrophy in the Alphaproteobacteria is that it occurred only once, when a methylotroph acquired methane monooxygenases (MMOs) via LGT.
    [Show full text]
  • View PDF Version
    RSC Advances View Article Online REVIEW View Journal | View Issue Guidance for engineering of synthetic methylotrophy based on methanol metabolism in Cite this: RSC Adv.,2017,7,4083 methylotrophy Wenming Zhang, Ting Zhang, Sihua Wu, Mingke Wu, Fengxue Xin, Weiliang Dong, Jiangfeng Ma, Min Zhang and Min Jiang* Methanol is increasingly becoming an attractive substrate for production of different metabolites, such as commodity chemicals, and biofuels via biological conversion, due to the increment of annual production capacity and decrement of prices. In recent years, genetic engineering towards native menthol utilizing organisms – methylotrophy has developed rapidly and attracted widespread attention. Therefore, it is vital to elucidate the distinct pathways that involve methanol oxidation, formaldehyde assimilation and disassimilation in the different methylotrophies for future synthetic work. In addition, this will also help to genetically construct some new and non-native methylotrophies. This review summarizes the Received 19th November 2016 Creative Commons Attribution-NonCommercial 3.0 Unported Licence. current knowledge about the methanol metabolism pathways in methylotrophy, discusses and Accepted 26th December 2016 compares different pathways on methanol utilization, and finally presents the strategies to integrate DOI: 10.1039/c6ra27038g the methanol metabolism with other chemicals, biofuels or other high value-added product formation www.rsc.org/advances pathways. 1. Introduction million tons per year and an expected annual growth rate in the range of 10–20%, a methanol-based bioeconomy has been With the rapid growth of the world population and develop- proposed.3 Especially recently, with the rise of the methanol This article is licensed under a ment of industry and society, energy demand is dramatically production process, the price of methanol steadily declined.
    [Show full text]
  • Bioconversion of Methanol Into Value- Added Chemicals in Native and Synthetic Methylotrophs
    Bioconversion of Methanol into Value- added Chemicals in Native and Synthetic Methylotrophs Min Zhang1, Xiao-jie Yuan1, Cong Zhang1, Li-ping Zhu1, Xu-hua Mo1, Wen-jing Chen1 and Song Yang1,2* 1School of Life Science, Qingdao Agricultural University, Shandong Province Key Laboratory of Applied Mycology, and Qingdao International Center on Microbes Utilizing Biogas, Qingdao, China. 2Key Laboratory of Systems Bioengineering, Ministry of Education, Tianjin University, Tianjin, China. *Correspondence: [email protected] htps://doi.org/10.21775/cimb.033.225 Abstract production of value-added chemicals. In particular, Methanol, commercially generated from methane, methanol is an important one-carbon (C1) feed- is a renewable chemical feedstock that is highly sol- stock that can be generated from either synthesis uble, relatively inexpensive, and easy to handle. Te gas (a mixture of CO and H2) or from biogas, concept of native methylotrophic bacteria serving assuming that large quantities of this feedstock as whole cell catalysts for production of chemicals could be produced at relatively low market price and materials using methanol as a feedstock is (Clomburg et al., 2017; Yang et al., 2018). Methylotrophic highly atractive. In recent years, the available omics bacteria are a diverse group of microbes that can use data for methylotrophic bacteria, especially for reduced C1 compounds such as methanol and Methylobacterium extorquens, the best-characterized methane as sole sources of both energy and carbon model methylotroph, have provided a
    [Show full text]
  • Revisiting Methylotrophy: the Impact of Lanthanides and Lanthanide-Dependent Enzymes on the Methylotrophic Metabolic Network
    REVISITING METHYLOTROPHY: THE IMPACT OF LANTHANIDES AND LANTHANIDE-DEPENDENT ENZYMES ON THE METHYLOTROPHIC METABOLIC NETWORK By Anna Frances Huff A THESIS Submitted to Michigan State University in partial fulfillment of the requirements for the degree of Microbiology and Molecular Genetics – Master of Science 2017 ABSTRACT REVISITING METHYLOTROPHY: THE IMPACT OF LANTHANIDES AND LANTHANIDE-DEPENDENT ENZYMES ON THE METHYLOTROPHIC METABOLIC NETWORK By Anna Frances Huff The recent discovery of lanthanide (Ln3+)-dependent enzymes renewed interest in methylotrophs, although the impact of these enzymes is not understood. In Methylobacterium extorquens AM1, the Ca2+-dependent MxaFI canonically oxidizes methanol to formaldehyde. The tetrahydromethanopterin (H4MPT) pathway oxidizes formaldehyde to formate. Formate is oxidized to CO2 by formate dehydrogenases (FDH) or partially reduced and assimilated. The genome of M. extorquens AM1 codes for three known Ln3+-dependent genes: xoxF, xoxF2, and exaF. XoxF may oxidize both methanol and formaldehyde in some organisms while ExaF demonstrated efficient activity with formaldehyde in the presence of La3+ providing a potential alternative to the H4MPT pathway. RNAseq data provided by Dr. Nathan Good found downregulation of mxa genes and the first gene of the H4MPT pathway, fae, and upregulation of xoxF, xoxF2, and exaF in the presence of La3+ suggesting changes to carbon distribution. I found a sharp decrease in accumulation formaldehyde and fourfold increase in accumulation of formate in the presence of La3+ and hypothesized this was due to the activity of Ln3+ enzymes. I measured the minimum inhibitory concentration (MIC) to methanol metabolism and found decreased sensitivity of a ∆fae mutant from 10 mM to more than 125 mM in the presence of La3+.
    [Show full text]