51
|
Metabolic engineering of Pseudomonas sp. strain VLB120 as platform biocatalyst for the production of isobutyric acid and other secondary metabolites. Microb Cell Fact 2014; 13:2. [PMID: 24397404 PMCID: PMC3897908 DOI: 10.1186/1475-2859-13-2] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2013] [Accepted: 12/29/2013] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Over the recent years the production of Ehrlich pathway derived chemicals was shown in a variety of hosts such as Escherichia coli, Corynebacterium glutamicum, and yeast. Exemplarily the production of isobutyric acid was demonstrated in Escherichia coli with remarkable titers and yields. However, these examples suffer from byproduct formation due to the fermentative growth mode of the respective organism. We aim at establishing a new aerobic, chassis for the synthesis of isobutyric acid and other interesting metabolites using Pseudomonas sp. strain VLB120, an obligate aerobe organism, as host strain. RESULTS The overexpression of kivd, coding for a 2-ketoacid decarboxylase from Lactococcus lactis in Ps. sp. strain VLB120 enabled for the production of isobutyric acid and isobutanol via the valine synthesis route (Ehrlich pathway). This indicates the existence of chromosomally encoded alcohol and aldehyde dehydrogenases catalyzing the reduction and oxidation of isobutyraldehyde. In addition we showed that the strain possesses a complete pathway for isobutyric acid metabolization, channeling the compound via isobutyryl-CoA into valine degradation. Three key issues were addressed to allow and optimize isobutyric acid synthesis: i) minimizing isobutyric acid degradation by host intrinsic enzymes, ii) construction of suitable expression systems and iii) streamlining of central carbon metabolism finally leading to production of up to 26.8 ± 1.5 mM isobutyric acid with a carbon yield of 0.12 ± 0.01 g g(glc)⁻¹. CONCLUSION The combination of an increased flux towards isobutyric acid using a tailor-made expression system and the prevention of precursor and product degradation allowed efficient production of isobutyric acid in Ps. sp. strain VLB120. This will be the basis for the development of a continuous reaction process for this bulk chemicals.
Collapse
|
52
|
Hallenbeck PC. Bioenergy from Microorganisms: An Overview. MICROBIAL BIOENERGY: HYDROGEN PRODUCTION 2014. [DOI: 10.1007/978-94-017-8554-9_1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
|
53
|
Chen X, Zhou L, Tian K, Kumar A, Singh S, Prior BA, Wang Z. Metabolic engineering of Escherichia coli: A sustainable industrial platform for bio-based chemical production. Biotechnol Adv 2013; 31:1200-23. [DOI: 10.1016/j.biotechadv.2013.02.009] [Citation(s) in RCA: 117] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2012] [Revised: 02/04/2013] [Accepted: 02/25/2013] [Indexed: 12/20/2022]
|
54
|
Abstract
Synthetic biology provides numerous great opportunities for chemical engineers in the development of new processes for large-scale production of biofuels, value-added chemicals, and protein therapeutics. However, challenges across all scales abound. In particular, the modularization and standardization of the components in a biological system, so-called biological parts, remain the biggest obstacle in synthetic biology. In this perspective, we will discuss the main challenges and opportunities in the rapidly growing synthetic biology field and the important roles that chemical engineers can play in its advancement.
Collapse
Affiliation(s)
- Yunzi Luo
- Department of Chemical and Biomolecular Engineering, University of Illinois at Urbana-Champaign, Urbana, IL 61801, United States
| | | | | |
Collapse
|
55
|
Metabolic engineering of Corynebacterium glutamicum for 2-ketoisocaproate production. Appl Microbiol Biotechnol 2013; 98:297-311. [DOI: 10.1007/s00253-013-5310-2] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2013] [Revised: 09/30/2013] [Accepted: 10/01/2013] [Indexed: 10/26/2022]
|
56
|
Straathof AJJ. Transformation of Biomass into Commodity Chemicals Using Enzymes or Cells. Chem Rev 2013; 114:1871-908. [DOI: 10.1021/cr400309c] [Citation(s) in RCA: 315] [Impact Index Per Article: 28.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Affiliation(s)
- Adrie J. J. Straathof
- Department of Biotechnology, Delft University of Technology, Julianalaan
67, 2628
BC Delft, The Netherlands
| |
Collapse
|
57
|
Yamamoto S, Suda M, Niimi S, Inui M, Yukawa H. Strain optimization for efficient isobutanol production usingCorynebacterium glutamicumunder oxygen deprivation. Biotechnol Bioeng 2013; 110:2938-48. [DOI: 10.1002/bit.24961] [Citation(s) in RCA: 85] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2013] [Revised: 04/18/2013] [Accepted: 05/08/2013] [Indexed: 01/20/2023]
Affiliation(s)
- Shogo Yamamoto
- Research Institute of Innovative Technology for the Earth (RITE); 9-2, Kizugawadai Kizugawa Kyoto 619-0292 Japan
| | - Masako Suda
- Research Institute of Innovative Technology for the Earth (RITE); 9-2, Kizugawadai Kizugawa Kyoto 619-0292 Japan
| | - Satoko Niimi
- Research Institute of Innovative Technology for the Earth (RITE); 9-2, Kizugawadai Kizugawa Kyoto 619-0292 Japan
| | - Masayuki Inui
- Research Institute of Innovative Technology for the Earth (RITE); 9-2, Kizugawadai Kizugawa Kyoto 619-0292 Japan
| | - Hideaki Yukawa
- Research Institute of Innovative Technology for the Earth (RITE); 9-2, Kizugawadai Kizugawa Kyoto 619-0292 Japan
| |
Collapse
|
58
|
Lan EI, Liao JC. Microbial synthesis of n-butanol, isobutanol, and other higher alcohols from diverse resources. BIORESOURCE TECHNOLOGY 2013. [PMID: 23186690 DOI: 10.1016/j.biortech.2012.09.104] [Citation(s) in RCA: 94] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
Microbial production of fuel and chemical feedstock is a promising approach to solving energy and environmental problems. n-Butanol, isobutanol and other higher alcohols are of particular interest because they can serve as both fuel and chemical feedstock. Alternative resources such as CO2, syngas, waste protein, and lignocellulose are currently being investigated for their potential to produce these compounds. Except for lignocellulose, utilization of such alternative resource has not been examined extensively. This review aims to summarize the development of metabolic pathways for efficient synthesis of these higher alcohols and the current status of microbial strain development for the conversion of diverse resources into higher alcohols.
Collapse
Affiliation(s)
- Ethan I Lan
- Department of Chemical and Biomolecular Engineering, University of California, Los Angeles, CA 90095, USA
| | | |
Collapse
|
59
|
Eriksen DT, Lian J, Zhao H. Protein design for pathway engineering. J Struct Biol 2013; 185:234-42. [PMID: 23558037 DOI: 10.1016/j.jsb.2013.03.011] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2012] [Revised: 02/23/2013] [Accepted: 03/21/2013] [Indexed: 02/02/2023]
Abstract
Design and construction of biochemical pathways has increased the complexity of biosynthetically-produced compounds when compared to single enzyme biocatalysis. However, the coordination of multiple enzymes can introduce a complicated set of obstacles to overcome in order to achieve a high titer and yield of the desired compound. Metabolic engineering has made great strides in developing tools to optimize the flux through a target pathway, but the inherent characteristics of a particular enzyme within the pathway can still limit the productivity. Thus, judicious protein design is critical for metabolic and pathway engineering. This review will describe various strategies and examples of applying protein design to pathway engineering to optimize the flux through the pathway. The proteins can be engineered for altered substrate specificity/selectivity, increased catalytic activity, reduced mass transfer limitations through specific protein localization, and reduced substrate/product inhibition. Protein engineering can also be expanded to design biosensors to enable high through-put screening and to customize cell signaling networks. These strategies have successfully engineered pathways for significantly increased productivity of the desired product or in the production of novel compounds.
Collapse
Affiliation(s)
- Dawn T Eriksen
- Department of Chemical and Biomolecular Engineering, University of Illinois at Urbana-Champaign, Urbana, IL 61801, United States
| | - Jiazhang Lian
- Department of Chemical and Biomolecular Engineering, University of Illinois at Urbana-Champaign, Urbana, IL 61801, United States
| | - Huimin Zhao
- Department of Chemical and Biomolecular Engineering, University of Illinois at Urbana-Champaign, Urbana, IL 61801, United States; Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, IL 61801, United States; Department of Biochemistry, University of Illinois at Urbana-Champaign, Urbana, IL 61801, United States; Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, United States.
| |
Collapse
|
60
|
Dietrich JA, Shis DL, Alikhani A, Keasling JD. Transcription factor-based screens and synthetic selections for microbial small-molecule biosynthesis. ACS Synth Biol 2013; 2:47-58. [PMID: 23656325 PMCID: PMC11245165 DOI: 10.1021/sb300091d] [Citation(s) in RCA: 144] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Continued advances in metabolic engineering are increasing the number of small molecules being targeted for microbial production. Pathway yields and productivities, however, are often suboptimal, and strain improvement remains a persistent challenge given that the majority of small molecules are difficult to screen for and their biosynthesis does not improve host fitness. In this work, we have developed a generalized approach to screen or select for improved small-molecule biosynthesis using transcription factor-based biosensors. Using a tetracycline resistance gene 3' of a small-molecule inducible promoter, host antibiotic resistance, and hence growth rate, was coupled to either small-molecule concentration in the growth medium or a small-molecule production phenotype. Biosensors were constructed for two important chemical classes, dicarboxylic acids and alcohols, using transcription factor-promoter pairs derived from Pseudomonas putida, Thauera butanivorans, or E. coli. Transcription factors were selected for specific activation by either succinate, adipate, or 1-butanol, and we demonstrate product-dependent growth in E. coli using all three compounds. The 1-butanol biosensor was applied in a proof-of-principle liquid culture screen to optimize 1-butanol biosynthesis in engineered E. coli, identifying a pathway variant yielding a 35% increase in 1-butanol specific productivity through optimization of enzyme expression levels. Lastly, to demonstrate the capacity to select for enzymatic activity, the 1-butanol biosensor was applied as synthetic selection, coupling in vivo 1-butanol biosynthesis to E. coli fitness, and an 120-fold enrichment for a 1-butanol production phenotype was observed following a single round of positive selection.
Collapse
Affiliation(s)
- Jeffrey A Dietrich
- UCSF-UCB Joint Graduate Group in Bioengineering, Berkeley, CA 94720, USA
| | | | | | | |
Collapse
|
61
|
Monnappa AK, Lee S, Mitchell RJ. Sensing of plant hydrolysate-related phenolics with an aaeXAB::luxCDABE bioreporter strain of Escherichia coli. BIORESOURCE TECHNOLOGY 2013; 127:429-434. [PMID: 23138066 DOI: 10.1016/j.biortech.2012.09.086] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/20/2012] [Revised: 08/06/2012] [Accepted: 09/21/2012] [Indexed: 06/01/2023]
Abstract
A bioluminescent Escherichia coli bioreporter strain to detect hydrolysate related phenolics was developed by cloning the aaeXAB promoter from E. coli upstream of the luxCDABE genes. E. coli str. DH5α carrying this plasmid (pDMA3) was responsive to sub-inhibitory concentrations of plant hydrolysate-related phenolics, such as ferulic and vanillic acids, responding to these compounds at concentrations as low as 9.8 and 4.9 mg/L, respectively. Experiments with a mixture of the compounds showed similar responses as with single compound tests, with a minimum detectable concentration of 19.5mg/L. Finally, tests using rice straw hydrolysates were conducted, with E. coli str. DH5α/pDMA3 showing a maximum induction of 33-fold and a minimum detectable phenolic concentration of 9.3mg/L, based upon Folin-Ciocalteu's reagent. These results demonstrate that this bioreporter maintains its sensitivity even with hydrolysate samples and that it can be potentially applied within biofuel industries to detect phenolics present within plant hydrolysates.
Collapse
Affiliation(s)
- Ajay Kalanjana Monnappa
- Dept of Nano-Bioscience and Chemical Engineering, Ulsan National Institute of Science and Technology, Ulsan, South Korea
| | | | | |
Collapse
|
62
|
Production of bulk chemicals via novel metabolic pathways in microorganisms. Biotechnol Adv 2012; 31:925-35. [PMID: 23280013 DOI: 10.1016/j.biotechadv.2012.12.008] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2012] [Revised: 12/09/2012] [Accepted: 12/23/2012] [Indexed: 02/05/2023]
Abstract
Metabolic engineering has been playing important roles in developing high performance microorganisms capable of producing various chemicals and materials from renewable biomass in a sustainable manner. Synthetic and systems biology are also contributing significantly to the creation of novel pathways and the whole cell-wide optimization of metabolic performance, respectively. In order to expand the spectrum of chemicals that can be produced biotechnologically, it is necessary to broaden the metabolic capacities of microorganisms. Expanding the metabolic pathways for biosynthesizing the target chemicals requires not only the enumeration of a series of known enzymes, but also the identification of biochemical gaps whose corresponding enzymes might not actually exist in nature; this issue is the focus of this paper. First, pathway prediction tools, effectively combining reactions that lead to the production of a target chemical, are analyzed in terms of logics representing chemical information, and designing and ranking the proposed metabolic pathways. Then, several approaches for potentially filling in the gaps of the novel metabolic pathway are suggested along with relevant examples, including the use of promiscuous enzymes that flexibly utilize different substrates, design of novel enzymes for non-natural reactions, and exploration of hypothetical proteins. Finally, strain optimization by systems metabolic engineering in the context of novel metabolic pathways constructed is briefly described. It is hoped that this review paper will provide logical ways of efficiently utilizing 'big' biological data to design and develop novel metabolic pathways for the production of various bulk chemicals that are currently produced from fossil resources.
Collapse
|
63
|
McEwen JT, Atsumi S. Alternative biofuel production in non-natural hosts. Curr Opin Biotechnol 2012; 23:744-50. [DOI: 10.1016/j.copbio.2011.12.019] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2011] [Revised: 12/16/2011] [Accepted: 12/16/2011] [Indexed: 11/16/2022]
|
64
|
Synthetic pathway for production of five-carbon alcohols from isopentenyl diphosphate. Appl Environ Microbiol 2012; 78:7849-55. [PMID: 22941086 DOI: 10.1128/aem.01175-12] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Synthetic biological pathways could enhance the development of novel processes to produce chemicals from renewable resources. On the basis of models that describe the evolution of metabolic pathways and enzymes in nature, we developed a framework to rationally identify enzymes able to catalyze reactions on new substrates that overcomes one of the major bottlenecks in the assembly of a synthetic biological pathway. We verified the framework by implementing a pathway with two novel enzymatic reactions to convert isopentenyl diphosphate into 3-methyl-3-butenol, 3-methyl-2-butenol, and 3-methylbutanol. To overcome competition with native pathways that share the same substrate, we engineered two bifunctional enzymes that redirect metabolic flux toward the synthetic pathway. Taken together, our work demonstrates a new approach to the engineering of novel synthetic pathways in the cell.
Collapse
|
65
|
Jang YS, Kim B, Shin JH, Choi YJ, Choi S, Song CW, Lee J, Park HG, Lee SY. Bio-based production of C2-C6 platform chemicals. Biotechnol Bioeng 2012; 109:2437-59. [DOI: 10.1002/bit.24599] [Citation(s) in RCA: 299] [Impact Index Per Article: 24.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2012] [Revised: 06/26/2012] [Accepted: 06/26/2012] [Indexed: 12/20/2022]
|
66
|
Lamsen EN, Atsumi S. Recent progress in synthetic biology for microbial production of C3-C10 alcohols. Front Microbiol 2012; 3:196. [PMID: 22701113 PMCID: PMC3370425 DOI: 10.3389/fmicb.2012.00196] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2012] [Accepted: 05/14/2012] [Indexed: 01/17/2023] Open
Abstract
The growing need to address current energy and environmental problems has sparked an interest in developing improved biological methods to produce liquid fuels from renewable sources. While microbial ethanol production is well established, higher-chain alcohols possess chemical properties that are more similar to gasoline. Unfortunately, these alcohols (except 1-butanol) are not produced efficiently in natural microorganisms, and thus economical production in industrial volumes remains a challenge. Synthetic biology, however, offers additional tools to engineer synthetic pathways in user-friendly hosts to help increase titers and productivity of these advanced biofuels. This review concentrates on recent developments in synthetic biology to produce higher-chain alcohols as viable renewable replacements for traditional fuel.
Collapse
Affiliation(s)
- Edna N Lamsen
- Department of Chemistry, University of California, Davis, CA, USA
| | | |
Collapse
|
67
|
Abstract
The biological production of fuels from renewable sources has been regarded as a feasible solution to the energy and environmental problems in the foreseeable future. Recently, the biofuel product spectrum has expanded from ethanol and fatty acid methyl esters (biodiesel) to other molecules, such as higher alcohols and alkanes, with more desirable fuel properties. In general, biosynthesis of these fuel molecules can be divided into two phases: carbon chain elongation and functional modification. In addition to natural fatty acid and isoprenoid chain elongation pathways, keto acid-based chain elongation followed by decarboxylation and reduction has been explored for higher alcohol production. Other issues such as metabolic balance, strain robustness, and industrial production process efficiency have also been addressed. These successes may provide both scientific insights into and practical applications toward the ultimate goal of sustainable fuel production.
Collapse
Affiliation(s)
- Han Li
- Department of Chemical and Biomolecular Engineering, University of California, Los Angeles, CA 90095, USA.
| | | | | |
Collapse
|
68
|
Jurgens G, Survase S, Berezina O, Sklavounos E, Linnekoski J, Kurkijärvi A, Väkevä M, van Heiningen A, Granström T. Butanol production from lignocellulosics. Biotechnol Lett 2012; 34:1415-34. [PMID: 22526420 DOI: 10.1007/s10529-012-0926-3] [Citation(s) in RCA: 84] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2012] [Accepted: 03/27/2012] [Indexed: 12/20/2022]
Abstract
Clostridium spp. produce n-butanol in the acetone/butanol/ethanol process. For sustainable industrial scale butanol production, a number of obstacles need to be addressed including choice of feedstock, the low product yield, toxicity to production strain, multiple-end products and downstream processing of alcohol mixtures. This review describes the use of lignocellulosic feedstocks, bioprocess and metabolic engineering, downstream processing and catalytic refining of n-butanol.
Collapse
Affiliation(s)
- German Jurgens
- Department of Biotechnology and Chemical Technology, Aalto University, 00076, Espoo, Finland.
| | | | | | | | | | | | | | | | | |
Collapse
|
69
|
Smith KM, Liao JC. An evolutionary strategy for isobutanol production strain development in Escherichia coli. Metab Eng 2011; 13:674-81. [DOI: 10.1016/j.ymben.2011.08.004] [Citation(s) in RCA: 92] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2011] [Revised: 07/30/2011] [Accepted: 08/29/2011] [Indexed: 11/29/2022]
|
70
|
Matsuda F, Furusawa C, Kondo T, Ishii J, Shimizu H, Kondo A. Engineering strategy of yeast metabolism for higher alcohol production. Microb Cell Fact 2011; 10:70. [PMID: 21902829 PMCID: PMC3184262 DOI: 10.1186/1475-2859-10-70] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2011] [Accepted: 09/08/2011] [Indexed: 01/27/2023] Open
Abstract
Background While Saccharomyces cerevisiae is a promising host for cost-effective biorefinary processes due to its tolerance to various stresses during fermentation, the metabolically engineered S. cerevisiae strains exhibited rather limited production of higher alcohols than that of Escherichia coli. Since the structure of the central metabolism of S. cerevisiae is distinct from that of E. coli, there might be a problem in the structure of the central metabolism of S. cerevisiae. In this study, the potential production of higher alcohols by S. cerevisiae is compared to that of E. coli by employing metabolic simulation techniques. Based on the simulation results, novel metabolic engineering strategies for improving higher alcohol production by S. cerevisiae were investigated by in silico modifications of the metabolic models of S. cerevisiae. Results The metabolic simulations confirmed that the high production of butanols and propanols by the metabolically engineered E. coli strains is derived from the flexible behavior of their central metabolism. Reducing this flexibility by gene deletion is an effective strategy to restrict the metabolic states for producing target alcohols. In contrast, the lower yield using S. cerevisiae originates from the structurally limited flexibility of its central metabolism in which gene deletions severely reduced cell growth. Conclusions The metabolic simulation demonstrated that the poor productivity of S. cerevisiae was improved by the introduction of E. coli genes to compensate the structural difference. This suggested that gene supplementation is a promising strategy for the metabolic engineering of S. cerevisiae to produce higher alcohols which should be the next challenge for the synthetic bioengineering of S. cerevisiae for the efficient production of higher alcohols.
Collapse
Affiliation(s)
- Fumio Matsuda
- Organization of Advanced Science and Technology, Kobe University, Rokkodaicho, Nada-ku, Kobe, Hyogo, Japan
| | | | | | | | | | | |
Collapse
|
71
|
Engineering microbial factories for synthesis of value-added products. J Ind Microbiol Biotechnol 2011; 38:873-90. [PMID: 21526386 DOI: 10.1007/s10295-011-0970-3] [Citation(s) in RCA: 150] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2011] [Accepted: 04/01/2011] [Indexed: 01/07/2023]
Abstract
Microorganisms have become an increasingly important platform for the production of drugs, chemicals, and biofuels from renewable resources. Advances in protein engineering, metabolic engineering, and synthetic biology enable redesigning microbial cellular networks and fine-tuning physiological capabilities, thus generating industrially viable strains for the production of natural and unnatural value-added compounds. In this review, we describe the recent progress on engineering microbial factories for synthesis of valued-added products including alkaloids, terpenoids, flavonoids, polyketides, non-ribosomal peptides, biofuels, and chemicals. Related topics on lignocellulose degradation, sugar utilization, and microbial tolerance improvement will also be discussed.
Collapse
|
72
|
Li S, Wen J, Jia X. Engineering Bacillus subtilis for isobutanol production by heterologous Ehrlich pathway construction and the biosynthetic 2-ketoisovalerate precursor pathway overexpression. Appl Microbiol Biotechnol 2011; 91:577-89. [PMID: 21533914 DOI: 10.1007/s00253-011-3280-9] [Citation(s) in RCA: 87] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2011] [Revised: 03/24/2011] [Accepted: 03/26/2011] [Indexed: 12/14/2022]
Abstract
In the present work, Bacillus subtilis was engineered as the cell factory for isobutanol production due to its high tolerance to isobutanol. Initially, an efficient heterologous Ehrlich pathway controlled by the promoter P(43) was introduced into B. subtilis for the isobutanol biosynthesis. Further, investigation of acetolactate synthase of B. subtilis, ketol-acid reductoisomerase, and dihydroxy-acid dehydratase of Corynebacterium glutamicum responsible for 2-ketoisovalerate precursor biosynthesis showed that acetolactate synthase played an important role in isobutanol biosynthesis. The overexpression of acetolactate synthase led to a 2.8-fold isobutanol production compared with the control. Apart from isobutanol, alcoholic profile analysis also confirmed the existence of 1.21 g/L ethanol, 1.06 g/L 2-phenylethanol, as well as traces of 2-methyl-1-butanol and 3-methyl-1-butanol in the fermentation broth. Under microaerobic condition, the engineered B. subtilis produced up to 2.62 g/L isobutanol in shake-flask fed-batch fermentation, which was 21.3% higher than that in batch fermentation.
Collapse
Affiliation(s)
- Shanshan Li
- Department of Biochemical Engineering, School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, China
| | | | | |
Collapse
|
73
|
Atsumi S, Wu TY, Machado IMP, Huang WC, Chen PY, Pellegrini M, Liao JC. Evolution, genomic analysis, and reconstruction of isobutanol tolerance in Escherichia coli. Mol Syst Biol 2011; 6:449. [PMID: 21179021 PMCID: PMC3018172 DOI: 10.1038/msb.2010.98] [Citation(s) in RCA: 197] [Impact Index Per Article: 15.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2010] [Accepted: 10/25/2010] [Indexed: 11/23/2022] Open
Abstract
Escherichia coli has been engineered to produce isobutanol, with titers reaching greater than the toxicity level. However, the specific effects of isobutanol on the cell have never been fully understood. Here, we aim to identify genotype–phenotype relationships in isobutanol response. An isobutanol-tolerant mutant was isolated with serial transfers. Using whole-genome sequencing followed by gene repair and knockout, we identified five mutations (acrA, gatY, tnaA, yhbJ, and marCRAB) that were primarily responsible for the increased isobutanol tolerance. We successfully reconstructed the tolerance phenotype by combining deletions of these five loci, and identified glucosamine-6-phosphate as an important metabolite for isobutanol tolerance, which presumably enhanced membrane synthesis. The isobutanol-tolerant mutants also show increased tolerance to n-butanol and 2-methyl-1-butanol, but showed no improvement in ethanol tolerance and higher sensitivity to hexane and chloramphenicol than the parental strain. These results suggest that C4, C5 alcohol stress impacts the cell differently compared with the general solvent or antibiotic stresses. Interestingly, improved isobutanol tolerance did not increase the final titer of isobutanol production.
Collapse
Affiliation(s)
- Shota Atsumi
- Department of Chemical and Biomolecular Engineering, University of California, Los Angeles, CA 90095, USA
| | | | | | | | | | | | | |
Collapse
|
74
|
Corynebacterium glutamicum tailored for efficient isobutanol production. Appl Environ Microbiol 2011; 77:3300-10. [PMID: 21441331 DOI: 10.1128/aem.02972-10] [Citation(s) in RCA: 215] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
We recently engineered Corynebacterium glutamicum for aerobic production of 2-ketoisovalerate by inactivation of the pyruvate dehydrogenase complex, pyruvate:quinone oxidoreductase, transaminase B, and additional overexpression of the ilvBNCD genes, encoding acetohydroxyacid synthase, acetohydroxyacid isomeroreductase, and dihydroxyacid dehydratase. Based on this strain, we engineered C. glutamicum for the production of isobutanol from glucose under oxygen deprivation conditions by inactivation of l-lactate and malate dehydrogenases, implementation of ketoacid decarboxylase from Lactococcus lactis, alcohol dehydrogenase 2 (ADH2) from Saccharomyces cerevisiae, and expression of the pntAB transhydrogenase genes from Escherichia coli. The resulting strain produced isobutanol with a substrate-specific yield (Y(P/S)) of 0.60 ± 0.02 mol per mol of glucose. Interestingly, a chromosomally encoded alcohol dehydrogenase rather than the plasmid-encoded ADH2 from S. cerevisiae was involved in isobutanol formation with C. glutamicum, and overexpression of the corresponding adhA gene increased the Y(P/S) to 0.77 ± 0.01 mol of isobutanol per mol of glucose. Inactivation of the malic enzyme significantly reduced the Y(P/S), indicating that the metabolic cycle consisting of pyruvate and/or phosphoenolpyruvate carboxylase, malate dehydrogenase, and malic enzyme is responsible for the conversion of NADH + H+ to NADPH + H+. In fed-batch fermentations with an aerobic growth phase and an oxygen-depleted production phase, the most promising strain, C. glutamicum ΔaceE Δpqo ΔilvE ΔldhA Δmdh(pJC4ilvBNCD-pntAB)(pBB1kivd-adhA), produced about 175 mM isobutanol, with a volumetric productivity of 4.4 mM h⁻¹, and showed an overall Y(P/S) of about 0.48 mol per mol of glucose in the production phase.
Collapse
|
75
|
Baez A, Cho KM, Liao JC. High-flux isobutanol production using engineered Escherichia coli: a bioreactor study with in situ product removal. Appl Microbiol Biotechnol 2011; 90:1681-90. [PMID: 21547458 PMCID: PMC3094657 DOI: 10.1007/s00253-011-3173-y] [Citation(s) in RCA: 147] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2010] [Revised: 02/03/2011] [Accepted: 02/04/2011] [Indexed: 11/27/2022]
Abstract
Promising approaches to produce higher alcohols, e.g., isobutanol, using Escherichia coli have been developed with successful results. Here, we translated the isobutanol process from shake flasks to a 1-L bioreactor in order to characterize three E. coli strains. With in situ isobutanol removal from the bioreactor using gas stripping, the engineered E. coli strain (JCL260) produced more than 50 g/L in 72 h. In addition, the isobutanol production by the parental strain (JCL16) and the high isobutanol-tolerant mutant (SA481) were compared with JCL260. Interestingly, we found that the isobutanol-tolerant strain in fact produced worse than either JCL16 or JCL260. This result suggests that in situ product removal can properly overcome isobutanol toxicity in E. coli cultures. The isobutanol productivity was approximately twofold and the titer was 9% higher than n-butanol produced by Clostridium in a similar integrated system.
Collapse
Affiliation(s)
- Antonino Baez
- Department of Chemical and Biomolecular Engineering, University of California, Los Angeles, 5531 Boelter Hall, 420 Westwood Plaza, Los Angeles, CA 90095 USA
| | - Kwang-Myung Cho
- Department of Chemical and Biomolecular Engineering, University of California, Los Angeles, 5531 Boelter Hall, 420 Westwood Plaza, Los Angeles, CA 90095 USA
| | - James C. Liao
- Department of Chemical and Biomolecular Engineering, University of California, Los Angeles, 5531 Boelter Hall, 420 Westwood Plaza, Los Angeles, CA 90095 USA
- Institute for Genomics and Proteomics, University of California, Los Angeles, 5531 Boelter Hall, 420 Westwood Plaza, Los Angeles, CA 90095 USA
| |
Collapse
|
76
|
|
77
|
Use of the valine biosynthetic pathway to convert glucose into isobutanol. J Ind Microbiol Biotechnol 2010; 38:1287-94. [DOI: 10.1007/s10295-010-0907-2] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2010] [Accepted: 11/09/2010] [Indexed: 10/18/2022]
|
78
|
Mainguet SE, Liao JC. Bioengineering of microorganisms for C3 to C5 alcohols production. Biotechnol J 2010; 5:1297-308. [DOI: 10.1002/biot.201000276] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
|
79
|
Affiliation(s)
- Tiangang Liu
- Department of Chemistry, Stanford University, Stanford, California 94305
| | - Chaitan Khosla
- Department of Chemistry, Stanford University, Stanford, California 94305
- Department of Chemical Engineering, Stanford University, Stanford, California 94305
- Department of Biochemistry, Stanford University, Stanford, California 94305;
| |
Collapse
|
80
|
Synthetic biology guides biofuel production. J Biomed Biotechnol 2010; 2010. [PMID: 20827393 PMCID: PMC2935196 DOI: 10.1155/2010/541698] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2010] [Accepted: 07/05/2010] [Indexed: 01/26/2023] Open
Abstract
The advancement of microbial processes for the production of renewable liquid fuels has increased with concerns about the current fuel economy. The development of advanced biofuels in particular has risen to address some of the shortcomings of ethanol. These advanced fuels have chemical properties similar to petroleum-based liquid fuels, thus removing the need for engine modification or infrastructure redesign. While the productivity and titers of each of these processes remains to be improved, progress in synthetic biology has provided tools to guide the engineering of these processes through present and future challenges.
Collapse
|
81
|
Barnard D, Casanueva A, Tuffin M, Cowan D. Extremophiles in biofuel synthesis. ENVIRONMENTAL TECHNOLOGY 2010; 31:871-888. [PMID: 20662378 DOI: 10.1080/09593331003710236] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
The current global energy situation has demonstrated an urgent need for the development of alternative fuel sources to the continually diminishing fossil fuel reserves. Much research to address this issue focuses on the development of financially viable technologies for the production of biofuels. The current market for biofuels, defined as fuel products obtained from organic substrates, is dominated by bioethanol, biodiesel, biobutanol and biogas, relying on the use of substrates such as sugars, starch and oil crops, agricultural and animal wastes, and lignocellulosic biomass. This conversion from biomass to biofuel through microbial catalysis has gained much momentum as biotechnology has evolved to its current status. Extremophiles are a robust group of organisms producing stable enzymes, which are often capable of tolerating changes in environmental conditions such as pH and temperature. The potential application of such organisms and their enzymes in biotechnology is enormous, and a particular application is in biofuel production. In this review an overview of the different biofuels is given, covering those already produced commercially as well as those under development. The past and present trends in biofuel production are discussed, and future prospects for the industry are highlighted. The focus is on the current and future application of extremophilic organisms and enzymes in technologies to develop and improve the biotechnological production of biofuels.
Collapse
Affiliation(s)
- Desire Barnard
- Institute for Microbial Biotechnology and Metagenomics, Department of Biotechnology, University of the Western Cape, Private Bag X17, Bellville 7535, Cape Town, South Africa
| | | | | | | |
Collapse
|
82
|
Smith KM, Cho KM, Liao JC. Engineering Corynebacterium glutamicum for isobutanol production. Appl Microbiol Biotechnol 2010; 87:1045-55. [PMID: 20376637 PMCID: PMC2886118 DOI: 10.1007/s00253-010-2522-6] [Citation(s) in RCA: 217] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2009] [Revised: 02/20/2010] [Accepted: 02/23/2010] [Indexed: 12/01/2022]
Abstract
The production of isobutanol in microorganisms has recently been achieved by harnessing the highly active 2-keto acid pathways. Since these 2-keto acids are precursors of amino acids, we aimed to construct an isobutanol production platform in Corynebacterium glutamicum, a well-known amino-acid-producing microorganism. Analysis of this host’s sensitivity to isobutanol toxicity revealed that C. glutamicum shows an increased tolerance to isobutanol relative to Escherichia coli. Overexpression of alsS of Bacillus subtilis, ilvC and ilvD of C. glutamicum, kivd of Lactococcus lactis, and a native alcohol dehydrogenase, adhA, led to the production of 2.6 g/L isobutanol and 0.4 g/L 3-methyl-1-butanol in 48 h. In addition, other higher chain alcohols such as 1-propanol, 2-methyl-1-butanol, 1-butanol, and 2-phenylethanol were also detected as byproducts. Using longer-term batch cultures, isobutanol titers reached 4.0 g/L after 96 h with wild-type C. glutamicum as a host. Upon the inactivation of several genes to direct more carbon through the isobutanol pathway, we increased production by ∼25% to 4.9 g/L isobutanol in a ∆pyc∆ldh background. These results show promise in engineering C. glutamicum for higher chain alcohol production using the 2-keto acid pathways.
Collapse
Affiliation(s)
- Kevin Michael Smith
- Department of Chemical and Biomolecular Engineering, University of California, Los Angeles, 5531 Boelter Hall, 420 Westwood Plaza, Los Angeles, CA 90095, USA
| | | | | |
Collapse
|
83
|
Connor MR, Cann AF, Liao JC. 3-Methyl-1-butanol production in Escherichia coli: random mutagenesis and two-phase fermentation. Appl Microbiol Biotechnol 2010; 86:1155-64. [PMID: 20072783 PMCID: PMC2844964 DOI: 10.1007/s00253-009-2401-1] [Citation(s) in RCA: 108] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2009] [Revised: 12/02/2009] [Accepted: 12/04/2009] [Indexed: 12/02/2022]
Abstract
Interest in producing biofuels from renewable sources has escalated due to energy and environmental concerns. Recently, the production of higher chain alcohols from 2-keto acid pathways has shown significant progress. In this paper, we demonstrate a mutagenesis approach in developing a strain of Escherichia coli for the production of 3-methyl-1-butanol by leveraging selective pressure toward L-leucine biosynthesis and screening for increased alcohol production. Random mutagenesis and selection with 4-aza-D,L-leucine, a structural analogue to L-leucine, resulted in the development of a new strain of E. coli able to produce 4.4 g/L of 3-methyl-1-butanol. Investigation of the host's sensitivity to 3-methyl-1-butanol directed development of a two-phase fermentation process in which titers reached 9.5 g/L of 3-methyl-1-butanol with a yield of 0.11 g/g glucose after 60 h.
Collapse
Affiliation(s)
- Michael R. Connor
- Department of Chemical and Biomolecular Engineering, University of California, Los Angeles, CA 90095 USA
| | - Anthony F. Cann
- Department of Chemical and Biomolecular Engineering, University of California, Los Angeles, CA 90095 USA
| | - James C. Liao
- Department of Chemical and Biomolecular Engineering, University of California, Los Angeles, CA 90095 USA
| |
Collapse
|
84
|
Nielsen DR, Yoon SH, Yuan CJ, Prather KLJ. Metabolic engineering of acetoin and meso-2, 3-butanediol biosynthesis in E. coli. Biotechnol J 2010; 5:274-84. [PMID: 20213636 DOI: 10.1002/biot.200900279] [Citation(s) in RCA: 80] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- David R Nielsen
- Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | | | | | | |
Collapse
|
85
|
Biofuel production in Escherichia coli: the role of metabolic engineering and synthetic biology. Appl Microbiol Biotechnol 2010; 86:419-34. [DOI: 10.1007/s00253-010-2446-1] [Citation(s) in RCA: 141] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2009] [Revised: 01/07/2010] [Accepted: 01/09/2010] [Indexed: 01/06/2023]
|
86
|
Dellomonaco C, Fava F, Gonzalez R. The path to next generation biofuels: successes and challenges in the era of synthetic biology. Microb Cell Fact 2010; 9:3. [PMID: 20089184 PMCID: PMC2817670 DOI: 10.1186/1475-2859-9-3] [Citation(s) in RCA: 133] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2009] [Accepted: 01/20/2010] [Indexed: 01/11/2023] Open
Abstract
Volatility of oil prices along with major concerns about climate change, oil supply security and depleting reserves have sparked renewed interest in the production of fuels from renewable resources. Recent advances in synthetic biology provide new tools for metabolic engineers to direct their strategies and construct optimal biocatalysts for the sustainable production of biofuels. Metabolic engineering and synthetic biology efforts entailing the engineering of native and de novo pathways for conversion of biomass constituents to short-chain alcohols and advanced biofuels are herewith reviewed. In the foreseeable future, formal integration of functional genomics and systems biology with synthetic biology and metabolic engineering will undoubtedly support the discovery, characterization, and engineering of new metabolic routes and more efficient microbial systems for the production of biofuels.
Collapse
|
87
|
|
88
|
Cann AF, Liao JC. Pentanol isomer synthesis in engineered microorganisms. Appl Microbiol Biotechnol 2010; 85:893-9. [PMID: 19859707 PMCID: PMC2804790 DOI: 10.1007/s00253-009-2262-7] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2009] [Revised: 09/11/2009] [Accepted: 09/11/2009] [Indexed: 01/05/2023]
Abstract
Pentanol isomers such as 2-methyl-1-butanol and 3-methyl-1-butanol are a useful class of chemicals with a potential application as biofuels. They are found as natural by-products of microbial fermentations from amino acid substrates. However, the production titer and yield of the natural processes are too low to be considered for practical applications. Through metabolic engineering, microbial strains for the production of these isomers have been developed, as well as that for 1-pentanol and pentenol. Although the current production levels are still too low for immediate industrial applications, the approach holds significant promise for major breakthroughs in production efficiency.
Collapse
Affiliation(s)
- Anthony F. Cann
- Department of Chemical and Biomolecular Engineering, University of California, Los Angeles, CA 90095 USA
| | - James C. Liao
- Department of Chemical and Biomolecular Engineering, University of California, Los Angeles, CA 90095 USA
| |
Collapse
|
89
|
Achievements and perspectives to overcome the poor solvent resistance in acetone and butanol-producing microorganisms. Appl Microbiol Biotechnol 2009; 85:1697-712. [DOI: 10.1007/s00253-009-2390-0] [Citation(s) in RCA: 225] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2009] [Revised: 11/27/2009] [Accepted: 11/28/2009] [Indexed: 11/26/2022]
|
90
|
Wen F, Nair NU, Zhao H. Protein engineering in designing tailored enzymes and microorganisms for biofuels production. Curr Opin Biotechnol 2009; 20:412-9. [PMID: 19660930 DOI: 10.1016/j.copbio.2009.07.001] [Citation(s) in RCA: 73] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2009] [Accepted: 07/02/2009] [Indexed: 10/20/2022]
Abstract
Lignocellulosic biofuels represent a sustainable, renewable, and the only foreseeable alternative energy source to transportation fossil fuels. However, the recalcitrant nature of lignocellulose poses technical hurdles to an economically viable biorefinery. Low enzymatic hydrolysis efficiency and low productivity, yield, and titer of biofuels are among the top cost contributors. Protein engineering has been used to improve the performance of lignocellulose-degrading enzymes, as well as proteins involved in biofuel synthesis pathways. Unlike its great success seen in other industrial applications, protein engineering has achieved only modest results in improving the lignocellulose-to-biofuels efficiency. This review will discuss the unique challenges that protein engineering faces in the process of converting lignocellulose to biofuels and how they are addressed by recent advances in this field.
Collapse
Affiliation(s)
- Fei Wen
- Department of Chemical and Biomolecular Engineering, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | | | | |
Collapse
|
91
|
Atsumi S, Wu TY, Eckl EM, Hawkins SD, Buelter T, Liao JC. Engineering the isobutanol biosynthetic pathway in Escherichia coli by comparison of three aldehyde reductase/alcohol dehydrogenase genes. Appl Microbiol Biotechnol 2009; 85:651-7. [PMID: 19609521 PMCID: PMC2802489 DOI: 10.1007/s00253-009-2085-6] [Citation(s) in RCA: 209] [Impact Index Per Article: 13.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2009] [Revised: 06/02/2009] [Accepted: 06/06/2009] [Indexed: 11/29/2022]
Abstract
Biofuels synthesized from renewable resources are of increasing interest because of global energy and environmental problems. We have previously demonstrated production of higher alcohols from Escherichia coli using a 2-keto acid-based pathway. Here, we have compared the effect of various alcohol dehydrogenases (ADH) for the last step of the isobutanol production. E. coli has the yqhD gene which encodes a broad-range ADH. Isobutanol production significantly decreased with the deletion of yqhD, suggesting that the yqhD gene on the genome contributed to isobutanol production. The adh genes of two bacteria and one yeast were also compared in E. coli harboring the isobutanol synthesis pathway. Overexpression of yqhD or adhA in E. coli showed better production than ADH2, a result confirmed by activity measurements with isobutyraldehyde.
Collapse
Affiliation(s)
- Shota Atsumi
- Department of Chemical and Biomolecular Engineering, University of California, Los Angeles, CA 90095, USA
| | | | | | | | | | | |
Collapse
|
92
|
Ensemble modeling for strain development of l-lysine-producing Escherichia coli. Metab Eng 2009; 11:221-33. [DOI: 10.1016/j.ymben.2009.04.002] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2008] [Revised: 02/27/2009] [Accepted: 04/10/2009] [Indexed: 11/18/2022]
|
93
|
Nielsen DR, Leonard E, Yoon SH, Tseng HC, Yuan C, Prather KLJ. Engineering alternative butanol production platforms in heterologous bacteria. Metab Eng 2009; 11:262-73. [DOI: 10.1016/j.ymben.2009.05.003] [Citation(s) in RCA: 254] [Impact Index Per Article: 16.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2008] [Revised: 05/13/2009] [Accepted: 05/13/2009] [Indexed: 10/20/2022]
|
94
|
Semi-continuous propagation and synchronous differentiation of hyper-solventogenic cells of Clostridium thermosaccharolyticum in a xylan medium at 56°C. J Taiwan Inst Chem Eng 2009. [DOI: 10.1016/j.jtice.2008.11.003] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
|
95
|
New microbial fuels: a biotech perspective. Curr Opin Microbiol 2009; 12:274-81. [DOI: 10.1016/j.mib.2009.04.004] [Citation(s) in RCA: 193] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2009] [Revised: 04/09/2009] [Accepted: 04/24/2009] [Indexed: 10/20/2022]
|
96
|
Connor MR, Liao JC. Microbial production of advanced transportation fuels in non-natural hosts. Curr Opin Biotechnol 2009; 20:307-15. [DOI: 10.1016/j.copbio.2009.04.002] [Citation(s) in RCA: 160] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2009] [Revised: 04/08/2009] [Accepted: 04/09/2009] [Indexed: 11/16/2022]
|
97
|
Yan Y, Liao JC. Engineering metabolic systems for production of advanced fuels. J Ind Microbiol Biotechnol 2009; 36:471-9. [PMID: 19198907 DOI: 10.1007/s10295-009-0532-0] [Citation(s) in RCA: 84] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2008] [Accepted: 01/14/2009] [Indexed: 11/26/2022]
Abstract
The depleting petroleum storage and increasing environmental deterioration are threatening the sustainable development of human societies. As such, biofuels and chemical feedstocks generated from renewable sources are becoming increasingly important. Although previous efforts led to great success in bio-ethanol production, higher alcohols, fatty acid derivatives including biodiesels, alkanes, and alkenes offer additional advantages because of their compatibility with existing infrastructure. In addition, some of these compounds are useful chemical feedstocks. Since native organisms do not naturally produce these compounds in high quantities, metabolic engineering becomes essential in constructing producing organisms. In this article, we briefly review the four major metabolic systems, the coenzyme-A mediated pathways, the keto acid pathways, the fatty acid pathway, and the isoprenoid pathways, that allow production of these fuel-grade chemicals.
Collapse
Affiliation(s)
- Yajun Yan
- Department of Chemical and Biomolecular Engineering, University of California at Los Angeles, 5531 Boelter Hall, 420 Westwood Plaza, Los Angeles, CA 90095, USA
| | | |
Collapse
|
98
|
Lee SK, Chou H, Ham TS, Lee TS, Keasling JD. Metabolic engineering of microorganisms for biofuels production: from bugs to synthetic biology to fuels. Curr Opin Biotechnol 2008; 19:556-63. [PMID: 18996194 DOI: 10.1016/j.copbio.2008.10.014] [Citation(s) in RCA: 334] [Impact Index Per Article: 20.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2008] [Revised: 10/24/2008] [Accepted: 10/24/2008] [Indexed: 10/21/2022]
Abstract
The ability to generate microorganisms that can produce biofuels similar to petroleum-based transportation fuels would allow the use of existing engines and infrastructure and would save an enormous amount of capital required for replacing the current infrastructure to accommodate biofuels that have properties significantly different from petroleum-based fuels. Several groups have demonstrated the feasibility of manipulating microbes to produce molecules similar to petroleum-derived products, albeit at relatively low productivity (e.g. maximum butanol production is around 20 g/L). For cost-effective production of biofuels, the fuel-producing hosts and pathways must be engineered and optimized. Advances in metabolic engineering and synthetic biology will provide new tools for metabolic engineers to better understand how to rewire the cell in order to create the desired phenotypes for the production of economically viable biofuels.
Collapse
Affiliation(s)
- Sung Kuk Lee
- Joint BioEnergy Institute, Emeryville, CA 95608, USA
| | | | | | | | | |
Collapse
|
99
|
Cann AF, Liao JC. Production of 2-methyl-1-butanol in engineered Escherichia coli. Appl Microbiol Biotechnol 2008; 81:89-98. [PMID: 18758769 PMCID: PMC7419481 DOI: 10.1007/s00253-008-1631-y] [Citation(s) in RCA: 96] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2008] [Revised: 07/18/2008] [Accepted: 07/24/2008] [Indexed: 11/04/2022]
Abstract
Recent progress has been made in the production of higher alcohols by harnessing the power of natural amino acid biosynthetic pathways. Here, we describe the first strain of Escherichia coli developed to produce the higher alcohol and potential new biofuel 2-methyl-1-butanol (2MB). To accomplish this, we explored the biodiversity of enzymes catalyzing key parts of the isoleucine biosynthetic pathway, finding that AHAS II (ilvGM) from Salmonella typhimurium and threonine deaminase (ilvA) from Corynebacterium glutamicum improve 2MB production the most. Overexpression of the native threonine biosynthetic operon (thrABC) on plasmid without the native transcription regulation also improved 2MB production in E. coli. Finally, we knocked out competing pathways upstream of threonine production (ΔmetA, Δtdh) to increase its availability for further improvement of 2MB production. This work led to a strain of E. coli that produces 1.25 g/L 2MB in 24 h, a total alcohol content of 3 g/L, and with yields of up to 0.17 g 2MB/g glucose.
Collapse
Affiliation(s)
- Anthony F Cann
- Department of Chemical and Biomolecular Engineering, University of California, Los Angeles, CA 90095, USA
| | | |
Collapse
|