関: Zymomonas mobilis

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出典(authority):フリー百科事典『ウィキペディア（Wikipedia）』「2014/03/22 20:39:21」(JST)

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Zymomonas is a genus of bacteria. Members of this genus are gram negative, facultative anaerobic, non-sporulating, polarly-flagellated, rod-shaped bacteria.

The best-known species from this genus is Zymomonas mobilis. It is a fermenting bacteria that contributes to cider sickness and beer spoilage. It has a near theoretical ethanol yield from glucose, no oxygen requirement thus negating the need for expensive oxygen transfer, and high ethanol tolerance making it an effective microbe for ethanol biofuel production. However, in spite of these attractive advantages, several factors prevent the commercial usage of Z. mobilis in cellulosic ethanol production. The foremost hurdle is that its substrate range is limited to glucose, fructose and sucrose. Wild-type Z. mobilis cannot ferment C5 sugars like xylose and arabinose, which are important components of lignocellulosic hydrolysates. Unlike E. coli and yeast, Z. mobilis cannot tolerate toxic inhibitors present in lignocellulosic hydrolysates such as acetic acid and various phenolic compounds.^[1] Concentration of acetic acid in lignocellulosic hydrolysates can be as high as 1.5% (w/v), which is well above the tolerance threshold of Z. mobilis.

Several attempts have been made to engineer Z. mobilis to overcome its inherent deficiencies. National Renewable Energy Laboratory (NREL), USA has made significant contributions in expanding its substrate range to include C5 sugars like xylose and arabinose.^[2]^,^[3] Acetic acid-resistant strains of Z. mobilis have been developed by rational metabolic engineering efforts, mutagenesis techniques ^[4] or adaptive mutation.^[5]^,^[6] However, when these engineered strains metabolize mixed sugars in presence of inhibitors, the yield and productivity are much lower, thus preventing their industrial application.

An extensive adaptation process was used to improve xylose fermentation in Z. mobilis.^[5] By adapting a strain in a high concentration of xylose, significant alterations of metabolism occurred. One noticeable change was reduced levels of xylitol, a byproduct of xylose fermentation which can inhibit the strain's xylose metabolism. One of the reasons for lower xylitol production was mutation in a putative gene encoding for an aldo-keto reductase that catalyzes the reduction of xylose to xylitol.^[7]^,^[8]

Beer spoilage[edit]

Zymomonas is a waterborne unwanted bacteria in beer, creating an estery-sulfury flavour due to the production of acetaldehyde and hydrogen sulfide. This can be likened to a rotten apple smell or fruity odor. Zymomonas have not been reported in lager breweries due to the low temperatures (8 to 12 degrees Celsius) and stringent carbohydrate requirements (able to ferment only sucrose, glucose, and fructose). It is commonly found in cask-conditioned ales where priming sugar is used to carbonate the beer. The optimum growth temperature is 25 to 30 degrees Celsius.

References[edit]

^ Doran-Peterson, Joy; Cook, Dana M.; Brandon, Sarah K. "Microbial conversion of sugars from plant biomass to lactic acid or ethanol". The Plant Journal 54 (4): 582–592. doi:10.1111/j.1365-313X.2008.03480.x. Cite uses deprecated parameters (help)
^ Zhang, M; Eddy, C; Deanda, K; Finkelstein, M; Picataggio, S (Jan 13, 1995). "Metabolic Engineering of a Pentose Metabolism Pathway in Ethanologenic Zymomonas mobiles". Science 267 (5195): 240–3. doi:10.1126/science.267.5195.240. PMID 17791346. Cite uses deprecated parameters (help)
^ Deanda, K; Zhang, M; Eddy, C; Picataggio, S (1996). "Development of an arabinose-fermenting Zymomonas mobilis strain by metabolic pathway engineering". Applied and environmental microbiology 62 (12): 4465–70. PMC 168273. PMID 8953718. Cite uses deprecated parameters (help)
^ Joachimsthal, E L; Rogers, PL (2000). "Characterization of a high-productivity recombinant strain of Zymomonas mobiles for ethanol production from glucose/xylose mixtures". Applied biochemistry and biotechnology. 84-86: 343–56. PMID 10849801. Cite uses deprecated parameters (help)
^ ^a ^b Agrawal, Manoj; Mao, Z; Chen, RR (2011). "Adaptation yields a highly efficient xylose-fermenting Zymomonas mobilis strain.". Biotechnology and Bioengineering 108 (4): 777–85. doi:10.1002/bit.23021. PMID 21404252. Cite uses deprecated parameters (help)
^ Chen, Rachel; Wang, Yun; Shin, Hyun-dong; Agrawal, Manoj; Mao, Zichao (2009). "Strains of Zymomonas mobiles for fermentation of biomass". US Patent Application no. 20090269797. Cite uses deprecated parameters (help)
^ Agrawal, Manoj; Chen, Rachel Ruizhen (2011). "Discovery and characterization of a xylose reductase from Zymomonas mobilis ZM4". Biotechnology Letters 33 (11): 2127–2133. doi:10.1007/s10529-011-0677-6. Cite uses deprecated parameters (help)
^ Chen, Rachel; Agrawal M (2012). "Industrial Applications of A Novel Aldo/Keto Reductase Of Zymomonas Mobilis". US Patent Application 20120196342. Cite uses deprecated parameters (help)

External links[edit]

Ethanol fermentation technology – Zymomonas mobilis

English Journal

Functional characterization of a putative β-lactamase gene in the genome of Zymomonas mobilis.

Rajnish KN, Asraf SA, Manju N, Gunasekaran P.SourceDepartment of Genetics, Center for Excellence in Genomic Sciences, School of Biological Sciences, Madurai Kamaraj University, Madurai, 625021, India, knrmku@gmail.com.
Biotechnology letters.Biotechnol Lett.2011 Jul 28. [Epub ahead of print]
Zymomonas mobilis ZM4 is resistant to β-lactam antibiotics but there are no reports of a β-lactam resistance gene and its regulation. A putative β-lactamase gene sequence (ZMO0103) in the genome of Z. mobilis showed a 55% amino acid sequence identity with class C β-lactamase genes. qPCR analysis
PMID 21796435

Genome sequence of the ethanol-producing Zymomonas mobilis subsp. pomaceae lectotype ATCC 29192.

Kouvelis VN, Davenport KW, Brettin TS, Bruce D, Detter C, Han C, Nolan M, Tapia R, Damoulaki A, Kyrpides NC, Typas MA, Pappas KM.SourceDepartment of Genetics & Biotechnology, Faculty of Biology, National and Kapodistrian University of Athens, Panepistimiopolis, Athens 15701, Greece.
Journal of bacteriology.J Bacteriol.2011 Jul 8. [Epub ahead of print]
Zymomonas mobilis is an alphaproteobacterium studied for bioethanol production. Different strains of this organism have been hitherto sequenced; they all belong to the Z. mobilis subsp. mobilis taxon. Here we report the finished and annotated genome sequence of strain ATCC 29192, a cider spoiling ag
PMID 21742897

Japanese Journal

Respiration-deficient mutants of Zymomonas mobilis show improved growth and ethanol fermentation under aerobic and high temperature conditions(MICROBIAL PHYSIOLOGY AND BIOTECHNOLOGY)

Hayashi Takeshi,Furuta Yoshifumi,Furukawa Kensuke
Journal of bioscience and bioengineering 111(4), 414-419, 2011-04
… Respiration-deficient mutant (RDM) strains of Zymomonas mobilis were isolated from antibiotic-resistant mutants. …
NAID 110008607494

3P-2060 高糖耐性Zymomonas mobilis野生株へのセルロース糖化発酵性賦与(5c バイオマス,資源,エネルギー工学,一般演題,環境バイオテクノロジー,伝統の技と先端科学技術の融合)

奥田洋,小島基,岡本賢治,簗瀬英司
日本生物工学会大会講演要旨集平成22年度, 158, 2010-09-25
NAID 110008084948

3P-2057 呼吸欠損ザイモモナス菌は好気エタノール発酵能と高温耐性能を獲得する(5c バイオマス,資源,エネルギー工学,一般演題,環境バイオテクノロジー,伝統の技と先端科学技術の融合)

林毅,古川謙介
日本生物工学会大会講演要旨集平成22年度, 158, 2010-09-25
NAID 110008084945

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リンク元	「ザイモモナス」「ザイモモナス属」
拡張検索	「Zymomonas属」「Zymomonas mobilis」

「ザイモモナス」

Zymomonas
Scientific classification
Kingdom:	Bacteria
Phylum:	Proteobacteria
Class:	Alpha Proteobacteria
Order:	Sphingomonadales
Family:	Sphingomonadaceae
Genus:	Zymomonas