Saccharide production from methanol by transposon 5 mutants derived from the extracellular polysaccharide-producing bacterium Methylobacillus sp. strain 12S.
A CH3OH-utilizing bacterium that has the ability to produce extracellular polysaccharide (EPS) was isolated from a soil sample, and was identified as the obligate methylotroph Methylobacillus sp. strain 12S on the basis of its 16S rDNA sequence and growth-substrate specificity. The EPS produced by strain 12S was purified and the sugar composition was analysed by GC-MS and HPLC to reveal that the EPS was a heteropolymer composed of glucosyl, galactosyl, and mannosyl residues in the molar ratio 3:1:1. In order to produce mono- and/or oligosaccharides by single-step fermentation from CH3OH, stain 12S was mutagenized by transposon 5. Among eleven EPS-deficient mutants, three strains were found to accumulate significant amounts of reducing sugars in the media. The amounts of the reducing sugars produced by the mutants ( > ca. 700 mg glucose equivalent/l) were > 11-22 times higher than those produced by the wild-type strain (<ca. 60 mg glucose equivalent/l). The GC-MS analysis showed that all the mutants accumulated glucose, erythrose, threose and a disaccharide-like compound in the media.
Yoshida
T
T
Biotechnology Research Center, University of Tokyo, Japan. aseigyo@mail.ecc.u-tokyo.ac.jp
Horinouchi
M
M
Ayabe
Y
Y
Yamaguchi
T
T
Shibuya
N
N
Habe
H
H
Nojiri
H
H
Yamane
H
H
Omori
T
T
D002851:Chromatography, High Pressure Liquid; D004251:DNA Transposable Elements; D004187:Disaccharides / Q000096:biosynthesis*; D008401:Gas Chromatography-Mass Spectrometry; D005947:Glucose / Q000096:biosynthesis; D000432:Methanol / Q000378:metabolism*; D020631:Methylobacillus / Q000145:classification / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D009005:Monosaccharides / Q000096:biosynthesis*; D009154:Mutation; D010084:Oxidation-Reduction; D011135:Polysaccharides, Bacterial / Q000096:biosynthesis* / Q000737:chemistry / Q000302:isolation & purification; D012988:Soil Microbiology; D013780:Tetroses / Q000096:biosynthesis
D004251:DNA Transposable Elements; D004187:Disaccharides; D009005:Monosaccharides; D011135:Polysaccharides, Bacterial; D013780:Tetroses; D005947:Glucose; C073321:erythrose; D000432:Methanol