title: A glycosyltransferase gene responsible for pullulan biosynthesis in Aureobasidium melanogenum P16.
abstract: In this study, one of the glucosyltransferase genes for pullulan production was cloned from Aureobasidum melanogenum P16 and charaterized. It was found that the UGT1 gene had 4774bp with four introns (47, 52, 54 and 46bp). The N-terminal part of the protein displayed a conserved sequence controlling both sugar donor and accepter for substrate specificity whereas its C-terminal part carried a DXD motif that coordinated donor sugar binding. After complete removal of the gene UGT1, the mutant 1152-3 still produced 27.7±3.1g/L of pullulan and 4.6U/g of the specific glucosyltransferase activity while its wild type strain P16 yielded 63.38±2.0g/L of pullulan and 5.7U/g of the specific glucosyltransferase activity. However, after overexpression of the gene UGT1, the transformant G63 could produce 78.0±3.01g/L of pullulan and 19.0U/g of the specific glucosyltransferase activity. It is interesting to note that the molecular weight of the produced pullulan by the wild type strain was 4.6×105while that of the produced pullulan by the transformant G63 was 6.2×105. During the 10-Litter fermentation, the pullulan titer produced by the transformant G63 reached 80.2±2.0 g/L within 132h.
authors.affiliation: College of Marine Life Sciences, Ocean University of China, Yushan Road, No. 5, Qingdao, China.
authors.forename: Xi
authors.initials: X
authors.lastname: Chen
authors.affiliation: College of Marine Life Sciences, Ocean University of China, Yushan Road, No. 5, Qingdao, China.
authors.forename: Qin-Qing
authors.initials: QQ
authors.lastname: Wang
authors.affiliation: College of Marine Life Sciences, Ocean University of China, Yushan Road, No. 5, Qingdao, China.
authors.forename: Nan-Nan
authors.initials: NN
authors.lastname: Liu
authors.affiliation: College of Marine Life Sciences, Ocean University of China, Yushan Road, No. 5, Qingdao, China.
authors.forename: Guang-Lei
authors.initials: GL
authors.lastname: Liu
authors.affiliation: College of Marine Life Sciences, Ocean University of China, Yushan Road, No. 5, Qingdao, China.
authors.forename: Zhe
authors.initials: Z
authors.lastname: Chi
authors.affiliation: College of Marine Life Sciences, Ocean University of China, Yushan Road, No. 5, Qingdao, China. Electronic address: zhenming@sdu.edu.cn.
authors.forename: Zhen-Ming
authors.initials: ZM
authors.lastname: Chi
mesh_terms: D000595:Amino Acid Sequence; D001203:Ascomycota / Q000201:enzymology* / Q000235:genetics*; D005285:Fermentation; D005936:Glucans / Q000096:biosynthesis* / Q000737:chemistry; D016695:Glycosyltransferases / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D008970:Molecular Weight; D009844:Oligosaccharides / Q000096:biosynthesis
chemical_list: D005936:Glucans; D009844:Oligosaccharides; C009109:pullulan; D016695:Glycosyltransferases
keywords: A. melanogenum; Gene disruption; Gene overexpression; Glucosyltransferase; Pullulan