title: Identification and characterization of a flavin-containing monooxygenase MoA and its function in a specific sophorolipid molecule metabolism in Starmerella bombicola.
abstract: The yeast Starmerella bombicola CGMCC 1576 can produce abundant sophorolipids (SLs) including almost equal proportion of acidic and lactonic SLs. In this study, a monooxygenase MoA responsible for the metabolism of a sophorolipid molecule, C18:2 diacetylated acidic sophorolipid (C18:2 DASL), was identified, through genomic analysis, protein modeling, and gene knocking out strategy. The yield and compositions of SLs produced by the deletion mutant ∆moA changed dramatically. In HPLC chromatogram, the UV absorption area of C18:2 DASL (one major acidic sophorolipid component) increased from 9.84 × 10(6) mAU × s to 34.26 × 10(6) mAU × s by an increase of 248.17 % when oleic acid was used as hydrophobic carbon source. Moreover, when linoleic acid was used as hydrophobic carbon source, the content of C18:2 DASL component produced by the overexpressed strain Peno::moA decreased significantly compared with that of wild type and △moA. Furthermore, the MoA enzyme was heterologously expressed in Escherichia coli JM109 (DE3) with a recombinant plasmid named pMAL-c2x-moA, and the purified enzyme was obtained through a maltose-binding protein (MBP) affinity chromatography column. The purified C18:2 DASL and C18:1 DASL were applied to be catalyzed by MoA enzyme, respectively; it turned to be that C18:1 DASL still remained in the MoA reaction system, but C18:2 DASL disappeared.
authors.affiliation: State Key Laboratory of Microbial Technology, School of Life Science, Shandong University, Shan Da Nan Road 27, Jinan, Shandong, 250100, People's Republic of China.
authors.forename: Jiashan
authors.initials: J
authors.lastname: Li
authors.affiliation: State Key Laboratory of Microbial Technology, School of Life Science, Shandong University, Shan Da Nan Road 27, Jinan, Shandong, 250100, People's Republic of China.
authors.forename: Hui
authors.initials: H
authors.lastname: Li
authors.affiliation: State Key Laboratory of Microbial Technology, School of Life Science, Shandong University, Shan Da Nan Road 27, Jinan, Shandong, 250100, People's Republic of China.
authors.forename: Weiwei
authors.initials: W
authors.lastname: Li
authors.affiliation: State Key Laboratory of Microbial Technology, School of Life Science, Shandong University, Shan Da Nan Road 27, Jinan, Shandong, 250100, People's Republic of China.
authors.forename: Chengqiang
authors.initials: C
authors.lastname: Xia
authors.affiliation: State Key Laboratory of Microbial Technology, School of Life Science, Shandong University, Shan Da Nan Road 27, Jinan, Shandong, 250100, People's Republic of China. songx@sdu.edu.cn.|National Glycoengineering Research Center, Shandong University, Shan Da Nan Road 27, Jinan, Shandong, 250100, People's Republic of China. songx@sdu.edu.cn.
authors.forename: Xin
authors.initials: X
authors.lastname: Song
mesh_terms: D000595:Amino Acid Sequence; D001203:Ascomycota / Q000145:classification / Q000201:enzymology* / Q000235:genetics / Q000378:metabolism; D005227:Fatty Acids / Q000737:chemistry / Q000378:metabolism*; D005656:Fungal Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D008969:Molecular Sequence Data; D015394:Molecular Structure; D010105:Oxygenases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D010802:Phylogeny; D016415:Sequence Alignment
chemical_list: D005227:Fatty Acids; D005656:Fungal Proteins; D010105:Oxygenases; C020066:dimethylaniline monooxygenase (N-oxide forming)
keywords: Acidic sophorolipid; Lactonic sophorolipid; Monooxygenase; Starmerella bombicola