title: Isolation and genetic improvement of Pseudomonas sp. strain HUT-78, capable of enzymatic production of L-cysteine from DL-2-amino-Δ2-thiazoline-4-carboxylic acid.
abstract: Microorganisms able to bioconvert DL-2-amino-Δ(2)-thiazoline-4-carboxylic acid (DL-ATC) into L-cysteine were originally isolated from 10 soil samples with DL-ATC as the sole nitrogen source. Ninety-seven L-cysteine-producing bacterial strains were screened out and obtained in pure culture. Among them, a strain, designated as HUT-78, was selected as the best producer, with a molar bioconversion rate of 60%. Based on the 16S rRNA gene sequence analysis, this isolate was placed within the genus Pseudomonas. A novel mutant of this strain with a significantly reduced activity of L-cysteine desulfhydrase, a L-cysteine-decomposing enzyme, was derived by UV-mutagenesis. This mutant, designated as mHUT-78, exhibited a 42% increase in L-cysteine producing activity. Moreover, the bioconversion reactions in both the parent and the mutant strain were significantly accelerated by co-overexpression of the two key enzymes, AtcB and AtcC, involved in the bioconversion reaction.
authors.affiliation: Key Laboratory of Fermentation Engineering (Ministry of Education), Hubei University of Technology, Wuhan, China.
authors.forename: Bo
authors.initials: B
authors.lastname: Yang
authors.forename: Zhigang
authors.initials: Z
authors.lastname: Liu
authors.forename: Bei
authors.initials: B
authors.lastname: Deng
authors.forename: Yulei
authors.initials: Y
authors.lastname: Zeng
authors.forename: Jiajun
authors.initials: J
authors.lastname: Hu
authors.forename: Weilin
authors.initials: W
authors.lastname: Li
authors.forename: Zheng
authors.initials: Z
authors.lastname: Hu
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D001711:Biotransformation; D003545:Cysteine / Q000378:metabolism*; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D004275:DNA, Ribosomal / Q000737:chemistry / Q000235:genetics; D015870:Gene Expression; D060847:Metabolic Engineering; D053858:Metabolic Networks and Pathways / Q000235:genetics*; D009154:Mutation; D009584:Nitrogen / Q000378:metabolism; D011549:Pseudomonas / Q000235:genetics / Q000302:isolation & purification* / Q000378:metabolism* / Q000528:radiation effects; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D017422:Sequence Analysis, DNA; D012988:Soil Microbiology; D013844:Thiazoles / Q000378:metabolism*; D014466:Ultraviolet Rays
chemical_list: D001426:Bacterial Proteins; D004269:DNA, Bacterial; D004275:DNA, Ribosomal; D012336:RNA, Ribosomal, 16S; D013844:Thiazoles; C015674:2-amino-delta(2)-thiazoline-4-carboxylic acid; D003545:Cysteine; D009584:Nitrogen