title: Enhancing production of L-serine by increasing the glyA gene expression in Methylobacterium sp. MB200.
abstract: Microbial fermentation using methylotrophic bacteria is one of the most promising methods for L-serine production. Here we describe the metabolic engineering of a Methylobacterium strain to increase the production of L-serine. The glyA gene, encoding serine hydroxymethyltransferase (SHMT), was isolated from the genomic DNA of Methylobacterium sp. MB200, using a DNA fragment encoding Methylobacterium extorquens AM1 SHMT as a probe, and inserted into the vector pLAFR3. The resulting construct was transformed into Methylobacterium sp. MB200 using triparental mating. The genetic-engineered strain, designated as Methylobacterium sp. MB202, was shown to produce 11.4 + or - 0.6 mg/ml serine in resting cell reactions from 30 mg/ml wet cells, 20 mg/ml glycine, and 70 mg/ml methanol in 2 days, representing a 4.4-fold increase from that of the wild strain. The results demonstrated the potential for improving L-serine production by manipulating the glyA in bacteria and should facilitate the production of L-serine using Methylobacterium sp. strains.
authors.affiliation: College of Life Science and Technology, The Key Laboratory of Ministry of Education for Microbial and Plant Genetic Engineering, Guangxi University, 100 Daxue Road, Nanning, Guangxi 530005, China.
authors.forename: Peihong
authors.initials: P
authors.lastname: Shen
authors.forename: Hongjun
authors.initials: H
authors.lastname: Chao
authors.forename: Chengjian
authors.initials: C
authors.lastname: Jiang
authors.forename: Zhangde
authors.initials: Z
authors.lastname: Long
authors.forename: Changhao
authors.initials: C
authors.lastname: Wang
authors.forename: Bo
authors.initials: B
authors.lastname: Wu
mesh_terms: D003001:Cloning, Molecular; D018628:Gene Dosage; D015870:Gene Expression; D005818:Genetic Engineering / Q000379:methods*; D012696:Glycine Hydroxymethyltransferase / Q000096:biosynthesis / Q000235:genetics* / Q000302:isolation & purification / Q000378:metabolism; D020580:Methylobacterium / Q000166:cytology / Q000235:genetics* / Q000378:metabolism*; D017422:Sequence Analysis, DNA; D012694:Serine / Q000096:biosynthesis*
chemical_list: D012694:Serine; D012696:Glycine Hydroxymethyltransferase