title: [Disruption of zwf2 gene to improve oxytetraclyline biosynthesis in Streptomyces rimosus M4018].
abstract: Genes of zwf1 and zwf2 encode two isozymes of glucose-6-phosphate dehydrogenase (G6PDH) of Streptomyces, respectively. G6PDH is the first enzyme in the oxidative pentose phosphate pathway (PPP) and the key enzyme for NADPH generation. Based on thermal sensitive plasmid pKC1139, a recombinant plasmid pKC1139-zwf2' was constructed and verified with restriction enzyme digestion. The plasmid pKC1139-zwf2' was electropolated into competent Streptomyces rimosus M4018 cells after it was demethylated by E. coli GM2929. Transformants grown on Tryptone Soya Agar (TSA) plate containing 500 ug/mL apramycin were selected, and identified using dot hybridization analysis and PCR amplification with apramycin resistant gene as primers. A positive clone was then selected and designated M4018-delta zwf2. With parent strain S. rimosus M4018 as control, mutant M4018-delta zwf2 was cultured in shaking flask. Specific acitivity of G6PDH of M4018-delta zwf2 was only half of that of parent strain whereas yield of oxytetracycline (OTC) of mutant was 27% higher to the mutant had a similar biomass profileto that of the control biosynthesis started when the growth entered stationary phase on the 4th day. However, specific oxytetracycline production of mutant was 31% higher than that of the parent strain, indicating that zwf2 disruption could enhance oxytetracycline biosynthesis in S. rimosus M4018-delta zwf2.
authors.affiliation: State Key Laboratory of Bioreactor Engineering, East China University of Science & Technology, Shanghai 200237, China. L_Z_Y2004@163.com
authors.forename: Zhiyong
authors.initials: Z
authors.lastname: Liu
authors.forename: Meijin
authors.initials: M
authors.lastname: Guo
authors.forename: Jiangchao
authors.initials: J
authors.lastname: Qian
authors.forename: Yingping
authors.initials: Y
authors.lastname: Zhuang
authors.forename: Siliang
authors.initials: S
authors.lastname: Zhang
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics* / Q000378:metabolism; D020868:Gene Silencing; D005954:Glucosephosphate Dehydrogenase / Q000235:genetics* / Q000378:metabolism; D010118:Oxytetracycline / Q000096:biosynthesis*; D013302:Streptomyces / Q000235:genetics* / Q000378:metabolism*
chemical_list: D001426:Bacterial Proteins; D005954:Glucosephosphate Dehydrogenase; D010118:Oxytetracycline