title: Generation of high-yield rapamycin-producing strains through protoplasts-related techniques.
abstract: Rapamycin is a 31-member ring macrolide produced by Streptomyces hygroscopicus and has many applications in clinical medicine. In the present work, several protoplasts-related techniques including protoplasts mutation, intraspecies and interspecies protoplasts fusion were tried to improve the rapamycin productivity in S. hygroscopicus. Although mutation and fusion of different protoplasts of S. hygroscopicus did not improve the productivity of rapamycin significantly, the interspecies fusion of protoplasts of S. hygroscopicus D7-804 and Streptomyces erythreus ZJU325 could have brought about one high-yield (345 mg/L) rapamycin producer with 23.6% higher than that of the parental strain. Then, with seven mutants of S. hygroscopicus with different features and rapamycin productivities as the parental strains, only one-round genome shuffling has generated a high-yield rapamycin-producing strain with an outstanding yield of 445 mg/L. The systematic research of protoplast-related techniques has established an applicable way to generate high-yield strains from original microorganisms which can only produce low amount of expected natural products, without information of target gene clusters and gene sequences.
authors.affiliation: Institute of Bioengineering, Zhejiang University, Hangzhou 310027, China.
authors.forename: Xiyang
authors.initials: X
authors.lastname: Chen
authors.forename: Peilian
authors.initials: P
authors.lastname: Wei
authors.forename: Limei
authors.initials: L
authors.lastname: Fan
authors.forename: Dong
authors.initials: D
authors.lastname: Yang
authors.forename: Xiangchen
authors.initials: X
authors.lastname: Zhu
authors.forename: Wenhe
authors.initials: W
authors.lastname: Shen
authors.forename: Zhinan
authors.initials: Z
authors.lastname: Xu
authors.forename: Peilin
authors.initials: P
authors.lastname: Cen
mesh_terms: D032621:DNA Shuffling; D005821:Genetic Techniques; D009154:Mutation; D011523:Protoplasts / Q000378:metabolism*; D020123:Sirolimus / Q000378:metabolism*; D013302:Streptomyces / Q000235:genetics* / Q000378:metabolism
chemical_list: D020123:Sirolimus