Enhancing tylosin production by combinatorial overexpression of efflux,SAM biosynthesis,and regulatory genes in hyperproducing Streptomyces xinghaiensis strain  

作　　者：Penghui Dai Yuyao Qin Luyuan Li Haidi Li Lihuo Lv Danying Xu Yuqing Song Tingting Huang Shuangjun Lin Zixin Deng Meifeng Tao 

机构地区：[1]State Key Laboratory of Microbial Metabolism,School of Life Sciences and Biotechnology,Shanghai Jiao Tong University,Shanghai,200240,China [2]Zhejiang Apeloa Biotechnology Co.,Ltd.,Jinhua,322109,China [3]Zhejiang Apeloa Jiayuan Pharmaceutical Co.,Ltd.,Jinhua,322118,China [4]Haihe Laboratory of Synthetic Biology,Tianjin,300308,China

出　　处：《Synthetic and Systems Biotechnology》2023年第3期486-497,共12页合成和系统生物技术（英文）

基　　金：the National Key Research and Development Program of China(grant no.2022YFC210540303);the“Major Project”of Haihe Laboratory of Synthetic Biology(22HHSWSS00001).

摘　　要：Tylosin is a 16-membered macrolide antibiotic widely used in veterinary medicine to control infections caused by Gram-positive pathogens and mycoplasmas.To improve the fermentation titer of tylosin in the hyperproducing Streptomyces xinghaiensis strain TL01,we sequenced its whole genome and identified the biosynthetic gene cluster therein.Overexpression of the tylosin efflux gene tlrC,the cluster-situated S-adenosyl methionine(SAM)synthetase gene metK_(cs),the SAM biosynthetic genes adoK_(cs)-metFcs,or the pathway-specific activator gene tylR enhanced tylosin production by 18%,12%,11%,and 11%in the respective engineered strains TLPH08-2,TLPH09,TLPH10,and TLPH12.Co-overexpression of metK_(cs)and adoK_(cs)-metFcs as two transcripts increased tylosin production by 22%in the resultant strain TLPH11 compared to that in TL01.Furthermore,combinational overexpression of tlrC,metK_(cs),adoK_(cs)-metFcs,and tylR as four transcripts increased tylosin production by 23%(10.93g/L)in the resultant strain TLPH17 compared to that in TL01.However,a negligible additive effect was displayed upon combinational overexpression in TLPH17 as suggested by the limited increment of fermentation titer compared to that in TLPH08-2.Transcription analyses indicated that the expression of tlrC and three SAM biosynthetic genes in TLPH17 was considerably lower than that of TLPH08-2 and TLPH11.Based on this observation,the five genes were rearranged into one or two operons to coordinate their overexpression,yielding two engineered strains TLPH23 and TLPH24,and leading to further enhancement of tylosin production over TLPH17.In particular,the production of TLPH23 reached 11.35 g/L.These findings indicated that the combinatorial strategy is a promising approach for enhancing tylosin production in high-yielding industrial strains.

关 键 词：Streptomyces xinghaiensis TYLOSIN Combinational metabolic engineering 

分 类 号：Q94[生物学—植物学]