Strain Improvement by Interspecific Protoplast Fusion of Streptomyces griseus and Streptomyces hygroscopicus producing Acetaminophen

이종간 원형질체 융합을 이용한 acetaminophen 생산균주 개량

Acetaminophen, a widely used analgesic, can be formed by N-acetylation and p-hydroxylation of aniline. Interspecific protoplast fusion technique was used to get acetaminophen directly from aniline and to increase the productivity of acetaminophen. Three auxotrophic mutants were obtained from S. griseus(ATCC 13273) and S. hygroscopicus(KCTC 1089) by N-methyl-N'-nitro-N-nitrosoguanidine(NTG) treatment. Regeneration frequencies of S. griseus$(his^-)$, S. griseus$(lys^-)$, S. hygroscopicus$(arg^-)$ were 42%, 45%, and 31%, respectively. Fusion of protoplasts carrying different auxotrophic markers was achieved by treatment with polyethylene glycol. When protoplasts were treated with 50% polyethylene glycol for 3 minutes, the fusion frequency between S. griseus$(his^-)$ and S. hygroscopicus$(arg^-)$ was $3.8{\times}10^{-5}$. The fusion frequency between S. griseus$(lys^-)$ and S. hygroscopicus$(arg^-)$ was $5.6{\times}10^{-4}$. When we checked the production of acetaminophen, thirty-four out of the fifty-six fusants produced larger amounts of acetaminophen than the parent strains did. Nine fusants produced twice more and twenty-five fusants produced one to two times more of acetaminophen than their parents.