Shin Chang-Hun, Cho Hang Su, Won Hyung-Jin, Kwon Ho Jeong, Kim Chan-Wha, Yoon Yeo Joon
Department of Biotechnology, College of Life Sciences and Biotechnology, Korea University, Seoul 02841, Republic of Korea.
Department of Biotechnology, College of Life Science and Biotechnology, Yonsei University, Seoul 03722, Republic of Korea.
J Ind Microbiol Biotechnol. 2021 Jun 4;48(3-4). doi: 10.1093/jimb/kuab004.
Clavulanic acid (CA) produced by Streptomyces clavuligerus is a clinically important β-lactamase inhibitor. It is known that glycerol utilization can significantly improve cell growth and CA production of S. clavuligerus. We found that the industrial CA-producing S. clavuligerus strain OR generated by random mutagenesis consumes less glycerol than the wild-type strain; we then developed a mutant strain in which the glycerol utilization operon is overexpressed, as compared to the parent OR strain, through iterative random mutagenesis and reporter-guided selection. The CA production of the resulting S. clavuligerus ORUN strain was increased by approximately 31.3% (5.21 ± 0.26 g/l) in a flask culture and 17.4% (6.11 ± 0.36 g/l) in a fermenter culture, as compared to that of the starting OR strain. These results confirmed the important role of glycerol utilization in CA production and demonstrated that reporter-guided mutant selection is an efficient method for further improvement of randomly mutagenized industrial strains.
由棒状链霉菌产生的克拉维酸（CA）是一种临床上重要的β-内酰胺酶抑制剂。已知甘油利用可显著改善棒状链霉菌的细胞生长和CA产量。我们发现，通过随机诱变产生的工业用CA生产菌株棒状链霉菌OR比野生型菌株消耗的甘油更少；然后，我们通过迭代随机诱变和报告基因引导的筛选，开发了一种突变菌株，与亲本OR菌株相比，该菌株中甘油利用操纵子过表达。与起始OR菌株相比，所得的棒状链霉菌ORUN菌株在摇瓶培养中的CA产量提高了约31.3%（5.21±0.26 g/l），在发酵罐培养中提高了17.4%（6.11±0.36 g/l）。这些结果证实了甘油利用在CA生产中的重要作用，并表明报告基因引导的突变体筛选是进一步改良随机诱变工业菌株的有效方法。
