ε-聚赖氨酸产生菌TUST-2的分离鉴定

Isolation and characterization of a new ε-poly-L-lysine-producing strain TUST-2

【目的】ε-聚赖氨酸是一种天然氨基酸同聚物,本研究目的为分离筛选新的ε-聚赖氨酸产生菌。【方法】采用一种新的分离方法从土壤中分离ε-PL产生菌。分离方法含3步:(1)富集培养ε-PL耐受菌;(2)通过改进的Nishikawa方法筛选;(3)挑选高浓度ε-PL耐受菌株。【结果】从海南省土样中分离获得ε-聚赖氨酸产生菌TUST-2。分类和形态特征属链霉菌属。16S rDNA序列分析比对结果表明TUST-2属淀粉酶产色链霉菌(Streptomyces diastatochromogenes)。经特征反应分析、水解物分析、红外光谱、1H NMR、13C NMR和MALDI-TOF-MS分析表明TUST-2发酵产物为ε-聚赖氨酸。【结论】根据16S rRNA基因序列比对和形态及生理生化特征表明ε-聚赖氨酸产生菌TUST-2属于淀粉酶产色链霉菌,命名为淀粉酶产色链霉菌TUST-2。

[ Objective] ε-Poly-L-Lysine （ε-PL） is a natural amino acid homopolymer. The study aimed at isolating new ε- PL-producing strains. [ Methods] ε-PL-producing strains were screened from the soil by using a new isolation approach which had three steps, （ 1 ） enrichment culturing ε-PL toleranting strains; （2） screening by improved Nishikawa＇ s method; （3） selection of strains with higher ε-PL tolerant ability. [ Resuhs] A new ε-PL-producing strain TUST-2 was isolated from the soil collected from Hainan province, China. Chemotaxonomic and morphological characteristics of the isolate were typical of strain of the genus Streptomyces. The strain TUST-2 was found to belong to Streptomyces diastatochromogenes by comparative 16S rRNA genc sequence analysis. The purified fermentation product of the strain TUST-2 was confirmed as ε-PL by characteristic analysis, hydrolysate analysis, infrared spectrum, ^1H NMR Spectrum, ^13C NMR Spectrum, and MALDI-TOF-MS. [ Conclusion] On the basis of 16S rRNA gene sequence analysis and its morphological and physiological characteristics, ε-PL-producing strain TUST-2 is a new isolate of Streptomyces diastatochromogenes, named as Streptomyces diastatochromogenes TUST-2.