右旋磷霉素手性转化菌株的筛选与鉴定

Screening and identification of strain which has the ability to chiral biotransformation dextral-fosfomycin

目的筛选以右旋磷霉素为唯一碳源转化产生左旋磷霉素的菌株并进行种属鉴定。方法采用固体琼脂块法对微生物菌种资源库中的真菌进行初步筛选;再利用液体摇瓶法对初筛阳性菌株进行复筛。利用薄层生物自显影的方法和质谱分析法对转化产物进行鉴定。采用形态学分类法及ITS-5.8S rDNA序列分析法对阳性菌株进行菌种鉴定。结果初筛了2856株真菌,获得138株阳性菌株;对其中转化能力比较强的15株阳性菌株进行液体摇瓶复筛,发现菌株2221的转化率最高,当底物投料量为0.05%时,转化率达到36.8%。根据菌株2221的形态特征以及ITS-5.8S rDNA序列比对,菌株2221被鉴定为沙门柏干酪青霉。结论沙门柏干酪青霉2221可手性转化右旋磷霉素为左旋磷霉素。

Objective To screen microorganism which can biotransform dextral-fosfomycin to levo-fosfomycin and to identify the species of the positive strains. Methods Fungal strains from microbiological resources were firstly screened by the agar block method, then the positive strains were screened by liquid shake-flask fermentation once more. The biotransformation product was detected by TLC combined with autobiography and mass spectrometry. The positive strain was identified by morphological characteristics and ITS-5.8S rDNA sequence. Results Totally 2856 fungal strains were screened by agar block method, and 138 strains showed positive results, 15 positive strains showed high biotransform ability by liquid shake-flask fermentation. Among them, strain 2221 was the best strain which could transform 36.8% dextral-fosfomycin to levo-fosfomycin when the concentration of substrate was 0.05%. According to morphological characteristics and ITS-5.8S rDNA sequence, strain 2221 was identified as Penicillium camemberti. Conclusion Dextral-fosfomycin can be chiral biotransformed to levo-fosfomycin by Penicillium camemberti 2221.