南京农业大学学报2025，Vol.48Issue(5)：1053-1059,7.DOI:10.7685/jnau.202404044
DL-丙氨酸不对称降解菌Penicillium levitum Slu-B的筛选及D-丙氨酸制备条件的优化
Screening of asymmetric DL-alanine degrader Penicillium levitum Slu-B and condition optimization for preparation of D-alanine
摘要
Abstract
[Objectives]The paper aimed to identify a newly isolated Penicillium strain Slu-B,and investigate its asymmetric degradation characteristics of DL-alanine and the feasibility of D-alanine preparation.[Methods]Fungal strains with high efficiency of asymmetric degradation of DL-alanine were isolated and screened from environmental samples,and identified to the corresponding species through microscopic morphology observation and rDNA ITS gene sequence homology comparison.With DL-alanine as the sole carbon and nitrogen source,the effects of temperature,medium pH,yeast extract addition,rotating velocity,liquid volume and inoculum size on the asymmetric degradation of the strain were studied through a series of shaking flask experiments,and the feasibility of preparing D-alanine by fed-batch fermentation was explored.[Results]An asymmetric DL-alanine degrading fungal strain Slu-B with asymmetric degradation index(ADI)value of 1 was isolated and identified as Penicillium levitum based on its microscopic morphological characteristics and ITS sequence homology.The optimal fermentative conditions for asymmetric degradation of DL-alanine by strain Slu-B were as follows:temperature 25-35 ℃,medium pH 4-6,rotating velocity 140-200 r·min-1,liquid volume in the shake flask 50-100 mL·500 mL-1,and the inoculum size 2.32 g·100 mL-1.Under these conditions,the concentration of accumulated D-alanine was 9.68 g·L-1,and theoretical D-alanine recovery rate of 96.75％was achieved when L-alanine was completely degraded during the fed-batch fermentation process.[Conclusions]The isolated strain Penicillium levitum Slu-B possesses complete asymmetric degradation activity of DL-alanine,and the recovery rate of D-alanine achieved during the fed-batch fermentation was as high as 96.75％,which represented a new strain resource for the preparation of D-alanine by biological method.关键词
不对称降解指数/DL-丙氨酸/D-丙氨酸/平滑青霉/分批补料发酵Key words
asymmetric degradation index/DL-alanine/D-alanine/Penicillium levitum/fed-batch fermentation分类
生物科学引用本文复制引用
黄文英,吴冬杰,顾向阳..DL-丙氨酸不对称降解菌Penicillium levitum Slu-B的筛选及D-丙氨酸制备条件的优化[J].南京农业大学学报,2025,48(5):1053-1059,7.基金项目
国家重点研发计划项目(2020YFD0900704) （2020YFD0900704）
