一株产抗菌肽芽孢杆菌的筛选、鉴定及其发酵条件优化研究

Screening,identification and optimization of fermentation conditions of a Bacillus producing antimicrobial peptides

研究旨在筛选、鉴定一株产抗菌肽的芽孢杆菌,优化芽孢杆菌的发酵条件。试验选取对病原细菌抑制效果最佳的菌株CGMCC 24209,经形态特征观察、生理生化鉴定以及16S rDNA测序分析鉴定,确定该菌株为地衣芽孢杆菌(Bacillus licheniformis)。通过摇瓶单因素试验,优化菌株CGMCC 24209的发酵时间、温度、接种量、转速、初始pH值等条件。结果显示:菌株CGMCC 24209的最适发酵条件为:初始pH值7.0、装液量150 m L/500 mL、接种量7%,于30℃、220 r/min摇床培养48 h。研究表明,此条件下的发酵液杀菌效价最高,为158573 IU/mL。

The study was to screen and identify a strain of Bacillus producing antimicrobial peptide and optimize the fermentation conditions of Bacillus.CGMCC 24209,which had the best inhibitory effect on pathogenic bacteria.It was identified as Bacillus licheniformis by morphological characteristics observation,physiological and biochemical identification and 16S rDNA sequencing analysis.The fermentation time,temperature,inoculum size,rotation speed and initial pH value of strain CGMCC 24209 were optimized by shaking flask single factor test.The results showed that the optimal fermentation conditions of strain CGMCC 24209 were as follows:Initial pH value 7.0,150 mL/500 mL,7%inoculum at 30℃and 220 r/min shaker for 48 h.The study indicates that the fermented liquid under the condition has the highest bactericidal titer,which is 158573 IU/mL.