产碱性蛋白酶地衣芽孢杆菌合成培养基筛选与优化OA北大核心CSTPCD

In this study,a systematic screening and optimization approach was employed to identify and characterize the optimal chemically defined medium for cultivating Bacillus licheniformis to produce alkaline protease.The initial chemically defined medium CDM0 was constructed based on the analysis of the composition of soybean meal and relevant literature reviews.The components that significantly affected the growth of the bacterium(growth reduced by more than 20％)were preliminarily identified through single component removal experiments,including three bases,four vitamins,11 amino acids,as well as various metal ions and inorganic salts.Based on this,the components that were taken out of CDM0 were added respectively and then five key nutrients with a more than 20％enhancement in cell growth were screened out.Then the optimal combination of(NH4)2SO4,adenine,and asparagine was obtained from a total of 26 combina-tions of the five key nutrients.Furthermore,the effects of glycerol,five monosaccharides,and three disaccharides on bacterial growth and alkaline protease chemically defined were also investigated.Ultimately,an optimized chemical complete synthesis medium,CDM3,was developed with galactose as the carbon source.The experimental results demonstrated that the cell growth and alkaline protease production under CDM3 were found to be significantly increased compared to the initial medium CDM0,where the enzyme viability was elevated by 2.5-fold to 10 300.7 U/mL.The findings of this experiment provide a foundation for future research on the metabolic characteristics of this strain.