Optimization of Bacillus licheniformis M109 culture medium in this research based on the orthogonal test, carbon source, nitrogen source and carbon nitrogen ratio were determine as necessary for fermentation medium of Bacillus licheniformis M109. In order to enhance Bacillus licheniformis M109 fermentation level, growth curve of Bacillus licheniformis M109 and trend of Ph, dissolved oxygen(DO) were studied. Though studying the fermentation process of growth, the optimal Ph and inoculation amount were determined. The results found that DO was a key factor that limited the growth of Bacillus licheniformis M109. It was studied regulation rotate speed of stirring to improve dissolved oxygen and the fermentation density in culture medium. Another study found that Bacillus licheniformis M109 fermentation level could be improved by adding fresh medium. Through optimization of culture medium and conditions, the fermentation level of Bacillus licheniformis M109 incneased to 1. 2×1010 CFU/Ml from the initial 1. 0×109 CFU/Ml and the rate of bacillus arrived to 88%.%试验旨在筛选一株地衣芽孢杆菌M109(Bacillus licheniformis M109)进行培养基和发酵条件的优化.采用单因素试验方法筛选出最佳碳源和氮源的培养基,并利用正交试验方法确定其最佳的碳氮比.为了继续提高地衣芽孢杆菌M109的发酵水平,研究其在发酵过程中的生长曲线、pH和溶氧(DO)水平的变化曲线,通过对发酵过程中生长参数的测定,优化了地衣芽孢杆菌M109最佳的接种量和最适pH.结果发现,溶氧限制是地衣芽孢杆菌M109生长的关键因素；在限定通风量的条件下,通过调节搅拌转速的方法来提高培养基中的溶氧水平,提高发酵密度；通过流加培养基的方法也能提高地衣芽孢杆菌M109的发酵水平.因此,通过对培养基和发酵条件的优化,使地衣芽孢杆菌M109的发酵水平由最初的1.0×109 CFU/mL提高到1.2×1010CFU/mL,芽孢形成率为88％.
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