枯草芽孢杆菌产芽孢条件的优化

为了提高枯草芽孢杆菌的芽孢数量及产芽孢率,采用分批培养法研究了营养条件、初始pH值、溶氧量对其生孢的影响。结果表明,麸皮和玉米粉分别是枯草芽孢杆菌生孢的最佳碳、氮源;无机盐和锰元素对芽孢生成有显著的影响。最佳生孢培养基组成:麸皮5 g,玉米粉10 g,NaCl 5 g,KH2PO41 g,MnSO4.H2O 0.4 g,水1 000 mL;最佳生孢条件:初始pH值为7.0,最佳装液量为250 mL锥形瓶装50 mL培养液。在150 r.min-1、30℃恒温培养72 h后,芽孢数可达到3.4×109cfu.mL-1,产芽孢率可达82.9%。

Optimization of sporulation conditions of Bacillus subtilis

In this paper,various nutritional supplements,initial pH and dissolved oxygen level were tested if they could stimulate the sporulation of Bacillus subtilis.Results suggested that the optimized sporulation medium was as follows:bran 5 g,cornmeal 10 g,NaCl 5 g,KH2PO4 1 g,MnSO4·H2O 0.4 g and distilled water 1 000 mL;The optimal sporulation conditions were initial pH 7.0 and 50 mL medium in 250 mL flask.With an optimized sporulation medium and sporulation conditions,the spore yield could reach to 3.4×109cfu·mL-1 and the highest sporulation efficiency was 82.9% after 72 h incubation at 150 r·min-1 and 30℃.