粗壮假丝酵母(Candida valida 20231)产脂肪酶发酵条件的研究

对粗壮假丝酵母(Candida valida 20231)产脂肪酶所需的培养基成分和发酵条件进行了优化。结果表明,粗壮假丝酵母在接种后3 h即进入对数期,18 h后转入稳定期,66 h后进入衰退期;发酵36 h达到最大酶活,至72 h仍然无明显下降趋势。最适合的培养基成分为:4.0%大豆粉,2.0%菜籽油,0.3%葡萄糖,0.3%NH_4NO_3,1.2%K_2HPO_4,0.42%NaH_2PO_4,0.4%MgSO_4·7H_2O。使用优化的培养基,最佳产酶的条件为:装液量80 mL(250 mL摇瓶),初始pH 6,接种量为2.0%,种子菌龄为12 h。在最佳产酶条件下,脂肪酶活力达到32.6 U/mL。

Studies on fermentation conditions for lipase production by Candida valida 20231

The optimization of medium components and fermentation conditions for lipase production by Candida vallida 20231 was investigated. The results showed that during fermentation period Candida valida entered logarithmic phase after 3 h, transferred to stationary phase after 18 h, and then cane into decline phase after 66 h. The lipase activity reached the maximum at 36 h after fermentation, and the obvious descending trend could not be observed even at 72 h. The optimum medium compositions were as follows： 4.0% soybean flour, 2.0% rapeseed oil, 0.3 % glucose, 0.3% NH4 NO3, 1.2 % K2 HPO4, 0.42 % NaH2 PO4, 0.4 % MgSO4 7H2O. The optimum conditions for lipase production using optimized medium were： liquid volume 80 mL in 250 mL shaking flask, the original pH value 6, the inoculation volume 2% and the seed cell age 12 h. Under the optimized conditions, the maximum lipase activity reached 32.6 U/mL.