培养基组成及发酵条件对黑曲霉变种产α-半乳糖苷酶的影响

    为获得高产α-半乳糖苷酶,通过单因素实验,研究黑曲霉变种Aspergillus niger v. Tiegh CGMCC1182在固态发酵条件下产α-半乳糖苷酶的培养基组成和发酵条件,继而采用Ln18(37)正交试验设计,对影响黑曲霉A. niger v.Tiegh CGMCC1182产α-半乳糖苷酶的7个主要因素进行研究,对影响产酶的重要因素进一步优化.结果表明,黑曲霉变种A. niger v. Tiegh CGMCC1182产α-半乳糖苷酶的最适培养基组成为:麸皮∶豆粕=7∶3(W/W),在此基础上添加2.0%的棉子糖、2.5%的(NH4)2SO4和0.5%的MgSO4;产酶最适发酵条件为:培养温度30 ℃,培养基含水率55%,培养基装量为250 mL三角瓶中装入14 g培养基,接入10%(V/W)的孢子悬浮液(孢子浓度107个·mL-1),静置培养68 h获得最高α-半乳糖苷酶产量,酶活达308.5 U·g-1.

Effect of medium composition and fermentation conditions on α-galactosidase production by Aspergillus niger v.Tiegh

"One-factor-at-a-time" method was applied to investigate the medium composition and fermentation conditions for α-galactosidase production by a mutant strain Aspergillus niger v. Tiegh CGMCC1182 in solid-state fermentation, and then orthogonal Ln18(37) design was used to further optimize the seven significant factors. The optimal medium was composed of wheat bran (WB) and soybean meal (SM) with a ratio of 7∶3 (W/W), 2.0% of raffinose, 2.5% of (NH4)2SO4 and 0.5% of MgSO4. The optimum temperature and moisture level for α-galactosidase production were 30.0 ℃ and 55%, respectively. Fourteen gram of medium with 10% (V/W) of inoculum (107 spores·mL-1) in a 250 mL flask was suitable for enzyme production, and the maximum α-galactosidase activity reached 308.5 U·g-1 at a period of 68 h cultivation.