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

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

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 nigerv.TieghCGMCC1182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.nigerv.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.nigerv.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.

＂One-factor-at-a-time＂ method was applied to investigate the medium composition and fermentation conditions for a-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 25： 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 a-galactosidase activity reached 308.5 U·g^-1 at a period of 68 h cultivation.