固态混菌发酵生产饲用复合酶制剂营养条件和培养条件的研究

Study on the optimal medium composition and culture conditions for complex enzyme by solid-state mixed fermentation

黑曲霉变种(A.niger v.Tiegh)CGMCC1182、黑曲霉MA-56(A.niger MA-56)CGMCC2722和黑曲霉XY-1(A.niger XY-1)CGMCC1182分别为α-半乳糖苷酶、β-甘露聚糖酶和木聚糖酶生产菌株。为获得高产α-半乳糖苷酶、β-甘露聚糖酶和木聚糖酶的复合酶制剂,通过单因素实验,研究了黑曲霉三种菌株在固态发酵条件下产复合酶制剂的培养基组成和培养条件。结果表明,黑曲霉混菌发酵生产复合酶的最适培养基组成为:麸皮∶豆粕为7∶3(m/m),在此基础上(以麸皮和豆粕总量为10 g计算)添加玉米芯1.0 g,魔芋粉0.1 g,葡萄糖0.5 g,(NH4)2SO4 0.2 g,NaNO3 0.1 g,MgSO4 0.1 g,KH2PO4 0.2 g,H2O 11 mL。产酶最适培养条件为:培养温度30℃,固形物与加水比1∶1,α-半乳糖苷酶、β-甘露聚糖酶和木聚糖酶接种比例为5∶6∶6,接种混合孢子悬浮液2.5 mL(以一支菌种斜面加30 mL无菌水为标准),300 mL三角瓶中装量8 g培养基,发酵60 h时,复合酶产量达到最优,α-半乳糖苷酶、β-甘露聚糖酶和木聚糖酶三种酶制剂的活力分别可以达到221、894、10188 IU/g。

The study was intended to obtain optimal medium composition and optimal culture conditions for α-galactosidase,β-mannanase and xylanase production by solid-state mixed fermentation.The optimal medium was composed of WB and SM(7∶3,m/m),and on the base of 10 g dry substrate,1.0 g corncob,0.1 g konjak flour,0.2 g(NH4)2SO4,0.1 g MgSO4,0.1 g NaNO3,and 0.2 g KH2PO4 and 11 mL H2O were added;The optimal temperature and moisture level for compound enzyme biosynthesis was found to be 30.0 ℃ and 50.0 %,respectively.About 8 g medium in 300 mL flask and 30 %(V/m)of inoculum(107spores/mL)with the ratio of 5∶6∶6 for α-galactosidase,β-mannanase and xylanase strains and with fermentation time 60 h were suitable for enzyme production.Under the optimal conditions,α-galactosidase,β-mannanase and xylanase enzyme activity reached 221,894 IU/g and 10188 IU/g.