Breeding of Strain Producing β-glucosidase and Research on its Characteristics
ZHU Feng-mei et al(College of Food Sciences,Shenyang Agricultural University,Shenyang,Liaoning 110161)
[Objective] The study aimed to screen the highyield strain of β-glucosidase and confirm the optimum technological condition of enzyme production.[Method] Several species of Aspergilluse niger were screened for producing β-glucosidase and A.niger 3.316,a high-yield strain of β-glucosidase was obtained.The optimum technological condition for producing the enzyme was confirmed through single factor and orthogonal experiments and the influences of different carbon(C) sources(bran,soluble starch,soybean meal and rice bran) on β-glucosidase activity under the same C source concentration(2%) and fermentation condition.[Result] The optimum technological conditions for the high-yield strain of β-glucosidase producing the enzyme were as follows: 2% bran,0.1% peptone and 0.1% KH2PO4 and initial pH of 6.0.The determined enzyme activity was 152.20 U/mg.The enzymological determination on β-glucosidase showed that when the reaction concentration was 0.1 mol/L acetic acid buffer,the enzyme activity was highest.The optimum reaction temperature was 55 ℃ and the optimum reaction pH was 5.0.[Conclusion] Different C sources had bigger influences on the enzyme production, which was highest when the C source was bran.
【CateGory Index】： Q93