ISSN:
1476-5535
Keywords:
Keywords: β-galactosidase; thermophilic fungus; Rhizomucor; extracellular; solid state fermentation
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
,
Process Engineering, Biotechnology, Nutrition Technology
Notes:
A thermostable β-galactosidase was produced extracellularly by a thermophilic Rhizomucor sp, with maximum enzyme activity (0.21 U mg−1) after 4 days under submerged fermentation condition (SmF). Solid state fermentation (SSF) resulted in a nine-fold increase in enzyme activity (2.04 U mg−1). The temperature range for production of the enzyme was 38–55°C with maximum activity at 45°C. The optimum pH and temperature for the partially purified enzyme was 4.5 and 60°C, respectively. The enzyme retained its original activity on incubation at 60°C up to 1 h. Divalent cations like Co2+, Mn2+, Fe2+ and Zn2+ had strong inhibitory effects on the enzyme activity. The K m and V max for p-nitrophenyl-β- D-galactopyranoside and o-nitrophenyl-β - D-galactopyranoside were 0.39 mM, 0.785 mM and 232.1 mmol min−1 mg−1 respectively. The K m and V max for the natural substrate lactose were 66.66 μM and 0.20 μ mol min−1 mg−1.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1038/sj.jim.2900452
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