 หัวเรื่อง:ไม่มีชื่อไทย (ชื่ออังกฤษ : Characterization of a Crude Thermostable ?-galactosidase by the Bacterium PD1 Isolated from the Pong Dueat Hot Spring) ผู้เขียน: Phimchanok Nakkharat, Arkom Tesnum, Arkira Maethawarakorn, Dietmar Haltrich,  นางจิรกานต์ เมืองนาโพธิ์ สื่อสิ่งพิมพ์:pdf Abstract?-Galactosidase is an enzyme that hydrolyses lactose to glucose and galactose. The present study focused on the characterization of ?-galactosidase from a thermophilic microoganism isolated from the Pong Dueat hot spring, Chaingmai Province, Thailand. o-Nitrophenyl-L-D-galactopyranoside (oNPG) was used as a substrate to determine the ?-galactosidase activity from a strain PD1, which was found to be the active strain producing the highest ?-galactosidase activity. The optimum pH and temperature for enzyme activity were 6.5 and 55?C, respectively. The enzyme was stable at pH range of 6 to 10. The half-life of enzyme at 80, 70, 60, 55, 50 and 45?C were 0.5, 2, 31, 62, 87 and 435 h, respectively. The Km and Vmax values for the synthetic substrate oNPG were 11 mM and 1.1?10-2 mmolL-1min-1, respectively. |