Tối ưu hóa sinh tổng hợp lactase từ Aspergillus oryzae sử dụng phương pháp đáp ứng bề mặt - phương án cấu trúc có tâm

Title:	Tối ưu hóa sinh tổng hợp lactase từ Aspergillus oryzae sử dụng phương pháp đáp ứng bề mặt - phương án cấu trúc có tâm
Authors:	Nguyễn, Thúy Hương Mai, Thục Di
Keywords:	Lactase;Aspergillus oryzae;RSM – CCD;Solid state fermentation
Issue Date:	2013
Publisher:	H. : ĐHQGHN

URI:	http://repository.vnu.edu.vn/handle/11126/13010

Aspergillus oryzae BK0 strain producing lactase was selected from 6 Aspergillus oryzae strains of laboratory. Aspergillus oryzae BK0 has the ability of producing the hightest activity of lactase and chosen to study the conditions of fermentation to produce lactase. from soil polluted with milk dairy factory effluents. Optimization of lactase (E.C 3.2.1.23) was carried out in Solid State Fermentation (SSF) with . rice bran and rice husk. Response surface methodology - Central composite design was used to investigate the effects of five fermentation parameters (lactose concentration, (NH4)2SO4 concentration, pH, initial moisture and spore ratio) on lactase enzyme production. Results of the statistical analysis showed that the fit of the model was good in all cases. Maximum specific enzyme activity of 4.120 U/g was obtained at the optimum levels of process variables (lactose (13.3%), (NH4)2SO4 (1.7%), pH (5.94), moisture (61.04%), spore ratio (1.05%)). The response surface methodology was found to be useful in optimizing and determining the interactions among process variables in lactase enzyme production. Testing the model obtained with lactase activity of 3.947 U/g.