Regulation of environmental factors on the expression of a solid-state specific lipase (Lip1) with Rhizopus chinensis by western blot and indirect Elisa.

To identify which solid-state typical environmental factors are involved in the induction of a solid-state special lipase (Lip1), western blot and Elisa based on Lip1 antibody were used. A low water activity played a significant role in the induction of Lip1, as evidenced by the increased expression level (20-46 microg/g dry cell) along with the decrease of water activity (0.927-0.969). Physical barrier against hyphal extension was found to be another required factor, since the expression of Lip1 was significantly enhanced by 3-fold using a membrane with smaller pore size (0.45 and 0.22 microm) covered on top of surface culture.