Lipase production by immobilised Rhizopus arrhizus

Immobilisation of Rhizopus arrhizus cells on a solid support (polyurethane foam) for lipase production has been explored. Lipase biosynthesis was repr essed at a high glucose level. Maximum productivity was recorded at 1 g l(- 1) glucose concentration. The inclusion of 0.5 g l(-1) corn oil (as an indu cer) in the fermentation medium resulted in 2.5-fold higher lipase producti on compared to the control where no oil was added. Repeated-batch experimen ts revealed that immobilised R. arrhizus cells demonstrated reproducible be haviour, producing the same amount of enzyme over a 120 h period. The stora ge stability of the enzyme was investigated and enzyme activity reduction w as 26% within 160 h. (C) 2000 Published by Elsevier Science Ltd. All rights reserved.