In this project the physiology and growth of Rhizopus
arrhizus was investigated in detail with a view to
developing an industrial fermentation process to produce
a lipase enzyme. Spore and vegetative inocula were
examined and biomass production was optimized in flasks
and fermenters. Pelleting of growth was controlled by
developing suitable inoculum procedures and media.
Storage conditions for stock cultures were optimized
also as part of this work. Factors affecting lipase
production were investigated initially m shake-flasks,
and later in stirred laboratory fermenters. The inoculum
development and production fermentations were then
integrated and scaled-up to plant-scale (3,000 litres).
Economic yields of lipase were obtained at this scale.
Other experiments were conducted to determine the
biochemical characteristics of several lipase enzymes
and to develop a rapid and inexpensive lipase assay.
Finally, growth morphology of R. arrhizus was examined
m a range of media to investigate some possible causes
and mechanisms associated with pelleting of growth.