A PRELIMINARY STUDY ON CULTIVATION OF MUCOR PLUMBEUS FOR MICROBIAL OIL PRODUCTION USING MOLASSES

SUGARCANE MOLASSES, SUGARCANE trash and bagasse are the major by-products generated in cane sugar production process. Conversion of these by-products into valuable products has the potential to improve the profitability of the sugarcane industry. Biofuels are one of the value-added products. However, the profits from the production of low value biofuels such as bioethanol and biodiesel are marginal under current market conditions. In recent years, production of high value advanced drop-in biofuels from renewable carbohydrate feedstocks has gained increasing interests worldwide. The research team at QUT is working together with industrial partners on advanced biofuels production from sugarcane processing by-products through a two-stage process. In the first stage, microbial oils are produced by oleaginous microorganisms. In the second stage, advanced biofuels are produced through hydrodeoxygenation of either microbial oils extracted from microbial biomass or microbial oils obtained from hydrothermal liquefaction of microbial biomass. In this study, microbial oil production by an oleaginous filamentous fungus, Mucor plumbeus, was carried out using molasses as a carbon source. Morphology control strategy and nutrient optimisation were firstly developed to improve biomass and microbial oil production. Furthermore, microbial oil production by M. plumbeus was scaled up from shake flasks to laboratory scale stirred tank reactors. Inoculation of crushed fungal pellet biomass led to the formation of dispersed short hyphae in reactors and improved biomass and oil production. Finally, the inoculation strategy was demonstrated in a 1 000 L reactor at Mackay Renewable Biocommodity Pilot Plant.