(625ac) Lignocellulosic Biomass Hydrolysate for Cultivation of Lipid-Producing Microorganisms

The utilization of biodiesel has greatly increased over the past two decades due in part to concerns about the environmental consequences of fossil fuel combustion, the low lubricity quality of ultralow sulfur diesel, and the rapid rise in crude oil prices. However, current biodiesel production is not cost-competitive with petroleum fuels due to the high cost of its feedstock. The cost of feedstock for producing biodiesel is responsible for almost 70-75% of the total cost of the process. Lignocellulosic biomass has been considered as a promising feedstock for the efficient production of biofuel due to its sustainability and abundance. This research explores the ability of two oleaginous microorganism Rhodotorula glutinis and Rhodococcus rhodochrous to utilize lignocellulosic biomass for the production of lipids feedstock for biodiesel production. Two hydrolysates from lignocellulosic biomass, paper sludge a solid waste from pulp and paper industry and bagasse, were used and their chemical compositions were determined. The degradation compounds for each model lignocellulosic substrate were studied. The fermentation was carried out in a 3 L aerobic batch bioreactor and the effect of these two model substrates on the growth and lipid accumulation of R. glutinis and R. rhodochrous was studied. In order to potentially offset some of the cost associated with the biodiesel production, pulp and paper wastewater was used as a fermentation medium for microbial lipid production from lignocellulosic biomass-derived sugars. The effect of lignocellulosic hydrolysate on fatty acid composition of storage lipid was then determined in order to evaluate the suitability of the microbial oil feedstock for biodiesel production.