Simultaneous utilization of glucose and xylose for lipid accumulation in black soldier fly

Abstract

Background: Lignocellulose is known to be an abundant source of glucose and xylose for biofuels. Yeasts can convert glucose into bioethanol. However, bioconversion of xylose by yeasts is not very efficient, to say nothing of the presence of both glucose and xylose. Efficient utilization of xylose is one of the critical factors for reducing the cost of biofuel from lignocelluloses. However, few natural microorganisms preferentially convert xylose to ethanol. The simultaneous utilization of both glucose and xylose is the pivotal goal in the production of biofuels. Results: In this paper, we found that 97.3 % of the glucose and 93.8 % of the xylose in our experiments was consumed by black soldier fly (BSF) simultaneously. The content of lipid reached its highest level (34.60 %) when 6 % xylose was added into the standard feed. 200 g of rice straw was pretreated with 1 % KOH, followed by enzymatic hydrolysis for fermentation of ethanol, the residue from this fermentation was then fed to BSF for lipid accumulation. In total, 10.9 g of bioethanol and 4.3 g of biodiesel were obtained. Conclusions: The results of this study suggest that BSF is a very promising organism for use in converting lignocellulose into lipid for biodiesel production.