(619d) Effects of Multiple Inhibitions in Corn Cob Hydrolysate on the Lipid Production of Rhodotorula Glutinis

Effects of multiple inhibitions in corn cob hydrolysate on the lipid production of Rhodotorula glutinis

Hongjuan Liu*, Zhangnan Lin, Jianan Zhang*

Institute of Nuclear and New Energy Technology, Tsinghua University, Beijing 100084, China. Email: liuhongjuan@tsinghua.edu.cn or zhangja@tsinghua.edu.cn

Abstract: As an alternative feedstock for biodiesel production, microbial lipid production with cheap renewable resources such as lignocellulosic biomass has attracted people’s attention. However, lignocellulose degradation byproducts that generated in the pretreatment process have various negative impacts on cell growth and lipid production. Ordinarily, the effects of the multiple inhibitors are synergy interaction. In this work, multiple inhibitions of acetic acid, furfural and 5-hydroxymethylfurfural (HMF) on the cell growth and lipid production of oleaginous yeast Rhodotorula glutinis with corn cob hydrolysate was studied. Among the three inhibitors, furfural is toxic most for the cells, followed by HMF and acetic acid. Rhodotorula glutinis has the strong tolerance to acetic acid. The cell growth and lipid production could even be stimulated when acetic acid concentrations were lower than 10 g/L. Synergy inhibition of furfural and acetic acid on Rhodotorula glutinis was significant, but it was not obvious between acetic acid and HMF or furfural and HMF. When acetic acid concentration higher than 4g/L combined with furfural concentration above 0.2 g/L, the biomass and lipid production declined dramatically. The results were useful for the deep understanding of Rhodotorula glutinis metabolism and helpful for the optimization of lipid production with liginocellulosic biomass.

Key words: liginocellulosic biomass, microbial lipid, inhibition, fermentation, Response surface analysis