Effect of Multiple Inhibitions in Corncob Hydrolysate on the Lipid Production by Rhodotorula glutinis

Abstract

Lignocellulosic biomass degradation byproducts generated in the pretreatment process have various negative impacts on microbes. This work investigated the effects of multiple inhibitors, such as acetic acid, furfural, and 5-hydroxymethylfurfural (HMF), on cell growth and lipid production by Rhodotorula glutinis. Single-factor experiments were performed to study the individual inhibitory actions. Among the three inhibitors, furfural is the most toxic for the cell growth, followed by HMF and then acetic acid. At 0.8 g/L furfural, the biomass and lipid concentrations decreased by 18.1 and 27.0% compared to the control. R. glutinis has a strong tolerance to acetic acid. Biomass and lipid production could even be stimulated when the acetic acid concentration was lower than 10 g/L. The effect of multiple inhibitions on the cell growth and lipid production was further studied using response surface methodology (RSM). The interaction of furfural and acetic acid was significant (p < 0.0001), but for the case of ac...