Microbial lipid production from pectin-derived carbohydrates by oleaginous yeasts

Yandan Wang, Zhiwei Gong, Xiaobing Yang, Hongwei Shen, Qian Wang, Jihui Wang, Zongbao K. Zhao

Abstract

Pectin-rich biomass is relatively less studied as feedstock for the production of biofuel and chemicals, partially because the major compositional carbohydrates galacturonate and arabinose are generally disfavored substrates for microorganisms. To explore the capability of microbial lipid production from pectic biomass, 10 oleaginous yeasts were evaluated by using galacturonate as sole carbon sources. Three strains belonging to Trichosporon cutaneum, Trichosporon fermentans and Cryptococcus curvatus were found to effectively convert galacturonate into lipid with lipid yields up to 0.12 g/g. Slightly higher lipid yields were also obtained on beet pulp hydrolysates, and cellular lipid contents were higher than 40.0% except for the T. fermentans strain. All of these lipid samples had long chain fatty acid compositional profiles similar to those of vegetable oils. The results demonstrate the potential of lipid production from pectic biomass, which is of great significance in terms of integrating wastes management and biofuel production.

Graphical abstract

Keywords: Sugar beet pulp; Galacturonate; Microbial lipid; Oleaginous yeasts; Pectic biomass; Pectin.