A comparative study on batch and fed-batch cultures of oleaginous yeast Cryptococcus sp. in glucose-based media and corncob hydrolysate for microbial oil production

• Published in: Fuel (Guildford) Vol. 105; pp. 711 - 717
• Main Authors: Chang, Yi-Huang, Chang, Ku-Shang, Hsu, Chuan-Liang, Chuang, Lu-Te, Chen, Chien-Yu, Huang, Fu-Yu, Jang, Hung-Der
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 01.03.2013; Elsevier
• Subjects: Applied sciences; Batch culture; Biomass; Corncob hydrolysates; Cryptococcus; Cryptococcus spp; Energy; Energy. Thermal use of fuels; Exact sciences and technology; Fed-batch culture; Fuels; Microbial lipid; Natural energy; Corncob hydrolysates; Batch culture; Cryptococcus spp; Microbial lipid; Fed-batch culture; Diesel fuel; Lipids; Biofuel; Biomass; Glucose; Inhibition; Comparative study
• ISSN: 0016-2361; 1873-7153
• DOI: 10.1016/j.fuel.2012.10.033

► Effect of culture mode on the production of oleaginous yeast lipid was studied. ► Accumulation of lipid strongly depended on the initial concentrations of glucose. ► Fed-batch culture diminished the substrate’s inhibition of lipid-accumulation. ► Maximal lipid content in the Cryptococcus sp. were 61.3% on dried weight basis. The production of microbial lipids by a batch or fed-batch culture of oleaginous yeast was compared using glucose and corncob hydrolysate as carbon sources. Batch cultures using 4%(w/w) glucose as the carbon source reached a dry biomass, lipid yields and cellular lipid content of 9.4g/l, 6.0g/l and 63.5%(w/w), respectively. However, batch cultures demonstrated that there was an inhibitory effect on the biomass and lipid yields when the glucose concentration increased up to 6%(w/w). It was found that the fed-batch culture diminished the substrate’s inhibition of microbial lipid-accumulation. Fed-batch cultures in the corncob hydrolysate-based media containing an initial 4% reducing sugar and an addition 2% glucose for 4d of cultivation resulted in dry biomass and cellular lipid content of 10.8g/l and 61.3%(w/w), respectively. The overall lipid productivity increased to 1.08g/l/d for the fed-batch culture with an initial 4% glucose in corncob hydrolysate and an addition of corncob hydrolysate containing 2% glucose. High concentrations of reducing sugar in the corncob hydrolysate can be efficiently and rapidly converted to Cryptococcus lipid in the fed-batch culture system. Therefore, microbial lipids from Cryptococcus sp. are prospects for a potential alternative oil resource for biodiesel production.