title: Efficient lipid production with Trichosporon fermentans and its use for biodiesel preparation.
abstract: Effects of medium components and culture conditions on biomass and lipid production of Trichosporon fermentans were studied. The optimal nitrogen source, carbon source and C/N molar ratio were peptone, glucose and 163, respectively. The favorable initial pH of the medium and temperature were 6.5 and 25 degrees C. Under the optimized conditions, a biomass of 28.1 g/l and a lipid content of 62.4% could be achieved after culture for 7 days, which were much higher than the original values (19.4 g/l and 50.8%) and the results reported by other groups. T. fermentans could grow well in pretreated waste molasses and a lipid yield of 12.8 g/l could be achieved with waste molasses of 15% total sugar concentration (w/v) at pH 6.0, representing the best result with oleaginous microorganisms on agro-industrial residues. Addition of various sugars to the pretreated molasses could efficiently enhance the accumulation of lipid and the lipid content reached as high as above 50%. Similar to vegetable oils, the lipid mainly contains palmitic acid, stearic acid, oleic acid and linoleic acid and the unsaturated fatty acids amount to about 64% of the total fatty acids. The microbial oil with an acid value of 5.6 mg KOH/g was transesterified to biodiesel by base catalysis after removal of free fatty acids and a high methyl ester yield of 92% was obtained.
authors.affiliation: Lab of Applied Biocatalysis, South China University of Technology, 381 Wushan Road, Tianhe District, Guangzhou 510640, PR China.
authors.forename: L Y
authors.initials: LY
authors.lastname: Zhu
authors.forename: M H
authors.initials: MH
authors.lastname: Zong
authors.forename: H
authors.initials: H
authors.lastname: Wu
mesh_terms: D018533:Biomass; D019149:Bioreactors; D002244:Carbon / Q000378:metabolism; D002384:Catalysis; D004736:Energy-Generating Resources; D005230:Fatty Acids, Nonesterified / Q000032:analysis; D005285:Fermentation; D005742:Gasoline; D005947:Glucose / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D008055:Lipids / Q000096:biosynthesis* / Q000737:chemistry; D008965:Molasses; D009584:Nitrogen / Q000378:metabolism; D010461:Peptones / Q000378:metabolism; D013696:Temperature; D013997:Time Factors; D014250:Trichosporon / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*
chemical_list: D005230:Fatty Acids, Nonesterified; D005742:Gasoline; D008055:Lipids; D010461:Peptones; D002244:Carbon; D005947:Glucose; D009584:Nitrogen