| Microbial lipid production from lignocellulose material was considered as a promising alternative source of biodiesel production. Oleaginous yeast Trichosporon cutaneum was found to be the most adopted strain to the lignocellulose degradation compounds. The optimum temperature for lipid accumulation and cellulase which is used in the saccharification phase are30℃and50-55℃.respectively. It is, therefore possible to screening thermophilic oleaginous yeast which can be used in simultaneous saccharification and fermentation (SSF). In this study, Trichosporon cutaneum CX1was mutagenesis with UV and EMS. Selection was performed with culture medium supplemented with cerulenin and sesamol under high temperature. By these methods, thermophilic mutant strain Trichosporon cutaneum G3was selected, and its lipid accumulation was improved by46.2%at42℃compared with reference. Analysis on the cytomembrane fatty acids for T.cutaneum G3and T.cutaneum CX1at normal temperature, T.cutaneum G3at42℃through GC-MS showed that the mutant strain enjoys a higher degree of saturation than the original strain on fatty acid in cytomembrane and higher temperature made the higher degree of saturation in the mutant strain. The influence of metal ions,organic acids and vitamins on lipid accumulation by T. cutaneum CXI under36℃and T. cutaneum G3under42℃was respectively investigated by single factor experiment and orthogonality test. Some inhibition factors were found with Mn2+,Zn2+, citric acid and acetic acid. Beneficial effects of Fe3+,Ca2+,Fe2+on lipid accumulation were observed. The results paved the foundation for the industrial application of microbial lipid from lignocellulose material. |
PDF Full Text Request