二步发酵丢糟生产微生物油脂的研究

Study on the Production of Microbial Oils Fermented by Two-step Fermentation with Distiller's Grains

目的:探索以黄曲霉和皮状丝孢酵母为菌种二步发酵大曲丢糟生产微生物油脂的最佳工艺条件。方法:利用黄曲霉对丢糟进行一步发酵,再以一步丢糟发酵物为基质,设定皮状丝孢酵母的接种量、培养温度、培养时间为三个因素,进行L9(33)正交试验。结果:黄曲霉一步发酵丢糟的最佳条件为接种量12%,在28℃下发酵5d,获得的一步丢糟发酵物还原糖含量为2.4051%;皮状丝孢酵母二步发酵丢糟生产微生物油脂的最佳条件为皮状丝孢酵母接种量12%,在30℃下培养4d,每1 000g发酵物中可得油脂19.32g。结论:利用黄曲霉的产纤维素酶的性能和皮状丝孢酵母积累油脂的性能进行二步发酵丢糟生产微生物油脂,具有一定的可行性。

Obiective： Using Aspergillus flavus and Trichosporon utaneum as strains, the optimum conditions were studied on the production of microbial oils fermented by two - step fermentation with distiller＇ s grains. Method： The distiller＇ s grains were first fermented by Asper- gillus flavus, and then the production was re -fermented by Trichosporon cutaneum. Using the inoculating quantity of Trichosporon cutane- urn,the culture temperature and the culture time as three factors, the best process conditions were determined by L9 （33） orthogonal test. Result：The reducing sugar content of the distiller＇ s grains fermented by Aspergillusflavus under the additive of Aspergillusflavus is 12 % at 28℃ for 5d was 2. 4051%. The microbial oils content of the distiller＇ s grains re - fermented by Trichosporon utaneum under the in- oculating quantity of Trichosporon cutaneum is 12% at 30℃ for4d was 19. 32g per 1 000g fermentation products. Conclusion：It is feasible that use Aspergillusflavus and Trichosporon cutaneum to ferment distiller＇s grains to produce microbial oils.