一株镰刀菌的分离鉴定及变温发酵条件对其脂肪酸合成的影响

Isolation and Identification on a Fusarium Fungus and Effect of Fatty Acid Synthesis under Change Temperature Fermentation Conditions

为筛选产多不饱和脂肪酸新资源,从葡萄园土壤中分离到一株真菌,通过对菌株进行菌落特征、显微特征和18S r DNA序列分析,将该菌株鉴定为镰刀菌一个新种(Fusarium sp.JM)。为研究菌株油脂生产能力,通过两阶段变温发酵,分析发酵条件对菌体油脂和脂肪酸合成的影响。结果表明,镰刀菌油脂中脂肪酸组成丰富,其中C16脂肪酸和C18脂肪酸的含量约占总脂肪酸的90%,采用25℃,4 d/18℃,3 d二阶段发酵条件,菌体生物量为9.8 g/L,油脂产量1.42 g/L,油脂中多不饱和脂肪酸含量占总脂肪酸含量的46%以上。推测利用镰刀菌发酵生产多不饱和脂肪酸具有一定的可行性。

In order to screen new resources for producing polyunsaturated fatty acids, a fungal strains was isolated from vineyard soil. According to colony characteristics, microscopic characteristics and 18S rDNA sequence analysis, the strain was identified as a new species ofFusarium sp. JM. The impacts of fermentation conditions on the synthesis of oil and fatty acids were analyzed by two-stage variable temperature fermentation for studying the oil production capacity of strain. The results showed that the fatty acids composition in Fusarium sp. JM was abundant, and the content of C16 fatty acids and C 18 fatty acids accounted for 90 percent of the total fatty acids. Under the two-stage fermentation condition of 25℃/4 d and 18℃/3 d, the mycelium biomass and the lipid output were 9.8 g/L and 1.42 g/L respectively, and the content of polyunsaturated fatty acids （PUFAs） composed more than 46%. We speculated that it was feasible for the fermentation of PUFAs by Fusarium sp. JM.