1株高产油脂长孢被孢霉MD-3菌株的诱变育种

Obtainment and Selection of a Mutant Strain of Mortierella elongata MD-3 Showing Improved Oil Production

为开发新型高产油脂的微生物菌种资源,以产油植物及其根系土壤为样品,筛选到1株丝状真菌MD-3,鉴定为长孢被孢霉(Mortierella elongata),其油脂质量分数和产量分别为30.15%和4.67 g/L。经常压室温等离子体诱变处理,获得1株遗传性状稳定的突变菌株MD-3-7,其油脂质量分数和产量分别为41.69%和6.62 g/L,比出发菌株分别提高了38.27%和41.76%。发现突变菌株菌丝球多呈绒毛状,菌丝变短且密度增加,有利于油脂积累;实时聚合酶链式反应结果表明,突变菌株的乙酰辅酶A羧化酶和脂肪酸合酶基因分别上调表达至9.25倍和4.37倍。本研究为产油脂微生物的开发利用提供有应用价值的菌源。

In this study,an oil-producing filamentous fungus,Mortierella elongata MD-3,was obtained from oil-producing plants and their rhizospheres with the aim to develop a new microbial oil resource.The oil content and yield of the strain were 30.15%and 4.67 g/L,respectively.A stable mutant designated MD-3-7 was obtained after treatment of strain MD-3 by atmospheric and room temperature plasma(ARTP),and its oil content and yield were 41.69%and 6.62 g/L,respectively,which increased by 38.27%and 41.76%compared with the original strain.It was found that most of the mycelial pellets of the mutant were villous,and compared to the parental strain,the mycelia became shorter and the density increased,conducive to the accumulation of oil;real-time polymerase chain reaction(real-time PCR)showed that the expression of the acetyl CoA carboxylase(ACC)and the fatty acid synthase(FAS)genes in the mutant strain were up-regulated by 9.25 and 4.37-fold,respectively.This study provides a valuable source for the development and utilization of oil-producing microorganisms.