为得到多不饱和脂肪酸高产菌株,通过氮离子注入产油粘红酵母(Rhodotorula glutinis),对其进行辐照诱变,发现当注入能量为10keV时,注入剂量80×2.6×10^13ion/cm2为最佳诱变参数。然后,采用含有脂肪酸合成酶抑制剂cerulenin的培养基对高产油脂粘红酵母进行初筛,并研究了cerulenin对粘红酵母细胞的抑制作用,结果表明,当cerulenin的浓度达到11.20×10^-6mol/L时.抑制率为90%.可以作为筛选浓度,利用酸热耦合超生波法和索氏抽提法验证了cerulenin筛选菌株的准确性。最终筛选出一株油脂产量比出发菌株提高32%的高产菌株D30,经多次传代实验表明,该菌株遗传稳定性较好。气相色谱分析其油脂组成,结果表明多不饱和脂肪酸含量为28.07%。
To obtain a highly productive polyunsaturated fatty acid-yielding mutant strain, Rhodotorula glutinis was treated by N+ ion implantation. The ion implantation at 10 keV with a doses of 80x2.6x1013 ion/cm2 was found to be optimum. The high-yield stains were screened by culture in medium with cerulenin, a fatty acid synthase inhibitors. With a cerulenin concentration of 11.20x10-6 mol/L, inhibition ratio was up to 90%, this concentration was therefore used as the optimum concentration. Accuracy of screening with cerulenin was confirmed separately with acid-heating plus ultrasonic extration and Soxhlet extraction methods. Lipid yield was increased by 32% in high-yield mutant strain D30 than in the original strain. Successive transfer of culture indicated that genetic characteristics of the mutant strain was stable. Gas chromatograph analysis indicated that the content of polyunsaturated fatty acids in the lipid fraction was 28.07%.