少根根霉γ-亚麻酸高产菌株选育及发酵条件优化

SELECTIVE BREEDING OF GAMMA LINOLENIC ACID HIGH-YIELDING STRAIN OF RHIZOPUS ARRHIZUS AND STUDIES ON SOLID STATE FERMENTATION CONDITIONS

经过He-Ne激光复合氯化锂对孢子诱变,以及He-Ne激光处理原生质体的方法,从一株产γ-亚麻酸(GLA)的原始菌株少根根霉(Rhizopus arrhizus)R8中选育出突变株RC378,摇瓶培养菌体油脂含量47.8%,其中GLA占油脂的12.6%,比原始菌株油脂含量提高了130.8%,GLA含量提高了276.7%.突变株油脂组分较原始菌株具明显差异.以麸皮、玉米粉为主要原料固态发酵干基油脂含量保持在9.4%～12.9%, GLA含量在9.8%～12.6%.

Rhizopus arrhizus mutant strain RC378 accumulating a large amount of lipid was successfully obtained when the original strain R8 was treated by U.V., He-Ne laser and LiCl .The content of lipid in RC378 cultivated in shaking flask was up to 47.8%, which was 130.8% higher than that in the original strain. The content of GLA in lipid from RC378 was 12.6%, which was 276.6% higher than that from R8. The best medium for lipid production are: wheat bran: corn powder: rapeseed residue: rice flour =6∶4∶2∶1, with the addition of 2% sucrose, 0.2% NH4Cl, 0.4% sodium citrate, 0.3% ZnSO4; the ratio of substrate and water was 1∶1.5. Inoculum was suspension spores. The isolate was cultivated at 30℃ for the first 72h, and then lowered the temperature to 24℃ for another 60h. The content of lipid kept at 9.4%~12.9% and GLA kept at 9.8%~12.6%.