关键词: 秦岭霉素, 原生质体融合, 融合子

Abstract: a novel lactam antibiotic, qinlingmycin, was isolated from fermentation products of one Streptomyces separated from the soil of qingling mountain. The bioactivity of qinlingmycin had been compared with Penicillin and Cephradine. the result showed that the inhibition activity of qinlingmycin against Bacillus cereus,Bacillus cirulans,Pleudomona aereuginosa were better than Penicillin and Cephradine. and the MIC was 1.2ug/ml,1.5 ug/ml and 2.0ug/ml respectively. against Sarcina Lutea Schroeter,Zscherichia coli was lower than Penicillin and Cephradine. The activity against Staphylococcus aureus is higher than Penicillin lower than Cephradine.No.24 and Ms-24 strain produce qinlingmycin but also pigment.No.24 and mutagensis Ms-24 strain’s protoplast were obtained in lysozyme.the protoplast were mixed at ratio of 1:1 with PEG was added to fuse protoplast.and marking the fusants with fluorescence.. qinlingmycin was obtained through isolation and purification.some relative conditions for preparation, fusion and regeneration of two strain’s protoplast were studied. it was proved that 0.25% Gly was optimal condition for preparation and regeneration of the protoplast. the lysozyme concentration was 1mg/ml,and the optimal treating time was 1h.PEG in different molecular weight tested in the experiment had little influence on fusion of the protoplasts. but its concentration was of importancel.PEG at a concentration on 50% was of benefit to the protoplast fusion. .among 163 fusants, strain, three highly qinlingmycin-producing strain pf77,pf126 and pf138 was obtained. the bioassay results showed that the fungicidal activity of three fusants increased by 43.48％，60.87％ and 65.22％。and the production of qinlingmycin increased by 36.59％，74.39％ and 91.46％. and three fusants was Successively cultured ten times in the Medium, heredity character was stable.