一种多聚羟基烷酸产生菌的诱变育种

MUTATION BREEDING OF XANTHOBACTER AUTOTROPHICUS PRODUCING POLY (HYDROXYBUTYRATE-CO-HYDROXYVALERATE)

以野生型自养黄杆菌为出发菌株，经亚硝酸、紫外线、60Coγ射线诱变处理选得三株性状优良的突变株（Uγ－、Uγ－17、Uγ－20）。Uγ－1突变株的菌落形态为菊花形，白色。Uγ-17和Uγ－20突变株的菌落形态均为圆凸光滑型，微黄色。40h的摇瓶发酵结果表明，Uγ－1、Uγ－17、Uγ－20突变株的干细胞产量分别为8．1g／1、11．2g／1、10．5g／1，其产物对干细胞的得率系数（yp/x）分别为0．74、0．75、0．79。与野生型菌株相比，这些突变株的干细胞产量yp/x分别增加了20％和7．2％以上。

The wild strain of X autotrophicus was mutated by induction of nitrous acid, ultraviolet ray and 60Co γ~ray Three mutant strains(Uγ-1, Uγ-17 and Uγ-20) were obtained by the initial and duplicate selections. The colony morphology of Uγ-1 mutant is chrysanthemum type and it is White. The colony morphology of Uγ-17 and Uγ-20 are circular, smooth and yellowish. The shake flask fermentation was cAned out for 40h. The results showed that the dry cell yield of Uγ-1, Uγ-17 and Uγ-20 mutant strains were 8.1g·L-1, 11.2g·L-1 and 10.5g·L-1 respectively. And the yield of P(HB-co-HV) tO the dry cell (yp/x) of the three mutant strains were 0.74. 0.75 and 0.79 respectively. Compared with the wild strain, the dry cell yield and yp/x of the mutant stains increased by over 20% and 7.2%, respectively.