Protoplast Fusion Between Single Inactivated Citrobacter freundii and Deinococcus radiodurans

Abstract:

Single inactivated protoplast fusion technique was adopted in the fusion of Citrobacter freundii and Deinococcus radiodurans, the condition of protoplast preparation and influence factor of fusion process were examined in this paper. With the lysozyme concentration, enzymolysis time increased and temperature rose, an upward trend of protoplast formation rate was showed, while regeneration rate was found gradually decreased in the test. In addition, the results of orthogonal experiment on fusion factors indicated that the optimal fusion condition was 40% PEG (6000) which induced protoplast for 10 minutes at 42°C, pH 8, and the highest fusion rate reached to 2.74 × 10-7. The screened fusants had been stably transferred for ten generations. Furthermore, the tolerance to uranium for fusant was greater than that of Citrobacter freundii under the concentration of 85 mg/L, and biosorption capability of fusant was better than that of parental strains appreciably in the comparison experiment. This works lay foundation for constructing radioresistant engineering strains.