INTERGENERIC PROTOPLAST FUSION BETWEEN METHYLOBACTERIUM EXTORQUENS AND XANTHOBACTER AUTOTROPHICUS AND GENETIC AND PHYLOGENETIC IMPLICATIONS OF RECOMBINANTS

摘要

Intergeneric protoplast fusion between Methylobacterium extorquens and Xanthobacter ^ autotrophicus was performed under strictly aerobic conditions and in presence of 40% PEG6000. Electron microscopic study showed enhancement in fusion events even multiple fusions when PEG-treated suspension was diluted in hypertonic broth and reincubated before fixation. After optimal post-PEG incubation, the majority of the protoplasts were seen to participate in fusion, and after the cytological fusion wall regeneration commenced. Fusion got completed after plating on the wall-regeneration medium. The fusion frequency obtained from the non-selective medium was about 0.7 x 10-6. The six fusants isolated were all gram negative aerobes differing in varying degrees to each of the parents. The high possibility of genetic recombination can be expected depending on electron microscopic evidence and biochemical and enzyme assays. The main objective was to study the kind of genetic recombination occurring in two microbesutilizing different pathways for methanol oxidation and the possibility of methanol oxidation (Mox) gene recombination.