Genetic recombination after cell fusion of protoplasts from the facultative alkaliphile Bacillus sp. C-125

摘要

Protoplasts were prepared from two auxotrophic and antibiotic-resistant strains (Met-Nalrand Thr-Strr, respectively) of the facultative alkaliphile Bacillus sp. C-125 by treatment with lysozyme. The protoplasts fused effectively in the presence of polyethylene glycol. Fusants obtained between two parental protoplasts were regenerated on solid medium containing the two antibiotics, nalidixic acid (Nal) and streptomycin (Str). Parental protoplasts were regenerated at high frequency (43-97%) on non-selective medium but not on selective medium. The NalrStrrfusants had the form of bacilli. Met and Thr markers segregated among the fusants with a predominantly Met+Thr+phenotype. The exfusants seemed to restore the parental ploidy.