[Possibility of the plasmid transfer within bacteria - compounds of the sulfidogenic microbial community]

Abstract

Extrachromosomal elements have been found within the isolates of ammonifying and iron-reducing bacteria obtained from the natural sulfidogenic community. These elements were small with size approximately 5-9 kb. Transconjugant strains Pseudomonas aeruginosa 27, P aeruginosa 28, P mendocina 29, Aeromonas hydrophila/caviae 30, harboured plasmids RP4 and R68.45 were obtained. The conjugation rate and retention of the plasmid within transconjugants were studied. P mendocina 29 cells with conjugation rate - 3.0*10(-6) CFU/ recipient cell, and P. aeruginosa 27 with rate 2.4*l0(-7) CFU/recipient cell were the most susceptible to R68.45 plasmid. The most stable retention is shown for transconjugated strains such as P aeruginosa 27 (R68.45), P. aeruginosa 27(RP4), P. mendocina 29(R68.45), A. hydrophila/caviae 30(RP4), A. hydrophila/caviae 30(R68.45). Thus, it was experimentally shown that corrosive-relevant bacteria form sulfidogenic microbial community which is able to accept extrachromosomal genetic elements from other bacteria when they act as recipients in conjugational process.