Abstract

With a view to exploring whether there was a correlation between a novel antibiotic and a plasmid, the plasmid was eliminated by SDS. Because the elimination of the plasmid had no effect on the bacterium’s producing antibiotic, it was determined that the plasmid had nothing to do with the antibiotic. However, with the plasmid being eliminated, the ability of the bacterium to secrete a kind of adhesive substance was lost, and the phenotype of the bacterium was also changed. This indicated that the plasmid was closely related to this adhesive substance and that the adhesive substance determined the bacterium’s phenotype. In addition, losing the plasmid meant losing life if the bacterium was under adverse circumstances like cold condition. It meant that the function of the plasmid (or the adhesive substance) was to protect the bacterium.

Key words: Plasmid, phenotype, antibiotic, viability, bacterium.