Screening and phylogenetic analysis of antibacterial strains isolated from antarctic

Abstract:

Escherichia coli, Bacillus subtilis, Staphylococcus aureus, Pseudomonas solanacearum, Pseudomonas aeruginosa and Bacillus thuringiensis were used as indicator strains respectively, four antibacterial strains, named as 97, Z11, Z18 and Z19 were screened from 580 strains of bacteria isolated from Antarctic by the method of agar diffusion. The growth curves, antibacterial curves and phylogenetic analysis of 4 antimicrobial strains were studied. The results showed that all of the four strains reached the log phase when they were cultured 24 h, strain 97 was in the log phase when it was cultured after 48 h, and the remaining three strains Z11, Z18 and Z19, were in the stationary when they were cultured after 60 h. They had the highest antibacterial activity when it was cultured after 84, 96, 72 and 72 h, respectively. Phylogenetic analysis indicated that these four strains belong to genera of Rheinheimera, Psychrobacter, Pseudomonas and Psychrobacter, respectively.

Key words:Antarctic bacteria, Antibacterial activity, Phylogenetic analysis