The survey of molecular and antimicrobial activity of isolated bacteria from the Caspian sea

Background and Aim: Marine microorganisms have an astonishing potential for producing antimicrobial substances against pathogenic bacteria. In this study, isolation and measurement of antimicrobial activity among these microorganisms against some pathogenic bacteria was carried out. Materials and methods: Samples were collected in autumn from the west of the Caspian Sea. Isolated samples were purified and antimicrobial activity among these samples against some pathogenic bacteria were measured by the use of two methods. At the end, genetic substance (DNA) of the strains with antimicrobial effect against pathogenic bacteria was extracted and polymerase chain reaction with universal primers was carried out. Isolated strains were identified by molecular method (16SrDNA PCR sequencing) and the strains were submitted and registered as new marine strains in the NCBI. Results: Results showed, the strains with antimicrobial activity had a noticeable effect on gram positive bacteria. So that gram positive bacteria were nearly inhibited in all cases but antimicrobial activity was restricted against gram negative bacteria, because gram negative bacteria were inhibited only in few cases. Finally, identification of stains with antimicrobial effect showed, the strains belong to Bacillus genus. Conclusion: According to this result; we can use marine bacteria for controlling growth of pathogenic bacteria that are resistant to drugs and as a big threat for the human health. Also we can optimize conditions for producing antimicrobial substances among them and we can extract them in industrial conditions for increasing quality and quantity antimicrobial substances in these bacteria for the use in different industries such as pharmaceutical industry.

The survey of molecular and antimicrobial activity of isolated bacteria from the Caspian sea Keywords:

Sea water , Disk diffusion antimicrobial test , Antimicrobial Agents , Polymerase chain reaction , Sequence analysis , Bacillus , آب دریا , تست ضد میکروبی انتشار از دیسک , عوامل ضد میکروبی , واکنش زنجیری پلیمراز , آنالیز توالی , باسیلوس