Identification of Antibiotic Producing Bacteria from Soil Samples of Dhaka, Bangladesh

Abstract

Multidrug-resistance in bacteria is a serious and common problem that demands an urgent need to discover new antibiotics. In recent years multiple approaches have been taken to develop novel, potent, and less toxic antibiotics from natural sources against pathogenic bacteria. Soil has been considered as a natural source of obtaining bacteria with the ability to produce noble antibiotics. We studied soil samples in Dhaka municipal area to identify bacteria having antibiotic producing ability. We have isolated three bacterial strains (named K1, K2, and K19) producing growth inhibitory components effective against both gram positive and gram negative bacteria. Bacteria were found to produce circular, regular, white colonies. Gram staining indicated that K1, K2 was gram negative, while K19 was gram positive. Cellular morphology was studied by scanned electron microscopy (SEM) and found that K1, K2, and K19 are short rod shaped. It was found that the antibacterial factors from the bacterium are released in to the cell culture medium. The antibacterial activity of the component(s) remains active when the cell culture supernatant was heated at 45oC for five minutes. Further characterization of the bacteria and their antibacterial compounds are in progress in our laboratory.