Identification of Biosurfactant-producing bacteria in petroleum contaminated soils in the city of Borujerd

Subject Areas : microbiology

Mohsen Mirzaei ¹ , reza yari ² , Morteza Cheloei ³

1 - Department of Laboratory Sciences, Borujerd Branch, Islamic Azad University, Borujerd, Iran.
2 - islamic azad university, Boroujerd branch
3 - Department of Biology, Borujerd Branch, Islamic Azad University, Borujerd, Iran.

Received: 2017-03-07 Accepted : 2017-04-30 Published : 2017-08-23

Keywords: Bacillus subtilis, Petroleum, Biosurfactant, Environmental pollution,

Abstract :

Background and Aim: Biosurfactant is a material valuable in industries such as oil, pharmaceutical, cosmetic, health food, medicine and agriculture industries. The aim of this study was to identify native biosurfactant-producing bacteria in oil contaminated soils. Materials and Methods: Sampling of petroleum contaminated soils around the city of Borujerd was done. After dilution and the cultivation, a variety of bacteria isolated. By using multiple tests of specifying biosurfactant-producing bacteria such as hemolysis test in blood agar, emulsification index measurement, destruction of drops, expansion of crude oil, the amount of petroleum hydrocarbons have been parsed biosurfactant-producing bacteria were isolated from other bacteria. The strongest biosurfactant-producing bacterial species were selected according to the screening tests and then was inoculated in Bushnell-Haas Broth medium with gasoline in a shaking incubator. After biosurfactant production and purification of the colony, to identify the genus and species of bacteria, a series of biochemical tests along with PCR of district 16 srRNA and sequencing were performed. Results: With multiple experiments it was found the bacteria produce a significant amount of biosurfactant. After DNA sequencing, in the software review was found that more than 97% genetic similarities is between the bacteria and Bacillus subtilis. Conclusions: Due to the abundance of the bacteria in soil and its ability to produce biosurfactant and extent of oil pollution in Iran, the bacteria can be easily used to eliminate environmental pollution.