Investigation the ability of bio-surfactant production by Bacillus laterosporus in various carbon sources
Subject Areas : Microbial BiotechnologyMahboobeh Varnaseri Ghandali 1 , Abdolamir Moezi 2 , Naeimeh Enayatizamir 3
1 - MS.c., Department of Soil Science, Shahid Chamran University, Ahvaz, Iran.
2 - Associate Professor, Department of Soil Science, Shahid Chamran University, Ahvaz, Iran.
3 - Assistant Professor, Department of Soil Science, Shahid Chamran University, Ahvaz, Iran.
Keywords: Biosurfactant, Surface tension, Bacillus laterosporus, Kerosene,
Abstract :
Background & Objectives: Biosurfactants are surface active compounds that produce by microorganisms. They are used in various industries such as petroleum, chemical, petrochemical, food industry, medicine, agriculture, etc. The purpose of this study was to optimize the production of biosurfactant in different carbon sources by Bacillus laterosporus. Materials & Methods: In this study, Bacillus laterosporus was provided from the microbial collection of Shahid Chamran University of Ahwaz. Biosurfactant production was evaluated in different carbon sources such as kerosene, glucose and sugar cane molasses at 30 and 37° C and the incubation periods of 48 and 168 hours. Screening of biosurfactant production was carried out using oil collapse and emulsification index, surface tension, and cell surface hydrophobicity. Results: Bacillus laterosporus showed the lowest surface tension reduction in kerosene carbon source after 168 hours incubation at 37 ° C, and decreased surface tension to 21.28 mN/m. The highest percentage of emulsification was related to medium containing molasses carbon source (43%). Bacillus laterosporus cell surface hydrophobicity in kerosene, molasses and glucose was 65, 58 and 50 %, respectively. Maximum biosurfactant production by Bacillus laterosporus obtained in kerosene carbon source around 8.4 gr/L Conclusion: The results showed that 37° C, 168 hours incubation and also using kerosene as carbon sources make the optimum condition for biosurfactant production by indigenous strain of Bacillus laterosporus.