Abstract

Aida Hussain Ibrahim and Marwa Shaker Mahmood

The present study focused on induce the production of biosurfactant from previously locally isolated Serratia marcessens using biotic and a biotic factor. The production of biosurfactant was detected by determination of emulsification index (E24%) and emulsification activity (E.A). Two bacterial cells were used as biotic factors for enhancing the production of the biosurfactant, the result showed the ability of these bacteria for enhancement, and the best elicitor concentration was 500 µl for both bacteria. Different types of oils were used in this study as abiotic elicitors, all used oils lead to increase the production, but the maximum increase obtained with the use of soybean and petroleum oils. Two types of nanoparticles in different concentrations were used in this study as abiotic elicitors, the result showed that the used nanoparticles had the ability of enhancing the productive surface active substances and three concentrations lead to increasing the production (5, 10, 20 mg/ml) but the best concentration was 5 mg/ml. Various solvents were used for extraction of biosurfactant, the result showed that methanol: chloroform was the best solvent for extraction with a maximum yield of biosurfactant 8.2 g/l. The result showed that the biosurfactant had antibacterial activity against tested pathogenic bacteria.