Isolation and characterization of the biosurfactants from hydrocarbon contaminated industrial effluents

Abstract

The presently conducted study is the first report on the characterization of biosurfactants from Fictibacillus phosphorivorans, Cytobacillus firmus, Aeromonas hydrophila, Chryseomicrobium amylolyticum and Citricoccus zhacaiensis. In the final chapter study was conducted to determine the possible emulsifying, antioxidant and antibacterial applications of the extracted crude biosurfactants which may enable them to be used in wide range of industries. The emulsification index of BS 1, at 24 hours, was ~ 63% for benzene, hexadecane and toluene and ~ 21% and 15% for diesel and hair oil respectively. BS 4 created stable emulsions with benzene, hair oil, hexadecane, tolune and xylene with emulsification index greater than 40 % at 24 hours. Most of the hydrocarbons were emulsified when mixed with BS 18. The microscopic images revealed the cells in control were normal and intact with undamaged smooth cell surface. However the treated cell showed deformation, lysis and roughness on the cell surface. Also, alteration in arrangement of cells and accumulation of cell debris with shrunken cells was evident in the images of treated cells which confirmed the antibacterial activity of the extracted biosurfactants. newline