Abstract:
Dairy industry is one of the major food industries in most of the countries of the world including India and this industry has grown rapidly due to the high demand of milk and milk products. Dairy industry generate large amount of wastewater which is very rich in biodegradable organics and nutrients. It also contains high level of fats and oils which are not easily biodegradable and often interfere with the normal biological treatment process. Therefore, pretreatment of dairy wastewater is essential to remove these fats and oils from the wastewater before subjecting it to final biological treatment. In comparison to the existing physical, chemical and biological methods for pretreaing the dairy wastewater biological pretreatment methods using microorganisms and/or their products are found to be the most effective and successful. Biosurfactant facilitated biodegradation of fats and oils, primarily by increasing its solubility has been identified to be a potential method to deal with high fats and oils in wastewaters. The present work focused on pretreatment of high fats and oils containing dairy wastewater by the sophorolipids (SLs, a glycolipids type of biosurfactant) producing yeast Candida bombicola. To reduce the SLs production cost two agro-industrial wastes namely cheese whey and sugarcane molasses were tested as a low cost hydrophilic carbon source in place of costly glucose for its production by the yeast in batch shake flasks as well as in a laboratory scale bioreactor.
