ABSTRACT
Numerous methods have been tried for the high-throughput screening. The Du-Nouy-Ring assay using a tensiometer is most widely applied for screening of BS-producing microbes. Persson and Molin described a similar assay using a glass surface instead of the oil-coated surface. Vaux and Cottingham developed and patented a method called microplate assay. The interaction between the anionic BS secreted by the microbes with the cationic surfactant cetyltrimethylammonium bromide and methylene blue results in the formation of insoluble ion pair. The success of commercial level BS production depends on the development of cheaper processes and the use of low-cost raw materials, accounting for 50% of the final product cost. Kitchen waste oils generated from domestic uses, vegetable oil refineries or the soap industries have been reported to be suitable to produce BS through microbial fermentation. Agro-industrial wastes are obtained at low cost from the respective processing industries and are as potent as low-cost substrates for industrial level BS production.
