Biosurfactants have become the most essential parts of several industrial processes. So the industrial demand for the biosurfactants is increasing 2.8% annually. The huge requirement can be satisfied by the non-economical, large-scale production of biosurfactants from cheap, easily available substrates. Biosurfactant-producing, high yielding Pseudomonas aeruginosa and Bacillus licheniformis were isolated from oil-contaminated soil and compared to the standard biosurfactant-producing bacteria B. licheniformis MTCC 429 in mineral salt broth medium with 2% paraffin (MSB). Soil bacterial isolate, B. licheniformis showed higher surface tension reduction and emulsification activities in MSB. Another soil bacterium, P. aeruginosa showed maximum reduction in surface tension from 0.072 N/m to 0.020 N/m and 86.66% of emulsificationin in mass production media having 2% of wheat bran extract. Biosurfactant produced in 2% of wheat extract medium was purified by acid precipitation and yielded 40 mg/ mL. Medium prepared from 0.5%, 1.0%, 1.5% and 2.0% of rice bran extract has not supported the growth of any organism. So, the biosurfactants can be mass produced from 2% wheat bran extract medium inoculated with indigenous bacteria P. aeruginosa, and it can be used for industrial purposes.

Most surfactants are produced from the nonrenewable sources and require costly synthesis and purification steps (Davidson and Mildsky, 1972). Biosurfactants are biological alternative to chemically-derived surfactants and are recognized for their therapeutic and industrial (paper, leather, textile, etc.) applications. World market for surfactants reached $24.33 bn in 2009 and it was nearly 2% up from the previous year. Researchers have envisaged that surfactant market would experience quite healthy growth by 2.8% annually till 2012 and by 3.5%-4% thereafter (Reznik et al., 2010). Long-term global surfactant usage has been predicted to reach 18 metric tons by 2050 (David, 1998). Such a demand for the biosurfactant can be satisfied through the use of inexpensive substrate for mass production of biosurfactant by higher yielding strains.

Nutritionally balanced agroindustrial wastes can serve as the economically cheap substrate for mass production of biosurfactant for commercial purposes. Agricultural countries release enormous amount of agricultural byproducts and are disposed as landfill or carrier material for plant growth, especially from wheat and rice, major cultivars of agriculture. The outermost covering of the wheat and rice grain removed by dehusking process is called wheat bran and rice bran respectively. Bran is not suitable for human consumption, but is rich in fiber, starch, protein, vitamin (niacin and thiamine), and minerals such as Mg, Mn, P, Zn, Na like ions and have not been explored much as microbial growth medium. So, the extract from the bran provides all nutrients required for growth and mass production of biosurfactant. In the present study, an attempt was made for the effective utilization of bran extract medium for biosurfactant production by high-yielding indigenous bacteria.

Biotechnology Journal, Stress Adaptation of Bacteria, Extremophiles, Bacterial Adaptation, Cytosolic Components, Denature Cellular Proteins, Reactive Oxygen Species, Monounsaturated Fatty Acids, Ultraviolet Radiation, Environmental Stress, Stress Management, Biological Systems, Cellular Economy.