Isolating biosurfactant-producing bacteria from composting

This study was performed to isolate biosurfactant-producing bacteria f rom composting at different fermenting temperatures, 45℃ and 55℃, and qualitat ive and quantitative characteristics of the biosurfactant were also determined. Experimental results indicated that among the biosurfactant-producing bacteria w idely existing in composting, Bacillus subtilis, whose biosurfactant was fur ther validated as some lipopeptide mixtures including surfactin, were the dominant b iosurfactant-producing strains during composting. In addition, conditions for t h e most active isolate, Bacillus subtilis B, producing lipopeptide biosurfact ant were optimized, which resulted in the enhanced production of lipopeptide biosurf actant with high activity and high concentration. The results indicated that the effect of carbon and nitrogen sources was the most significant while that of Fe ~(2+) was not dramatic. The potential application of the biosurfactant-produ cing ba cteria isolated and their biosurfactants in municipal solid waste were also prop osed.