Studies on bioemulsifier production by <i style="">Actinopolyspora</i> sp. A18 isolated from garden soil

Abstract

Out of the 13 species of actinomycetes isolated from garden soil, 10 tested positive for lipase and emulsification activity. <i style="">Actinopolyspora</i> sp. A18 exhibiting maximum activity was further studied and partially purified. <i style="">Actinopolyspora</i> sp. A18 exhibited maximum bioemulsifier production during stationary phase at 72 h. Maximum bioemulsifier production was obtained at 30^oC, <i style="">p</i>H 8, 250 rpm and 2% (w/v) NaCl concentration. Emulsification activity was maximum (316 EU mL^-1) with sunflower oil as substrate. The yield of purified bioemulsifier was 1 g/L and reduced the surface tension of water slightly (7 mN/m). Partially purified bioemulsifier from <i style="">Actinopolyspora</i> sp. A18 was a glycolipopeptide comprising of 68% protein, 22.20% non-reducing sugars, 4.80% reducing sugars and 5% lipids. The bioemulsifier produced was stable at room temperature for 7 d.