Production of bioemulsifier by <i style="">Acinetobacter</i> species isolated from healthy human skin

70-76Six Acinetobacter sp. isolated from healthy human skin were checked for the production of bioemulsifier. Optimization studies indicated that Luria Bertani broth pH 7 supplemented with calcium chloride (1%) was the optimum medium. Temperature at 37°C was optimum and inducer oils in the medium did not enhance bioemulsifier production. Partial purification of bioemulsifier and chemical analysis revealed that it is a proteoglycan with protein (53%), polysaccharide (43%) and lipid (2%). Maximum emulsification activity obtained was 400 EU/ml. Thin layer chromatography revealed the presence of mannose and rhamnose sugar and oleic and palmitic acids as parts of lipids. The yield obtained was 1.9 g / l. Reconstitution studies revealed that the protein and polysaccharide fractions together display 94.55% of emulsification activity. It was also noted that the bioemulsifier was stable for 72 hr at 37°C and displayed good cleaning property towards different oils. The partially purified bioemulsifier formed stable oil-in-water emulsions with plant oils

Optimization of medium for lipase production by <i>Acinetobacter haemolyticus </i>from healthy human skin

936-941 A lipase producing Acinetobacter haemolyticus TA106 was isolated from healthy human skin of tribal population. The maximum activity of 55 U/ml was observed after medium optimization using the “one variable at a time” and the statistical approaches. The optimal composition of the medium was determined as (% w/v or v/v): tryptone - 1, yeast extract - 0.5, sodium chloride-1, olive oil-1, Tween - 80 1, manganese sulphate - 5 mM, sucrose- 1, pH-7. It was found that maximum production occurred in late log phase i.e. after 72 h and at 200 rpm. From factorial design and statistical analysis, it was found that pH, temperature, salt, inoculum density and aeration significantly affected the lipase production. It was also noted that inoculum density of 3 % (v/v), sucrose (1% w/v) and manganese sulphate (5 mM) displayed maximum lipase activity of 55 U/ml by conventional as well as statistical method. Optimization studies also indicated the increase in specific activity from 0.2 U/mg to 6.7 U/mg.</smarttagtype