New Biosurfactants of Culture Pseudomonas Aureofaciens NB-1

Background. Important problems of technologies of biosurfactants production are the search for active strain-producers, optimization of their biosynthesis, as well as elaboration of effective methods of biosurfactants isolation from cultural liquid after fermentation. Objective. The influence of extractants to release surfactant lipids from the supernatant of cultural liquid of the strain P. aureofaciens NB-1 and investigation of their ability to use for protection of the steel against corrosion. Methods. Surfactants were isolated by extraction of various solvents and their mixtures, their composition and weight were analyzed. The effectiveness of corrosion inhibition was analyzed by corrosion rate of steel plates. Results. Microorganisms of strain P. aureofaciens NB-1 synthesize extracellular biosurfactants of rhamnolipid and lipopeptid nature. It was shown that at pH 11, biosurfactants yield using ethylacetate and isopropanol (2:1) was 3.71 g/L, exceeding their output at pH 3 to 54 %. The efficacy of using the supernatant of cultural liquid P. aureofaciens NB-1 (dilution 1:10) for corrosion protection of St3 steel in aggressive medium was shown. Conclusions. The methods of optimal isolation of surfactant of P. aureofaciens NB-1by the selection solvents and control of pH indicators were elaborated. As a result the synthesis parameters were significantly increased. It was shown that obtained product is perspective as inhibitor of metal corrosion.