PECULIARITIES OF NOCARDIA VACCINII ІМV В-7405 SURFACTANTS SYNTHESIS ON WASTE OIL OF DIFFERENT QUALITY AND THEIR ANTIMICROBIAL PROPERTIES BY

Abstract

Aim. To study possible reasons of different levels of antimicrobial activity of Nocardia vaccinii ІMV B-7405 surfactants (surface-active substances, SAS) synthesized on waste after frying meat and potatoes sunflower oil. Methods. Surfactants were extracted from supernatant of cultural liquid by mixture of chloroform and methanol (2: 1). The criterion of surfactant antimicrobial activity were minimal inhibitory concentrations (MIC), which were determined by two-fold serial dilutions in a meat-peptone broth (for bacteria) and liquid wort (yeast). Results. It was established that MIC against bacteria (Bacillus subtilis BT-2, Escherichia coli ІEM-1, Proteus vulgaris PA-12, Staphylococcus aureus BMS-1, Pseudomonas sp. MI-2, Enterobacter cloacae P-8, Erwinia aroideae H-3) and yeast (Can-dida tropicalis PE-2, Candida albicans D-6) of N. vaccinii ІMV B-7405 surfactants synthesized on waste after frying potatoes oil was on average 2.5−8 times lower than the corresponding index of SAS obtained on waste after frying meat substrate. The increase from 5 to 7 days of during N. vaccinii ІMV B-7405 cultivation on waste after frying potatoes oil was accompanied by surfactant synthesis, MIC of which against most studied test cultures was decreased in 1,4−4 times. Index of minimum inhibitory concentration of N. vaccinii ІMV B-7405 surfactant correlated to the presence of aminolipids in SAS composition and activity of NADP+-dependent glutamate dehydrogenase − a key enzyme of them biosynthesis. Conclusions. Dependence of surfactant antimicrobial activity on quality waste oil and processing duration indicates the need for research the influence of producer cultivation conditions on the biological properties of final product. Data on the qualitative composition of surfactant and the activity of key enzyme of aminolipids biosynthesis show the possibility of regulation of SAS antimicrobial activity by change of producer cultivation conditions.