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"Biotechnologia Acta" V. 9, No 6, 2016
Р. 50-57, Bibliography 21, English
Universal Decimal Classification:  759.873.088.5:661.185

 6 2016


P. Pirog, I. V. Sidor, D. A. Lutsai

National university of food technology,  Kiyv,  Ukraine

The aim of the work was to study the effect of calcium and magnesium cations on NADP+-dependent glutamate dehydrogenase activity (key enzyme of biosynthesis of Acinetobacter calcoaceticus ІMV B-7241 surface-active aminolipids) followed by modification of medium composition and determining antimicrobial and antiadhesive activity of synthesized surfactants.
The strain IMV B-7241 was grown in medium with ethanol. NADP+-dependent glutamate dehydrogenase  activity of the cell-free extract was analyzed using  the formation of glutamate in the oxidation of  NADPH. Surfactants were extracted from supernatant of cultural liquid by mixture of chloroform and methanol (2:1). Antimicrobial against bacteria properties of the surfactants were determined by index of the minimal inhibitory concentration. The number of attached cells and the degree of biofilm destruction were analyzed spectrophotometrically.

It was established that in the presence of 10 mM Cа2+ and  Mg2 NADP+-dependent glutamate dehydrogenase activity in the cell-free extract increased to 1.5 times in comparison with that without cations. Increasing concentration of magnesium sulfate to 0.2 g/l, or adding CaCl2 (0.1 g/l) into cultivation medium of IMV B-7241 strain was accompanied by rise of NADP+-dependent glutamate dehydrogenase activity in 2.4 and 3.0 times respectively, as well as increasing antimicrobial and antiadhesive activity of synthesized surfactants. Minimal inhibitory concentration of surfactants synthesized in modified media against some bacteria was in 1.3?3.5 times, adhesion on abiotic surfaces treated with such surfactants in an average of 7?13% lower, and the degree of biofilm destruction in 7?13% higher as compared to indicators for the surfactant produced in the base medium.

The obtained results indicated the possibility of regulating antimicrobial and anti-adhesive activity of surfactants under producer cultivation.

Ключові слова: Acinetobacter calcoaceticus IMV B-7405, surfactants, NADP+-dependent glutamate dehydrogenase activity, calcium and magnesium cations.

© Palladin Institute of Biochemistry of National Academy of Sciences of Ukraine, 2016