[Intensification of surfactants synthesis by Nocardia vaccinii K-8 on crude glycerol].

The authors studied the effect of components of crude glycerol (potassium and sodium salts, ethanol, methanol) - the by-products of biodiesel production on formation of surfactants (surface-active substances, SAS) by Nocardia vaccinii K-8, as well as possibility to intensify the SAS synthesis by the strain K-8 on crude glycerol in the presence ofbiosynthesis precursors (glucose, sun-flower oil, organic substances). It has been established that the introduction of potassium (sodium) chloride in concentration 2.5 % and ethanol (methanol) in concentration 0.3 % into the medium with refined glycerol (1 %) was accompanied by the 14-1.7-fold increase of conditional SAS concentration as compared with indices on the medium without adding salts and alcohols. Under cultivation conditions of strain K-8 on the medium with crude glycerol the conditional SAS concentration was 3-fold higher than on the medium with refined substrate. Introduction of glucose (0.05 %), sun-flower oil (0.05 %), fumarate and citrate (0.1 %) during the stationary growth phase of N. vaccinii K-8 into the medium with crude glycerol (2.2%) was accompanied by the increase in the amount of synthesized SAS h by 17-44 % compared with cultivation of bacteria on the medium without precursors.