Clarification dynamics of fresh apple must obtained from different apple cultivars grown in the south of Russia

The present study was aimed at analyzing the ability of a new paraffin-degrading strain, Gordonia amicalis G2, isolated from the contaminated sand of a seaport in Vietnam, to produce biosurfactants. The production of biosurfactants by the Gordonia amicalis G2 strain was monitored during bacterial growth in batch culture with the use of hexadecane as the growth medium. The effectiveness of produced biosurfactants was evaluated in terms of surface and interfacial tension. The surface and interfacial tension of biosurfactant solutions were determined using the du Noüy ring method by means of a Kruss K6 tensiometer. Surface tension decreased to 39 mN/m; interfacial tension, to 2 mN/m. The chemical structure of biosurfactants was characterized using thin-layer chromatography and Fourier transform infrared spectroscopy. A qualitative assessment revealed the glycolipid nature of secondary metabolites. The critical micelle concentration was determined from the inflection point of the curves showing the dependence of surface tension on the biosurfactant content. The critical micelle concentration amounted to 200 mg/L at a constant surface tension of 39 mN/m. The new Gordonia amicalis G2 strain was found to have an effective ability to produce glycolipid biosurfactants. Given the ability of Gordonia amicalis G2 to participate in the synthesis of carotenoids, an integrated technology could be developed for secondary metabolite production by this strain.