Colloidal Characteristics of Water Systems of Rhamnolipid Biocomplex of Strain Pseudomonas sp. PS-17 with Tween-80 and their Prospects for Biotechnology

Abstract

Background. Efficiency of mixed systems of biogenic and synthetic surfactants, based on their colloidal chemical properties, in environmentally safe technologies. Objective. The aim of the paper is the study of the aqueous systems’ colloidal characteristics of the rhamnolipid biocomplex with Twееn-80 nonionic surfactant, as well as the study of the obtained mixtures’ action for the emulsion stabilization and for plant growth stimulation. Methods. The surface tension of RBC, Tween-80, and their mixture solutions was measured by the Du-Nui method (with a platinum ring). The dependence of the surface tension on the surfactant concentration was determined for mixtures with RBC content, %: 0.0; 11.1; 25.0; 42.9; 66.7; 100. The emulsifying activity of the surfactant mixtures was determined on the emulsification index (E24). The surfactant influence on plants was assessed by their morphometric parameters after presowing seed treatment. Results. It was found that the obtained mixture behavior, regardless of the surfactant concentration, deviates from the ideal mixture – the deviation is negative, which indicates the predominance of RBC in the surface layer. The shapes of the surface tension curves for different surfactant ratios indicate synergistic effects before and after micelle formation. The optimum ratio in the RBC-Tween-80 system for sunflower growth and sunflower oil emulsification is 2:1. Conclusions. The peculiarities of colloid-chemical characteristics of RBC and Tween-80 systems are determined, the prospects of their use for increasing efficiency of emulsification and sunflower growth stimulation are determined.

Keywords

• Surface activity
• Rhamnolipid biocomplex
• Twееn-80
• Surfactant systems
• Еmulsification
• Plant growth stimulation