EFFECT OF TEMPERATURE ON PARTITION BEHAVIOUR AND THERMODYNAMIC CHARACTERISTICS OF BIOACTIVE PHENOLICS TRANSFER IN AQUEOUS TWO-PHASE EXTRACTION SYSTEM AND EVALUATION OF ANTIMICROBIAL ACTIVITY

The present study was to develop a cost-effective and eco-friendly separation and purification method of bioactive phenolics from Phanerochaete chrysosporium biomass using aqueous two-phase extraction system. The extraction system comprised of 50% (w/w) ethanol, 20% (w/w) di-potassium hydrogen phosphate, distilled water and solid biomass. The extraction was conducted at different temperatures range, from 25°C to 65°C for 2 hours at pH 7. The highest partition coefficient (K) and recovery (R) of bioactive phenolics were found at 25°C with values of 2.37 and 93.89%, respectively. From the thermodynamics analysis, the Gibbs energy change (?G), enthalpy change (?H) and entropy change (?S) values were -2138.95kJmol-1, -11504.91 kJmol-1 and-31.10 kJmol-1, respectively. These negative values reflected that the extraction process was spontaneous, exothermic and preferential partitioning in the ethanol-rich phase at lower extraction temperature. Antimicrobial activities were assayed using well and diffusion methods. The extract at 25°C showed the highest zone of inhibition against Aspergillus nigerand Escherichia coli.Finally, the bioactive phenolic constituents were analyzed using reversed-phase high performance liquid chromatography (RP-HPLC).