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Biosurfactants are biomolecules produced by microorganisms, which possess several advantages over their chemical counterparts. Production can be cost-effective if renewable wastes are utilized as substrates. In this study, optimization of biosurfactant production by Pseudomonas aeruginosa strain CGA1 was carried out using response surface methodology. The conventional "One factor at a time" method of optimization was initially adopted to ascertain the impact of different renewable wastes on biosurfactant production. Four independent variables were tested: carbon and nitrogen concentration, medium volume, and inoculum size. Biosurfactant production was based on the emulsification index measurement. Results indicated that the preferred carbon source by the isolate was sugar cane molasses. A 2.31-fold increase in biosurfactant yield and emulsification index of 96.3% ± 0.75% under optimized cultural conditions of 20 g/L of molasses, 5 g/L of sodium nitrate, 1.93 ml inoculum size and 60 ml medium volume in 250 ml conical flask were obtained. The regression coefficient (R 2) value of 84.15% implied adequate fitness of the model. The surface tension of distilled water was reduced from 72.1 mN/m to 35.0 ± 0.0 mN/m, and critical micelle concentration was attained at 60 mg•L −1. FTIR and GC-MS analysis indicated that the biosurfactant was a lipopeptide having characteristic lipid and peptide peak values. This study proves that the sole use of agro-industrial wastes for the production of biosurfactant is very efficient, and ensures the economic feasibility of biosurfactant production.

Mixed fruit wine (pineapple and watermelon) was produced using Saccharomyces cerevisiae isolated from palm wine. Primary and secondary fermentation of the fruits lasted for 7 and 28 days respectively, during which aliquot samples analysis of pH, titrable acidity, specific gravity, alcohol content and reducing sugar were carried out using standard procedures. Specific gravity of the wine was observed to reduce drastically as the fermentation progresses. The pH of the fruit must during the period of fermentation ranged from 3.0 to 4.46. During the fermentation period, consistent increase in alcohol content was observed with time. At the end of the 28 th day of fermentation, the alcohol content was observed to be 3.2%. The titrable acidity of the wine was observed to show steady trend with time throughout the period of fermentation. This study showed that acceptable wine can be produced from mixed fruits pineapple and watermelon using yeasts especially Saccharomyces cerevisiae isolated from palm wine.

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