PRODUCTION OF SINGLE CELL PROTEIN FROM PINEAPPLE AND WATERMELON WASTE USING Saccharomyces cerevisiae

The fast growing population of the world has led to an increased demand for protein rich food. The conversion of fruit wastes into single-cell protein is an alternative solution to the worldwide protein deficiency and environmental pollution concerns. In this study, watermelon and pineapple fruit peels were used to produce single cell protein by submerged fermentation. The organism used for the single cell production was isolated from Palm wine. The organism was characterized via standard microbiological methods – morphological, biochemical and molecular characterization. For the molecular characterization the internal transcribed spaces ITS 1and ITS4 genes were targeted and sequenced using Sanger Sequencing method. In addition, the isolate evolutionary relatedness was performed on the basis of rDNA comparison of the obtained data sequence with known sequences in the GenBank. Five different hydrolysate media were compounded and used to determine the growth profile of the isolate and single cell protein production. The formulates from the fruits include: FHM, GH, GHM, GNF and MF. The rDNA sequence comparison identified the organism as Saccharomyces cerevisiae with accession number OK172582 with 99.62 % homology to the type strain of Saccharomyces cerevisiae strain YBA 08. The pineapple and watermelon fruit hydrolysate media supplemented with molasses recorded high concentrations of total protein (0.53-0.66 mg/mL) respectively on the 7th day of fermentation, as compared to that of the fruit hydrolysate media without supplementation which produced 0.01-0.06 mg/mL of protein respectively. Similarly, fruit hydrolysate media supplemented with glucose and nitrogen recorded a high content of protein (0.24-0.52mg/mL) while fruit hydrolysate media supplemented with glucose produced (0.07-0.20mg/mL) of protein and the supplemented fruit hydrolysate media produced (0.12-0.17mg/mL) protein. It was observed that supplementation with molasses as a carbon source greatly increased SCP production in both fruit combinations. This suggest that microbial growth on fruit peels can be best improved by addition of molasses as a nutrient supplement rather than just the fruit peels. The findings in this study indicated that pineapple and watermelon peels could serve as a good substrate for SCP production