Bioconversion of Saw Dust Powder Acid Hydrolysis to Single Cell Protein by the Yeast Candida tropicalis

Abstract

This study was aimed to grow the local isolates yeast Candida tropicalis on locally prepared sawdust powder hydrolysate as a basal medium and carbon source with respect to single cell protein (SCP) production. The saw dust powder was treated with 10% H2SO4 for one hour at 100 0C. After cooling the supernatant containing the isolated sugar separated from debris by filtration and used as a carbon source and basal medium for yeast growth and SCP production. A high amount of SCP was achieved after five days of incubation, the percentage of the produced SCP 39.05% of the biomass dry weight, which is equivalent to 3.07g/l. SCP formation biosynthesis was affected by the level of nitrogen present in the medium; a high amount of protein being achieved in fermentation medium containing 0.3% urea in which the percentage of the yielded SCP was increased to 42.54%, (3.71g/l) of the biomass dry weight. The effect of varying nitrogen sources on SCP accumulation was also assayed. Medium containing ammonium phosphate greatly stimulated protein production in which the produced SCP was increased to reach 5.90 g/l. The produced amount equivalent to (48.22%) of the biomass dry weight. Conversely, a medium containing sodium nitrate had a suppressive effect on SCP production. This evidence clearly suggests that the metabolic versatility of Candida tropicalis may be employed in the conversion of low-grade material into high SCP product.