ON METHODS FOR REDUCTION OF NUCLEIC-ACIDS CONTENT IN A SINGLE-CELL PROTEIN FROM GAS OIL

Single-cell protein (SCP) was produced by utilization of Morgan gas-oi l as the carbon source by Candida lipolytica YB-423. The chemical cons tituents of the gas oil SCP were compared with SCP produced by C. lipo lytica YB-423 grown on yeast extract and malt extract (YM), Saccharomy ces carlsbergensis grown on malt (obtained from the Al-Ahram Beer Comp any) and Sac. cerevisiae on molasses (obtained from the Egyptian Sugar and Distillation Company). The whole cells produced on gas-oil contai ned more crude protein (42%) and crude fat (6.98%) than the other SCP. The gas-oil cells were treated by different techniques to reduce the nucleic acid content. The most suitable technique was extraction of pr otein from yeast cells with sodium hydroxide, which increased the tota l protein (about 1.68 fold) in the product and removed about 75% of th e RNA and 81% of the DNA. The protein-extract solubility was higher th an that of the crude yeast cell, except at the highest pH values.