Bioconversion of whey into biomass of Kluyveromyces sp. and its nutritional study

Growth characteristics, gross composition and the nutritive value in terms of liver protein regeneration capacity, protein efficiency ratio and the protein digestibility of the biomass of Kluyveromyces marxiamis subsp. marxianus NRRL Y-2415 were determined after growth in concentrated acid whey (12.72% lactose) at 30°C. The biomass (11.2 g/L) had a crude protein content of 49.8% and true protein content of 42.4%. Groups of 5 male albino rats 21-28 days old when given diets with protein supplied by casein, protein biomass from Kluyveromyces marxianus subsp. marxianus NRRL Y-2415 or the protein biomass supplemented with 0.5% DL-methionine showed liver protein regeneration capacity (after a 2-day fast) of 90%, 34% and 93.3%, protein efficiency ratio 2.6, 1.76 and 2.83 and true protein digestibility of 93.30, 93.31 and 93.43%, respectively. Feeding of rats with single cell protein showed no ill effects on the rats.