Availabilities of Energy and Phosphorus of Yeast and Bacteria grown on Methanol and Ethanol by Growing Chicks

Abstract

Available energy and phosphorus availability of two samples of yeast grown on methanol, a sample of yeast grown on ethanol, two samples of bacteria grown on methanol, and two samples of brewer's yeast as a kind of reference were determined by bioassay procedure developed and reported by the authors.Crude protein contents of the yeasts were 50-56%, while those of the bacteria were over 70%. Conventional procedure of feed analysis for crude fat by ethyl ether extraction was found unsatisfactory to get true value of lipid content. That of crude ash burning the sample at 600°C for 2 hours was also unsatisfactory because of residual organic matters.Available energies of the samples except brewer's Yeast N were from 3.01 to 2.26kcal/g. The sample of Yeast N had low gross protein value, which was improved in a new sample produced by revised heating process. Available energy of the new sample of Yeast N would be higher than 1.72kcal/g determined in this bioassay.Phosphorus availabilities of the samples except brewer's yeasts and Bacteria P were from 89.4 to 57.4. Low availability of phosphorus in methanol Yeast K, methanol Bacteria P, and brewer's Yeast O were significantly improved from 28-14 to 83.9-63.7, by modifying the heating process after cultivation of single cell protein.