The Nutritive Value of Yeast Grown on Hydrocarbon Fractions for Broiler Chicks

YEASTS have been used by man for centuries, primarily in the production of alcoholic drinks and making bread. The use of yeasts grown on carbohydrate substrates as an ingredient in the diet of man or animals dates from before the beginning of this century (Llewelyn, 1967). One of the most recent applications of yeast culture for food materials has been the development of yeast cultures which can utilize hydrocarbon fractions as a substrate. Over 100 bacteria, yeast, actinomycetes and fungi are known to grow at the expense of hydrocarbons (Foster, 1962). The utilization of gaseous hydrocarbons by soil microorganisms has been studied as a means of detecting petroleum gas emanations in prospective areas (Davies, 1956). Mixed cultures of yeast have been grown on gas oil (Miller and Johnson, 1966a) and n-paraffins (Miller and Johnson, 1966b). Generation times of 3 to 8 hours with cell yields of 70–90% of substrate…