Yeasts in soils spray-irrigated with dairy factory wastes

摘要

An examination was made of the yeast flora of eight soils under pasture which were spray-irrigated with dairy factory wastes, also of the yeast flora of some of the irrigants and of leaves of pasture plants from an irrigated site. Provided that the irrigant contained lactose, numbers of yeasts in irrigated soils increased by 50 to 1,000 times; where lactose had been extracted from the irrigant there was no increase in numbers. After irrigation with wastes containing lactose, the composition of the yeast flora changed from one dominated byCandida curvataorCryptococcus terreusto one in whichCandida humicolaorTrichosporon cutaneumwas most often the dominant species. There was no qualitative change in the yeast flora of a soil irrigated with wastes from which lactose had been extracted.