Antibacterial Substances in Water Extracts of Pure Forest Litter

Abstract

IT was reported by Melin¹ that cold water extracts prepared from single species litter of Swedish forest trees contain substances inhibiting the growth of soil fungi. The fungi tested showed, however, pronounced differences in their sensitivity to the antibiotic agents present in the extracts. The species acting as mycorrhizal fungi were the most sensitive ones whereas the species inhabiting litter and causing its decomposition proved to be insensitive. Passage through a Seitz filter does not seem to reduce the antibiotic activity, the growth-inhibiting effects produced by the filtered extracts being approximately equal to those exerted by the corresponding untreated extracts. On autoclaving at a temperature of 120° C. the antibiotic activity of the extracts made from litter of Acer platanoides L. and Fagus sylvatica L. was increased to a considerable degree. The antibiotic substances present in these extracts had a marked growth-inhibiting effect both on litter-decomposing and mycorrhiza-forming fungi.