Influence of oxygen upon growth and respiratory behaviour of fungi from decomposing rye-grass roots

Abstract

The influence of aeration upon the growth in culture of fungi isolated from decomposing roots of perennial rye-grass and the effects of variation in oxygen concentration upon their respiratory behaviour were investigated. Although the growth of fungi from the outer cortex and root surfaces was impaired in low oxygen concentrations, their high growth rates may have contributed to the production of inhibitory concentrations of carbon dioxide in the growth tubes employed in these experiments. Also, the method of measuring growth (daily increase in length of colony) was not regarded as satisfactory. The respiratory rates of fungi in various oxygen concentrations were measured by manometric methods and the results indicated that the isolates from the inner cortex were more tolerant of low oxygen concentrations than were those from the outer cortex and root surfaces. The respiratory quotients of the fungi from the root surfaces and outer cortex were found to be higher in reduced oxygen concentrations than those of fungi from the inner cortex.