Investigations on the root nodule bacteria of leguminous plants

Abstract

THE excretion of N-compounds from leguminous root nodules has been the subject of many years' research in this laboratory. Apart from its great significance in nature and agriculture the excretion has also rendered possible a closer examination of the chemical processes of biological N-fixation which have been completely obscure. As established in several publications' from this labora- tory the excretion in certain cases assumes such proportions that over 80 % of the total fixed N is excreted from the nodules to the medium by young legumes. This fact and the special composition of the excreted products show that the excreted N-compounds are products of N-fixation and not secondary products of protein decomposition. A thorough chemical investigation of the excretion products was therefore necessary for the elucidation of the mechanism of N-fixation.