Physiological studies on some bacteria isolated from clover roots : Thesis presented for the degree of Master of Science, University of New Zealand

Abstract

This investigation begun with the idea of studying the nodule bacterium associated with subterranean clover. Its incidence in different soil types was put under preliminary investigation, and an attempt was made to learn some of the physiological characteristics of the bacterium itself. These proposed studies, however, were diverted into other channels when it was found that bacterial types other Rhizobium were being studied. These types, although in many cases similar to Rhizobium in macroscopic appearance, all differed from it in their biochemical reactions. They were found to occur in the roots of Trifolium species and their presence supplies additional evidence in support of the comparatively recent finding that normal healthy plant tissue is not sterile but supports a mixed bacterial population of passive habit.