Members of the bacterial genus Frankia enter into a dinitrogen- fixing symbiosis with several non-leguminous plants; one of the unusual aspects of this symbiosis is the presence of hopanoid lipids in the root nodules. An aim of this research is to isolate and examine mutants deficient in one or another aspect of hopanoid biosynthesis in order to determine the functional role of these lipids in the symbiosis. A second aim will be to assess the influence of hopanoids in establishing the symbiosis.
