title: Micromonospora is a normal occupant of actinorhizal nodules.
abstract: Actinorhizal plants have been found in eight genera belonging to three orders (Fagales, Rosales and Cucurbitales). These all bear root nodules inhabited by bacteria identified as the nitrogen-fixing actinobacterium Frankia. These nodules all have a peripheral cortex with enlarged cells filled with Frankia hyphae and vesicles. Isolation in pure culture has been notoriously difficult, due in a large part to the growth of fast-growing contaminants where, it was later found, Frankia was slow-growing. Many of these contaminants, which were later found to be Micromonospora, were obtained from Casuarina and Coriaria. Our study was aimed at determining if Micromonospora were also present in other actinorhizal plants. Nodules from Alnus glutinosa, Alnus viridis, Coriaria myrtifolia, Elaeagnus x ebbingei, Hippophae rhamnoides, Myrica gale and Morella pensylvanica were tested and were all found to contain Micromonospora isolates. These were found to belong to mainly three species: Micromonospora lupini, Micromonospora coriariae and Micromonospora saelicesensis. Micromonospora isolates were found to inhibit some Frankia strains and to be innocuous to other strains.
authors.affiliation: Universite Lyon 1, Universite de Lyon, CNRS, Ecologie Microbienne UMR5557, Villeurbanne 69622 Cedex, France.
authors.forename: Lorena
authors.initials: L
authors.lastname: Carro
authors.forename: Petar
authors.initials: P
authors.lastname: Pujic
authors.forename: Martha E
authors.initials: ME
authors.lastname: Trujillo
authors.forename: Philippe
authors.initials: P
authors.lastname: Normand
mesh_terms: D029661:Alnus / Q000382:microbiology / Q000502:physiology; D000898:Antibiosis; D019662:Cucurbitaceae / Q000382:microbiology / Q000502:physiology; D003470:Culture Media; D004269:DNA, Bacterial / Q000145:classification / Q000235:genetics* / Q000302:isolation & purification; D031263:Elaeagnaceae / Q000382:microbiology / Q000502:physiology; D029962:Fagaceae / Q000382:microbiology / Q000502:physiology; D040161:Frankia / Q000254:growth & development / Q000302:isolation & purification; D031281:Hippophae / Q000382:microbiology / Q000502:physiology; D008847:Micromonospora / Q000145:classification / Q000235:genetics / Q000254:growth & development / Q000302:isolation & purification*; D031641:Myrica / Q000382:microbiology / Q000502:physiology; D009586:Nitrogen Fixation / Q000502:physiology; D010802:Phylogeny; D053204:Root Nodules, Plant / Q000382:microbiology* / Q000502:physiology; D019685:Rosales / Q000382:microbiology / Q000502:physiology; D013559:Symbiosis
chemical_list: D003470:Culture Media; D004269:DNA, Bacterial