Pseudomonas Azotoformans Research Articles

Pseudomonas panacis sp. nov., isolated from the surface of rusty roots of Korean ginseng

A Gram-negative, aerobic bacterium, designated CG20106(T), was isolated from the surface tissues of rusty root lesions of Korean ginseng. Phylogenetic analysis of the 16S rRNA gene sequence revealed that this isolate represents a hitherto unknown subline within the genus Pseudomonas. Strain CG20106(T) was catalase- and oxidase-positive, motile and rod-shaped. The overall phenotypic features of the ginseng isolate were similar to those of Pseudomonas cedrina, Pseudomonas migulae and Pseudomonas azotoformans. However, several physiological and chemotaxonomic properties can be weighted to distinguish the isolate from these organisms. The major fatty acids were C(16:1)omega7c and/or iso-C(15:0) 2-OH (summed feature 3, 36.4+/-0.4%), C(16:0) (27.5+/-0.7%) and C(18:1)omega7c (19.4+/-0.2%). The DNA G+C content was 61.4 mol%. On the basis of the polyphasic results revealed in this study, the name Pseudomonas panacis sp. nov. is proposed for strain CG20106(T). The type strain is CG20106(T) (=IMSNU 14100(T)=CIP 108524(T)=KCTC 12330(T)).

Rhizome-associated bacterial communities of healthy and declining reed stands in Lake Velencei, Hungary

Lake Velencei is a shallow soda lake with extensive reed coverage. In this study, the bacterial communities of reed (Phragmites australis (Cav.) Trin. ex Steudel) rhizomes from healthy and declining stands were compared. Inner and outer rhizome surfaces were sampled. Samples were plated and isolated in September 1998 and June 1999. Phenotypic data of 371 bacterial strains were used for cluster analysis. Identification of phena was based on partial 16S rDNA sequence analysis of representative strains. Healthy reed stand rhizomes in fall 1998 were dominantly colonised by facultatively fermentative organisms, like Erwinia billingiae, Aeromonas sobria, Pantoea agglomerans, and Pseudomonas azotoformans. In the June 1999 sample, mainly Kocuria rosea and various Bacillus spp. dominated. In declining stands of September 1998, a saprotrophic community was found: Acinetobacter spp., Aeromonas hydrophila, Curtobacterium luteum, Agrobacterium vitis, and two further groups representing presumably new taxa. In June 1999, reed rhizomes were colonised by Kocuria rosea, but Dietzia maris and Bacillus cohnii could be isolated as well. Healthy and declining reed stand rhizomes can be distinguished based on the culturable bacterial community. No obligately plant pathogenic bacteria were found, however the possibility of a local, opportunistic bacterial invasion can not be ruled out (e.g. Curtobacterium). The presence of potentially beneficial bacterial species was demonstrated in the healthy reed rhizome rhizosphere (e.g. Pseudomonas azotoformans, Pantoea agglomerans).

MICROBIOLOGICAL STUDIES ON PETROLEUM AND NATURAL GAS

Determinative studies were carried out with the pseudomonads isolated from oil-brines and the other related materials obtained in petroleum zones in Japan, and the following species were identified: Pseudomonas iners nov. sp., 2 strains; Pseudomonas stutzeri (LEHMANN and NEUMANN) KLUYVER, 10 strains; Pseudomonas putrefaciens (DERBY and HAMMER) LONG and HAMMER, 2 strains; Pseudomonas azotoformans IIZUKA and KOMAGATA, 7 strains; Pseudomonas nitroreducens IIZUKA and KOMAGATA, 3 strains; Pseudomonas schuylkilliensis CHESTER, 4 strains; and Pseudomonas aeruginosa (SCHROETER) MIGULA, 4 strains. From the physiological and biochemical characteristics of these pseudomonads, the authors discussed the reason for their occurrence in oil-brines.