Taxonomic characterization and plant colonizing abilities of some bacteria related to Bacillus amyloliquefaciens and Bacillus subtilis

• Published in: FEMS microbiology ecology 2004-05, Vol.48 (2), p.249-259
• Main Authors: Reva, Oleg N., Dixelius, Christina, Meijer, Johan, Priest, Fergus G.
• Format: Article
• Language: English
• Subjects: 16S rRNA; Arabidopsis - microbiology; Bacillus; Bacillus - classification; Bacillus - genetics; Bacillus - isolation & purification; Bacillus - physiology; Bacillus amyloliquefaciens; Bacillus mojavensis; Bacillus subtilis; Bacteria; Bacterial Proteins - genetics; Bacteriology; Barley; Biological and medical sciences; Biological control; Brassica; Brassica - microbiology; Brassica napus; cheA; CheA protein; Cluster Analysis; Colonization; DNA Gyrase - genetics; DNA, Bacterial - chemistry; DNA, Bacterial - genetics; DNA, Ribosomal - chemistry; DNA, Ribosomal - genetics; Ecology; Fundamental and applied biological sciences. Psychology; Gene sequencing; gyrA; Histidine; Histidine Kinase; Hordeum - microbiology; Hordeum vulgare; Identification; Kinases; Microbiology; Miscellaneous; Molecular Sequence Data; Phylogeny; Pigments, Biological - biosynthesis; Plant colonization; Protein Kinases - genetics; Rapeseed; Rhizosphere; RNA, Ribosomal, 16S - genetics; rRNA 16S; Scanning electron microscopy; Seedlings; Seeds; Sequence Analysis, DNA; Soil Microbiology; Strains (organisms); α-Amylase
• ISSN: 0168-6496; 1574-6941
• DOI: 10.1016/j.femsec.2004.02.003

The phylogenetic relationships of 17 Bacillus strains isolated from plants and soil were determined from partial sequences of genes encoding 16S rRNA, gyraseA ( gyrA) and the cheA histidine kinase. Five strains were closely related to Bacillus subtilis subsp. subtilis, three strains were more closely related to B. subtilis subsp. spizizeni and two strains were identified as B. mojavensis. The remaining seven strains formed a cluster closely related to, but distinct from, Bacillus amyloliquefaciens. Some of these strains formed red-pigmented colonies. The abilities of selected strains to survive in the rhizosphere and to colonize plants were studied using oilseed rape ( Brassica napus), barley ( Hordeum vulgare) and thale cress ( Arabidopsis thaliana) as model plants. It was shown by following the titre of bacteria in seedlings and by scanning electron microscopy that survival of Bacillus cells on the roots of seedlings during the first week after treatment of seeds with spore suspensions was crucial for colonization of the rhizosphere and for biocontrol activity. The group of strains related to B. amyloliquefaciens were generally better adapted to colonization of the rhizosphere of plants than other members of the B. subtilis group and could be considered a distinct ecotype of B. amyloliquefaciens. Bacteria in this taxon could be recognized on the basis of amplification of a PCR product with primers directed to the tetB(L) locus but no product with primers directed to the α-amylase gene of B.amyloliquefaciens sensu stricto.