Identification and potential enzyme capacity of flavobacteria isolated from the rhizosphere of barley (Hordeum vulgare L.).
The diversity of 99 flavobacterium-like isolates from a barley rhizosphere is described. They were identified on 1/10 strength tryptic soy agar by their yellowish colour and a flexirubin reaction after exposure to 10% KOH.16S rDNA partial sequencing identified the majority (70%) of isolates as Flavobacterium. Twelve percent of the isolates belonged to other genera in the phylum Bacteroidetes. Finally 17% of the isolates did not belong to the phylum Bacteroidetes. Most of the Flavobacterium isolates were affiliated to various aquatic, validly named species and likely represent a bulk of undescribed soil Flavobacterium species found in especially high numbers in the rhizosphere of young plant roots. Most Flavobacterium isolates showed gliding motility on CY agar and VY/2 agar, whereas none of the other isolates shared this feature. A high percentage of Flavobacterium strains produced enzymes involved in polysaccharide and protein digestion as well as extracellular phosphatases, compared with strains related to other genera in the phylum Bacteroidetes.
Department of Environmental Chemistry and Microbiology, National Environmental Research Institute, DK-4000 Roskilde, Denmark. JnJo@novonordisk.com
Jens Efsen
JE
Johansen
Preben
P
Nielsen
Svend Jørgen
SJ
Binnerup
D015373:Bacterial Typing Techniques; D004269:DNA, Bacterial / Q000032:analysis; D004275:DNA, Ribosomal; D041965:Flavobacteriaceae / Q000145:classification / Q000201:enzymology* / Q000235:genetics / Q000302:isolation & purification; D001467:Hordeum / Q000382:microbiology*; D008969:Molecular Sequence Data; D009068:Movement; D010641:Phenotype; D010802:Phylogeny; D018517:Plant Roots / Q000382:microbiology*; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D017422:Sequence Analysis, DNA; D012988:Soil Microbiology
D004269:DNA, Bacterial; D004275:DNA, Ribosomal; D012336:RNA, Ribosomal, 16S