Evidence of cytokinin production by a marine bacterium and its taxonomic characteristics

Cytokinin-active compounds produced by marine bacteria have been conclusively detected for the first time. A bacterial strain isolated from marine sediment produced cytokinin-active compounds extracellularly during the logarithmic phase of growth. Taxonomical examinations showed that this bacterium belonged to the genus Vibrio. The cytokinins were identified and quantified as isopentenyladenine (0.28 μg/L) and isopentenyladenosine (0.14 μg/L) by gas chromatography -mass spectrometric analysis of their trimethylsilyl derivatives. Results of a plasmid survey suggests that genes specifying the cytokinin biosynthesis in this bacterium are located on the chromosome, not on a plasmid.