Chemotaxis of rhizoplane bacteria to amino acids comprising eelgrass (Zostera marina L.) root exudate

Scanning electron microscopy showed a large bacterial population on Zostera marina L. roots. The five dominant motile rhizoplane bacteria isolated were chemotactically attracted to Z. marina root exudate. Dansylation and thin-layer chromatography analysis of root exudate identified the presence of serine, threonine, glycine, alanine, and valine. When gentamicin sulfate was added during exudate collection, serine, and threonine were not detected. Exudate amino acids were shown to chemotactically attract motile rhizoplane isolates.