Quorum Sensing Influences Vibrio harveyi Growth Rates in a Manner Not Fully Accounted For by the Marker Effect of Bioluminescence

The light-emitting Vibrios provide excellent material for studying the interaction of cellular communication with growth rate because bioluminescence is a convenient marker for quorum sensing. However, the use of bioluminescence as a marker is complicated because bioluminescence itself may affect growth rate, e.g. by diverting energy. quorum mutants. growth rate can be either positive or negative and includes both bioluminescence-dependent and independent components. Bioluminescence tends to slow growth rate but not enough to account for the effects of quorum sensing on growth rate

Identification of Deep-Sea-Sediment Bacteria Which Produce Tetrodotoxin

Forty-nine bacterial strains were isolated from deep-sea sediments. Among them, 22 strains were shown by the tissue culture assay method to produce sodium channel blockers. For some strains, high-performance liquid chromatography analysis confirmed that the blocker was tetrodotoxin. Tetrodotoxin-producing bacteria seem to be widespread in marine sediment