Characterization of luminescent Vibrio campbellii LZ5 and its potential application in the detection of environmental heavy metals

luminescent strain was isolated and identified as Vibrio campbellii strain LZ5 by 16S rDNA analysis. It grew well in broad living conditions, and the relative fluorescence intensity was stable at pH ranging from 5 to 7.5, NaCl concentrations from 0% to 3%, KCl from 1.5% to 5%, and CaCl2 from 1% to 3%. In contrast, the relative fluorescence intensity was negatively correlated with both CdCl2 and HgCl2 concentrations from 0 to 1 mg/L. The luminescent fraction from the cell lysate was purified by ion-exchange chromatography, and identified as a luciferase by using matrix-assisted laser desorption/ionization-time of flight mass spectrometry. Furthermore, the biofilm of V. campbellii LZ5 was formed constantly under different conditions, and was not affected by heavy metal ions. The data collectively reveal that strain LZ5 has the potential to be developed into a biosensor for real-time monitoring of heavy metals.