Toxicity monitoring of solvents, hydrocarbons, and heavy metals using statistically optimized model of luminous Vibrio sp. 6HFE

BACKGROUND: The utilization of bioluminescent bacteria in environmental monitoring of water contaminates considers being a vital and powerful approach. This study aimed to isolate, optimize, and apply luminescent bacteria for toxicity monitoring of various toxicants in wastewater. RESULTS: On the basis of light intensity, strain Vibrio sp. 6HFE was initially selected, physiologically/morphologically characterized, and identified using the 16SrDNA gene. The luminescence production was further optimized by employing statistical approaches (Plackett-Burman design and central composite design). The maximum bioluminescence intensity recorded 1.53 × 10(6) CPS using optimized medium containing (g/L), yeast extract (0.2g), CaCl(2) (4.0), MgSO(4) (0.1), and K(2)HPO(4) (0.1) by 2.3-fold increase within 1h. The harnessing of Vibrio sp. 6HFE as a bioluminescent reporter for toxicity of organic solvents was examined using a bioluminescence inhibition assay. According to IC(50) results, the toxicity order of such pollutants was chloroform > isoamyl > acetic acid > formamide > ethyl acetate > acetonitrile > DMSO > acetone > methanol. However, among eight heavy metals tested, the bioluminescence was most sensitive to Ag(+) and Hg(+) and least sensitive to Co(2+) and Ni(2+). Additionally, the bioluminescence was inhibited by benzene, catechol, phenol, and penta-chlorophenol at 443.1, 500, 535.1, and 537.4 ppm. CONCLUSION: Vibrio sp. 6HFE succeeded in pollution detection at four different environmental and wastewater samples revealing its efficiency in ecotoxicity monitoring.