Comparison of gram positive and gram negative bacterial strains cloned with different types of luciferase genes in bioluminescence cytotoxicity tests

The bacterial bioluminescence assay is widely used to estimate chemical cytotoxicity. This assay is performed most often by using luminescent bacteria Vibrio fisheri NRRL‐B‐11177 (earlier cited as Photobacterium phosphoreum NRRL‐B‐11177) as a test organism. In this work we have used cloned gram(+) and gram(‐) bacterial strains for the evaluation of chemical toxicity. Two types of luciferase genes were used as reporter genes, one of which was ATP‐dependent eukaryotic luciferase from Pyrophorus plagiophthalamus and the other was FMN‐dependent bacterial luciferase from Vibrio harveyi. These cloned strains were used to evaluate the effects of differences in cell wall structures in the bioluminescence cytotoxicity test using small molecular weight toxic chemicals as model compounds. The strains were found to have remarkably similar behavior and sensitivity toward test toxicants regardless of rather different kinds of membrane structure. However, the eukaryotic luciferase was found in every aspect more useful in toxicity tests than bacterial luciferase mainly because of increased sensitivity and ease of operation. The general behavior of the light emission is described and several aspects affecting the usefulness of the strains are discussed. © by John Wiley & Sons, Inc.