Detection of microbial toxic concentrations on 11 microbial lyophilized strains – validation compared to MARA’s test-

Abstract

This project meets the interest and the legislative needs at the national and international levels to characterize the toxic effects of the chemical compounds on the environment by the bacterial microbiotests, a modern and quick alternative to the classic toxicity tests on vertebrates. The studies realized during this project gave information about the metabolic process and bacterial growth of the bacteria from the DCP-B INCD-ECOIND data base: i) Escherichia coli (gram-negative bacterium), ii) Salmonella enterica (gram-negative bacterium), iii) Enterococcus faecalis (gram-positive bacterium), iv) Pseudomonas aeruginosa (gram-negative aerobic bacillum). All bacterial strains used had a robust growth in their specific growth medium. This groeth rate was modulated in presence of chlorpyrifos methyl pesticide (Reldan). The new bacterial microbiotests was more sensitive than MARA tests decreasing the MTC50 threshold from 0.44g/l to 0.25g/l. Moreover, the duration length of the new bacterial microbiotests decreased to 3h compared to MARA’s tests (18h). Overall, this project developed a more modern, radip and economically efficient new bacterial microbiotest as an alternative to the classic MARA’s test.