title: A new microbial assay for the toxicity detection of contaminated soils.
abstract: A comparative study to detect toxicity prior to bioremediation treatment was set in order to investigate dehydrogenase activity inhibition of a common soil bacterium caused by soil contaminated with Cu, Pb, and As. A spectrophotometric test with Pseudomonas fluorescens strain ATCC 13525 utilising the 2,3,5-triphenyl tetrazolium chloride (TTC) reduction by microbial dehydrogenase has been adapted for this purpose. Soil samples are incubated for 48 hours at 30 +/- 1 degrees C in 18-ml tubes in the presence of TTC as an artificial electron-acceptor. The reduced TTC forms a reddish colour substance named triphenyl formazan (TPF), which can be extracted from the microbial cells and measured colorimetrically. The rapid response of biological activity in microorganisms and the reported sensitivity to the toxicants in the contaminated samples are reflected by the TTC reduction method, which is a sensitive tool for toxicity screening of contaminated sites, routine monitoring of bioremediation processes, as well as for feasibility studies of bioremediation treatments, in order to assess whether a specific pollutant or any other substance at a site location could inhibit the microbiological processes.
authors.affiliation: Centro Interdipartimentale di Ricerca per le Scienze Ambientali, Università degli Studi di Bologna, Via dell'Agricoltura 5, 48100 Ravenna. r.guerra@ambra.unibo.it
authors.forename: Roberta
authors.initials: R
authors.lastname: Guerra
authors.forename: Antonella
authors.initials: A
authors.lastname: Iacondini
authors.forename: Federica
authors.initials: F
authors.lastname: Abbondanzi
authors.forename: Chiara
authors.initials: C
authors.lastname: Matteucci
authors.forename: Luigi
authors.initials: L
authors.lastname: Bruzzi
mesh_terms: D001151:Arsenic / Q000378:metabolism* / Q000633:toxicity; D003300:Copper / Q000378:metabolism* / Q000633:toxicity; D007854:Lead / Q000378:metabolism* / Q000633:toxicity; D010088:Oxidoreductases / Q000378:metabolism; D011551:Pseudomonas fluorescens / Q000201:enzymology* / Q000378:metabolism; D012988:Soil Microbiology / Q000592:standards*; D012989:Soil Pollutants / Q000378:metabolism* / Q000633:toxicity; D013056:Spectrophotometry, Ultraviolet; D013778:Tetrazolium Salts / Q000737:chemistry
chemical_list: D012989:Soil Pollutants; D013778:Tetrazolium Salts; D007854:Lead; D003300:Copper; D010088:Oxidoreductases; D001151:Arsenic