“…A basal level of enzyme activity at low substrate concentrations vs. an induced activity at higher concentrations have been described previously for halophenol (He & Sanford, 2002), trichlorobenzene (Rapp, 2001), naphthalene (Guerin & Boyd, 1995) and methyl tertbutyl ether (Schmidt et al, 2008)-degrading bacterial strains. In contrast, however, a cease in the degradation activity by different bacteria on reducing the contaminant concentration has been described in several other studies (Lechner & Straube, 1984;Schmidt et al, 1987;van der Meer et al, 1987).…”