The Use of a Genetically Engineered Pseudomonas Species (Shk1) as a Bioluminescent Reporter for Heavy Metal Toxicity Screening in Wastewater Treatment Plant Influent

Abstract

Heavy metals are known to be inhibitory and toxic to the activated-sludge microbial community in biological wastewater treatment plants. Toxicity screening of aqueous mixtures of these heavy metal ions in plant influent could use both chemical and biological methods. As a biological method, luminescent bacterial bioreporters offer the advantages of a simple test procedure and rapid response.Current biologically based methods for screening aqueous streams for toxicity are labor-intensive, inaccurate, or difficult to use in continuous monitoring applications. In the present study, a system was developed that is simple and easily automated. This system is based on the bacterium Shk1, a genetically engineered bioluminescent Pseudomonad whose parent strain was originally isolated from activated sludge. Compared with other bioluminescence-based systems (specifically, the Microtox assay), the system of the present study more accurately reflects the effects of the toxicity of common metal ions on activated-sludge respirometry without being overly sensitive to typical constituents of wastewater. The use of Shk1 as a bioluminescent reporter for heavy metal toxicity testing for the application of wastewater treatment influent toxicity screening is presented in this study. Water Environ. Res., 75, 21 (2003).

Ecotoxicological Characterization of Waste

“…Spiller (2006) describes an automated test system using a 1,536 well MP with miniaturized conductivity to measure cells for high throughput testing. Other novel developments are genetically engineered bioluminescent Pseudomonas strains for testing heavy metal toxicity (Ren & Frymier 2003;Ren & Frymier 2005). But so far to the author's knowledge no commercially available ready-to-use test kit exists.…”

BIOLUMBASE?the database of natural and transgenic bioluminescent organisms

“…This is due to the simplicity of the bioluminescence reaction and the possibility of integrating lux genes, with modern molecular biology techniques, into various organisms that initially lack this particular feature. Such transgenic strains are commonly used nowadays for the analysis of pollutants in the environment (20,21,24). The specific promoters of either stability to heavy metals or degradation of complex organic compounds (e.g.…”

“…For the existing luminous microorganisms, their basic characteristics, the features of luminescence expression (2,4,(6)(7)(8)(9)(10)(11)(12)(13)(14) and their application in medicine (15,16), ecology (5,(17)(18)(19)(20)(21)(22), biotechnology and other fields (2,4,(23)(24)(25)(26)(27) are known in some detail. This information, however, is rather scattered through various scientific sources, thus complicating its search and use.…”

Genetically modified whole-cell bioreporters for environmental assessment

“…Strain Shk1 was shown to respond to a range of toxicants including cadmium, dinitrophenol, and hydroquinone. It also has been successfully used to monitor toxicant loads in wastewater influents (Kelly et al, 2004; Lajoie et al, 2003; Ren and Frymier, 2003). Additionally, plasmid pUCD607 containing the luxCDABE genes isolated from V. fischeri (Shaw and Kado, 1986) has been introduced to non-luminescent bacteria for bioreporter development.…”