Laser/Microbe Bioassay System

Newest approaches to quantitative assessment of bioactive organotins

“…The development of a cocktail for delivery of the test material ensures that a high concentration of toxicant reaches the target cell and/or appropriate enzyme system to generate metabolites. We have previously established that the cocktail does not cause a detectable change in growth of the bacteria at concentration levels used in this study (Felkner et a/., 1989) although it is possible that the cocktail may influence toxicant uptake. The use of the generation time (TAU) permits us to study kinetics and toxicokinetics within the context of chemical speciation in environmental matrices.…”

“…pesticides, polyaromatic hydrazines, hydrogenics, and various carcinogenic chemical species (Felkner et al, 1989;Felkner et al, 1988;Felkner et al, 1981;Shaiau et al, 1980) that are considered to be common pollutants in the environment From the results of our ongoing efforts to increase the utility of the laser/bacterial bioassay as a tool for assaying toxicants, including metals and organometals, in soil, water, and vegetation matrices and because the prototype system we are using can be made portable powered by battery, we feel that it shows promise as a rapid and inexpensive system to monitor both organic and inorganic (e.g. metals) toxicant'> on site.…”

“…Data exist for all of these toxicants in numerous short-term mutagenicity assays as well as in chronic toxicity/oncogenicity assays (DeSerres and Ashby, 1981). From our accumulated and published genotoxicity/mutagenicity data (Shiau et al, 1980) on malathion (MAL) and experience in assaying this pesticide from field spraying oil cards (CF-V Tee jet Spraying Systems Co. Wheaton, IL), MAL was selected for use as a control chemical for the cocktail solvent since it gave a significant positive genotoxic response (Felkner et al, 1989) in the absence of S9 activation.…”

“…Readings are normally taken at 0 and 66 min to determine growth inhibition and/or any changes in shape or size of the cells as a measure of toxic response; however, readings at earlier or later intervals may be taken to facilitate kinetic studies. These measured responses are dose related (Felkner et al, 1989) and are therefore quantitative for the toxicant concentration.…”

“…Further extension of such promising bioassay technology represents th principal goal and delivery of the work described herein. Development and application of the novel laser/microb bioassay was oriented initially toward rapid detection of ver low concentrations of priority pollutants in diverse environmental matrices such as complex sediments, effluents, and even potable waters (Felkner et a/., 1989). The current paper reports the toxicities of various organotin species on bacterial cell growth as detected by differential light scattering (DLS).…”