ABSTRACT
This chapter analyses the literature on microbial and enzymatic tests which are used to screen for chemical toxicity in the research laboratory or in aquatic system, and presents in detail some of the more commonly used microbial toxicity screening procedures. There are two main groups of toxicity screening tests: in vitro “health effect” tests and “ecological effect” tests. With the increased world-wide industrialization, and with the concomitant higher demand for chemicals, both the developed and developing nations face increasing ecological and toxicological problems from the release of toxic contaminants to the environment. There are many proposed mechanisms by which toxicants inhibit and eventually kill bacteria. Toxicants may cause damage to the genetic material or may lead to protein denaturation, e.g., halogens. Since enzymes drive numerous key metabolic reactions in microbial, plant, and animal cells, their inhibition could be the underlying cause of toxicity to the cells.
