Laboratory Methods and Formulations
Microorganisms are routinely identified by their ability to grow and by the form of their growth on various liquid or solid media. This chapter describes available media commonly used for culturing corrosion causing bacteria. The standard methods of enumeration of viable microbial cells involve placing known volumes of diluted samples on solid growth media. Two common methods of determining antimicrobial activity are the minimum inhibitory concentration (MIC) and "time-kill" test. In the MIC test, the biocide is diluted in a medium suitable for the growth of the microorganism used, and an aliquot of a suspension of this organism is added to each dilution of biocide. Some large companies are able to perform their own tests in microbiological laboratories, but the majority of biocide users will have to employ outside help for such purposes. The conditions of environment and the microorganisms incorporated into the test should be chosen to match the intended uses of the biocide.