Most of the problems in Metalworking Fluids are caused by unwanted bacterial and fungal colonization. Species of Mycobacteria create unwanted odors, and almost all bacteria and fungi consume specific fluid components leading to the loss of fluid function. The species of the genus Mycobacterium are broadly grouped into two major categories on the basis of pathogenicity for animals and humans. The extremely pathogenic organisms M. tuberculosis and M. leprae are obligate parasites (the must transfer directly from host-to-host without residence in the environment), but the majority of the species, such as M. smegmatis and M. terrae, are ubiquitous in the environment.

Rapid measurement of the biological population of a system is critical to best metalworking fluid management practice.  How to rapidly quantify the microbial population is a fundamental problem in the investigation of Mycobacterium in complex environments like metalworking fluids. Mycobacterium are slow-growing organisms that are difficult to quantify with traditional culture techniques. PCR is a now commonly used technique for this purpose.

Quantitative PCR (qPCR) is possible through the combined use of specialized PCR reagents (e.g., TaqMan) and refined instrumentation. This advance is particularly useful in environmental microbiology because the population size, the amount of a particular organism, can be determined, and thus population changed can be tracked over time or in response to a change in the environment. The authors of this article have been applying these methods to Mycobacterium detection, identification, and population size determination in metalworking fluids.

Microbe Inotech Laboratories, Inc. has conducted R&D in the microbiological arena for over 30 years. In this article, they talk more about Mycobacterium and its real time measurement.