Metagenomic analysis of automotive metalworking fluids from three different manufacturing facilities

Metalworking fluids are used in metal machining and cutting as lubricants and coolants, and sometimes for their anti-corrosion properties. Metalworking fluids are commonly used in automotive manufacturing plants where potential contamination by bacteria poses public health concern. This study was conducted to evaluate the usefulness of metagenomics in determining the identity of bacteria and the diversity and richness of microbial communities in metalworking fluids. Five metalworking fluid samples from three different plants, located in two different U.S. states, were obtained. A protocol was optimized to isolate DNA from metalworking fluids. A metagenomic analysis was performed by sequencing the 16S rRNA V3-V4 regions. Microbial communities were analyzed and the diversity and richness of the samples were determined. Genera such as Mycobacterium and Pseudomonas were relatively abundant in samples from some plants, whereas other genera such as Comamonas and Acinetobacter were more abundant in other samples. All five samples were found to have bacterial communities that included opportunistic pathogens, emphasizing the importance of surveillance and treatment of metalworking fluids as important steps in addressing potential public health concern for automotive manufacturing workers.