Characterization of metalworking fluids as a function of time in the system.
Metalworking Fluids Symposium II, The Industrial Metalworking Environment: Assessment and Control of Metal Removal Fluids. September 15-17, 1997, Detroit, Michigan. DA Felinski, JB D'ARcy, eds., Washington, DC: American Automobile Manufacturers Association, 1998 Nov; :129-131
This report describes the results of a pilot study to examine changes in the biological component of metalworking fluids (MWF) as a function of use. Fluid samples were taken from two newly-charged systems at one-week intervals and characterized with respect to the kinds and numbers of bacteria present and the presence of soluble protein in cell-free supernatants. In addition, pelleted cells were examined by gas chromatography/mass spectroscopy for the kinds of relative amounts of phospholipid fatty acids (PLFA) present. Thirteen different bacterial species were cultured and identified, more than half (8/13) of which were Gram-negative. Total CFU reached levels of 2.2 X 10^3 / ml in one system and 2.4 X 10^5 / ml in the other. The most common genus isolated was Pseudomonas. There was no soluble protein detected in any of the samples. Both the numbers and the amounts of PLFA increased as fluids aged in the systems. In samples from both systems, the chromatograms were dominated by two large peaks that increased with time. These peaks are thought to correspond to unusual fatty acids, not usually associated with pseudomonads.
Metalworking; Metalworking-fluids; Metalworking-industry; Gas-chromatography; Bacteria; Phospholipids; Fatty-acids; Sampling
Metalworking Fluids Symposium II, The Industrial Metalworking Environment: Assessment and Control of Metal Removal Fluids. September 15-17, 1997, Detroit, Michigan