metal-working fluids. Microbial growth and accumulation in industrial

surfaces by the circulating MWFwith the aid of the diffu-sors. After appropriate incubation periods in the MWF,thetest surfaces wererinsed bya waterstream for 15 s in orderto remove unattached bacteria from the surfaces. Micro-scopic analysis wasperformed with epifluorescence micros-copy after the surfaces were stained.Chemical determination ofPseudomonas spp. by gas chro-matographic analysis of 3-hydroxylauric acid. The MWFsample (1.5 ml) was diluted with 9.5 ml 1-butanol andcentrifugedat 2,500 x gand