Microbioma do fluido de corte utilizado na indústria metal-mecânica brasileira: composições quantitativa e qualitativa, fatores que influenciam a presença de microrganismos, biodegradação e impacto nas propriedades lubri-refrigerante ; Cutting fluid microbiome used in the Brazilian metal-mechanic industry: biodegradation and impact on lubricant and refrigerant properties

Introduction: Cutting fluids (CF) are complex mixtures of chemicals used in the metalworking industry for cooling and lubricating of different types of machining processes, and their performance can directly affect the productivity of these processes. Objectives: i.) determine the dominant biome in miscible cutting fluids in water; ii.) analyze quantitatively and qualitatively this biome, including for the presence of M. immunogenum; iii.) determining the physic-chemical parameters such as pH, and others such as temperature and concentration of the fluid during biodegradation; iv.) evaluate the influence of biocides in the contamination of CFs; v.) determine the lubrication and cooling performance of two CFs after artificial contamination "in vitro" in two moments of biodegradation: when it reaches 105 CFU / mL (lag growth phase) and after 70 days of artificial biodegradation "in vitro" (last growth phase ), compared with new cutting fluids / uncontaminated and dry environment; and, vi.) to evaluate aspects of fluid management, as the use of prevention practices of accidents / health of employees, of injuries resulting in absenteeism and hygiene and cleanliness. Methods: In total, 114 samples were analyzed microbiologically of FCs three metal-mechanical industries located in the Brazilian Southeast (2) and South (1), all non-automotive. The microbial monitoring of bacteria and fungi was performed by viable count by specific means. The investigation of microbial contamination and degradation of CFs containing (7) or not biocide (2) was performed by monitoring, random (three industries) and continuous (two industries). Additionally, in one industry two CFs were selected for a study artificial contamination "in vitro" for a period of 70 days using as the most prevalent microorganism’s inoculum when the ongoing monitoring this industry. The test pendulum rebound hammer was used to evaluate the influence of microbial contamination in the performance of the properties of FCs as well as possible effects on the quality ...