Use of MTT assay for determination of the biofilm formation capacity of microorganisms in metalworking fluids
- PDF / 390,615 Bytes
- 9 Pages / 595.276 x 790.866 pts Page_size
- 85 Downloads / 202 Views
ORIGINAL PAPER
Use of MTT assay for determination of the biofilm formation capacity of microorganisms in metalworking fluids El_zbieta Anna Trafny • Rafał Lewandowski • Irena Zawistowska-Marciniak • Małgorzata Ste˛pin´ska
Received: 3 November 2012 / Accepted: 15 March 2013 / Published online: 21 March 2013 Ó Springer Science+Business Media Dordrecht 2013
Abstract Biofilm formation is a well-known problem in management of metalworking fluid systems. Due to persistence of microorganisms within biofilms, the reappearance of various species of bacteria, including nontuberculous mycobacteria is often observed after the use of biocides and/or cleaning of delivery systems and replacement of cooling fluid. The aim of this study was to determine the usefulness of the tetrazolium salt assay (MTT assay) for assessing the viability of bacteria in biofilms formed in vitro in fresh and used cutting oils, as well as their susceptibility to antimicrobial biocides. Biofilms were established in the microtiter plate format. The results showed that quantification of formazan, a product of the tetrazolium salt reduction by electron transport system could be used for determination of the propensity of bacteria to form biofilms in these complex media. The use of the assay allows also determination of antimicrobial activity of biocides against biofilms in fresh and used metalworking fluids. Biofilms produced by Gramnegative isolates recovered from field metalworking fluids as well as the wild bacterial communities differed in metabolic activity depending on the type of fresh coolants. The MTT assay has high-throughput potential and can be efficiently used for determination of biofilm-forming capacity of microorganisms from individual machines in metalworking industry. The use of the assay may also guide the selection of the most appropriate biocide to fight these microorganisms.
E. A. Trafny (&) R. Lewandowski I. Zawistowska-Marciniak M. Ste˛pin´ska Department of Microbiology, Military Institute of Hygiene and Epidemiology, Kozielska 4, 01-163 Warsaw, Poland e-mail: [email protected]
Keywords Biocides
MTT assay Metalworking fluids Biofilm
Introduction Microorganisms frequently contaminate the cooling and lubricating fluids (Saha and Donofrio 2012). Contamination of coolants leads to the necessity of their frequent replacement and/or use of biocides. It also causes deterioration with time in various metal parts manufactured in the industry (Rabenstein et al. 2009). Despite the appropriate microbiological surveillance of cooling liquids, and even use of biocides, large quantities of bacteria and fungi have often been found in metalworking fluids (MWFs) (Perkins and Angenent 2010). This leads to exposure of workers, who have contact with oil mist generated during machining, to the harmful bio-aerosols that contain both pathogenic microorganisms and their fragments with allergenic properties (Burton et al. 2012). One possible reason for ineffective eradication of microorganisms from MWF delivery systems may be their growth
Data Loading...
