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ARS Home » Northeast Area » Beltsville, Maryland (BARC) » Beltsville Agricultural Research Center » Environmental Microbial & Food Safety Laboratory » Research » Publications at this Location » Publication #328734

Research Project: Sensing Technologies for the Detection and Characterization of Microbial, Chemical, and Biological Contaminants in Foods

Location: Environmental Microbial & Food Safety Laboratory

Title: Detecting contaminating microorganism in human food and water from Raman mapping through biofilms

item Nguyen, Julie
item HEIGHTON, LYNN - University Of Maryland
item XU, YUNFENG - Forest Service (FS)
item Nou, Xiangwu
item Schmidt, Walter

Submitted to: BARC Poster Day
Publication Type: Abstract Only
Publication Acceptance Date: 4/27/2016
Publication Date: 4/27/2016
Citation: Nguyen, J.K., Heighton, L., Xu, Y., Nou, X., Schmidt, W.F. 2016. Detecting contaminating microorganism in human food and water from Raman mapping through biofilms. BARC Poster Day. 2016 BARC Poster Day.

Interpretive Summary:

Technical Abstract: Detecting microbial growth can help experts determine how to prevent the outbreaks especially if human food or water has been contaminated. Biofilms are a group of microbial cells that can either grow on living surfaces or surrounding themselves as they progress. Biofilms are not necessarily uniform, but if there is more than one type of microbial bacteria that are grown, Raman mapping is performed to determine the growth patterns. Microbial bacteria can grow in various patterns such as symmetrical or scattered on a surface. Biofilms need to be intact in order to preclude and potentially figuring out the relative intensity of different components in a biofilm mixture. Three types of biofilms that are grown include Listeria (L), Ralstonia (R), and a mixture (LR). Biofilms were grown on stainless steel surface slides since microbe deposits on metal surfaces are quite suitable for detection and growth. Each slide was microscopically viewed at 100X and using a 532nm laser. Raman Mapping helps determine the bacterial growth and intensity. The Raman Microscope mapped each slides for approximately 18.5 hours in a dimension of 36x36µm. The results showed the location and position of how each bacterium is grown. The brighter shade of color of the Raman Map showed how high the intensity of the peaks is. With high intensity with the sharp peaks from the Raman Spectrum at different wavenumbers, it is easy to identify various chemical structures then proceed for microbial outbreak preventions.