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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 #325174

Research Project: DEVELOPMENT OF SENSING AND INSTRUMENTATION TECHNOLOGIES FOR FOOD SAFETY AND SANITATION INSPECTION IN FRESH FRUIT AND VEGETABLE PROCESSING

Location: Environmental Microbial & Food Safety Laboratory

Title: Raman mapping of intact biofilms on stainless steel surfaces

Author
item Nguyen, Julie
item Heighton, Lynn - University Of Maryland
item Xu, Yunfeng - University Of Maryland
item Nou, Xiangwu
item Schmidt, Walter

Submitted to: Proceedings of SPIE
Publication Type: Proceedings
Publication Acceptance Date: 2/1/2016
Publication Date: 5/17/2016
Citation: Nguyen, J.K., Heighton, L., Xu, Y., Nou, X., Schmidt, W.F. 2016. Raman mapping of intact biofilms on stainless steel surfaces. Proceedings of SPIE. In: Proceedings for SPIE meeting, April 19-21, 2017, Baltimore, Maryland.

Interpretive Summary: Biofilms are a community of microbial cells that grow on various surfaces, both biotic and abiotic. Since biofilms are not necessarily uniform, Raman Mapping can be performed to determine the patterns of growth. Raman spectroscopy is a technique for identifying the chemical composition of biological materials. Depending on the type of bacteria, they can grow asymmetrically or scattered all over the surface. In this study, three types of bacteria were grown on a stainless steel surface slide. Each slide was viewed under a Raman Microscope at 100X and using a 532nm laser which provided for enhanced resolution. Using this technique, we mapped how the bacteria were growing, at which intensities they were detected, and were able to assign specific signature markers to microbes in the biofilms. This information should be useful to other scientists.

Technical Abstract: Each slide under the Raman Microscope was mapped for approximately 18.5 hours with a dimension of 36x36 that provides a greater result compared to doing a smaller dimension scan. The results from the Raman Mapping show the location and position of how the bacteria are growing scattered or straight and where it is located within the stainless steel slide. The brighter the color from the Raman Map shows how high the intensity of the peaks from the Raman Spectrum and each color shows which wavelength it's present and what time of chemical structures. The L Biofilms show a scattered pattern growth of lots of green mapping points. With the R Biofilms appears to grow in a straight line with some red mapping points. With the mixture of both L and R (LR) Biofilms, the Raman Mapping shows more of the R Biofilms is present than the L Biofilms within the LR Biofilm sample. Each biofilm sample show high intensity with the sharp peaks from the Raman Spectrum and at different wavelengths to easily identify various chemical structures.