Effect of Sample Preparation on the Discrimination of Bacterial Isolates Cultured in Liquid Nutrient Media Using Laser-Induced Breakdown Spectroscopy (LIBS)

摘要: Laser-induced breakdown spectroscopy (LIBS) is used as the basis for discrimination between two genera of gram-negative bacteria and gram-positive representing pathogenic threats commonly found in poultry processing rinse waters. Because LIBS-based relies primarily upon relative proportions inorganic cell components including Na, K, Mg, Ca, this study aims to determine effects trace mineral content pH water source isolate reliability resulting discriminant analysis. All four were cultured using tryptic soy agar (TSA) nutrient medium, grown under identical environmental conditions. The only variable introduced bacteria. Cultures each bacterium produced deionized (DI) atmosphere conditions, reverse osmosis (RO) water, tap phosphate buffered saline (PBS) TRIS water. After 3 days culture growth, centrifuged washed three times same source. Bacteria then freeze dried, mixed with microcrystalline cellulose, a pellet was made LIBS Principal component analysis (PCA) extract related variations spectral data among six types bacteria, Mahalanobis (MDA) classification. Results indicate not that can be discriminated from other type, but genus by type isolation. It concluded order reliable repeatable method liquid media, care must taken insure purification precisely controlled regarding pH, ionic strength, proportionate amounts cations present.