Nutrient substrates used by bacterial isolates from the poultry processing environment.

Abstract

In order to successfully prevent pathogens found in biofilms in poultry processing facilities from contaminating products, knowledge of the sources and properties of the bacteria from these environments is needed. Bacteria were isolated from fresh cut-up meat samples (breast with or without skin, wings, and thighs) that were not stored or were stored at 4 or 13 C (temperatures relevant to poultry processing facilities). Profiles of the nutrient substrates used by individual bacterial species were determined using Biolog microtiter plates with different substrates in 95 wells of each plate. Pure cultures of bacterial isolates were inoculated onto gram-positive (GP) or gram-negative (GN) Biolog plates, and transformation of specific substrates was determined by reduction (indicated by a purple color) of the tetrazolium violet included in each well. Of the 62 substrates common to GP and GN microtiter plates, one-third were used by 50% or more of all bacterial isolates. Similarly, approximately one-third of the substrates were used by gram-negative bacteria but not by gram-positive bacteria. One-fourth of the substrates were also only used by a single isolate in the respective gram-type category. For the remaining 33 substrates on each of the GP and GN plates, a higher percentage of substrates on GN than on GP plates were used by the respective isolates. These substrate utilization profiles of bacteria isolated from the poultry processing environment are a useful reference for selecting nutrients for the growth or control of these bacteria, especially pathogens.