Location: Poultry Microbiological Safety Research
Title: Changes in profiles of substrates and volatile emissions of individual species and mixed consortia from the poultry production and processing environment Author
Submitted to: American Society for Microbiology Meeting
Publication Type: Proceedings
Publication Acceptance Date: August 29, 2008
Publication Date: October 13, 2008
Citation: Arnold, J.W. 2008. Changes in profiles of substrates and volatile emissions of individual species and mixed consortia from the poultry production and processing environment. American Society for Microbiology Meeting. Technical Abstract: Analysis of diverse profiles of volatile compounds emitted from single bacteria and from mixed populations demonstrate changes that occur when pathogens are introduced into communities of normal bacterial flora. Responses of bacteria within a biofilm to stimuli from external bacteria sets the stage for the pathogen relationship with the remaining consortia. Innate physiological responses that mediate the balance between the pathogens and the other microorganisms within the consortia determine the survival and growth of the pathogen and biofilm. We have studied both substrate utilization profiles and volatile emissions of individual bacterial species and mixed microbial communities (biofilm) associated with samples from the poultry production and processing environment. The rapidity and frequency of utilization of individual and groups (i.e., polymers, carbohydrates, etc.) of substrates varied by the microflora, and changed when stored at meat storage temperatures, 4 and 13oC. Differences occurred among the volatile compounds produced by the microbial consortia associated with the samples stored at these two temperatures. Currently, because of the seasonal and flock-to-flock variations of bacteria on poultry, it is difficult to determine storage quality of poultry meat other than by enumeration of microbial load. Surface odors are noted when the bacterial counts reach about log10 6-7 cfu g-1; and, at storage temperatures of 10'C or lower, are caused primarily by species of Pseudomonas and Acinetobacter. Metabolism of groups of chemically related substrates followed the order polymers> carbohydrates> carboxylic acids>miscellaneous or amino acids>amides/amines at 13'C. Utilization of these substrate groups was not as variable at 4'C as the profile of volatile emissions. Although the frequency of metabolism of each individual substrate group varied only 3-16% between samples stored at 4 and 13'C, a difference of more than 30% in frequency of utilization of 17 individual substrates was noted. Such divergences may be useful in characterizing biofilm communities that affect food quality of poultry products. Understanding the metabolic processes of microorganisms from the poultry production and processing environment progresses toward the ultimate goal of controlling these processes to yield safer poultry products with less potential for spoilage.