Author
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Boothe, Dorothy |
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Arnold, Judy |
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Chew, Victor |
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Submitted to: Poultry Science
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 9/1/1999 Publication Date: N/A Citation: N/A Interpretive Summary: Bacteria use, or metabolize, a variety of chemical compounds as food for growth and survival. Several factors may affect which chemicals are used by specific bacteria; among these are the presence of other bacteria and their collective interaction. Identifying the compounds used by bacterial groups on chicken meat is of importance for food safety and product integrity. In particular, recognizing and reducing the amount of chemicals used by groups of bacteria on chicken meat may also decrease the presence of individual bacteria causing foodborne illness and spoilage. One purpose of the present study was to identify the compounds used collectively by bacteria on chicken meat samples stored at two temperatures: 1) refrigeration temperature and 2) a temperature common in poultry processing areas. The meat samples tested were stored at the respective temperatures for an increasing number of days prior to analysis. A new method was developed for use in determining which chemicals were metabolized by groups of bacteria on chicken meat samples stored under the differing conditions. Profiles of compounds used by the bacterial groups were compiled. Divergences which were noted in the profiles may be useful in characterizing and subsequently preventing the presence of bacterial groups implicated in foodborne illness or spoilage of poultry products. Technical Abstract: Understanding and controlling the metabolism of microorganisms associ- ated with chicken meat can lead to safer poultry products with a longer shelf life. The objective of the present study was three-fold: 1) to determine the feasibility of using 96-well Biolog GN microtiter plates to assess substrate utilization profiles of bacterial communities (bio- film) as they develop on poultry products, 2) to identify substrates metabolized by microbial populations associated with stored chicken meat and 3) to compare the substrate utilization profiles of biofilm communi- ties as they develop on meat stored at 4 degrees C (refrigeration temperature) for up to 5 days or at 13 degrees C (common in poultry pro- cessing areas) for 2 days. The protocol for preparing inocula for microplates wells allowed the collection of optical density values (590 nm) as an indicator of microbial substrate utilization over time. Data from treatment of chicken meat samples using this protocol indicate that most of the 95 substrates tested were metabolized by microbial communi- ties present as early as 1 day after storage at 4 or at 13 C. However, the rapidity and frequency of metabolism of the substrates by the biofilm communities varied from 4-164 hours of plate incubation and from 17-100% of microplates, respectively. Metabolism of chemically related substrate groups followed the order polymers>carbohydrates>carboxylic acids>miscellaneous or amino acids>amides/amines at 13 C. Use of these substrate groups was less variable at 4 C. A difference of more than 30% in frequency of metabolism of 17 individual substrates was noted at the two temperatures; such divergences may be used to characterize biofilm communities implicated in pathogenicity/affecting poultry food quality. |
