Difficulty: Easy
Correct Answer: Pseudomonas–Achromobacter group
Explanation:
Introduction / Context:
Packaging influences the spoilage microbiota. Polyethylene bags provide moisture retention and some oxygen limitation but usually still permit enough oxygen for psychrotrophic aerobes to act on poultry.
Given Data / Assumptions:
Concept / Approach:
In non-barrier poly wraps, oxygen is present and water activity is high. Psychrotrophic aerobic Gram-negative rods such as Pseudomonas and the related Achromobacter complex thrive, causing slime and off-odors. True vacuum/MAP would shift flora more strongly to LAB, but simple poly does not eliminate oxygen sufficiently.
Step-by-Step Solution:
Assess package permeability → PE bags allow some oxygen transmission.
Match microbial ecology → Pseudomonas–Achromobacter dominate aerobic, moist, chilled conditions.
Exclude others → LAB dominate in stricter oxygen limitation; thermophiles are irrelevant at chill.
Therefore select the Pseudomonas–Achromobacter group.
Verification / Alternative check:
Plate counts from bagged poultry commonly recover high Pseudomonas/Achromobacter numbers correlating with slime and taint development.
Why Other Options Are Wrong:
Alcaligenes alone is less predictive; heterofermentative LAB dominate in vacuum/MAP, not simple poly; catalase-negative cocci are not the principal spoilers here.
Common Pitfalls:
Assuming any plastic wrap equals anaerobiosis; permeability matters greatly.
Final Answer:
Pseudomonas–Achromobacter group.
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