Food safety — If thermal canning is inadequate, which type of microorganism is most likely to proliferate in the sealed, oxygen-depleted can and pose a serious health risk?

Introduction / Context:
Canned foods are processed to inactivate spores of dangerous anaerobes, particularly Clostridium botulinum. Failure to reach proper lethality permits spore survival and germination in the oxygen-poor interior of sealed cans, potentially producing botulinum neurotoxin, a life-threatening hazard.

Given Data / Assumptions:

• Post-processing environment inside cans is anaerobic.
• Concern centers on spore-formers that grow without oxygen.
• Acid content and processing schedule influence required lethality.

Concept / Approach:
Obligate anaerobes, especially Clostridium species, thrive in oxygen-free settings. Proper canning (retort) schedules target spore inactivation (e.g., 12D reduction for C. botulinum in low-acid foods). Aerobes cannot grow in sealed anaerobic cans; mesophile merely describes temperature preference; acidophiles favor low pH but many canned goods are low-acid and need severe processing to suppress anaerobes.

Step-by-Step Solution:

Verification / Alternative check:
Food safety standards (e.g., for low-acid canned foods) emphasize spore control of C. botulinum through validated thermal processes and container integrity checks (no swelling, gas).

Why Other Options Are Wrong:

• Obligate aerobe: cannot grow in anaerobic cans.
• Acidophile: growth determined by pH, not the primary risk in most low-acid canned foods.
• Mesophile: broad category lacking oxygen requirements.

Common Pitfalls:
Assuming refrigeration alone prevents botulism; psychrotrophic strains and improper storage still pose risks if processing was inadequate.

Final Answer:
Obligate anaerobe