Vinegar production – slimy spoilage: Which species of vinegar bacteria is most commonly cited in classical texts for causing sliminess (“mother of vinegar”) in vinegar?

Introduction / Context:
Vinegar is produced by acetic acid bacteria oxidizing ethanol to acetic acid. However, certain species generate surface pellicles and viscous polysaccharides, leading to consumer-perceived “sliminess” or the so-called “mother of vinegar.”

Given Data / Assumptions:

• We are focused on vinegar bacterial species, not yeasts or lactic bacteria.
• Choice reflects classical naming used in food technology questions.
• Pellicle formation and viscosity are the key symptoms.

Concept / Approach:
Historically, Acetobacter aceti and related acetic acid bacteria have been implicated in pellicle/slime formation during surface fermentation. While cellulose-producing strains (now often classified as Komagataeibacter/Gluconacetobacter spp.) are leading culprits, exam conventions typically credit A. aceti as the most important vinegar bacterium associated with sliminess in legacy terminology.

Step-by-Step Solution:
Restrict attention to acetic acid bacteria. Identify the species traditionally cited in food microbiology texts for slimy pellicles. Select Acetobacter aceti as the best match among given options.

Verification / Alternative check:
Observations of cellulose pellicle (“mother”) in artisanal vinegars align with acetic acid bacteria activity and oxygen-rich surfaces; strain-level ID may vary but classical references emphasize A. aceti.

Why Other Options Are Wrong:
Saccharomyces – a yeast, not the cause of vinegar sliminess.

Lactobacillus lactis – lactic fermentations, not vinegar sliming.

Gluconobacter oxydans – an acetic acid bacterium but less classically cited for sliminess in this exam context.

Common Pitfalls:
Conflating modern taxonomy with exam-style legacy species names; answer according to classical food tech usage.

Final Answer:
Acetobacter aceti.