In fermented cabbage (sauerkraut) production, excessively high fermentation temperature primarily inhibits the growth of which lactic acid bacterium that starts the fermentation and creates the desired flavor profile?

Introduction:
Sauerkraut fermentation is a sequential, mixed-culture process in food microbiology. The early stage is dominated by Leuconostoc species, which are heterofermentative lactic acid bacteria that set pH, produce aroma compounds, and pave the way for subsequent Pediococcus and Lactobacillus species. This question tests how temperature affects that microbial succession and the quality of the final product.

Given Data / Assumptions:

• Classic sauerkraut fermentation begins with Leuconostoc (temperature sensitive), then shifts to Pediococcus/Lactobacillus (more heat tolerant).
• High temperature means above the recommended moderate range for cabbage fermentations.
• Target outcomes are rapid acid development, crisp texture, and desirable flavor.

Concept / Approach:
Leuconostoc spp. thrive at cooler to moderate temperatures. When temperature is excessive, their growth is suppressed. This disrupts the normal succession, allowing later-stage, heat-tolerant lactic acid bacteria to dominate too early. The result can be harsh acidity, off-flavors, soft texture, and gas defects because the balanced, heterofermentative stage is truncated or lost.

Step-by-Step Solution:
Recognize the starter role of Leuconostoc in early heterofermentation. Note temperature sensitivity: excessive heat suppresses Leuconostoc activity. Understand that Pediococcus is relatively more heat tolerant and can prevail at higher temperatures. Conclude that the organism most inhibited by excessive heat is Leuconostoc.

Verification / Alternative check:
Industry guidance recommends moderate temperature control (not too high) to ensure a proper Leuconostoc-dominated phase, confirmed by sensory and pH/acid curves collected during well-run ferments.

Why Other Options Are Wrong:

• Pediococcus cerevisiae: More heat tolerant; not the primary casualty of high temperature.
• Both/None: Overstates or understates; the key sensitive group is Leuconostoc.

Common Pitfalls:
Confusing “fast acid” at higher temperature with “better” fermentation; skipping Leuconostoc impairs flavor complexity and texture.

Final Answer:
Leuconostoc growth is inhibited by excessively high fermentation temperature.