Traditional fermentations: microorganism used in the preparation of “sonti” Identify the primary mold traditionally used as the starter microorganism for producing the rice-based beverage called sonti.

Introduction / Context:
Sonti is a traditional rice-based alcoholic beverage whose production resembles other Asian koji-type fermentations. Understanding the starter culture highlights the role of molds in saccharifying starches prior to alcoholic fermentation.

Given Data / Assumptions:

• Substrate is cooked rice (starchy, low in fermentable sugars initially).
• Traditional process relies on a mold (koji) to hydrolyze starch.
• Yeasts may subsequently ferment released sugars to ethanol.

Concept / Approach:
Aspergillus oryzae is a classic koji mold that secretes amylases, proteases, and other enzymes to break down rice starch and proteins, producing fermentable sugars and nutrients for yeast. This is analogous to sake production and many rice fermentations across Asia. While yeasts carry out ethanol fermentation, the defining saccharification step is performed by A. oryzae.

Step-by-Step Solution:

Verification / Alternative check:
Food microbiology texts describe koji-based rice fermentations (sake, huangjiu, and regional variants) as employing A. oryzae; sonti follows the same principle.

Why Other Options Are Wrong:

• Rhizopus sonti: sounds plausible but is not the standard koji mold.
• Lactobacillus vermiformis: lactic bacterium; not primary saccharifier.
• Saccharomyces pyriformis/Zygosaccharomyces: yeasts ferment sugars but do not perform the main saccharification step.

Common Pitfalls:
Confusing the saccharifying mold (A. oryzae) with the ethanologenic yeast stage; both occur, but the starter is the mold.

Final Answer:
Aspergillus oryzae