Which microorganism is responsible for the fermentation of soybeans to produce the traditional Indonesian food "tempeh"?

Step-by-step solution

1. Recall that tempeh is produced by the mould Bacillus subtilis (also called Bacillus amyloliquefaciens).
2. Exclude Lactobacillus acidophilus – it is a lactic acid bacterium used in dairy products.
3. Exclude Aspergillus oryzae – it is used for miso and soy sauce, not tempeh.
4. Exclude Saccharomyces cerevisiae – it is a yeast used in beer and bread.
5. Conclude that Bacillus subtilis is the correct fermenting microbe for tempeh.

Concept tested: Microbes in food fermentation

Published 23 September 2026 · How this solution was prepared and checked