91. Yeast cells obtained from batch fermentation can be reutilized for the production of:
A. Beer
B. Trypsin
C. Chloramphenicol
D. Acetic acid

Detailed Explanation:

In industrial and traditional fermentation processes, yeast cells play a pivotal role as biological catalysts in converting sugars into alcohol and carbon dioxide. After completing a batch fermentation cycle, especially in brewing, these yeast cells can be harvested and reused in subsequent batches to optimize production and reduce costs.

Why Yeast is Reused in Beer Production:

• Yeast from beer fermentation (primarily Saccharomyces cerevisiae) remains viable after the fermentation cycle.

• Post-fermentation, the yeast is settled at the bottom of the fermentation vessel or collected using centrifugation or filtration.

• These cells are then washed and re-pitched into new wort for another cycle of fermentation.

• Reusing yeast helps:

  • Maintain consistency in the beer’s flavor and quality.

  • Lower production costs by reducing the need for new yeast cultures.

  • Support sustainability by minimizing waste.

While yeast can technically be reused in other fermentative processes, its primary and most common reuse is in beer production. The biochemical requirements and strain specificity for producing other substances like trypsin (an enzyme), chloramphenicol (an antibiotic), or acetic acid (a product of acetic acid bacteria like Acetobacter) are different and do not typically involve reused brewing yeast.

Correct Answer:

A. Beer