You are growing Bacillus subtilis,an aerobic bacterium that can also carry out fermentation,when required,in a bioreactor and notice that the growth rate has slowed and the pH has decreased.What could you add?

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Quizplus · Accepted Answer

Bacillus subtilis is an aerobic bacterium indicating that it requires oxygen for growth. The decrease in pH could indicate the depletion of dissolved oxygen in the bioreactor. Therefore, adding oxygen will help to improve growth rates and maintain the pH. Adding glucose or lactose could contribute to acidification of the media and fermentation, which may not be desirable. Peptides could also be used as a nitrogen source for growth but would not address the decrease in pH. Lactic acid is a byproduct of fermentation and adding it would further contribute to the acidification of the media, making it a poor choice.

You Are Growing Bacillus Subtilis,an Aerobic Bacterium That Can Also