With the exception of water,which one of the following is possibly the most important accessory chemical substance in industrial processes?

Which microorganism is used for the commercial production of citric acid?

Which of the following participates in the manufacturing of dextrans?

Which of the following enzymes is produced on an industrial scale?

Read the following statement having two blanks ($A$ and $B$).
$A$ drug used for $A$ patients is obtained from a species of the organism $B$.
The one correct option for the two blanks is

The large holes in Swiss cheese are developed due to the production of a large amount of . . . . . . gas.