The initial step in the preparation of beer is:

$A$: Fermentation stops when the alcohol concentration in a sugar solution reaches about $13 \%$.
$R$: $Saccharomyces \ cerevisiae$ are killed by the high concentration of alcohol,and zymase activity is inhibited.

The microorganism commonly used in the alcohol industry for the production of ethanol is:

Which one of the following has been commercialised as a blood-cholesterol lowering agent?

Match Column $I$ (Antibiotic) with Column $II$ (Source) and choose the correct option from the codes given below.

Column $I$	Column $II$
$A$. Fumagillin	$1$. Gliocladium virens
$B$. Bacitracin	$2$. Streptomyces griseus
$C$. Streptomycin	$3$. Bacillus polymyxa
$D$. Viridin	$4$. Aspergillus fumigatus
$E$. Polymixin	$5$. Bacillus licheniformis

Codes:
$A \quad B \quad C \quad D \quad E$

Which organism is indirectly useful for patients who have undergone organ transplantation?