Bottled fruit juices bought from the market are clarified by using:

Identify the blank spaces $a, b, c$ and $d$ given in the following table and select the correct answer.

Type of microbes	Scientific name	Commercial product
Bacterium	$a$	Clot buster enzyme
$b$	Aspergillus niger	Citric acid
Fungus	Trichoderma polysporum	$c$
Bacterium	$d$	Butyric acid

$A$ brewery subjects about $1$ tonne of purified jaggery to fermentation under ideal conditions. If it has produced $0.3$ tonne of alcohol, what quantity of $CO_2$ has it expelled into the atmosphere (in $tonne$)?

An immunosuppressive agent used in organ-transplant patients is

Penicillin was discovered by

Which type of fatty acid is produced by the bacterium $Clostridium$ $butyricum$?