Penicillin was accidentally discovered when Alexander Fleming was working with the culture of

Activated sludge is

A. Formed after sequential filtration and sedimentation in primary settling tank.

B. Bacterial floc settling after secondary treatment.

C. Passed into anaerobic sludge digester.

Read the following statement with respect to biogas production, and state true (T) and false (F).

A. The type of the gas produced depends upon the microbes and the organic substrate they utilize.

B. Certain bacteria that grow aerobically on cellulose material produce large amount of methane along with ${\mathrm{CO}}_2$ and ${\mathrm{H}}_2$.

C. Methanobacterium is a common methanogen.

D. Methanogens are commonly found in the anaerobic sludge during sewage treatment.