Question

What may cause foaming in a bioreactor?

(a) A decrease in agitation

(b) The formation of large stable bubbles

(c) The formation of small unstable bubbles

(d) The breaking of large unstable bubbles

The question was asked in class test.

My doubt stems from Antibiotics topic in portion Antibiotics & Enzyme Immobilization of Drug Biotechnology

Answer 1

The correct answer is (d) The breaking of large unstable bubbles

Best explanation: Large weak foam bubbles are easily broken by mechanical forces (i.e., agitation) and may form new tiny bubbles which are much more stable. Tiny bubbles has higher surface area to volume ratio which gives more mass transfer.