Question

What do you mean by wall growth in bioreactors?

(a) Growth of cells in the wall

(b) Consumption of paints by the cells from the coated walls

(c) Biomass concentration is increased

(d) Immobilized cells consumes substrate within reactors

This question was addressed to me in an international level competition.

My enquiry is from Continuous Culture in chapter Microbial Growth Kinetics of Bioprocess Engineering

Answer 1

Right choice is (d) Immobilized cells consumes substrate within reactors

Explanation: Wall growth is commonly encountered practical difficulty in which the organism adheres to the inner surfaces of the reactor resulting an increase in heterogeneity. The immobilized cells are not subject to removal from the vessel but will consume substrate resulting in the suspended biomass concentration being lower than predicted.