Question

Crabtree effect is which type of process?

(a) Aerobic

(b) Anaerobic

(c) Biomass yield

(d) Oxidative phosphorylation

This question was posed to me during an interview.

My question is based upon Monitoring and Control of Bioreactors in portion Reactor Engineering of Bioprocess Engineering

Answer 1

The correct choice is (a) Aerobic

Easy explanation: The Crabtree effect describes the phenomenon whereby the yeast, Saccharomyces cerevisiae, produces ethanol (alcohol) in aerobic conditions and high external glucose concentrations rather than producing biomass via the tricarboxylic acid (TCA) cycle, the usual process occurring aerobically in most yeasts e.g. Kluyveromyces spp. Increasing concentrations of glucose accelerates glycolysis (the breakdown of glucose) which results in the production of appreciable amounts of ATP through substrate-level phosphorylation. This reduces the need of oxidative phosphorylation done by the TCA cycle via the electron transport chain and therefore decreases oxygen consumption.