Steady state and the chemostat in ecology

If translated with a slight bias: “Who wouldn’t praise a laureate, but would you read him? No. Accepting praise, he still prefers you’d understand him though,” Lessing’s lament appears to apply to science as well as to poetry and seems to be as timely today as it was in the days of Klopstock. It deplores assuming an eminent man’s idea without really taking the pain of reading his original writings and perceiving their meaning in the proper perspective. As a corollary, concepts arise and turn into methodologies which, although patched with respectable names, often do not hold water. The laureate in question here is Jaques Monod who reported (Monod 1942) that the growth rate of bacteria in certain culture media was controlled by a substrate (carbon or nitrogen source) as the sole limiting factor within a certain range of concentration. For a “data-fitting” mathematical function he proposed the most simple one, containing the constants a and b : x = ay/b + y, or in its common form: E,L= p,,$/K, + S (p-growth rate, ,u,-maximum growth rate, S-concentration of the growth-limiting substrate, &-saturation or affinity constant+ubstrate concentration at