La crescita batterica. II: Il processo di desincronizzazione di una coltura

Ageno, Mario

Atti della Accademia nazionale dei Lincei. Rendiconti della Classe di scienze fisiche, matematiche e naturali, Série 8, Tome 82 (1988) no. 3, pp. 595-602

Résumé

The initial phase of growth of a bacterial culture in liquid medium is examined, in relation to the transition from the initial conditions, in which any distribution of the bacterial ages can be pre-arranged by the experimentalist, to the ordinary phase of exponential growth, in which the distribution of the bacterial ages is stationary. We realize that a synchronized culture is more ordered than a desynchronized one, and the natural tendency of any culture to desynchronize itself follows as a consequence of the second principle of thermodynamics. The fundamental nature of the causes of this trend is discussed and the effects of the consequent fluctuations in the bacterial duplication time, $\tau_{N}$, are considered. From all that, a simple method to evaluate the entropy of desynchronization of a bacterial culture is devised and the calculation effected. The result is: $$\Delta S_{des} = k_{B} N ln \left[ \frac{e}{2 \, ln2} \right] = 0,673366 \, k_{B} N$$ nearly $(2/3)\, k_{B}$ per bacterium.