Negentropy concept revisited: Standard thermodynamic properties of 16 bacteria, fungi and algae species

TL;DR

This study measures thermodynamic properties of 16 microorganisms and analyzes their growth phases and entropy changes, revisiting the negentropy concept in biological systems.

Contribution

It provides new thermodynamic data for diverse microorganisms and links entropy changes to colony growth and nutrient limitations, revisiting the negentropy concept.

Findings

Thermodynamic properties vary among bacteria, fungi, and algae.

Entropy increases during initial growth phases and decreases during decline.

Nutrient limitation stabilizes and then reduces entropy in colonies.

Abstract

Standard molar and specific (per gram) enthalpy of formation, entropy and Gibbs free energy of formation of biomatter have been determined for 16 microorganism species, including Methylococcus capsulatus, Klebsiella aerogenes, Paracoccus denitrificans, Escherichia coli, Pseudomonas C12B, Aerobacter aerogenes, Magnetospirillum gryphiswaldense, Saccharomyces cerevisiae, Candida utilis, Chlorella, Chlorella a sp. MP-1, C. minutissima, C. pyrenoidosa and C. vulgaris. The average values of ${\Delta}_{f}H{\deg}$ are for bacteria -4.22 kJ/g, for fungi -5.03 kJ/g and for algae -4.40 kJ/g. The average values of S{\deg} are for bacteria 1.48 J/g K, for fungi 1.45 J/g K and for algae 1.48 J/g K. The average values of ${\Delta}_{f}G{\deg}$ are for bacteria -2.30 kJ/g, for fungi -3.15 kJ/g and for algae -2.48 kJ/g. Based on the results, an analysis was made of colony growth in time. In the first three phases, entropy change of microorganisms plated in a Petri dish is positive and entropy of the colony increases. In the fourth phase, due to limitation of nutrients, entropy remains constant. In the fifth phase, due to lack of nutrients, entropy of the colony decreases and microorganisms die-off. Based on the results, the negentropy concept is analyzed.