Applicability and information value of biocalorimetry for the monitoring of fungal solid-state fermentation of lignocellulosic agricultural by-products

Biocalorimetry-aided monitoring of fungal pretreatment of lignocellulosic agricultural residues

“…Previous studies have already established biocalorimetry for process monitoring in order to identify unexpected metabolic events (Maskow and Kleinsteuber 2004 ), to record metabolic shifts (Duboc et al 1998 ; Maskow and Babel 1998 ), to control the conversion of toxic substrates into valuable products such as biopolyesters, or to protect compounds in fed-batch or a continuous manner (Maskow and Babel 2001 ; Maskow et al 2006 ; Rohde et al 2016 ). In previous studies we have applied the non-invasive measurement of metabolic heat fluxes to monitor fungal activity during the colonisation of wheat straw, which was used as a solid lignocellulosic agricultural residue of global relevance (Duong et al 2022a , b ). Fungal biomass yields observed during fungal growth on wheat straw were strongly correlated with the released metabolic heat, which enabled to determine a range of species-specific growth-related activity parameters being indicative of different fungal strategies employed during resource utilisation (Duong et al 2022b ).…”

“…These fractions were linked to corresponding species-specific Y Q / X values. Y Q / X is a measure of the metabolic heat released (in J) to form a certain amount of biomass (in g) and was calorimetrically quantified as described before (Duong et al 2022a , b ). In order to cover a broad range of potential SSF applications, fungi dwelling in diverse habitats and employing different strategies in utilising lignocellulosic substrates were used.…”

“…In order to cover a broad range of potential SSF applications, fungi dwelling in diverse habitats and employing different strategies in utilising lignocellulosic substrates were used. The wine-cap mushroom Stropharia rugosoannulata served as a litter decaying and comparatively slowly growing white-rot reference strain (Singh et al 2014 ; Duong et al 2022a ). The basidiomycete G. trabeum was chosen as a brown-rot representative (Goodell 2003 ; Krueger et al 2015 ; Duong et al 2022b ).…”

“…Schizophyllum commune was selected as an intermediate between brown-rot and white-rot fungi, lacking lignin-degrading peroxidases (like brown-rot fungi) but possessing enzymes acting on crystalline cellulose (like white-rot fungi) (Riley et al 2014 ; Duong et al 2022b ). The soft-rot ascomycetes T. reesei , Stachybotrys chlorohalonata , and P. chrysogenum and the mucoromycete Gongronella butleri were also included (Duong et al 2022a , b ).…”

Omicron BA.2.75 Sublineage (Centaurus) Follows the Expectations of the Evolution Theory: Less Negative Gibbs Energy of Biosynthesis Indicates Decreased Pathogenicity

“…During growth and biosynthesis, the state of the animate matter system changes [27], consequently, the thermodynamic properties of the organism change during biosynthesis [28][29][30][31]. Biothermodynamic research in microorganisms has been conducted in various environments, from bioreactors [32,33], through soil [34,35], to human infections [12]. During the evolution of viruses, mutations occur that change not only the thermodynamic properties due to a change in elemental composition, but also the information content [36][37][38].…”