Biocalorimetry-aided monitoring of fungal pretreatment of lignocellulosic agricultural residues.

The present study aimed to investigate whether and how non-invasive biocalorimetric measurements could serve for process monitoring of fungal pretreatment during solid-state fermentation (SSF) of lignocellulosic agricultural residues such as wheat straw. Seven filamentous fungi representing different lignocellulose decay types were employed. Water-soluble sugars being immediately available after fungal pretreatment and those becoming water-extractable after enzymatic digestion of pretreated wheat straw with hydrolysing (hemi)cellulases were considered to constitute the total bioaccessible sugar fraction.

Enhancing insights: exploring the information content of calorespirometric ratio in dynamic soil microbial growth processes through calorimetry.

Catalytic activity of microbial communities maintains the services and functions of soils. Microbial communities require energy and carbon for microbial growth, which they obtain by transforming organic matter (OM), oxidizing a fraction of it and transferring the electrons to various terminal acceptors. Quantifying the relations between matter and energy fluxes is possible when key parameters such as reaction enthalpy (), energy use efficiency (related to enthalpy) (EUE), carbon use efficiency (CUE), calorespirometric ratio (CR), carbon dioxide evolution rate (CER), and the apparent specific growth rate () are known.

Core-Shell Polydopamine/Cu Nanometer Rods Efficiently Deactivate Microbes by Mimicking Chloride-Activated Peroxidases.

Cu-modified nanoparticles have been designed to mimic peroxidase, and their potent antibacterial and anti-biofilm abilities have been widely investigated. In this study, novel core-shell polydopamine (PDA)/Cu(OH)SO crystal (PDA/Cu) nanometer rods were prepared. The PDA/Cu nanometer rods show similar kinetic behaviors to chloride-activated peroxidases, exhibit excellent photothermal properties, and are sensitive to the concentrations of pH values and the substrate (i.

Fungal Lignocellulose Utilisation Strategies from a Bioenergetic Perspective: Quantification of Related Functional Traits Using Biocalorimetry.

In the present study, we investigated whether a non-invasive metabolic heat flux analysis could serve the determination of the functional traits in free-living saprotrophic decomposer fungi and aid the prediction of fungal influences on ecosystem processes. For this, seven fungi, including ascomycete, basidiomycete, and zygomycete species, were investigated in a standardised laboratory environment, employing wheat straw as a globally relevant lignocellulosic substrate. Our study demonstrates that biocalorimetry can be employed successfully to determine growth-related fungal activity parameters, such as apparent maximum growth rates (), cultivation times until the observable onset of fungal growth at (), quotients formed from the and (herein referred to as competitive growth potential, ), and heat yield coefficients (), the latter indicating the degree of resource investment into fungal biomass versus other functional attributes.

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

The applicability of biocalorimetry for monitoring fungal conversion of lignocellulosic agricultural by-products during solid-state fermentation (SSF) was substantiated through linking the non-invasive measurement of metabolic heat fluxes to conventional invasive determination of fungal activity (growth, substrate degradation, enzyme activity) parameters. For this, the fast-growing, cellulose-utilising ascomycete Stachybotrys chlorohalonata and the comparatively slow-growing litter-decay basidiomycete Stropharia rugosoannulata were investigated as model organisms during growth on solid wheat straw. Both biocalorimetric and non-calorimetric data may suggest R (ruderal)- and C (combative)-selected life history strategies in S.

Enzymatic degradation of polyethylene terephthalate nanoplastics analyzed in real time by isothermal titration calorimetry.

Plastics are globally used for a variety of benefits. As a consequence of poor recycling or reuse, improperly disposed plastic waste accumulates in terrestrial and aquatic ecosystems to a considerable extent. Large plastic waste items become fragmented to small particles through mechanical and (photo)chemical processes.

New thermodynamic activity-based approach allows predicting the feasibility of glycolysis.

Thermodynamic feasibility analyses help evaluating the feasibility of metabolic pathways. This is an important information used to develop new biotechnological processes and to understand metabolic processes in cells. However, literature standard data are uncertain for most biochemical reactions yielding wrong statements concerning their feasibility.

Thermodynamics and Kinetics of Glycolytic Reactions. Part I: Kinetic Modeling Based on Irreversible Thermodynamics and Validation by Calorimetry.

In systems biology, material balances, kinetic models, and thermodynamic boundary conditions are increasingly used for metabolic network analysis. It is remarkable that the reversibility of enzyme-catalyzed reactions and the influence of cytosolic conditions are often neglected in kinetic models. In fact, enzyme-catalyzed reactions in numerous metabolic pathways such as in glycolysis are often reversible, i.

Thermodynamics and Kinetics of Glycolytic Reactions. Part II: Influence of Cytosolic Conditions on Thermodynamic State Variables and Kinetic Parameters.

For systems biology, it is important to describe the kinetic and thermodynamic properties of enzyme-catalyzed reactions and reaction cascades quantitatively under conditions prevailing in the cytoplasm. While in part I kinetic models based on irreversible thermodynamics were tested, here in part II, the influence of the presumably most important cytosolic factors was investigated using two glycolytic reactions (i.e.

Influence of cytosolic conditions on the reaction equilibrium and the reaction enthalpy of the enolase reaction accessed by calorimetry and van 't HOFF.

Background: Thermodynamic methods are finding more and more applications in systems biology, which attempts to understand cell functions mechanistically. Unfortunately, the state variables used (reaction enthalpy and Gibbs energy) do not take sufficient account of the conditions inside of cells, especially the crowding with macromolecules.

Methods: For this reason, the influence of crowding agents and various other parameters such as salt concentrations, pH and temperature on equilibrium position and reaction enthalpy of the glycolytic example reaction 9 (2-Phospoglycerate - > Phosphoenolpyruvate + HO) was investigated.

Rapid culture-based detection of Legionella pneumophila using isothermal microcalorimetry with an improved evaluation method.

The detection and quantification of Legionella pneumophila (responsible for legionnaire's disease) in water samples can be achieved by various methods. However, the culture-based ISO 11731:2017, which is based on counts of colony-forming units per ml (CFU·ml ) is still the gold standard for quantification of Legionella species (spp.).

Standard Gibbs energy of metabolic reactions: V. Enolase reaction.

The glycolytic pathway is one of the most important pathways for living organisms, due to its role in energy production and as supplier of precursors for biosynthesis in living cells. This work focuses on determination of the standard Gibbs energy of reaction Δg' of the enolase reaction, the ninth reaction in the glycolysis pathway. Exact Δg' values are required to predict the thermodynamic feasibility of single metabolic reactions or even of metabolic reaction sequences under cytosolic conditions.

Rapid Calorimetric Detection of Bacterial Contamination: Influence of the Cultivation Technique.

Modern isothermal microcalorimeters (IMC) are able to detect the metabolic heat of bacteria with an accuracy sufficient to recognize even the smallest traces of bacterial contamination of water, food, and medical samples. The modern IMC techniques are often superior to conventional detection methods in terms of the detection time, reliability, labor, and technical effort. What is missing is a systematic analysis of the influence of the cultivation conditions on calorimetric detection.

Photocalorespirometry (Photo-CR): A Novel Method for Access to Photosynthetic Energy Conversion Efficiency.

One key parameter for assessing the CO fixation in aquatic ecosystems but also for the productivity of photobioreactors is the energy conversion efficiency (PE) by the photosynthetic apparatus. PE strictly depends on a range of different fluctuating environmental conditions and is therefore highly variable. PE is the result of complex metabolic control.

High-frequency, dielectric spectroscopy for the detection of electrophysiological/biophysical differences in different bacteria types and concentrations.

This paper describes a novel technique to quantify and identify bacterial cultures of Bacillus Subtilis (2.10-1.30 × 10 CFU mL) and Escherichia Coli (1.

An enhanced bioindicator for calorimetric monitoring of prophage-activating chemicals in the trace concentration range.

Viruses that infect bacteria (bacteriophages) can either lyse bacteria directly or integrate their genome into the bacterial genome. In the latter case, the viral genome (called prophage) remains dormant, and both phages and bacteria are able to survive in this state. But the silent prophages can be reactivated by, e.

A fast and reliable method for monitoring of prophage-activating chemicals.

Bacteriophages, that is viruses that infect bacteria, either lyse bacteria directly or integrate their genome into the bacterial genome as so-called prophages, where they remain at a silent state. Both phages and bacteria are able to survive in this state. However, prophages can be reactivated with the introduction of chemicals, followed by the release of a high number of phage particles, which could infect other bacteria, thus harming ecosystems by a viral bloom.

A simple method for the measurement of metabolic heat production rates during solid-state fermentations using β-carotene production with as a model system.

Solid-state fermentation (SSF) technology has been rapidly developed for the past 10 years as a production platform for secondary metabolites, biofuels, food, and pharmaceuticals. Yet, the main drawback of SSF is the local temperature rise of up to 20 K, which potentially reduces the strain activity and inactivates heat sensible products. Due to the low heat capacity and thermal conductivity of mixtures of air with plant material, in comparison to aqueous suspensions in submerged fermentations, heat from metabolic processes is less efficiently dissipated.

Mn-Doped ZnSe quantum dots initiated mild and rapid cation exchange for tailoring the composition and optical properties of colloid nanocrystals: novel template, new applications.

Although cation exchange (CE) has been studied for many years and some mechanisms were proposed, there is still a knowledge gap in CE and problems such as the need for high temperature and it being time-consuming are still unaddressed. We developed a new mild strategy for CE by introducing a new ideal template and first applied this doping strategy to detect Cd and Hg. This strategy adopted Mn-doped ZnSe quantum dots (QDs) as the template and the introduction occurs via a two-step CE reaction: first Zn was partially substituted by X (X = Cd, Hg, Cu, Ag or Pb), later Mn (in the deep structure of QDs) was substituted by X.

Calorespirometric feeding control enhances bioproduction from toxic feedstocks-Demonstration for biopolymer production out of methanol.

The sustainable production of fuels and industrial bulk chemicals by microorganisms in biotechnological processes is promising but still facing various challenges. In particular, toxic substrates require an efficient process control strategy. Methanol, as an example, has the potential to become a major future feedstock due to its availability from fossil and renewable resources.

Exploiting mixtures of H2, CO2, and O2 for improved production of methacrylate precursor 2-hydroxyisobutyric acid by engineered Cupriavidus necator strains.

Current manufacturing of most bulk chemicals through petrochemical routes considerably contributes to common concerns over the depletion of fossil carbon sources and greenhouse gas emissions. Sustainable future production of commodities thus requires the shift to renewable feedstocks in combination with established or newly developed synthesis routes. In this study, the potential of Cupriavidus necator H16 for autotrophic synthesis of the building block chemical 2-hydroxyisobutyric acid (2-HIBA) is evaluated.

What does calorimetry and thermodynamics of living cells tell us?

This article presents and compares several thermodynamic methods for the quantitative interpretation of data from calorimetric measurements. Heat generation and absorption are universal features of microbial growth and product formation as well as of cell cultures from animals, plants and insects. The heat production rate reflects metabolic changes in real time and is measurable on-line.

A thermodynamic investigation of the glucose-6-phosphate isomerization.

In this work, Δ(R)g(+) values for the enzymatic G6P isomerization were determined as a function of the G6P equilibrium molality between 25 °C and 37 °C. The reaction mixtures were buffered at pH=8.5.