Application of Ionic Liquids in the Utilization of the Agricultural Wastes: Towards the One-Step Pre-Treatment and Cellulose Hydrolysis

Cheap, renewable lignocellulosic materials are relevant to the future of biofuel production. Wood and agricultural wastes (e.g. straw, corn stover) provide a raw material source that cannot be used for human consumption, thus biofuels from such sources do not threaten the food supply. The aim of the work was to carry out the pre-treatment and hydrolysis of lignocellulosic material in the same ionic liquid solvent (1-n-butyl-3- methyl-imidazolium-chloride, [Bmim]Cl), using ground wheat straw and a mixture of corn (Zea mays) leaf and stover, as substrates. Our measurements show that it is possible to achieve an acceptable glucose content from the cellulose by applying Cellic® CTec2 and Cellic® HTec2 enzyme complexes

Enzyme kinetics approach to assess biocatalyst inhibition and deactivation caused by [bmim][Cl] ionic liquid during cellulose hydrolysis

The aim of this work was to study the inhibition and deactivation of commercial enzyme cocktail (Cellic® Htec2) in the presence of [bmim][Cl] ionic liquid employing model cellulosic substrate, carboxymethyl cellulose (CMC). It turned out from the experiements – relying on enzyme kinetics appproach – that [bmim][Cl] could act as a competitive inhibitor. Furthermore, depending on the process conditions i.e. contact of enzyme solution with high concentration [bmim][Cl], severe biocatalyst inactivation should be also taken into account as a potential risk during the enzymatic cellulose hydrolysis even in as short process times as few minutes

Thermally induced inactivation and aggregation of urease : experiments and population balance modelling

We present a population balance model for enzyme deactivation and aggregation kinetics with a limited number of physically relevant parameters and use this model to analyse the experimental data for thermal inactivation of jack bean urease. The time dependence of the relative enzymatic activity was found to follow the second order kinetics, which was consistent with pre-equilibrated folding/unfolding of the native enzyme, followed by irreversible cluster–cluster aggregation of the non-native enzyme resulting in gradual and permanent loss of enzymatic activity. Monomer–cluster aggregation scenario was considered but was not consistent with the observed kinetic order of monomer disappearance at longer times. We analysed time evolution of the average hydrodynamic radius obtained from dynamic light scattering measurements and by fitting these data with our model, we were able to estimate the value of the unfolding equilibrium constant with a reasonable accuracy (Kc around 0.05 at 80 degrees C). We were also able to make order of magnitude estimates of the maximum number of enzyme molecules in the aggregated clusters (hundreds)as well as the aggregation rate constant of the non-native enzyme

Kinetics of Salicylic Acid Adsorption on Activated Carbon

The adsorption and desorption of salicylic acid from water solutions was investigated in HPLC microcolumns packed with activated carbon. The adsorption isotherm was obtained by the step-up frontal analysis method in a concentration range of 0-400 mg/L and was well fitted with the Langmuir equation. The investigation of rate aspects of salicylic acid adsorption was based on adsorption/desorption column experiments where different inlet concentrations of salicylic acid were applied in the adsorption phase and desorption was conducted with pure water. The concentration profiles of individual adsorption/desorption cycles data were fitted using several single-parameter models of the fixed-bed adsorption to assess the influence of different phenomena on the column behavior. It was found that the effects of axial dispersion and extraparticle mass transfer were negligible. A rate-determining factor of fixed-bed column dynamics was the kinetics of pore surface adsorption.Abimodal kinetic model reflecting the heterogeneous character of adsorbent pores was verified by a simultaneous fit of the column outlet concentration in four adsorption/ desorption cycles. The fitted parameters were the fraction of mesopores and the adsorption rate constants in micropores and mesopores, respectively. It was shown that the former rate constant was an intrinsic one whereas the latter one was an apparent value due to the effects of pore blocking and diffusional hindrances in the micropores

Progress in biocatalysis with immobilized viable whole cells: systems development, reaction engineering and applications

Viable microbial cells are important biocatalysts in the production of fine chemicals and biofuels, in environmental applications and also in emerging applications such as biosensors or medicine. Their increasing significance is driven mainly by the intensive development of high performance recombinant strains supplying multienzyme cascade reaction pathways, and by advances in preservation of the native state and stability of whole-cell biocatalysts throughout their application. In many cases, the stability and performance of whole-cell biocatalysts can be highly improved by controlled immobilization techniques. This review summarizes the current progress in the development of immobilized whole-cell biocatalysts, the immobilization methods as well as in the bioreaction engineering aspects and economical aspects of their biocatalytic applications.Scopu

CUPID pre-CDR

CUPID is a proposed future tonne-scale bolometric neutrinoless double beta decay ($0\nu\beta\beta$) experiment to probe the Majorana nature of neutrinos and discover Lepton Number Violation in the so-called inverted hierarchy region of the neutrino mass. CUPID will be built on experience, expertise and lessons learned in CUORE, and will exploit the current CUORE infrastructure as much as possible. In order to achieve its ambitious science goals, CUPID aims to dramatically reduce the backgrounds in the region of interest introducing a high efficiently $\alpha$/$\beta$ discrimination techniques, also demonstrated by the CUPID-0 and CUPID-Mo experiments, and using a high transition energy double beta decay nucleus, $^100$Mo. This document describe the main concepts related with the design of the CUPID experiment and indicates the projected sensitivities and the global scientific goal of the experiment