Selectivity and Sustainability of Electroenzymatic Process for Glucose Conversion to Gluconic Acid

Electroenzymatic processes are interesting solutions for the development of new processes based on renewable feedstocks, renewable energies, and green catalysts. High-selectivity and sustainability of these processes are usually assumed. In this contribution, these two aspects were studied in more detail. In a membrane-less electroenzymatic reactor, 97% product selectivity at 80% glucose conversion to gluconic acid was determined. With the help of nuclear magnetic resonance spectroscopy, two main side products were identified. The yields of D-arabinose and formic acid can be controlled by the flow rate and the electroenzymatic reactor mode of operation (fuel cell or ion-pumping). The possible pathways for the side product formation have been discussed. The electroenzymatic cathode was found to be responsible for a decrease in selectivity. The choice of the enzymatic catalyst on the cathode side led to 100% selectivity of gluconic acid at somewhat reduced conversion. Furthermore, sustainability of the electroenzymatic process is estimated based on several sustainability indicators. Although some indicators (like Space Time Yield) are favorable for electroenzymatic process, the E-factor of electroenzymatic process has to improve significantly in order to compete with the fermentation process. This can be achieved by an increase of a cycle time and/or enzyme utilization which is currently low.

An off/on thrombin activated energy driven molecular machine for sensitive detection of human thrombin via non-enzymatic catalyst recycling amplification

A novel dual signal on/off amplification strategy by integrating thrombin mediated strand displacement reaction and non-enzyme catalyst recycling DNA machine.

Esterification of acetic acid with alcohol isoamyl in the presence of enzymatic catalyst

The Candida antarctica Lipase B immobilized on polyurethane catalysed esterification of acetic acid with isoamyl alcohol in mechanical and ultrasonic system in a system solvent-free, was studied. The maximum esterification of isoamyl acetate used immobilized catalyst was the highest esterification, 666.05 U/g with 19 cycles of reuse after 360 minutes of reaction time in mechanical system and 1319.48 U/g was observed and 14 cycles de reuse after 60 minutes of reaction time in ultrasound system. Thus, the process was considered efficient with significant reduction of the reaction time, low instrumental requirements and improve the bioprocess performance. Until now, there were no studies available in the open literature in relation to the ester synthesis catalyzed by immobilized Lipase in polyurethane as support in the ultrasound system. In addition, considered an environmentally correct and economically viable technology, it can be used in cosmetics, pharmaceuticals and food industry.

Renewable boronic acid affiliated glycerol nano-adsorbents for recycling enzymatic catalyst in biodiesel fuel production

Renewable boronic acid affiliated silica nanoparticles exhibit pH-responsive glycerol adsorption/release behavior to recycle free lipases in biodiesel production.