The effect of viscosity,friction, and sonication on the morphology and metabolite production from Aspergillus terreus ATCC 20542

Bioprocess and Biosystems Engineering - This study investigates the effects of viscosity, friction, and sonication on the morphology and the production of lovastatin, (+)-geodin, and sulochrin by...     

Stabilization of Thermolysin Induced by a Decrease in the PH and Dielectric Constant of the Reaction Medium Resulting from a Temperature Increase in Z-Phe-Phe-OMe Synthesis

Thermolysin was stabilized by increasing the reaction temperature from 90°C to 110°C during peptide synthesis of N-(benzyloxycarbonyl)-_L-phenylalanyl-_L-phenylalanine methyl ester (Z-Phe-Phe-OMe). The stabilization energy was acquired from the drop in both pH and dielectric constant due to the temperature increase. The acquired stabilization energy was as high as ca. 42 kJ/mol (corresponding to 20°C). This acquired stabilization energy did not result from a single event such as a change in electrical charges. It was evaluated as the overall stabilization energy at and around the active site area of the enzyme using an electrostatic potential equation.