Recovery and partial purification of thermophilic β-xylosidase derived from recombinant Bacillus megaterium

A polymer–salt-based aqueous two-phase system (ATPS) was developed for the effective extraction and purification of extracellular β-xylosidase from the fermentation broth of recombinant Bacillus megaterium MS941. The effect of molecular weight (MW) of polyethylene glycol (PEG), tie-line length (TLL), volume ratio (VR), crude loading and pH on the recovery performance was evaluated. Under the optimal extraction conditions, β-xylosidase was successfully purified up to 23-fold with a recovery yield of 99% in the bottom salt-rich phase at PEG 4,000/potassium phosphate ATPS comprising TLL of 41.8, VR of 2.3, crude loading (CL) of 30% (w/w) at pH 6

New combined kinetic and thermodynamic approach to model glucose-6-phosphate dehydrogenase activity and stability

G6PD from S. cerevisiae was partitioned in this work by a reverse micellar system containing SL in isooctane and hexanol, using some significant variations with respect to the standard extraction procedure to improve the yield. The influence of the extraction process on the kinetic and thermodynamic properties of this enzyme was investigated, since these parameters can provide useful information about the activity of S. cerevisiae pentose phosphate pathway and the biosynthesis of several physiologically important biomolecules. To this purpose a new modeling approach combining kinetic and thermodynamic parameters of both enzyme activity and thermal inactivation was proposed, which gave more reliable results than previous attempts