Concentrating Cellulases from Fermented Broth Using a Temperature‐Sensitive Hydrogel

Abstract

A temperature‐sensitive poly(N‐isopropylacrylamide) hydrogel was used to concentrate cellulases from the fermentation broth of Trichoderma reesei. The steady‐state gel volume was less and the gel collapse temperature was lower in fermented broth compared to those in water. Upon a long (24 h) temperature swing for gel swelling, a gel with lower monomer and cross‐linker content showed a larger volume increase, and it took longer to reach a constant volume which was smaller than the steady‐state volume. Upon a long (24 h) temperature swing for gel collapsing, different gels reached the same collapsed volume in a short period of time. The largest volume increase per unit temperature decrease was obtained for a temperature swing between 28 and 33 °C. For short temperature swings (1–5 h), swollen and collapsed gel volumes were reproducible and were approximately the same as the final volumes during long (24 h) swings. Separation efficiency was higher for the gel with a smaller volume change because of higher concentrations of monomer or cross‐linking agent. When the gels were reused, separation efficiency was improved.

Structure and protein separation efficiency of poly(N-isopropylacrylamide) gels: Effect of synthesis conditions

“…Thus, depending on the heat transfer characteristics of the synthelivery, 16 immobilized-enzyme reactors, [17][18][19] and separation processes. [20][21][22][23][24][25][26] For example, when a sis molds, PNIPA gels with various structures may be obtained from the same starting monomer shrunken PNIPA gel is added to a dilute protein solution, the gel swells and absorbs water and solution. 31 Furthermore, the presence of impurities in NIPA monomer purchased from the supother small molecules; while macromolecules, such as proteins, are not absorbed.…”

Concentrating alkaline serine protease, subtilisin, using a temperature-sensitive hydrogel

“…However, the hydrogel ultrafiltration process did not appear useful for concentrating cellu!ase enzymes because separation efficiency was only 30 -40% (Park and Orozco-Avila, 1992). This study showed that enzyme separation efficiency could be increased to 84% if the gel was allowed to swell at a lower temperature of 20"C or below.…”

Concentrating aqueous solutions of water soluble polymers by thermoreversible swelling of poly[( N ‐isopropylacrylamide)‐ co ‐(acrylic acid)] hydrogels

“…solutions [4][5][6][7][8][9][10] . Concentrating such solutions is important due to the wide variety of biological and synthetic materials existing or produced as very dilute solutions.…”

“…PNIPA hydrogels are probably the most widely studied of this class of material and have previously been used for concentrating dilute aqueous solutions of soluble macromolecules 5,8,11) . However, the concentrating capacity is limited due to the low swellability of the network.…”