Effects of NIPAm polymer additives on the enzymatic hydrolysis of Avicel and pretreated Miscanthus

Abstract

There is currently much interest in the economic use of cellulosic biomass as a source of renewable fuels. This process typically involves the enzymatic hydrolysis of plant matter to afford soluble sugars for subsequent fermentation steps. The cost of cellulase enzymes presents a critical barrier to the commercialization of these processes. In this work, we demonstrate that a new family of polymer additives based on NIPAm can increase enzyme performance substantially. When applied to an industrially relevant combination of enzymes and lignin-containing biomass, polymer additives allow a 60% reduction in enzyme loading to achieve the same level of saccharification. Evidence presented herein suggests that these polymers function through multiple mechanisms, including (1) preventing enzyme denaturation through shear and interfacial interactions, (2) preventing non-productive adsorption to lignin, and (3) altering the cellulose structure. An advantage of these polymers over other additives is their thermoresponsive behavior, enabling their recovery and reuse.

Benefits from additives and xylanase during enzymatic hydrolysis of bamboo shoot and mature bamboo

“…The dosage of xylanase (XYL) was 1 mg/g DM. The dosage of additives (BSA, PEG 6000, and Tween 80) was 250 mg/g DM as recommended by many authors (Eriksson et al, 2002;Börjesson et al, 2007;Mackenzie and Francis, 2014). Samples were withdrawn at 48 h and boiled for 10 min to stop the enzymatic hydrolysis.…”

Immobilization of cellulase onto a recyclable thermo-responsive polymer as bioconjugate

“…A commercial crude cellulase (Novozymes) from Trichoderma reesei was used as experimental material. The thermo-responsive polymer was designed to have an LCST value above the optimum activity of cellulase which is around 50 • C. However, common thermo-responsive polymers such as poly(N-isopropylacrylamide) and poly(N-vinylcaprolactam) have LCST values between 30.0 • C and 35.0 • C [18][19][20][21][22]. These polymers would be aggregated or precipitated at the desired cellulose degradation temperature hence http://dx.doi.org/10.1016/j.molcatb.2016.03.007 1381-1177/© 2016 Elsevier B.V. All rights reserved.…”

Polymer Conjugation to Enhance Cellulase Activity and Preserve Thermal and Functional Stability

“…Here, the thermophilic cellulase Fn Cel5a is modified with synthetic polymers using a GT approach to influence and enhance its enzymatic activity and potential for use in biofuels. In the literature, limited studies have been performed on cellulase polymer conjugates, , and to the best of our knowledge, no systematic study of how polymer functionality affects cellulase activity and stability has been performed. The work herein creates a library of polymers of comparable molecular weight and varied functionality synthesized by RAFT and grafted to Fn Cel5a.…”