A mathematical model for the inhibitory effects of lignin in enzymatic hydrolysis of lignocellulosics

Strength of adsorption of polyethylene glycol on pretreated Pinus radiata wood and consequences for enzymatic saccharification

“…The curves obtained in the presence of PEG-4000 reached a plateau at 71% cellulose conversion and the best fit curve for the control data trended towards the same plateau. This limit was attributed to occlusion of pores in the substrate, so that some of the cellulose remained inaccessible to enzymes regardless of the enzyme loading or the length of the incubation time [27]. The curves for PEG-4000 loadings of 0.02 and 0.2 g g À1 substrate were coincident in Fig.…”

“…In the model used here, described in more detail elsewhere [27], enzymatic hydrolysis competes with permanent deactivation of cellulase through chemical reactions with lignin. Conversion of cellulose to glucose ceases when all cellulase enzyme cocktail has been deactivated.…”

Improved saccharification of steam-exploded Pinus radiata on supplementing crude extract of Penicillium sp.

“…SEW was produced in the steam explosion apparatus (Newman et al 2013 ). 0.75 kg chips were taken with a moisture content of 60 %, impregnated with SO 2 (3 % w/w) and heated with steam at 215 °C for 3 min.…”

Mechanisms employed by cellulase systems to gain access through the complex architecture of lignocellulosic substrates

“…It is unclear if adding these chemicals in an industrial setting would be cost effective. To account for the phenomenon of declining reaction rates Newman et al developed a mathematical model of the inhibitory effect of lignin on enzymatic hydrolysis [39]. Using three parameters (blocked cellulose, enzyme loading, and a mechanism index) and with cellulose accessibility remaining constant during the enzymatic conversion they concluded that declining reaction rates are attributed to enzyme deactivation caused by non-productive binding.…”