The Influence of Nonionic Surfactant Adsorption on Enzymatic Hydrolysis of Oil Palm Fruit Bunch

Abstract

Nonionic surfactants have been utilized to improve the enzymatic hydrolysis of lignocellulosic materials. However, the role of surfactant adsorption affecting enzymatic hydrolysis has not been elaborated well. In this work, nonionic surfactants differing in their molecular structures, namely the polyoxyethylene sorbitan monooleate (Tween 80), the secondary alcohol ethoxylate (Tergitol 15-S-9), and the branched alcohol ethoxylate (Tergitol TMN-6), were studied for their effects on the enzymatic hydrolysis of palm fruit bunch (PFB). The PFB was pretreated with a 10% w/v sodium hydroxide solution and then hydrolyzed using the cellulase enzyme from Trichoderma reesei (ATCC 26921) at 50 °C and pH 5. The optimal conditions providing similar yields of reducing sugar required Tween 80 and Tergitol TMN-6 at 0.25% w/v, while Tergitol 15-S-9 was required at 0.1% w/v. All the surfactants improved the enzymatic conversion efficiency and reduced unproductive binding of the enzyme to lignin. In addition, the adsorption isotherm of cellulase was fit well by the Freundlich isotherm, while adsorption of the three nonionic surfactants agreed well with the Langmuir isotherm. Adsorption capacities of the three nonionic surfactants were consistent with their enhancement efficiencies in hydrolysis. The critical micelle concentration was observed as a key property of nonionic surfactant for adsorption capacity.

Synergistic Enzyme Cocktail to Enhance Hydrolysis of Steam Exploded Wheat Straw at Pilot Scale

“…for its efficient hydrolysis (Loman and Ju, 2016;Lee et al, 2017;Kane and French, 2018;Sanhueza et al, 2018). Although a number of factors are responsible for lower biomass hydrolysis high cellulase crystallinity, low enzyme accessibility, non-productive enzyme-lignin binding, competitive, and feedback inhibition of the enzyme have been predominantly reported (Agrawal et al, 2015b;Parnthong et al, 2018). Thus, usually a high amount of enzyme is required to achieve high biomass hydrolysis but it negatively affects the commercial viability of the process.…”

Interplays of enzyme, substrate, and surfactant on hydrolysis of native lignocellulosic biomass

“…The addition of nonionic surfactants has been shown to promote enzymatic hydrolysis of lignocellulosic materials and increase sugar release [ 43 , 44 ]. However, this study and regression analysis suggested that the addition of Triton X-100 to enzymatic hydrolysis of untreated rice straw showed no improvement in sugar release.…”

Potential of Palm Kernel Alkanolamide Surfactant for Enhancing Oil Recovery from Sandstone Reservoir Rocks

“…From the data listed in Table 1, Tergitol TMN-6 has a higher CMC than Tergitol 15-S-9, indicating smaller micellar size. Additionally, Tergitol 15-S-9 has similar hydrocarbon chain length as PKA, but its hydrophilic moiety is larger (Parnthong et al, 2018;Wetchakul, 2013). This causes greater repulsion between Tergitol 15-S-9 head groups and decreases aggregation number as well as size of micelles.…”