Issue 15, 2016

The strong association of condensed phenolic moieties in isolated lignins with their inhibition of enzymatic hydrolysis

Abstract

Residual lignin plays an inhibitory role in the enzymatic hydrolysis of cellulosic biomass. In this study, we examined the structural changes in isolated lignins from the hot water hydrothermal pretreatment of aspen and their inhibitory effects on the enzymatic hydrolysis of Avicel. The functional groups of the isolated lignins were determined using quantitative 13C, 2D HSQC and 31P NMR. The increase in pretreatment severity significantly increased the condensed and non-condensed syringyl and guaiacyl OH group content in the isolated lignins, but decreased the aliphatic OH, p-hydroxybenzoate OH and carboxylic OH group content. A compelling adverse association (r2 = 0.998) was observed between the condensed syringyl and guaiacyl phenolic OH group content in lignins and their inhibitory effects on enzymatic hydrolysis. Langmuir adsorption isotherms showed that a higher pretreatment severity resulted in a higher binding ability between the isolated lignins and the cellulase enzymes, which led to more non-productive binding. It is hypothesized that condensed syringyl and guaiacyl phenolic units are mainly responsible for the inhibitory effect of lignin on enzymatic hydrolysis, in which the condensed aromatic rings enhance the hydrophobic interactions and the phenolic OH group boosts the hydrogen bonding. The combination of hydrophobic interactions and hydrogen bonding can further intensify undesirable non-productive binding.

Graphical abstract: The strong association of condensed phenolic moieties in isolated lignins with their inhibition of enzymatic hydrolysis

Supplementary files

Article information

Article type
Paper
Submitted
09 Mar 2016
Accepted
06 May 2016
First published
06 May 2016

Green Chem., 2016,18, 4276-4286

Author version available

The strong association of condensed phenolic moieties in isolated lignins with their inhibition of enzymatic hydrolysis

S. Sun, Y. Huang, R. Sun and M. Tu, Green Chem., 2016, 18, 4276 DOI: 10.1039/C6GC00685J

To request permission to reproduce material from this article, please go to the Copyright Clearance Center request page.

If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given.

If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page.

Read more about how to correctly acknowledge RSC content.

Social activity

Spotlight

Advertisements