Study of the Difference between Enzyme Adsorption onto Hydrotropic and Alkali Lignin Separated from Eucalyptus and Bamboo

Hongyan Mou, Shubin Wu, Mengyun He, Hao Liu, Hongquan Huang, Chaochao Xu

Abstract


Enzymatic hydrolysis of lignocellulosic biomass is the key step for controlling the cost of bioethanol production. However, the non-productive adsorption of cellulase onto lignin in biomass severely hampers the enzyme activity and hydrolysis efficiency. Thus, understanding the adsorption mechanism of cellulase onto lignin is critical for the development of enzyme mixtures and enzymatic hydrolysis. In this investigation, cellulase, β-glucosidase (BG), and xylanase adsorption onto lignin from eucalyptus and bamboo, extracted by alkali and hydrotropic techniques, were compared. The physico-chemical properties of the four types of isolated lignin were detected. Langmuir isotherms were used to interpret the cellulase adsorption kinetics of the lignin. The hydrophobicity was found to be the major factor that affected the cellulase adsorption affinity of lignin. The surface charge was important for the adsorption of BG and xylanase onto the lignin. A comparison was made between hydrotropic and alkali lignin, and the hydrotropic lignin from eucalyptus had the highest cellulase adsorption capacity and lowest BG and xylanase adsorption capacities.

Keywords


Alkali lignin; Hydrotropic lignin; Cellulase; Xylanase; β-glucosidase; Adsorption interaction

Full Text: PDF

Welcome to BioResources! This online, peer-reviewed journal is devoted to the science and engineering of biomaterials and chemicals from lignocellulosic sources for new end uses and new capabilities. The editors of BioResources would be very happy to assist you during the process of submitting or reviewing articles. Please note that logging in is required in order to submit or review articles. Martin A. Hubbe, (919) 513-3022, hubbe@ncsu.edu; Lucian A. Lucia, (919) 515-7707, lucian.lucia@gmail.com URLs: bioresourcesjournal.com; http://ncsu.edu/bioresources ISSN: 1930-2126