A mechanistically based kinetic model for the enzymatic hydrolysis of cellulosic biomass has been developed that incorporates the distinct modes of action of cellulases on insoluble cellulose polymer chains. Cellulose depolymerization by an endoglucanase (endoglucanase I, EG(I) ) and an exoglucanase (cellobiohydrolase I, CBH(I)) is modeled using population-balance equations, which provide a kinetic description of the evolution of a polydisperse distribution of chain lengths. The cellulose substrate is assumed to have enzyme-accessible chains and inaccessible interior chains. EG(I) is assumed to randomly cleave insoluble cellulose chains. For CBH(I), distinct steps for adsorption, complexation, processive hydrolysis, and desorption are included in the mechanistic description. Population-balance models that employ continuous distributions track the evolution of the spectrum of chain lengths, and do not require solving equations for all chemical species present in the reacting mixture, resulting in computationally efficient simulations. The theoretical and mathematical development needed to describe the hydrolysis of insoluble cellulose chains embedded in a solid particle by EG(I) and CBH(I) is given in this article (Part I). Results for the time evolution of the distribution of chain sizes are provided for independent and combined enzyme hydrolysis. A companion article (Part II) incorporates this modeling framework to study cellulose conversion processes, specifically, solution kinetics, enzyme inhibition, and cooperative enzymatic action.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1002/bit.23355 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Cecal microbial composition and serum concentration of short-chain fatty acids in laying hens fed different fiber sources.
Braz J Microbiol
January 2025
Department of Animal Science, Veterinary School, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil.
The intestinal microbiota is widely recognized as an integral factor in host health, metabolism, and immunity. In this study, the impact of dietary fiber sources on the intestinal microbiota and the production of short-chain fatty acids (SCFAs) was evaluated in Lohmann White laying hens. The hens were divided into four treatment groups: a control diet without fiber, a diet with wheat bran (mixed fibers), a diet with insoluble fiber (cellulose), and a diet with soluble fiber (pectin), with six replicates of four hens each.
View Article and Find Full Text PDFSustainable Lipase Immobilization: Chokeberry and Apple Waste as Carriers.
Biomolecules
December 2024
Department of Chemistry, Institute of Food Sciences, Warsaw University of Life Sciences-SGGW (WULS-SGGW), 159c Nowoursynowska St., 02-776 Warsaw, Poland.
In the modern world, the principles of the bioeconomy are becoming increasingly important. Recycling and reusability play a crucial role in sustainable development. Green chemistry is based on enzymes, but immobilized biocatalysts are still often designed with synthetic polymers.
View Article and Find Full Text PDFIsolation and characterization of cellulose-mineralizing haloalkaliphilic bacteria from Siberian soda lakes.
Front Microbiol
December 2024
Winogradsky Institute of Microbiology, Federal Research Centre of Biotechnology, Russian Academy of Sciences, Moscow, Russia.
Soda lakes are unique double-extreme habitats characterized by high salinity and soluble carbonate alkalinity, yet harboring rich prokaryotic life. Despite intensive microbiology studies, little is known about the identity of the soda lake hydrolytic bacteria responsible for the primary degradation of the biomass organic matter, in particular cellulose. In this study, aerobic and anaerobic enrichment cultures with three forms of native insoluble cellulose inoculated with sediments from five soda lakes in south-western Siberia resulted in the isolation of four cellulotrophic haloalkaliphilic bacteria and their four saccharolytic satellites.
View Article and Find Full Text PDFThe Effect of Accessibility of Insoluble Substrate on the Overall Kinetics of Enzymatic Degradation.
Biotechnol Bioeng
January 2025
Institute of Biotechnology and Biochemical Engineering, Graz University of Technology, Graz, Austria.
The enzymatic reaction kinetics on cellulose and other solid substrates is limited by the access of the enzyme to the reactive substrate sites. We introduce a general model in which the reaction rate is determined by the active surface area, and the resulting kinetics consequently reflects the evolving relationship between the exposed substrate surface and the remaining substrate volume. Two factors influencing the overall surface-to-volume ratio are considered: the shape of the substrate particles, characterized by a single numerical parameter related to its dimensionality, and the distribution of the particle sizes.
View Article and Find Full Text PDFAre cellulases slow? Kinetic and thermodynamic limitations for enzymatic breakdown of cellulose.
BBA Adv
December 2024
Novonesis, 2 Biologiens Vej, DK-2800 Lyngby Denmark.
Cellulases are of paramount interest for upcoming biorefineries that utilize residue from agriculture and forestry to produce sustainable fuels and chemicals. Specifically, cellulases are used for the conversion of recalcitrant plant biomass to fermentable sugars in a so-called saccharification process. The vast literature on enzymatic saccharification frequently refers to low catalytic rates of cellulases as a main bottleneck for industrial implementation, but such statements are rarely supported by kinetic or thermodynamic considerations.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!