Investigating the effects of substrate morphology and experimental conditions on the enzymatic hydrolysis of lignocellulosic biomass through modeling
| Autor: | Jessica C. Rohrbach, Jeremy S. Luterbacher |
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| Předmět: |
0106 biological sciences
cellulase-binding porosity bioconversion Diffusion Lignocellulosic biomass Biomass Cellulase Management Monitoring Policy and Law 01 natural sciences Applied Microbiology and Biotechnology trichoderma-reesei 03 medical and health sciences chemistry.chemical_compound TP315-360 010608 biotechnology Mass transfer mass transfer Cellulose lignocellulosic biomass 030304 developmental biology degradation 0303 health sciences cellulase biology Renewable Energy Sustainability and the Environment Research Substrate (chemistry) modeling Fuel yield inhibition General Energy chemistry Chemical engineering hydrolysis adsorption fundamentals biology.protein Particle size dilute-acid pretreatment TP248.13-248.65 Biotechnology recalcitrance |
| Zdroj: | Biotechnology for Biofuels, Vol 14, Iss 1, Pp 1-14 (2021) Biotechnology for Biofuels |
| Popis: | Background Understanding how the digestibility of lignocellulosic biomass is affected by its morphology is essential to design efficient processes for biomass deconstruction. In this study, we used a model based on a set of partial differential equations describing the evolution of the substrate morphology to investigate the interplay between experimental conditions and the physical characteristics of biomass particles as the reaction proceeds. Our model carefully considers the overall quantity of cellulase present in the hydrolysis mixture and explores its interplay with the available accessible cellulose surface. Results Exploring the effect of various experimental and structural parameters highlighted the significant role of internal mass transfer as the substrate size increases and/or the enzyme loading decreases. In such cases, diffusion of cellulases to the available cellulose surface limits the rate of glucose release. We notably see that increasing biomass loading, while keeping enzyme loading constant should be favored for both small- (R $$\mu m$$ μ m ) and middle-ranged (300 R $$\mu m$$ μ m ) substrates to enhance enzyme diffusion while minimizing the use of enzymes. In such cases, working at enzyme loadings exceeding the full coverage of the cellulose surface (i.e. eI>1) does not bring a significant benefit. For larger particles (R > 1000 $$\mu m$$ μ m ), increases in biomass loading do not offset the significant internal mass transfer limitations, but high enzyme loadings improve enzyme penetration by maintaining a high concentration gradient within the particle. We also confirm the well-known importance of cellulose accessibility, which increases with pretreatment. Conclusions Based on the developed model, we are able to propose several design criteria for deconstruction process. Importantly, we highlight the crucial role of adjusting the enzyme and biomass loading to the wood particle size and accessible cellulose surface to maintain a strong concentration gradient, while avoiding unnecessary excess in cellulase loading. Theory-based approaches that explicitly consider the entire lignocellulose particle structure can be used to clearly identify the relative importance of bottlenecks during the biomass deconstruction process, and serve as a framework to build on more detailed cellulase mechanisms. |
| Databáze: | OpenAIRE |
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