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Timoumi A, Nguyen TC, Le T, Kraiem H, Cescut J, Anne-Archard D, Gorret N, Molina-Jouve C, To KA, Fillaudeau L. Comparison of methods to explore the morphology and granulometry of biological particles with complex shapes: Interpretation and limitations. POWDER TECHNOL 2022. [DOI: 10.1016/j.powtec.2022.118067] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Digaitis R, Thybring EE, Thygesen LG. Investigating the role of mechanics in lignocellulosic biomass degradation during hydrolysis: Part II. Biotechnol Prog 2020; 37:e3083. [PMID: 32935452 PMCID: PMC7988658 DOI: 10.1002/btpr.3083] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2020] [Revised: 07/28/2020] [Accepted: 09/14/2020] [Indexed: 11/29/2022]
Abstract
Lignocellulose breakdown in biorefineries is facilitated by enzymes and physical forces. Enzymes degrade and solubilize accessible lignocellulosic polymers, primarily on fiber surfaces, and make fibers physically weaker. Meanwhile physical forces acting during mechanical agitation induce tearing and cause rupture and attrition of the fibers, leading to liquefaction, that is, a less viscous hydrolysate that can be further processed in industrial settings. This study aims at understanding how mechanical agitation during enzymatic saccharification can be used to promote fiber attrition. The effects of reaction conditions, such as substrate and enzyme concentration on fiber attrition rate and hydrolysis yield were investigated. To gain insight into the fiber attrition mechanism, enzymatic hydrolysis was compared to hydrolysis by use of hydrochloric acid. Results show that fiber attrition depends on several factors concerning reactor design and operation including drum diameter, rotational speed, mixing schedule, and concentrations of fibers and enzymes. Surprisingly, different fiber attrition patterns during enzymatic and acid hydrolysis were found for similar mixing schedules. Specifically, for tumbling mixing, slow continuous mixing appears to function better than faster, intermittent mixing even for the same total number of drum revolutions. The findings indicate that reactor design and operation as well as hydrolysis conditions are key to process optimization and that detailed insights are needed to obtain fast liquefaction without sacrificing saccharification yields.
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Affiliation(s)
- Ramūnas Digaitis
- Department of Geosciences and Natural Resource Management, Faculty of Science, University of Copenhagen, Frederiksberg C, Denmark.,Biofilms Research Center for Biointerfaces, Malmö University, Malmö, Sweden
| | - Emil Engelund Thybring
- Department of Geosciences and Natural Resource Management, Faculty of Science, University of Copenhagen, Frederiksberg C, Denmark
| | - Lisbeth Garbrecht Thygesen
- Department of Geosciences and Natural Resource Management, Faculty of Science, University of Copenhagen, Frederiksberg C, Denmark
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Gaikwad A. Interactions of mixing and reaction kinetics of depolymerization of cellulose to renewable fuels. CHEM ENG COMMUN 2017. [DOI: 10.1080/00986445.2017.1371015] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Affiliation(s)
- Ashwin Gaikwad
- Department of Chemical Engineering, Visvesvaraya National Institute of Technology, Nagpur, India
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Cardona MJ, Tozzi EJ, Karuna N, Jeoh T, Powell RL, McCarthy MJ. A process for energy-efficient high-solids fed-batch enzymatic liquefaction of cellulosic biomass. BIORESOURCE TECHNOLOGY 2015; 198:488-496. [PMID: 26432053 DOI: 10.1016/j.biortech.2015.09.042] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/05/2015] [Revised: 09/04/2015] [Accepted: 09/05/2015] [Indexed: 06/05/2023]
Abstract
The enzymatic hydrolysis of cellulosic biomass is a key step in the biochemical production of fuels and chemicals. Economically feasible large-scale implementation of the process requires operation at high solids loadings, i.e., biomass concentrations >15% (w/w). At increasing solids loadings, however, biomass forms a high viscosity slurry that becomes increasingly challenging to mix and severely mass transfer limited, which limits further addition of solids. To overcome these limitations, we developed a fed-batch process controlled by the yield stress and its changes during liquefaction of the reaction mixture. The process control relies on an in-line, non-invasive magnetic resonance imaging (MRI) rheometer to monitor real-time evolution of yield stress during liquefaction. Additionally, we demonstrate that timing of enzyme addition relative to biomass addition influences process efficiency, and the upper limit of solids loading is ultimately limited by end-product inhibition as soluble glucose and cellobiose accumulate in the liquid phase.
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Affiliation(s)
- M J Cardona
- Department of Chemical Engineering and Materials Science, University of California, Davis, One Shields Ave, Davis, CA 95616, USA
| | - E J Tozzi
- Aspect Imaging, One Shields Ave, Davis, CA 95616, USA
| | - N Karuna
- Department of Biological and Agricultural Engineering, University of California, Davis, One Shields Ave, Davis, CA 95616, USA
| | - T Jeoh
- Department of Biological and Agricultural Engineering, University of California, Davis, One Shields Ave, Davis, CA 95616, USA.
| | - R L Powell
- Department of Chemical Engineering and Materials Science, University of California, Davis, One Shields Ave, Davis, CA 95616, USA; Department of Food Science and Technology, University of California, Davis, One Shields Ave, Davis, CA 95616, USA
| | - M J McCarthy
- Department of Biological and Agricultural Engineering, University of California, Davis, One Shields Ave, Davis, CA 95616, USA; Department of Food Science and Technology, University of California, Davis, One Shields Ave, Davis, CA 95616, USA
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Rheology of Lignocellulose Suspensions and Impact of Hydrolysis: A Review. ADVANCES IN BIOCHEMICAL ENGINEERING/BIOTECHNOLOGY 2015; 149:325-57. [PMID: 25786712 DOI: 10.1007/10_2015_323] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
Abstract
White biotechnologies have several challenges to overcome in order to become a viable industrial process. Achieving highly concentrated lignocellulose materials and releasing fermentable substrates, with controlled kinetics in order to regulate micro-organism activity, present major technical and scientific bottlenecks. The degradation of the main polymeric fractions of lignocellulose into simpler molecules is a prerequisite for an integrated utilisation of this resource in a biorefinery concept. The characterisation methods and the observations developed for rheology, morphology, etc., that are reviewed here are strongly dependent on the fibrous nature of lignocellulose, are thus similar or constitute a good approach to filamentous culture broths. This review focuses on scientific works related to the study of the rheological behaviour of lignocellulose suspensions and their evolution during biocatalysis. In order to produce the targeted molecules (synthon), the lignocellulose substrates are converted by enzymatic degradation and are then metabolised by micro-organisms. The dynamics of the mechanisms is limited by coupled phenomena between flow, heat and mass transfers in regard to diffusion (within solid and liquid phases), convection (mixing, transfer coefficients, homogeneity) and specific inhibitors (concentration gradients). As lignocellulose suspensions consist of long entangled fibres for the matrix of industrial interest, they exhibit diverse and complex properties linked to this fibrous character (rheological, morphological, thermal, mechanical and biochemical parameters). Among the main variables to be studied, the rheological behaviour of such suspensions appears to be determinant for process efficiency. It is this behaviour that will determine the equipment to be used and the strategies applied (substrate and biocatalysis feed, mixing, etc.). This review provides an overview of (i) the rheological behaviour of fibrous materials in suspension, (ii) the methods and experimental conditions for their measurements, (iii) the main models used and (iv) their evolution during biocatalytic reactions with a focus on enzymatic hydrolysis.
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Gourlay K, Hu J, Arantes V, Penttilä M, Saddler JN. The use of carbohydrate binding modules (CBMs) to monitor changes in fragmentation and cellulose fiber surface morphology during cellulase- and Swollenin-induced deconstruction of lignocellulosic substrates. J Biol Chem 2014; 290:2938-45. [PMID: 25527502 DOI: 10.1074/jbc.m114.627604] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
Although the actions of many of the hydrolytic enzymes involved in cellulose hydrolysis are relatively well understood, the contributions that amorphogenesis-inducing proteins might contribute to cellulose deconstruction are still relatively undefined. Earlier work has shown that disruptive proteins, such as the non-hydrolytic non-oxidative protein Swollenin, can open up and disaggregate the less-ordered regions of lignocellulosic substrates. Within the cellulosic fraction, relatively disordered, amorphous regions known as dislocations are known to occur along the length of the fibers. It was postulated that Swollenin might act synergistically with hydrolytic enzymes to initiate biomass deconstruction within these dislocation regions. Carbohydrate binding modules (CBMs) that preferentially bind to cellulosic substructures were fluorescently labeled. They were imaged, using confocal microscopy, to assess the distribution of crystalline and amorphous cellulose at the fiber surface, as well as to track changes in surface morphology over the course of enzymatic hydrolysis and fiber fragmentation. Swollenin was shown to promote targeted disruption of the cellulosic structure at fiber dislocations.
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Affiliation(s)
- Keith Gourlay
- From the Forest Products Biotechnology/Bioenergy Group, Department of Wood Science, Faculty of Forestry, University of British Columbia, Vancouver, British Columbia V6T 1Z4, Canada and
| | - Jinguang Hu
- From the Forest Products Biotechnology/Bioenergy Group, Department of Wood Science, Faculty of Forestry, University of British Columbia, Vancouver, British Columbia V6T 1Z4, Canada and
| | - Valdeir Arantes
- From the Forest Products Biotechnology/Bioenergy Group, Department of Wood Science, Faculty of Forestry, University of British Columbia, Vancouver, British Columbia V6T 1Z4, Canada and
| | - Merja Penttilä
- the VTT Technical Research Centre of Finland, Metallimiehenkuja 2 (Espoo), FI-02044 VTT, Finland
| | - Jack N Saddler
- From the Forest Products Biotechnology/Bioenergy Group, Department of Wood Science, Faculty of Forestry, University of British Columbia, Vancouver, British Columbia V6T 1Z4, Canada and
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