Kolby Hirth - Academia.edu (original) (raw)

Papers by Kolby Hirth

ACS Applied Materials & Interfaces, Mar 19, 2015

The role of ions in the fungal decay process of lignocellulose biomaterials, and more broadly fun... more The role of ions in the fungal decay process of lignocellulose biomaterials, and more broadly fungal metabolism, has implications for diverse research disciplines ranging from plant pathology and forest ecology, to carbon sequestration. Despite the importance of ions in fungal decay mechanisms, the spatial distribution and quantification of ions in lignocellulosic cell walls and fungal hyphae during decay is not known. Here we employ synchrotron-based X-ray fluorescence microscopy (XFM) to map and quantify physiologically relevant ions, such as K, Ca, Mn, Fe, and Zn, in wood being decayed by the model brown rot fungus Serpula lacrymans. Two-dimensional XFM maps were obtained to study the ion spatial distributions from mm to submicron length scales in wood, fungal hyphae with the dried extracellular matrix (ECM) from the fungus, and Ca oxalate crystals. Three-dimensional ion volume reconstructions were also acquired of wood cell walls and hyphae with ECM. Results show that the fungus actively transports some ions, such as Fe, into the wood and controls the distribution of ions at both the bulk wood and cell wall length scales. These measurements provide new insights into the movement of ions during decay and illustrate how synchrotron-based XFM is uniquely suited study these ions. Understanding the role of ions in fungal degradation of woody biomass is salient to a wide range of research disciplines including carbon sequestration 1,2 , forest ecology 3,4 , plant pathology 5 , biorefinery 6,7 , basic fungal physiology 8 , and the durability and utility of wood in structural applications 9-13. It is estimated that 10% of the lumber harvested each year is used to replace in-service wood that has been attacked by decay fungi 14. Nearly all structural lumber in the northern hemisphere is comprised of softwoods (conifers, gymnosperms); these wood species are especially susceptible to attack from brown rot fungi. Ion transport related to biomimicry of brown rot is also of particular interest in developments to improve the efficiency of processing biomass for platform chemical production 6,7. Brown rot is a specialized mode of wood decay employed by approximately 6% of the species of wood rotting fungi. Mechanisms of brown rot are not fully understood, but have been shown to involve a complex sequence of reactions including mediated redox chemistry, chelation and reduction of metals, and acidification of the substrate 15,16. The goal of this

Applied Biochemistry and Biotechnology, Nov 13, 2020

Biocatalysis using molecular oxygen as the electron acceptor has significant potential for select... more Biocatalysis using molecular oxygen as the electron acceptor has significant potential for selective oxidations at low cost. However, oxygen is poorly soluble in water, and its slow rate of mass transfer in the aqueous phase is a major obstacle, even for laboratory-scale syntheses. Oxygen transfer can be accelerated by vigorous mechanical methods, but these are often incompatible with biological catalysts. Gentler conditions can be achieved with shallow, high surface area bag reactors that are designed for single use and generally for specialized cell culture applications. As a less-expensive alternative to these high-end bioreactors, we describe repurposing inflatable shipping pillows with resealable valves to provide high surface area mixing under oxygen for preparative synthesis of glucosone (Darabino-hexos-2-ulose) from D-glucose using non-growing Escherichia coli whole cells containing recombinant pyranose 2-oxidase (POX) as catalyst. Parallel reactions permitted systematic study of the effects of headspace composition (i.e., air vs 100% oxygen), cell density, exogenous catalase, and reaction volume in the oxidation of 10% glucose. Importantly, only a single charge of 100% oxygen is required for stoichiometric conversion on a multi-gram scale in 18 h with resting cells, and the conversion was successfully repeated with recycled cells.

the yield and characteristics of wood cellulose nanocrystals (CNC) using concentrated acid hydrol... more the yield and characteristics of wood cellulose nanocrystals (CNC) using concentrated acid hydrolysis

Cellulose, 2021

Properties of cellulose nanocrystals (CNCs) depend upon their supramolecular structures, which ar... more Properties of cellulose nanocrystals (CNCs) depend upon their supramolecular structures, which are important to understand in order to optimize their applications. In this investigation, the structures of CNCs produced upon 48-64% H 2 SO 4 hydrolysis of hydrothermally-treated poplar, bleached kraft pulp, Electronic supplementary material The online version of this article (

Applied Biochemistry and Biotechnology, 2020

Biocatalysis using molecular oxygen as the electron acceptor has significant potential for select... more Biocatalysis using molecular oxygen as the electron acceptor has significant potential for selective oxidations at low cost. However, oxygen is poorly soluble in water, and its slow rate of mass transfer in the aqueous phase is a major obstacle, even for laboratory-scale syntheses. Oxygen transfer can be accelerated by vigorous mechanical methods, but these are often incompatible with biological catalysts. Gentler conditions can be achieved with shallow, high surface area bag reactors that are designed for single use and generally for specialized cell culture applications. As a less-expensive alternative to these high-end bioreactors, we describe repurposing inflatable shipping pillows with resealable valves to provide high surface area mixing under oxygen for preparative synthesis of glucosone (D-arabino-hexos-2-ulose) from D-glucose using non-growing Escherichia coli whole cells containing recombinant pyranose 2-oxidase (POX) as catalyst. Parallel reactions permitted systematic st...

Wood and Fiber Science, 2019

This article reports on the development of accelerated laboratory methods to allow estimation of ... more This article reports on the development of accelerated laboratory methods to allow estimation of preservative leaching from pressure-treated wood exposed to precipitation. End-matched lumber specimens were pressure-treated with a boron-copper formulation and exposed to natural weathering for 1 yr, laboratory immersion protocols, or a laboratory-simulated rainfall protocol. The rainfall runoff or immersion water was collected at intervals according to the method used and analyzed for concentrations of copper and boron. Of the laboratory methods evaluated, the simulated rainfall approach resulted in leaching patterns most similar to outdoor exposure, especially in the case of copper. However, this method is relatively complex and not ideally suited for standardized use. Although the immersion methods evaluated initially exaggerated leaching, reasonable approximations of leaching from 1 yr of natural weathering were achieved with accelerated testing. Models were developed to relate hours of immersion to millimeters of precipitation, and used to evaluate how well the immersion methods might predict leaching from natural weathering over many years of exposure. One of the methods produced boron and copper leaching estimates that were within 15% and 7%, respectively, of losses predicted for wood exposed to 5 yr of natural weathering. The results indicate that laboratory immersion methods have value in estimating long-term preservative leaching from treated wood products exposed to precipitation.

An extractive compound with a novel ring system was isolated from the wood of Salix alba and was ... more An extractive compound with a novel ring system was isolated from the wood of Salix alba and was given the name Salucci. The compound was primarily identified from the 1D NMR, 2D NMR and LC-MSMS data and the structure investigated through reactions and derivatizations.

Applied and environmental microbiology, Mar 14, 2024

Journal of Cleaner Production

The mechanisms by which chemical modifications, specifically acetylation, improve the decay resis... more The mechanisms by which chemical modifications, specifically acetylation, improve the decay resistance of wood are a topic of active research. In the early stages of decay, fungi secrete lowmolecular-weight oxidants or oxidant precursors. These oxidants diffuse through the wet wood cell wall and oxidize cell wall polymers, which enable the decay process to proceed. One hypothesis states that acetylation stops decay by dramatically inhibiting the diffusion of these oxidants through the cell wall (Zeiinka et. al. 2016). Data showing a drastic difference in Fe uptake from solution between control and acetylated wood appear to support this (Hoseinipour and Mai 2016).

An extractive compound with a novel ring system was isolated from the wood of Salix alba and was ... more An extractive compound with a novel ring system was isolated from the wood of Salix alba and was given the name Salucci. The compound was primarily identified from the 1D NMR, 2D NMR and LC-MSMS data and the structure investigated through reactions and derivatizations. INTRODUCTION The fractions extractable from wood with organic solvents are generally very complex mixtures of numerous compounds of various types, none of which amounts to much more than 5% of the total fraction. Upon examination of the acetone extract of Salix species we have made the unanticipated discovery of the presence of a single compound that accounts for about 60% of the total extractive content and from 5-6% of the weight of the airdried wood. Furthermore, upon extraction of the knotty part of the wood, up to 95% of the acetone extractives consisted of this single compound. NMR examination of the compound was not consistent with any of the Salix extractives reported in the literature. Furthermore, the compou...

Wood and Fiber Science, 2017

Current standardized methods are not well-suited for estimating in-service preservative leaching ... more Current standardized methods are not well-suited for estimating in-service preservative leaching from treated wood products. This study compared several alternative leaching methods to a commonly used standard method, and to leaching under natural exposure conditions. Small blocks or lumber specimens were pressure treated with a wood preservative containing borax and copper hydroxide. The specimens were leached using scenarios involving short periods of immersion, simulated rainfall, or to a longer period of outdoor exposure to natural precipitation. When compared with lumber specimens exposed to natural precipitation, leaching from immersed small blocks overestimated losses of both copper and of boron, whereas immersion of lumber specimens underestimated losses of copper. Stirring during immersion, which is required by some standard methods, did not affect leaching. Simulated rainfall most closely simulated leaching during outdoor exposure, but is relatively complex and may be diff...

Wood and Fiber Science, 2017

Current standardized methods are not well-suited for estimating in-service preservative leaching ... more Current standardized methods are not well-suited for estimating in-service preservative leaching from treated wood products. This study compared several alternative leaching methods to a commonly used standard method, and to leaching under natural exposure conditions. Small blocks or lumber specimens were pressure treated with a wood preservative containing borax and copper hydroxide. The specimens were leached using scenarios involving short periods of immersion, simulated rainfall, or to a longer period of outdoor exposure to natural precipitation. When compared with lumber specimens exposed to natural precipitation, leaching from immersed small blocks overestimated losses of both copper and of boron, whereas immersion of lumber specimens underestimated losses of copper. Stirring during immersion, which is required by some standard methods, did not affect leaching. Simulated rainfall most closely simulated leaching during outdoor exposure, but is relatively complex and may be diff...

GCB Bioenergy, 2021

Wheat straw was rapidly fractionated using maleic acid (MA) as an acid hydrotrope at atmospheric ... more Wheat straw was rapidly fractionated using maleic acid (MA) as an acid hydrotrope at atmospheric pressure under a range of conditions. MA hydrotropic fractionation (MAHF) was very selective in dissolving lignin and hemicelluloses resulting in a cellulose‐rich water insoluble solids (WIS), which was evaluated for producing fibers through bleaching and cellulosic nanofibrils by fibrillation, as well as glucose through enzymatic saccharification. The residual lignin (RL) within the WIS has a low degree of condensation, which eased bleaching. The RL was also carboxylated through MAHF, which facilitated nanofibrillation to produce lignin‐containing cellulose nanofibrils. The carboxylation also aided enzymatic saccharification of WIS by decreasing nonproductive cellulase binding to RL through electrostatic repulsion between carboxylated (charged) RL and the cellulase at elevated pH (>cellulase isoelectric point). The dissolved lignin (DL) from MAHF also has a low degree of condensation...

ChemSusChem, 2020

This study reports on a comparative study of acid hydrotropic fractionation (AHF) of birch wood u... more This study reports on a comparative study of acid hydrotropic fractionation (AHF) of birch wood using maleic acid (MA) and p‐toluenesulfonic acid (p‐TsOH). Under the same level of delignification, lignin dissolved by MA is much less condensed with a higher content of ether aryl β‐O‐4 linkages. Lignin depolymerization dominated in MA hydrotropic fractionation (MAHF) and resulted in a single lower molecular weight peak, in contrast to the competitive depolymerization and repolymerization in p‐TsOH AHF with a bimodal distribution. The less condensed MA‐dissolved lignin facilitated catalytic conversion to monophenols. Carboxylation of residual lignin in fractionated cellulosic water‐insoluble solids (WISs) enhanced enzymatic saccharification by decreasing nonproductive cellulase binding to lignin. At a low cellulase loading of 10 FPU g−1 glucan, saccharification of WIS‐MT120 from MAHF at 120 °C was 95 % compared with 48 % for WIS‐PT85 from p‐TsOH AHF at 85 °C under the same level of del...

Forests, 2020

Acetylation is widely used as a wood modification process that protects wood from fungal decay. T... more Acetylation is widely used as a wood modification process that protects wood from fungal decay. The mechanisms by which acetylation protects wood are not fully understood. With these experiments, we expand upon the literature and test whether previously observed differences in iron uptake by wood were a result of decreased iron binding capacity or slower diffusion. We measured the concentration of iron in 2 mm thick wood sections at 0, 10, and 20% acetylation as a function of time after exposure to iron solutions. The iron was introduced either strongly chelated with oxalate or weakly chelated with acetate. The concentrations of iron and oxalate in solution were chosen to be similar to those found during brown rot decay, while the concentration of iron and acetate matched previous work. The iron content of oxalate-exposed wood increased only slightly and was complete within an hour, suggesting little absorption and fast diffusion, or only slight surface adsorption. The increase in i...

Industrial Crops and Products, 2021

Green Chemistry, 2020

Maleic acid for wood fractionation at atmospheric pressure to result in carboxylated lignin with ... more Maleic acid for wood fractionation at atmospheric pressure to result in carboxylated lignin with minimal condensation, light color, and to facilitate processing of fractionated solids. 2D 1H–13C HQSC and HMBC analyses confirmed lignin esterification.

ACS Applied Materials & Interfaces, Mar 19, 2015

The role of ions in the fungal decay process of lignocellulose biomaterials, and more broadly fun... more The role of ions in the fungal decay process of lignocellulose biomaterials, and more broadly fungal metabolism, has implications for diverse research disciplines ranging from plant pathology and forest ecology, to carbon sequestration. Despite the importance of ions in fungal decay mechanisms, the spatial distribution and quantification of ions in lignocellulosic cell walls and fungal hyphae during decay is not known. Here we employ synchrotron-based X-ray fluorescence microscopy (XFM) to map and quantify physiologically relevant ions, such as K, Ca, Mn, Fe, and Zn, in wood being decayed by the model brown rot fungus Serpula lacrymans. Two-dimensional XFM maps were obtained to study the ion spatial distributions from mm to submicron length scales in wood, fungal hyphae with the dried extracellular matrix (ECM) from the fungus, and Ca oxalate crystals. Three-dimensional ion volume reconstructions were also acquired of wood cell walls and hyphae with ECM. Results show that the fungus actively transports some ions, such as Fe, into the wood and controls the distribution of ions at both the bulk wood and cell wall length scales. These measurements provide new insights into the movement of ions during decay and illustrate how synchrotron-based XFM is uniquely suited study these ions. Understanding the role of ions in fungal degradation of woody biomass is salient to a wide range of research disciplines including carbon sequestration 1,2 , forest ecology 3,4 , plant pathology 5 , biorefinery 6,7 , basic fungal physiology 8 , and the durability and utility of wood in structural applications 9-13. It is estimated that 10% of the lumber harvested each year is used to replace in-service wood that has been attacked by decay fungi 14. Nearly all structural lumber in the northern hemisphere is comprised of softwoods (conifers, gymnosperms); these wood species are especially susceptible to attack from brown rot fungi. Ion transport related to biomimicry of brown rot is also of particular interest in developments to improve the efficiency of processing biomass for platform chemical production 6,7. Brown rot is a specialized mode of wood decay employed by approximately 6% of the species of wood rotting fungi. Mechanisms of brown rot are not fully understood, but have been shown to involve a complex sequence of reactions including mediated redox chemistry, chelation and reduction of metals, and acidification of the substrate 15,16. The goal of this

Applied Biochemistry and Biotechnology, Nov 13, 2020

Biocatalysis using molecular oxygen as the electron acceptor has significant potential for select... more Biocatalysis using molecular oxygen as the electron acceptor has significant potential for selective oxidations at low cost. However, oxygen is poorly soluble in water, and its slow rate of mass transfer in the aqueous phase is a major obstacle, even for laboratory-scale syntheses. Oxygen transfer can be accelerated by vigorous mechanical methods, but these are often incompatible with biological catalysts. Gentler conditions can be achieved with shallow, high surface area bag reactors that are designed for single use and generally for specialized cell culture applications. As a less-expensive alternative to these high-end bioreactors, we describe repurposing inflatable shipping pillows with resealable valves to provide high surface area mixing under oxygen for preparative synthesis of glucosone (Darabino-hexos-2-ulose) from D-glucose using non-growing Escherichia coli whole cells containing recombinant pyranose 2-oxidase (POX) as catalyst. Parallel reactions permitted systematic study of the effects of headspace composition (i.e., air vs 100% oxygen), cell density, exogenous catalase, and reaction volume in the oxidation of 10% glucose. Importantly, only a single charge of 100% oxygen is required for stoichiometric conversion on a multi-gram scale in 18 h with resting cells, and the conversion was successfully repeated with recycled cells.

the yield and characteristics of wood cellulose nanocrystals (CNC) using concentrated acid hydrol... more the yield and characteristics of wood cellulose nanocrystals (CNC) using concentrated acid hydrolysis

Cellulose, 2021

Properties of cellulose nanocrystals (CNCs) depend upon their supramolecular structures, which ar... more Properties of cellulose nanocrystals (CNCs) depend upon their supramolecular structures, which are important to understand in order to optimize their applications. In this investigation, the structures of CNCs produced upon 48-64% H 2 SO 4 hydrolysis of hydrothermally-treated poplar, bleached kraft pulp, Electronic supplementary material The online version of this article (

Applied Biochemistry and Biotechnology, 2020

Biocatalysis using molecular oxygen as the electron acceptor has significant potential for select... more Biocatalysis using molecular oxygen as the electron acceptor has significant potential for selective oxidations at low cost. However, oxygen is poorly soluble in water, and its slow rate of mass transfer in the aqueous phase is a major obstacle, even for laboratory-scale syntheses. Oxygen transfer can be accelerated by vigorous mechanical methods, but these are often incompatible with biological catalysts. Gentler conditions can be achieved with shallow, high surface area bag reactors that are designed for single use and generally for specialized cell culture applications. As a less-expensive alternative to these high-end bioreactors, we describe repurposing inflatable shipping pillows with resealable valves to provide high surface area mixing under oxygen for preparative synthesis of glucosone (D-arabino-hexos-2-ulose) from D-glucose using non-growing Escherichia coli whole cells containing recombinant pyranose 2-oxidase (POX) as catalyst. Parallel reactions permitted systematic st...

Wood and Fiber Science, 2019

This article reports on the development of accelerated laboratory methods to allow estimation of ... more This article reports on the development of accelerated laboratory methods to allow estimation of preservative leaching from pressure-treated wood exposed to precipitation. End-matched lumber specimens were pressure-treated with a boron-copper formulation and exposed to natural weathering for 1 yr, laboratory immersion protocols, or a laboratory-simulated rainfall protocol. The rainfall runoff or immersion water was collected at intervals according to the method used and analyzed for concentrations of copper and boron. Of the laboratory methods evaluated, the simulated rainfall approach resulted in leaching patterns most similar to outdoor exposure, especially in the case of copper. However, this method is relatively complex and not ideally suited for standardized use. Although the immersion methods evaluated initially exaggerated leaching, reasonable approximations of leaching from 1 yr of natural weathering were achieved with accelerated testing. Models were developed to relate hours of immersion to millimeters of precipitation, and used to evaluate how well the immersion methods might predict leaching from natural weathering over many years of exposure. One of the methods produced boron and copper leaching estimates that were within 15% and 7%, respectively, of losses predicted for wood exposed to 5 yr of natural weathering. The results indicate that laboratory immersion methods have value in estimating long-term preservative leaching from treated wood products exposed to precipitation.

An extractive compound with a novel ring system was isolated from the wood of Salix alba and was ... more An extractive compound with a novel ring system was isolated from the wood of Salix alba and was given the name Salucci. The compound was primarily identified from the 1D NMR, 2D NMR and LC-MSMS data and the structure investigated through reactions and derivatizations.

Applied and environmental microbiology, Mar 14, 2024

Journal of Cleaner Production

The mechanisms by which chemical modifications, specifically acetylation, improve the decay resis... more The mechanisms by which chemical modifications, specifically acetylation, improve the decay resistance of wood are a topic of active research. In the early stages of decay, fungi secrete lowmolecular-weight oxidants or oxidant precursors. These oxidants diffuse through the wet wood cell wall and oxidize cell wall polymers, which enable the decay process to proceed. One hypothesis states that acetylation stops decay by dramatically inhibiting the diffusion of these oxidants through the cell wall (Zeiinka et. al. 2016). Data showing a drastic difference in Fe uptake from solution between control and acetylated wood appear to support this (Hoseinipour and Mai 2016).

An extractive compound with a novel ring system was isolated from the wood of Salix alba and was ... more An extractive compound with a novel ring system was isolated from the wood of Salix alba and was given the name Salucci. The compound was primarily identified from the 1D NMR, 2D NMR and LC-MSMS data and the structure investigated through reactions and derivatizations. INTRODUCTION The fractions extractable from wood with organic solvents are generally very complex mixtures of numerous compounds of various types, none of which amounts to much more than 5% of the total fraction. Upon examination of the acetone extract of Salix species we have made the unanticipated discovery of the presence of a single compound that accounts for about 60% of the total extractive content and from 5-6% of the weight of the airdried wood. Furthermore, upon extraction of the knotty part of the wood, up to 95% of the acetone extractives consisted of this single compound. NMR examination of the compound was not consistent with any of the Salix extractives reported in the literature. Furthermore, the compou...

Wood and Fiber Science, 2017

Current standardized methods are not well-suited for estimating in-service preservative leaching ... more Current standardized methods are not well-suited for estimating in-service preservative leaching from treated wood products. This study compared several alternative leaching methods to a commonly used standard method, and to leaching under natural exposure conditions. Small blocks or lumber specimens were pressure treated with a wood preservative containing borax and copper hydroxide. The specimens were leached using scenarios involving short periods of immersion, simulated rainfall, or to a longer period of outdoor exposure to natural precipitation. When compared with lumber specimens exposed to natural precipitation, leaching from immersed small blocks overestimated losses of both copper and of boron, whereas immersion of lumber specimens underestimated losses of copper. Stirring during immersion, which is required by some standard methods, did not affect leaching. Simulated rainfall most closely simulated leaching during outdoor exposure, but is relatively complex and may be diff...

Wood and Fiber Science, 2017

Current standardized methods are not well-suited for estimating in-service preservative leaching ... more Current standardized methods are not well-suited for estimating in-service preservative leaching from treated wood products. This study compared several alternative leaching methods to a commonly used standard method, and to leaching under natural exposure conditions. Small blocks or lumber specimens were pressure treated with a wood preservative containing borax and copper hydroxide. The specimens were leached using scenarios involving short periods of immersion, simulated rainfall, or to a longer period of outdoor exposure to natural precipitation. When compared with lumber specimens exposed to natural precipitation, leaching from immersed small blocks overestimated losses of both copper and of boron, whereas immersion of lumber specimens underestimated losses of copper. Stirring during immersion, which is required by some standard methods, did not affect leaching. Simulated rainfall most closely simulated leaching during outdoor exposure, but is relatively complex and may be diff...

GCB Bioenergy, 2021

Wheat straw was rapidly fractionated using maleic acid (MA) as an acid hydrotrope at atmospheric ... more Wheat straw was rapidly fractionated using maleic acid (MA) as an acid hydrotrope at atmospheric pressure under a range of conditions. MA hydrotropic fractionation (MAHF) was very selective in dissolving lignin and hemicelluloses resulting in a cellulose‐rich water insoluble solids (WIS), which was evaluated for producing fibers through bleaching and cellulosic nanofibrils by fibrillation, as well as glucose through enzymatic saccharification. The residual lignin (RL) within the WIS has a low degree of condensation, which eased bleaching. The RL was also carboxylated through MAHF, which facilitated nanofibrillation to produce lignin‐containing cellulose nanofibrils. The carboxylation also aided enzymatic saccharification of WIS by decreasing nonproductive cellulase binding to RL through electrostatic repulsion between carboxylated (charged) RL and the cellulase at elevated pH (>cellulase isoelectric point). The dissolved lignin (DL) from MAHF also has a low degree of condensation...

ChemSusChem, 2020

This study reports on a comparative study of acid hydrotropic fractionation (AHF) of birch wood u... more This study reports on a comparative study of acid hydrotropic fractionation (AHF) of birch wood using maleic acid (MA) and p‐toluenesulfonic acid (p‐TsOH). Under the same level of delignification, lignin dissolved by MA is much less condensed with a higher content of ether aryl β‐O‐4 linkages. Lignin depolymerization dominated in MA hydrotropic fractionation (MAHF) and resulted in a single lower molecular weight peak, in contrast to the competitive depolymerization and repolymerization in p‐TsOH AHF with a bimodal distribution. The less condensed MA‐dissolved lignin facilitated catalytic conversion to monophenols. Carboxylation of residual lignin in fractionated cellulosic water‐insoluble solids (WISs) enhanced enzymatic saccharification by decreasing nonproductive cellulase binding to lignin. At a low cellulase loading of 10 FPU g−1 glucan, saccharification of WIS‐MT120 from MAHF at 120 °C was 95 % compared with 48 % for WIS‐PT85 from p‐TsOH AHF at 85 °C under the same level of del...

Forests, 2020

Acetylation is widely used as a wood modification process that protects wood from fungal decay. T... more Acetylation is widely used as a wood modification process that protects wood from fungal decay. The mechanisms by which acetylation protects wood are not fully understood. With these experiments, we expand upon the literature and test whether previously observed differences in iron uptake by wood were a result of decreased iron binding capacity or slower diffusion. We measured the concentration of iron in 2 mm thick wood sections at 0, 10, and 20% acetylation as a function of time after exposure to iron solutions. The iron was introduced either strongly chelated with oxalate or weakly chelated with acetate. The concentrations of iron and oxalate in solution were chosen to be similar to those found during brown rot decay, while the concentration of iron and acetate matched previous work. The iron content of oxalate-exposed wood increased only slightly and was complete within an hour, suggesting little absorption and fast diffusion, or only slight surface adsorption. The increase in i...

Industrial Crops and Products, 2021

Green Chemistry, 2020

Maleic acid for wood fractionation at atmospheric pressure to result in carboxylated lignin with ... more Maleic acid for wood fractionation at atmospheric pressure to result in carboxylated lignin with minimal condensation, light color, and to facilitate processing of fractionated solids. 2D 1H–13C HQSC and HMBC analyses confirmed lignin esterification.