Ivana Brzonova - Academia.edu (original) (raw)

Papers by Ivana Brzonova

Bioresource Technology, Dec 1, 2014

h i g h l i g h t s Release and removal of monosaccharides occur prior to lignin biodecomposition... more h i g h l i g h t s Release and removal of monosaccharides occur prior to lignin biodecomposition. Monosaccharide products may be collected separately from phenolics. TD-Pyr-GC-MS confirmed that lignin decomposition as a result of microbial action. Biomass and lignin degradation were similar for fungi and bacteria.

Jasmine Kreft and all REU students. I would also like to thank my entire family for their love an... more Jasmine Kreft and all REU students. I would also like to thank my entire family for their love and support; to my parents for being the very best role examples of an engineer, my mom, and a scientist, my father; all my friends for all the fun, arguments, adventure, build up, support, care and love.

World Academy of Science, Engineering and Technology, International Journal of Biotechnology and Bioengineering, Oct 8, 2015

World Academy of Science, Engineering and Technology, International Journal of Biotechnology and Bioengineering, Oct 8, 2015

Jasmine Kreft and all REU students. I would also like to thank my entire family for their love an... more Jasmine Kreft and all REU students. I would also like to thank my entire family for their love and support; to my parents for being the very best role examples of an engineer, my mom, and a scientist, my father; all my friends for all the fun, arguments, adventure, build up, support, care and love.

World Academy of Science, Engineering and Technology, International Journal of Biotechnology and Bioengineering, 2015

World Academy of Science, Engineering and Technology, International Journal of Biotechnology and Bioengineering, 2015

Scientific reports, Jan 13, 2017

Unlike previous lignin biodegradation studies, white rot fungi were used to produce functional bi... more Unlike previous lignin biodegradation studies, white rot fungi were used to produce functional biopolymers from Kraft lignin. Lignin-based polymers (hydrogel precursors) partially soluble in both aqueous and organic solvents were produced employing a relatively fast (6 days) enzymation of Kraft lignin with basidiomycetes, primarily Coriolus versicolor, pre-grown on kenaf/lignin agar followed by either vacuum evaporation or acid precipitation. After drying followed by a treatment with alkaline water, this intermediate polymer became a pH-sensitive anionic hydrogel insoluble in either aqueous or organic solvents. The yield of this polymer increased from 20 to 72 wt% with the addition of 2% dimethylsulfoxide to distilled water used as a medium. The mechanical stability and buffering capacity of this hydrogel can be adjusted by washing the intermediate polymer/hydrogel precursor prior to drying with solvents of different polarity (water, methanol or ethanol). Any of these polymers featu...

Renewable and Sustainable Energy Reviews, 2017

Lignin, one of the major components of plant/lignocellulosic biomass, is an irregular 3-D polymer... more Lignin, one of the major components of plant/lignocellulosic biomass, is an irregular 3-D polymer comprised of potentially valuable phenolic monomers. Currently lignin and its colloidal solution in water, black liquor, obtained as by-products in many biomass treatment processes, e.g., pulping in paper industry, remain to be considered recalcitrant substrates of a limited commercial value. This study reviews the recent research on both fungal and bacterial lignin degradation, with a focus on the characterization of degradation products. The specific features and biological treatment of industrial lignin and black liquor are detailed along with the degradation conditions employed, complementing other review articles focusing on natural lignin degradation. An overview of ligninolytic enzymes frequently identified among microorganisms is presented, with the emphasis on factors responsible for their regulation and induction including the mediators involved and multienzyme systems employed by natural lignin degraders. Efficient regulation of ligninolytic enzymes can be achieved through the optimization of a cultivation medium composition with supplementation of strain specific stimulatory components such as salts, low molecular weight phenolic compounds and nutrition sources. Current research efforts in characterizing lignin degradation products are reviewed with the emphasis on both destructive and non-destructive gas chromatographic methods as they are essential for future detailed kinetic and mechanistic studies.

Bioresource Technology, 2016

Indulin AT biodegradation by basidiomycetous fungi, actinobacteria and commercial laccases was ev... more Indulin AT biodegradation by basidiomycetous fungi, actinobacteria and commercial laccases was evaluated using a suite of chemical analysis methods. The extent of microbial degradation was confirmed by novel thermal carbon analysis (TCA), as the treatments altered the carbon desorption and pyrolysis temperature profiles in supernatants. Laccase treatments caused only minor changes, though with increases occurring in the 850 °C and char precursor fractions. After fungal treatments, lignin showed a similar change in the TCA profile, along with a gradual decrease of the total carbon, signifying lignin mineralization (combined with polymerization). By contrast, bacteria produced phenolic monomers without their further catabolism. After 54 days of cultivation, a 20 wt.% weight loss was observed only for fungi, Coriolus versicolor, corroborating the near-80% carbon mass balance closure obtained by TCA. Compositional changes in lignin as a result of biodegradation were confirmed by Thermal Desorption (TD)-Pyrolysis-GC-MS validating the carbon fractionation obtained by TCA.

Bioresource technology, 2014

The efficiency and dynamics of simultaneous kenaf biomass decomposition by basidiomycetous fungi ... more The efficiency and dynamics of simultaneous kenaf biomass decomposition by basidiomycetous fungi and actinobacteria were investigated. After 8weeks of incubation, up to 34wt.% of the kenaf biomass was degraded, with the combination of fungi and bacteria being the most efficient. Lignin decomposition accounted for ∼20% of the observed biomass reduction, regardless of the culture used. The remaining 80% of biomass degradation was due to carbohydrate based polymers. Major monosaccharides were produced in tangible yields (26-38%) at different times. Glucose, fructose and xylose were then fully consumed by day 25 while some galactose persisted until day 45. Once monosaccharides were depleted, the production of laccase, manganese-dependent peroxidase and lignin peroxidase enzymes, essential for lignin decomposition, was induced. The products of lignin biodecomposition were shown to be water-soluble and characterized by thermal desorption-pyrolysis-gas chromatography.

European Journal of Pharmaceutics and Biopharmaceutics, 2011

Excess ''free'' iron which occurs under certain physiological conditions participates in the form... more Excess ''free'' iron which occurs under certain physiological conditions participates in the formation of toxic reactive oxygen species via the ''fenton'' chemistry. The reactive oxygen species oxidize biomolecules and have been implicated in many oxidative stress-related diseases. However, the ideal therapy for treating iron overload problems in humans has not yet been developed. In this study, the phenolic molecules catechol, caffeic acid, and 2,5-dihydroxybenzoic acid were successfully coupled to glucosamine as model substrate in a 1:1 ratio using laccase. Furthermore, coupling of these molecules onto chitosans of different sizes was demonstrated, resulting in decrease in-NH 2 groups as quantified via derivatization. A concomitant increase in iron-chelating capacity from below 3% to up to 70% upon phenolic functionalization was measured for the chitosans based on reduced ferrozine/Fe 2+ complex formation. Interesting these phenolic compounds seems to also participate as cross-linkers in producing characteristic microspheres. This work therefore opens-up new strategies aimed at developing a new generation of iron-chelating biomedical polymers.

Industrial & Engineering Chemistry Research, May 16, 2017

Low substrate solubility and slow decomposition/ biotransformation rate are among the main impedi... more Low substrate solubility and slow decomposition/ biotransformation rate are among the main impediments for industrial scale lignin biotreatment. The outcome and dynamics of Kraft lignin biomodification by basidiomycetous fungi, Coriolus versicolor, were investigated in the presence of dimethyl sulfoxide (DMSO). The addition of 2 vol% DMSO to aqueous media increased the lignin solubility up to 70%, while the quasi-immobilized fungi (pre-grown on agar containing Kenaf biomass) maintained their ability to produce lignolytic enzymes. Basidiomycetous fungi were able to grow on solid media containing both 5-25 g/L lignin and up to 5 vol% DMSO, in contrast to no growth in liquid media as a free suspended culture. When a fungal culture pre-grown on agar was used for lignin treatment in an aqueous medium containing 2-5% DMSO with up to 25 g/L of lignin, significant lignin modification was observed in 1-6 days. The product analysis suggests that lignin was biotransformed, rather than biodegraded, into an oxygenated and crosslinked phenolic polymer. The resulting product showed the removal of phenolic monomers and/or their immediate precursors based on gas chromatography and thermal desorptionpyrolysisgas chromatographymass spectrometry analyses. Significant intramolecular cross-linking among the reaction products was shown by thermal carbon analysis

Industrial & Engineering Chemistry Research

Abstract Excess “free” iron which occurs under certain physiological conditions participates in t... more Abstract
Excess “free” iron which occurs under certain physiological conditions participates in the formation of toxic reactive oxygen species via the “fenton” chemistry. The reactive oxygen species oxidize biomolecules and have been implicated in many oxidative stress-related diseases. However, the ideal therapy for treating iron overload problems in humans has not yet been developed. In this study, the phenolic molecules catechol, caffeic acid, and 2,5-dihydroxybenzoic acid were successfully coupled to glucosamine as model substrate in a 1:1 ratio using laccase. Furthermore, coupling of these molecules onto chitosans of different sizes was demonstrated, resulting in decrease in –NH2 groups as quantified via derivatization. A concomitant increase in iron-chelating capacity from below 3% to up to 70% upon phenolic functionalization was measured for the chitosans based on reduced ferrozine/Fe2+ complex formation. Interesting these phenolic compounds seems to also participate as cross-linkers in producing characteristic microspheres. This work therefore opens-up new strategies aimed at developing a new generation of iron-chelating biomedical polymers.

Bioresource technology, 2014

The efficiency and dynamics of simultaneous kenaf biomass decomposition by basidiomycetous fungi ... more The efficiency and dynamics of simultaneous kenaf biomass decomposition by basidiomycetous fungi and actinobacteria were investigated. After 8weeks of incubation, up to 34wt.% of the kenaf biomass was degraded, with the combination of fungi and bacteria being the most efficient. Lignin decomposition accounted for ∼20% of the observed biomass reduction, regardless of the culture used. The remaining 80% of biomass degradation was due to carbohydrate based polymers. Major monosaccharides were produced in tangible yields (26-38%) at different times. Glucose, fructose and xylose were then fully consumed by day 25 while some galactose persisted until day 45. Once monosaccharides were depleted, the production of laccase, manganese-dependent peroxidase and lignin peroxidase enzymes, essential for lignin decomposition, was induced. The products of lignin biodecomposition were shown to be water-soluble and characterized by thermal desorption-pyrolysis-gas chromatography.

Bioresource Technology, Dec 1, 2014

h i g h l i g h t s Release and removal of monosaccharides occur prior to lignin biodecomposition... more h i g h l i g h t s Release and removal of monosaccharides occur prior to lignin biodecomposition. Monosaccharide products may be collected separately from phenolics. TD-Pyr-GC-MS confirmed that lignin decomposition as a result of microbial action. Biomass and lignin degradation were similar for fungi and bacteria.

Jasmine Kreft and all REU students. I would also like to thank my entire family for their love an... more Jasmine Kreft and all REU students. I would also like to thank my entire family for their love and support; to my parents for being the very best role examples of an engineer, my mom, and a scientist, my father; all my friends for all the fun, arguments, adventure, build up, support, care and love.

World Academy of Science, Engineering and Technology, International Journal of Biotechnology and Bioengineering, Oct 8, 2015

World Academy of Science, Engineering and Technology, International Journal of Biotechnology and Bioengineering, Oct 8, 2015

Jasmine Kreft and all REU students. I would also like to thank my entire family for their love an... more Jasmine Kreft and all REU students. I would also like to thank my entire family for their love and support; to my parents for being the very best role examples of an engineer, my mom, and a scientist, my father; all my friends for all the fun, arguments, adventure, build up, support, care and love.

World Academy of Science, Engineering and Technology, International Journal of Biotechnology and Bioengineering, 2015

World Academy of Science, Engineering and Technology, International Journal of Biotechnology and Bioengineering, 2015

Scientific reports, Jan 13, 2017

Unlike previous lignin biodegradation studies, white rot fungi were used to produce functional bi... more Unlike previous lignin biodegradation studies, white rot fungi were used to produce functional biopolymers from Kraft lignin. Lignin-based polymers (hydrogel precursors) partially soluble in both aqueous and organic solvents were produced employing a relatively fast (6 days) enzymation of Kraft lignin with basidiomycetes, primarily Coriolus versicolor, pre-grown on kenaf/lignin agar followed by either vacuum evaporation or acid precipitation. After drying followed by a treatment with alkaline water, this intermediate polymer became a pH-sensitive anionic hydrogel insoluble in either aqueous or organic solvents. The yield of this polymer increased from 20 to 72 wt% with the addition of 2% dimethylsulfoxide to distilled water used as a medium. The mechanical stability and buffering capacity of this hydrogel can be adjusted by washing the intermediate polymer/hydrogel precursor prior to drying with solvents of different polarity (water, methanol or ethanol). Any of these polymers featu...

Renewable and Sustainable Energy Reviews, 2017

Lignin, one of the major components of plant/lignocellulosic biomass, is an irregular 3-D polymer... more Lignin, one of the major components of plant/lignocellulosic biomass, is an irregular 3-D polymer comprised of potentially valuable phenolic monomers. Currently lignin and its colloidal solution in water, black liquor, obtained as by-products in many biomass treatment processes, e.g., pulping in paper industry, remain to be considered recalcitrant substrates of a limited commercial value. This study reviews the recent research on both fungal and bacterial lignin degradation, with a focus on the characterization of degradation products. The specific features and biological treatment of industrial lignin and black liquor are detailed along with the degradation conditions employed, complementing other review articles focusing on natural lignin degradation. An overview of ligninolytic enzymes frequently identified among microorganisms is presented, with the emphasis on factors responsible for their regulation and induction including the mediators involved and multienzyme systems employed by natural lignin degraders. Efficient regulation of ligninolytic enzymes can be achieved through the optimization of a cultivation medium composition with supplementation of strain specific stimulatory components such as salts, low molecular weight phenolic compounds and nutrition sources. Current research efforts in characterizing lignin degradation products are reviewed with the emphasis on both destructive and non-destructive gas chromatographic methods as they are essential for future detailed kinetic and mechanistic studies.

Bioresource Technology, 2016

Indulin AT biodegradation by basidiomycetous fungi, actinobacteria and commercial laccases was ev... more Indulin AT biodegradation by basidiomycetous fungi, actinobacteria and commercial laccases was evaluated using a suite of chemical analysis methods. The extent of microbial degradation was confirmed by novel thermal carbon analysis (TCA), as the treatments altered the carbon desorption and pyrolysis temperature profiles in supernatants. Laccase treatments caused only minor changes, though with increases occurring in the 850 °C and char precursor fractions. After fungal treatments, lignin showed a similar change in the TCA profile, along with a gradual decrease of the total carbon, signifying lignin mineralization (combined with polymerization). By contrast, bacteria produced phenolic monomers without their further catabolism. After 54 days of cultivation, a 20 wt.% weight loss was observed only for fungi, Coriolus versicolor, corroborating the near-80% carbon mass balance closure obtained by TCA. Compositional changes in lignin as a result of biodegradation were confirmed by Thermal Desorption (TD)-Pyrolysis-GC-MS validating the carbon fractionation obtained by TCA.

Bioresource technology, 2014

The efficiency and dynamics of simultaneous kenaf biomass decomposition by basidiomycetous fungi ... more The efficiency and dynamics of simultaneous kenaf biomass decomposition by basidiomycetous fungi and actinobacteria were investigated. After 8weeks of incubation, up to 34wt.% of the kenaf biomass was degraded, with the combination of fungi and bacteria being the most efficient. Lignin decomposition accounted for ∼20% of the observed biomass reduction, regardless of the culture used. The remaining 80% of biomass degradation was due to carbohydrate based polymers. Major monosaccharides were produced in tangible yields (26-38%) at different times. Glucose, fructose and xylose were then fully consumed by day 25 while some galactose persisted until day 45. Once monosaccharides were depleted, the production of laccase, manganese-dependent peroxidase and lignin peroxidase enzymes, essential for lignin decomposition, was induced. The products of lignin biodecomposition were shown to be water-soluble and characterized by thermal desorption-pyrolysis-gas chromatography.

European Journal of Pharmaceutics and Biopharmaceutics, 2011

Excess ''free'' iron which occurs under certain physiological conditions participates in the form... more Excess ''free'' iron which occurs under certain physiological conditions participates in the formation of toxic reactive oxygen species via the ''fenton'' chemistry. The reactive oxygen species oxidize biomolecules and have been implicated in many oxidative stress-related diseases. However, the ideal therapy for treating iron overload problems in humans has not yet been developed. In this study, the phenolic molecules catechol, caffeic acid, and 2,5-dihydroxybenzoic acid were successfully coupled to glucosamine as model substrate in a 1:1 ratio using laccase. Furthermore, coupling of these molecules onto chitosans of different sizes was demonstrated, resulting in decrease in-NH 2 groups as quantified via derivatization. A concomitant increase in iron-chelating capacity from below 3% to up to 70% upon phenolic functionalization was measured for the chitosans based on reduced ferrozine/Fe 2+ complex formation. Interesting these phenolic compounds seems to also participate as cross-linkers in producing characteristic microspheres. This work therefore opens-up new strategies aimed at developing a new generation of iron-chelating biomedical polymers.

Industrial & Engineering Chemistry Research, May 16, 2017

Low substrate solubility and slow decomposition/ biotransformation rate are among the main impedi... more Low substrate solubility and slow decomposition/ biotransformation rate are among the main impediments for industrial scale lignin biotreatment. The outcome and dynamics of Kraft lignin biomodification by basidiomycetous fungi, Coriolus versicolor, were investigated in the presence of dimethyl sulfoxide (DMSO). The addition of 2 vol% DMSO to aqueous media increased the lignin solubility up to 70%, while the quasi-immobilized fungi (pre-grown on agar containing Kenaf biomass) maintained their ability to produce lignolytic enzymes. Basidiomycetous fungi were able to grow on solid media containing both 5-25 g/L lignin and up to 5 vol% DMSO, in contrast to no growth in liquid media as a free suspended culture. When a fungal culture pre-grown on agar was used for lignin treatment in an aqueous medium containing 2-5% DMSO with up to 25 g/L of lignin, significant lignin modification was observed in 1-6 days. The product analysis suggests that lignin was biotransformed, rather than biodegraded, into an oxygenated and crosslinked phenolic polymer. The resulting product showed the removal of phenolic monomers and/or their immediate precursors based on gas chromatography and thermal desorptionpyrolysisgas chromatographymass spectrometry analyses. Significant intramolecular cross-linking among the reaction products was shown by thermal carbon analysis

Industrial & Engineering Chemistry Research

Abstract Excess “free” iron which occurs under certain physiological conditions participates in t... more Abstract
Excess “free” iron which occurs under certain physiological conditions participates in the formation of toxic reactive oxygen species via the “fenton” chemistry. The reactive oxygen species oxidize biomolecules and have been implicated in many oxidative stress-related diseases. However, the ideal therapy for treating iron overload problems in humans has not yet been developed. In this study, the phenolic molecules catechol, caffeic acid, and 2,5-dihydroxybenzoic acid were successfully coupled to glucosamine as model substrate in a 1:1 ratio using laccase. Furthermore, coupling of these molecules onto chitosans of different sizes was demonstrated, resulting in decrease in –NH2 groups as quantified via derivatization. A concomitant increase in iron-chelating capacity from below 3% to up to 70% upon phenolic functionalization was measured for the chitosans based on reduced ferrozine/Fe2+ complex formation. Interesting these phenolic compounds seems to also participate as cross-linkers in producing characteristic microspheres. This work therefore opens-up new strategies aimed at developing a new generation of iron-chelating biomedical polymers.

Bioresource technology, 2014

The efficiency and dynamics of simultaneous kenaf biomass decomposition by basidiomycetous fungi ... more The efficiency and dynamics of simultaneous kenaf biomass decomposition by basidiomycetous fungi and actinobacteria were investigated. After 8weeks of incubation, up to 34wt.% of the kenaf biomass was degraded, with the combination of fungi and bacteria being the most efficient. Lignin decomposition accounted for ∼20% of the observed biomass reduction, regardless of the culture used. The remaining 80% of biomass degradation was due to carbohydrate based polymers. Major monosaccharides were produced in tangible yields (26-38%) at different times. Glucose, fructose and xylose were then fully consumed by day 25 while some galactose persisted until day 45. Once monosaccharides were depleted, the production of laccase, manganese-dependent peroxidase and lignin peroxidase enzymes, essential for lignin decomposition, was induced. The products of lignin biodecomposition were shown to be water-soluble and characterized by thermal desorption-pyrolysis-gas chromatography.