scholarly journals Importance of Defluviitalea raffinosedens for Hydrolytic Biomass Degradation in Co-Culture with Hungateiclostridium thermocellum

2020 ◽  
Vol 8 (6) ◽  
pp. 915
Author(s):  
Regina Rettenmaier ◽  
Martina Schneider ◽  
Bernhard Munk ◽  
Michael Lebuhn ◽  
Sebastian Jünemann ◽  
...  
Keyword(s):  
Plant Biomass ◽  
Cellulose Hydrolysis ◽  
Taxonomic Composition ◽  
Process Conditions ◽  
Cellulose Breakdown ◽  
Metabolic Properties ◽  
Reactor Operating ◽  
First Time ◽  
Hydrolysis Of

Bacterial hydrolysis of polysaccharides is an important step for the production of sustainable energy, for example during the conversion of plant biomass to methane-rich biogas. Previously, Hungateiclostridium thermocellum was identified as cellulolytic key player in thermophilic biogas microbiomes with a great frequency as an accompanying organism. The aim of this study was to physiologically characterize a recently isolated co-culture of H. thermocellum and the saccharolytic bacterium Defluviitalea raffinosedens from a laboratory-scale biogas fermenter. The characterization focused on cellulose breakdown by applying the measurement of cellulose hydrolysis, production of metabolites, and the activity of secreted enzymes. Substrate degradation and the production of volatile metabolites was considerably enhanced when both organisms acted synergistically. The metabolic properties of H. thermocellum have been studied well in the past. To predict the role of D. raffinosedens in this bacterial duet, the genome of D. raffinosedens was sequenced for the first time. Concomitantly, to deduce the prevalence of D. raffinosedens in anaerobic digestion, taxonomic composition and transcriptional activity of different biogas microbiomes were analyzed in detail. Defluviitalea was abundant and metabolically active in reactor operating at highly efficient process conditions, supporting the importance of this organism for the hydrolysis of the raw substrate.

scholarly journals New methods of acid hydrolysis of cellulose and plant raw materials

2021 ◽  
Vol 57 (1) ◽  
pp. 119-128
Author(s):  
V. S. Boltovsky
Keyword(s):  
Acid Hydrolysis ◽  
Plant Biomass ◽  
Raw Materials ◽  
Agricultural Waste ◽  
Feed Additives ◽  
Process Conditions ◽  
Catalytic Systems ◽  
Plant Raw Materials ◽  
Hydrolysis Of Cellulose ◽  
Hydrolysis Of

Prospects for the development of hydrolysis production are determined by the relevance of industrial use of plant biomass to replace the declining reserves of fossil organic raw materials and increasing demand for ethanol, especially for its use as automobile fuel, protein-containing feed additives that compensate for protein deficiency in feed production, and other products. Based on the review of the research results presented in the scientific literature, the analysis of modern methods of liquid-phase acid hydrolysis of cellulose and various types of plant raw materials, including those that differ from traditional ones, is performed. The main directions of increasing its efficiency through the use of new catalytic systems and process conditions are identified. It is shown that the most promising methods for obtaining monosaccharides in hydrolytic processing of cellulose and microcrystalline cellulose, pentosan-containing agricultural waste and wood, are methods for carrying out the process at elevated and supercritical temperatures (high-temperature hydrolysis), the use of new types of solid-acid catalysts and ionic liquids. 

scholarly journals Stochastic modelling of cellulose hydrolysis with Gauss and Weibull distributed transition probabilities

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Joseph Mcgreg Duru ◽  
Oana Cristina Pârvulescu ◽  
Tănase Dobre ◽  
Cristian Eugen Răducanu
Keyword(s):  
Acid Hydrolysis ◽  
Stochastic Models ◽  
Transition Probabilities ◽  
Stochastic Modelling ◽  
Cellulose Hydrolysis ◽  
Process Conditions ◽  
Hydrolysis Of Cellulose ◽  
Model Equations ◽  
Kinetics Of ◽  
Hydrolysis Of

AbstractTwo Markov-type stochastic models were developed to describe the kinetics of acid hydrolysis of cellulose. One of them involved a Gauss (normal) distribution of probabilities of chemical bond breaking, the other a Weibull distribution. It was considered that the random breaking of cellulose was based on the cleavage of a parent macromolecule into two descendants. Model equations and kinetics of acid hydrolysis of cellulose consisting of 10 and 100 units of cellobiose were presented. The effects of acid concentration and temperature on the kinetics of hydrolysis process were taken into account. The results obtained applying both stochastic models were in a reasonable agreement with those obtained using a deterministic kinetic model. These stochastic models can accurately describe the kinetics of acid hydrolysis and cover the drawbacks of some deterministic kinetic models, e.g., large number of model equations and parameters, modification of parameter values by changing the process conditions.

scholarly journals The Role of Evolving Interfacial Substrate Properties on Heterogeneous Cellulose Hydrolysis Kinetics

2019 ◽  
Author(s):  
Jennifer Nill ◽  
Tina Jeoh
Keyword(s):  
Binding Sites ◽  
Binding Capacity ◽  
Cellulose Hydrolysis ◽  
Reaction Rates ◽  
Hydrolysis Kinetics ◽  
Substrate Complex ◽  
Enzyme Substrate ◽  
Substrate Properties ◽  
Hydrolysis Of

AbstractInterfacial enzyme reactions require formation of an enzyme-substrate complex at the surface of a heterogeneous substrate, but often multiple modes of enzyme binding and types of binding sites complicate analysis of their kinetics. Excess of heterogeneous substrate is often used as a justification to model the substrate as unchanging; but using the study of the enzymatic hydrolysis of insoluble cellulose as an example, we argue that reaction rates are dependent on evolving substrate interfacial properties. We hypothesize that the relative abundance of binding sites on cellulose where hydrolysis can occur (productive binding sites) and binding sites where hydrolysis cannot be initiated or is inhibited (non-productive binding sites) contribute to rate limitations. We show that the initial total number of productive binding sites (the productive binding capacity) determines the magnitude of the initial burst phase of cellulose hydrolysis, while productive binding site depletion explains overall hydrolysis kinetics. Furthermore, we show that irreversibly bound surface enzymes contribute to the depletion of productive binding sites. Our model shows that increasing the ratio of productive- to non-productive binding sites promotes hydrolysis, while maintaining an elevated productive binding capacity throughout conversion is key to preventing hydrolysis slowdown.

scholarly journals Exploring the role of the rumen microbiota in determining the feed efficiency of dairy cows

2011 ◽  
Author(s):  
Itzhak Mizrahi ◽  
Bryan A. White
Keyword(s):  
Dairy Cows ◽  
Feed Efficiency ◽  
Plant Biomass ◽  
Taxonomic Composition ◽  
Food Resources ◽  
Gene Content ◽  
Energetic Efficiency ◽  
Rumen Microbiome ◽  
Coding Capacity

Expanding world hunger calls for increasing available food resources. Ruminants have the remarkable ability to convert human-indigestible plant biomass into human-digestible food products, due to a complex microbiome residing in the rumen compartment of their upper digestive tract. One way to tackle the problem of diminishing food resources is to increase the animals' energetic efficiency, i.e., the efficiency with which they convert energy from feed, thereby increasing food availability while lowering the environmental burden, as these animals would produce more and eat less. We hypothesize that the cow's feed efficiency is dependent on the taxonomic composition, coding capacity and activity of its reticulorumenmicrobiota. To test this hypothesis, three aims are defined: (1) Evaluation of the feed efficiency of 146 dairy cows and defining two groups representing the highest and lowest 25% using the Israeli group's unique facility; (2) Comparing these two groups for microbiota diversity, identity and coding capacity using next-generation sequencing and metagenomic approaches; (3) Comparing the reticulorumenmicrobiota metabolic activity parameters. We measured feed efficiency in 146 milking cows and analyzed the taxonomic composition, gene content, microbial activity and metabolomic composition of rumen microbiomes from the 78 most extreme animals. Lower richness of microbiome gene content and taxa was tightly linked to higher feed efficiency. Microbiome genes and species accurately predicted the animals' feed-efficiency phenotype. Specific enrichment of microbes and metabolic pathways in each of these microbiome groups resulted in increasing valuable metabolites and decreasing unusable ones such as methane in efficient animals. This ecological and mechanistic understanding of the rumen microbiome could lead to an increase in available food resources and environmentally friendly livestock agriculture.

The Role of Enzyme Loading on Starch and Cellulose Hydrolysis of Food Waste

2019 ◽  
Vol 10 (12) ◽  
pp. 3753-3762 ◽  
Author(s):  
Erfaneh Salimi ◽  
Konstantinos Saragas ◽  
Mir Edris Taheri ◽  
Jelica Novakovic ◽  
Elli Maria Barampouti ◽  
...  
Keyword(s):  
Food Waste ◽  
Cellulose Hydrolysis ◽  
Enzyme Loading ◽  
Hydrolysis Of

Role of a Labile Terpene Compound in the Assessment of the Age of a Fossil Wood from Siena (Tuscany, Italy)

Holzforschung ◽  
2000 ◽  
Vol 54 (6) ◽  
pp. 591-596 ◽  
Author(s):  
G. Staccioli ◽  
A. Meli ◽  
G. Menchi ◽  
U. Matteoli ◽  
G. Ricottini
Keyword(s):  
Pinus Sylvestris ◽  
Cation Exchange ◽  
Cation Exchange Capacity ◽  
Exchange Capacity ◽  
Partial Loss ◽  
Wood Component ◽  
First Time ◽  
Geological Formations ◽  
Hydrolysis Of

Summary Fossil samples of Pinus sylvestris found near Siena (Tuscany, Italy) in geological formations 2–3 million years old were chemically examined in order to solve the problem of the contrast between the age of geological formations and their good degree of preservation. Comparison with a living Pinus sylvestris was carried out on standard wood component analyses, cation exchange capacity and residual terpene content. The analyses of wood components were close to those of the reference pine, whilst the cation exchange capacity values showed remarkable changes. The increase of salt carboxyls suggested the hydrolysis of ester carboxyls originally present, whilst the reduction of total carboxyls revealed a partial loss of hemicelluloses. Both changes were attributed to the percolation of salt-bearing water through the wood, thus causing ester hydrolysis, carboxyl salification and hemicellulose solubilisation. Residual terpene analysis showed, for the first time in a terrestrial fossil, tetrahydroabietic acid which forms by disproportion of the abietic acid. The 14C dating assigned the fossil to an age of about 18,000 years and suggested a landslide of Wurmian interglacial age occurred inside the geological formations of 2–3 million years old. Transient terpene compounds, formed in incipient diagenesis, are proposed as tracers for the assessment of particular ranges of fossil age, as previously suggested by the analyses of both a Larix decidua 14,500 years old and a Picea abies 100,000 years

scholarly journals Effect of Bioaugmentation with Anaerobic Fungi Isolated from Ruminants on the Hydrolysis of Corn Silage and Phragmites australis

2021 ◽  
Vol 11 (19) ◽  
pp. 9123
Author(s):  
Bhargavi Ravi ◽  
Valentine Nkongndem Nkemka ◽  
Xiying Hao ◽  
Jay Yanke ◽  
Tim A. McAllister ◽  
...  
Keyword(s):  
Phragmites Australis ◽  
Volatile Fatty Acids ◽  
Plant Biomass ◽  
Biological Activities ◽  
Hydrolytic Enzymes ◽  
Process Conditions ◽  
Anaerobic Fungi ◽  
Significant Difference ◽  
The Impact ◽  
Hydrolysis Of

Anaerobic fungi produce extracellular hydrolytic enzymes that facilitate degradation of cellulose and hemicellulose in ruminants. The purpose of this work was to study the impact of three different anaerobic fungal species (Anaeromyces mucronatus YE505, Neocallimastix frontalis 27, and Piromyces rhizinflatus YM600) on hydrolysis of two different lignocellulosic substrates, corn (Zea mays L.) silage and reed (Phragmites australis (Cav.) Trin. ex Steud.). Biomass from each plant species was incubated anaerobically for 11 days either in the presence of live fungal inoculum or with heat-inactivated (control) inoculum. Headspace gas composition, dry matter loss, soluble chemical oxygen demand, concentration of volatile fatty acids, and chemical composition were measured before and after hydrolysis. While some microbial activity was observed, inoculation with anaerobic fungi did not result in any significant difference in the degradation of either type of plant biomass tested, likely due to low fungal activity or survival under the experimental conditions tested. While the premise of utilizing the unique biological activities of anaerobic fungi for biotechnology applications remains promising, further research on optimizing culturing and process conditions is necessary.

scholarly journals Metataxonomic Review To Elucidate The Role of The Microbiome In Celiac Disease Across The Gastrointestinal Tract.

2021 ◽  
Author(s):  
Juliana Arcila ◽  
Viviana Loria-Kohen ◽  
Ana Ramírez de Molina ◽  
Enrique Carrillo de Santa Pau ◽  
Laura Judith Judith Zambrano
Keyword(s):  
Immune Response ◽  
Celiac Disease ◽  
Gastrointestinal Tract ◽  
High Throughput Sequencing ◽  
Short Chain Fatty Acids ◽  
Taxonomic Composition ◽  
Rrna Gene ◽  
Immunogenic Peptides ◽  
First Time

Abstract Background: Dysbiosis of the microbiome has been related to the Celiac disease (CeD) progress, an autoimmune disease characterised by gluten intolerance developed in genetically susceptible individuals under certain environmental factors. The microbiome contributes to CeD pathophysiology modulating the immune response by the action of short-chain fatty acids (SCFA), affecting gut barrier integrity allowing the entrance of gluten derived proteins, and degrading immunogenic peptides of gluten through endoprolyl peptidase enzymes. Results: We reviewed state of the art in taxonomic composition for CeD and compiled the larger dataset of 16S prokaryotic ribosomal RNA (rRNA) gene high-throughput sequencing for consensus profiling. We present for the first time an integrative analysis of metataxonomic data from CeD patients, including samples from different body sites (saliva, pharynx, duodenum, and stool). We found the presence of coordinated changes through the gastrointestinal tract characterised by an increase in Actinobacteria species in the upper tract (pharynx and duodenum), and an increase in Proteobacteria in the lower tract (duodenum and stool), as well as site-specific changes evidencing a dysbiosis in CeD patients' microbiota. Moreover, we described the effect of adherence to a gluten-free diet (GFD) evidenced by an increase in beneficial bacteria and a decrease in some Betaproteobacteriales but not fully restoring CeD-related dysbiosis. Conclusions: We illustrate that the gut microbiota acts as an enhancer of immune response in CeD through the production of lipopolysaccharides and other bacterial components that activate the immune response and by decrease SCFA producers bacteria. Furthermore, microbial changes observed through the gastrointestinal tract of CeD patients may help manage the disease and follow-up GFD treatment.

scholarly journals Metataxonomic review to elucidate the role of the microbiome in Celiac disease across the gastrointestinal tract

2021 ◽  
Author(s):  
Juliana Estefania Arcila Galvis ◽  
Viviana Loria-Kohen ◽  
Ana Ramirez de Molina ◽  
Enrique Castillo de Santa Pau ◽  
Laura Judith Marcos-Zambrano
Keyword(s):  
Immune Response ◽  
Celiac Disease ◽  
Gastrointestinal Tract ◽  
High Throughput Sequencing ◽  
Short Chain Fatty Acids ◽  
Taxonomic Composition ◽  
Rrna Gene ◽  
Immunogenic Peptides ◽  
First Time

Dysbiosis of the microbiome has been related to the Celiac disease (CeD) progress, an autoimmune disease characterised by gluten intolerance developed in genetically susceptible individuals under certain environmental factors. The microbiome contributes to CeD pathophysiology modulating the immune response by the action of short-chain fatty acids (SCFA), affecting gut barrier integrity allowing the entrance of gluten derived proteins, and degrading immunogenic peptides of gluten through endoprolyl peptidase enzymes. We reviewed state of the art in taxonomic composition for CeD and compiled the larger dataset of 16S prokaryotic ribosomal RNA (rRNA) gene high-throughput sequencing for consensus profiling. We present for the first time an integrative analysis of metataxonomic data from CeD patients, including samples from different body sites (saliva, pharynx, duodenum, and stool). We found the presence of coordinated changes through the gastrointestinal tract characterised by an increase in Actinobacteria species in the upper tract (pharynx and duodenum), and an increase in Proteobacteria in the lower tract (duodenum and stool), as well as site-specific changes evidencing a dysbiosis in CeD patients' microbiota. Moreover, we described the effect of adherence to a gluten-free diet (GFD) evidenced by an increase in beneficial bacteria and a decrease in some Betaproteobacteriales but not fully restoring CeD-related dysbiosis. We illustrate that the gut microbiota acts as an enhancer of immune response in CeD through the production of lipopolysaccharides and other bacterial components that activate the immune response and by decrease SCFA producers bacteria. Furthermore, microbial changes observed through the gastrointestinal tract of CeD patients may help manage the disease and follow-up GFD treatment.

Psychological Resilience Provides No Independent Protection From Suicidal Risk

Crisis ◽  
2016 ◽  
Vol 37 (2) ◽  
pp. 130-139 ◽  
Author(s):  
Danica W. Y. Liu ◽  
A. Kate Fairweather-Schmidt ◽  
Richard Burns ◽  
Rachel M. Roberts ◽  
Kaarin J. Anstey
Keyword(s):  
Risk Factors ◽  
Well Being ◽  
Current Status ◽  
Psychological Resilience ◽  
Cross Sectional ◽  
Life Project ◽  
Resilience Factors ◽  
First Time

Abstract. Background: Little is known about the role of resilience in the likelihood of suicidal ideation (SI) over time. Aims: We examined the association between resilience and SI in a young-adult cohort over 4 years. Our objectives were to determine whether resilience was associated with SI at follow-up or, conversely, whether SI was associated with lowered resilience at follow-up. Method: Participants were selected from the Personality and Total Health (PATH) Through Life Project from Canberra and Queanbeyan, Australia, aged 28–32 years at the first time point and 32–36 at the second. Multinomial, linear, and binary regression analyses explored the association between resilience and SI over two time points. Models were adjusted for suicidality risk factors. Results: While unadjusted analyses identified associations between resilience and SI, these effects were fully explained by the inclusion of other suicidality risk factors. Conclusion: Despite strong cross-sectional associations, resilience and SI appear to be unrelated in a longitudinal context, once risk/resilience factors are controlled for. As independent indicators of psychological well-being, suicidality and resilience are essential if current status is to be captured. However, the addition of other factors (e.g., support, mastery) makes this association tenuous. Consequently, resilience per se may not be protective of SI.

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