Journal articles: 'Biomass degrading enzymes'

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Lunin, Vladimir, Markus Alahuhta, Gregg Beckham, et al. "Structural studies of biomass degrading enzyme systems." Acta Crystallographica Section A Foundations and Advances 70, a1 (2014): C1812. http://dx.doi.org/10.1107/s2053273314081881.

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Renewable energy today comprises wind, photovoltaics, geothermal, and biofuels. Biomass is the leading source of renewable, sustainable energy used for the production of liquid transportation fuels. While the focus is shifting today from the ethanol towards next generation or advanced biofuels the real challenge however remains the same: reducing the recalcitrance of biomass to deconstruction, which yields the sugars needed for further processing. NREL's Biosciences Center conducts studies of the fundamental nature of the plant cell wall; as well as those enzyme systems utilized in Nature to deconstruct it. These systems could be classified in two ways: the "free enzymes" and the "cellulosomes." Cellulosomes are self-assembling, multi-enzyme machinery that can include dozens and hundreds of catalytic domains and cellulose binding modules interconnected by linker peptides. We will present a structural overview of the biomass degrading enzymes from fungi using Trichoderma reesei and Penicillum funiculosum as examples. The bacterial cellulosome system discussed will be from a thermophile Clostridium thermocellum and bacterial free enzyme example will be the hyperthermophile, Caldicellulosiruptor bescii. To study these systems, we combined classical biochemistry and molecular biology, mass spectrometry, electron microscopy, high throughput robotics, macromolecular crystallography, and molecular dynamics. We seek to understand the properties and structure of biomass and plant cell walls, the structure-function relationships of the relevant hydrolytic enzymes, and the ways these enzymes interact with and alter the biomass during the degradation. Thorough understanding of the details of the molecular machinery at work has led to the development of improved enzyme cocktails that have reduced the cost of biomass conversion to renewable fuels so that today, this technology is becoming competitive with traditional fossil fuels.

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Lee, Charles C. "Screening assays for biomass-degrading enzymes." Biofuels 1, no. 4 (2010): 575–88. http://dx.doi.org/10.4155/bfs.10.26.

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Frandsen, Kristian E. H., Tobias Tandrup, Jens-Christian N. Poulsen, et al. "Active site evolution in biomass degrading enzymes." Acta Crystallographica Section A Foundations and Advances 75, a2 (2019): e124-e124. http://dx.doi.org/10.1107/s2053273319094324.

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Saini, Anita, Neeraj K. Aggarwal, Anuja Sharma, and Anita Yadav. "Actinomycetes: A Source of Lignocellulolytic Enzymes." Enzyme Research 2015 (December 17, 2015): 1–15. http://dx.doi.org/10.1155/2015/279381.

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Lignocellulose is the most abundant biomass on earth. Agricultural, forest, and agroindustrial activities generate tons of lignocellulosic wastes annually, which present readily procurable, economically affordable, and renewable feedstock for various lignocelluloses based applications. Lignocelluloses are the focus of present decade researchers globally, in an attempt to develop technologies based on natural biomass for reducing dependence on expensive and exhaustible substrates. Lignocellulolytic enzymes, that is, cellulases, hemicellulases, and lignolytic enzymes, play very important role in the processing of lignocelluloses which is prerequisite for their utilization in various processes. These enzymes are obtained from microorganisms distributed in both prokaryotic and eukaryotic domains including bacteria, fungi, and actinomycetes. Actinomycetes are an attractive microbial group for production of lignocellulose degrading enzymes. Various studies have evaluated the lignocellulose degrading ability of actinomycetes, which can be potentially implemented in the production of different value added products. This paper is an overview of the diversity of cellulolytic, hemicellulolytic, and lignolytic actinomycetes along with brief discussion of their hydrolytic enzyme systems involved in biomass modification.

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Agrawal, Ruchi, Ruchi Gaur, Anshu Mathur, et al. "Improved saccharification of pilot-scale acid pretreated wheat straw by exploiting the synergistic behavior of lignocellulose degrading enzymes." RSC Advances 5, no. 87 (2015): 71462–71. http://dx.doi.org/10.1039/c5ra13360b.

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Book, Adam J., Gina R. Lewin, Bradon R. McDonald, et al. "Cellulolytic Streptomyces Strains Associated with Herbivorous Insects Share a Phylogenetically Linked Capacity To Degrade Lignocellulose." Applied and Environmental Microbiology 80, no. 15 (2014): 4692–701. http://dx.doi.org/10.1128/aem.01133-14.

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ABSTRACTActinobacteria in the genusStreptomycesare critical players in microbial communities that decompose complex carbohydrates in the soil, and these bacteria have recently been implicated in the deconstruction of plant polysaccharides for some herbivorous insects. Despite the importance ofStreptomycesto carbon cycling, the extent of their plant biomass-degrading ability remains largely unknown. In this study, we compared four strains ofStreptomycesisolated from insect herbivores that attack pine trees: DpondAA-B6 (SDPB6) from the mountain pine beetle, SPB74 from the southern pine beetle, and SirexAA-E (SACTE) and SirexAA-G from the woodwasp,Sirex noctilio. Biochemical analysis of secreted enzymes demonstrated that only two of these strains, SACTE and SDPB6, were efficient at degrading plant biomass. Genomic analyses indicated that SACTE and SDPB6 are closely related and that they share similar compositions of carbohydrate-active enzymes. Genome-wide proteomic and transcriptomic analyses revealed that the major exocellulases (GH6 and GH48), lytic polysaccharide monooxygenases (AA10), and mannanases (GH5) were conserved and secreted by both organisms, while the secreted endocellulases (GH5 and GH9 versus GH9 and GH12) were from diverged enzyme families. Together, these data identify two phylogenetically related insect-associatedStreptomycesstrains with high biomass-degrading activity and characterize key enzymatic similarities and differences used by these organisms to deconstruct plant biomass.

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Wu, Vincent W., Nils Thieme, Lori B. Huberman, et al. "The regulatory and transcriptional landscape associated with carbon utilization in a filamentous fungus." Proceedings of the National Academy of Sciences 117, no. 11 (2020): 6003–13. http://dx.doi.org/10.1073/pnas.1915611117.

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Filamentous fungi, such asNeurospora crassa, are very efficient in deconstructing plant biomass by the secretion of an arsenal of plant cell wall-degrading enzymes, by remodeling metabolism to accommodate production of secreted enzymes, and by enabling transport and intracellular utilization of plant biomass components. Although a number of enzymes and transcriptional regulators involved in plant biomass utilization have been identified, how filamentous fungi sense and integrate nutritional information encoded in the plant cell wall into a regulatory hierarchy for optimal utilization of complex carbon sources is not understood. Here, we performed transcriptional profiling ofN. crassaon 40 different carbon sources, including plant biomass, to provide data on how fungi sense simple to complex carbohydrates. From these data, we identified regulatory factors inN. crassaand characterized one (PDR-2) associated with pectin utilization and one with pectin/hemicellulose utilization (ARA-1). Using in vitro DNA affinity purification sequencing (DAP-seq), we identified direct targets of transcription factors involved in regulating genes encoding plant cell wall-degrading enzymes. In particular, our data clarified the role of the transcription factor VIB-1 in the regulation of genes encoding plant cell wall-degrading enzymes and nutrient scavenging and revealed a major role of the carbon catabolite repressor CRE-1 in regulating the expression of major facilitator transporter genes. These data contribute to a more complete understanding of cross talk between transcription factors and their target genes, which are involved in regulating nutrient sensing and plant biomass utilization on a global level.

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Patyshakuliyeva, Aleksandrina, Daniel L. Falkoski, Ad Wiebenga, Klaas Timmermans, and Ronald P. de Vries. "Macroalgae Derived Fungi Have High Abilities to Degrade Algal Polymers." Microorganisms 8, no. 1 (2019): 52. http://dx.doi.org/10.3390/microorganisms8010052.

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Marine fungi associated with macroalgae are an ecologically important group that have a strong potential for industrial applications. In this study, twenty-two marine fungi isolated from the brown seaweed Fucus sp. were examined for their abilities to produce algal and plant biomass degrading enzymes. Growth of these isolates on brown and green algal biomass revealed a good growth, but no preference for any specific algae. Based on the analysis of enzymatic activities, macroalgae derived fungi were able to produce algae specific and (hemi-)cellulose degrading enzymes both on algal and plant biomass. However, the production of algae specific activities was lower than the production of cellulases and xylanases. These data revealed the presence of different enzymatic approaches for the degradation of algal biomass by macroalgae derived fungi. In addition, the results of the present study indicate our poor understanding of the enzymes involved in algal biomass degradation and the mechanisms of algal carbon source utilization by marine derived fungi.

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Bissaro, Bastien, Zarah Forsberg, Yan Ni, Frank Hollmann, Gustav Vaaje-Kolstad, and Vincent G. H. Eijsink. "Fueling biomass-degrading oxidative enzymes by light-driven water oxidation." Green Chemistry 18, no. 19 (2016): 5357–66. http://dx.doi.org/10.1039/c6gc01666a.

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Henske, John K., Sean P. Gilmore, Charles H. Haitjema, Kevin V. Solomon, and Michelle A. O'Malley. "Biomass-degrading enzymes are catabolite repressed in anaerobic gut fungi." AIChE Journal 64, no. 12 (2018): 4263–70. http://dx.doi.org/10.1002/aic.16395.

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Meilleur, Flora. "Characterization of biomass-degrading enzymes using neutron diffraction and scattering." Neutron News 32, no. 1 (2021): 13–14. http://dx.doi.org/10.1080/10448632.2021.1875777.

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Mezule, Linda, and Anna Civzele. "Bioprospecting White-Rot Basidiomycete Irpex lacteus for Improved Extraction of Lignocellulose-Degrading Enzymes and Their Further Application." Journal of Fungi 6, no. 4 (2020): 256. http://dx.doi.org/10.3390/jof6040256.

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Lignocellulosic biomass can be used as a source for energy, fuel and valuable chemical production. From all available technologies, biological approaches have been recognized as the most environmentally friendly and sustainable ones. At the same time, high conversion costs, low efficiency and environmental issues still hinder the introduction of biological processes into industrial scale manufacturing. The aim of this study was to determine the most suitable enzyme cocktail recovery conditions from a biomass–fungal culture of the white-rot basidiomycete Irpex lacteus. Subsequent evaluation of the overall enzyme cocktail efficiency to release fermentable carbohydrates from biomass showed that prolonged fungal cultivation decreases the quality of the produced enzyme cocktail. At the same time, introduction of ultrasound pre-treatment during enzyme extraction improved the recovered enzyme cocktail efficiency in converting biomass to fermentable sugars, yielding up to 0.25 g of fermentable sugar per g dry hay biomass and up to 0.11 g per g dried straw or microalgae substrates. The results demonstrated that the production of lignocellulose-degrading enzymes from fungi is more sensitive than previously described, especially in terms of fungal growth, culture sterility and incubation conditions.

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Lange, Lene, Kristian Barrett, and Anne S. Meyer. "New Method for Identifying Fungal Kingdom Enzyme Hotspots from Genome Sequences." Journal of Fungi 7, no. 3 (2021): 207. http://dx.doi.org/10.3390/jof7030207.

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Fungal genome sequencing data represent an enormous pool of information for enzyme discovery. Here, we report a new approach to identify and quantitatively compare biomass-degrading capacity and diversity of fungal genomes via integrated function-family annotation of carbohydrate-active enzymes (CAZymes) encoded by the genomes. Based on analyses of 1932 fungal genomes the most potent hotspots of fungal biomass processing CAZymes are identified and ranked according to substrate degradation capacity. The analysis is achieved by a new bioinformatics approach, Conserved Unique Peptide Patterns (CUPP), providing for CAZyme-family annotation and robust prediction of molecular function followed by conversion of the CUPP output to lists of integrated “Function;Family” (e.g., EC 3.2.1.4;GH5) enzyme observations. An EC-function found in several protein families counts as different observations. Summing up such observations allows for ranking of all analyzed genome sequenced fungal species according to richness in CAZyme function diversity and degrading capacity. Identifying fungal CAZyme hotspots provides for identification of fungal species richest in cellulolytic, xylanolytic, pectinolytic, and lignin modifying enzymes. The fungal enzyme hotspots are found in fungi having very different lifestyle, ecology, physiology and substrate/host affinity. Surprisingly, most CAZyme hotspots are found in enzymatically understudied and unexploited species. In contrast, the most well-known fungal enzyme producers, from where many industrially exploited enzymes are derived, are ranking unexpectedly low. The results contribute to elucidating the evolution of fungal substrate-digestive CAZyme profiles, ecophysiology, and habitat adaptations, and expand the knowledge base for novel and improved biomass resource utilization.

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Foreman, Pamela K., Doug Brown, Lydia Dankmeyer, et al. "Transcriptional Regulation of Biomass-degrading Enzymes in the Filamentous FungusTrichoderma reesei." Journal of Biological Chemistry 278, no. 34 (2003): 31988–97. http://dx.doi.org/10.1074/jbc.m304750200.

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Taggar, Monica Sachdeva. "Insect cellulolytic enzymes: Novel sources for degradation of lignocellulosic biomass." Journal of Applied and Natural Science 7, no. 2 (2015): 625–30. http://dx.doi.org/10.31018/jans.v7i2.656.

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Alternative and renewable fuels derived from lignocellulosic biomass offer the potential to reduce our dependence on fossil fuels and mitigate global climate change. Cellulose is one of the major structural components in all lignocellulosic wastes and enzymatic depolymerization of cellulose by cellulases is an essential step in bio-ethanol production. Wood-degrading insects are potential source of biochemical catalysts for converting wood lignocellulose into biofuels. Cellulose digestion has been demonstrated in more than 20 insect families representing ten distinct insect orders. Termite guts been have considered as the “world’s smallest bioreactors” since they digest a significant proportion of cellulose (74-99%) and hemicellulose (65-87%) components of lignocelluloses they ingest. The lower termites harbor protistan symbionts in hindgut whereas higher termites lack these in the hind gut. Studies on cellulose digestion in termites and other insects with reference to ligno-cellulose degrading enzymes have been well focused in this review. The studies on insect cellulolytic systems can lead to the discovery of a variety of novel biocatalysts and genes that encode them, as well as associated unique mechanisms for efficient biomass conversion into biofuels.

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Blumer-Schuette, Sara E. "Insights into Thermophilic Plant Biomass Hydrolysis from Caldicellulosiruptor Systems Biology." Microorganisms 8, no. 3 (2020): 385. http://dx.doi.org/10.3390/microorganisms8030385.

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Plant polysaccharides continue to serve as a promising feedstock for bioproduct fermentation. However, the recalcitrant nature of plant biomass requires certain key enzymes, including cellobiohydrolases, for efficient solubilization of polysaccharides. Thermostable carbohydrate-active enzymes are sought for their stability and tolerance to other process parameters. Plant biomass degrading microbes found in biotopes like geothermally heated water sources, compost piles, and thermophilic digesters are a common source of thermostable enzymes. While traditional thermophilic enzyme discovery first focused on microbe isolation followed by functional characterization, metagenomic sequences are negating the initial need for species isolation. Here, we summarize the current state of knowledge about the extremely thermophilic genus Caldicellulosiruptor, including genomic and metagenomic analyses in addition to recent breakthroughs in enzymology and genetic manipulation of the genus. Ten years after completing the first Caldicellulosiruptor genome sequence, the tools required for systems biology of this non-model environmental microorganism are in place.

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van den Brink, Joost, Gonny C. J. van Muiswinkel, Bart Theelen, Sandra W. A. Hinz, and Ronald P. de Vries. "Efficient Plant Biomass Degradation by Thermophilic Fungus Myceliophthora heterothallica." Applied and Environmental Microbiology 79, no. 4 (2012): 1316–24. http://dx.doi.org/10.1128/aem.02865-12.

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ABSTRACTRapid and efficient enzymatic degradation of plant biomass into fermentable sugars is a major challenge for the sustainable production of biochemicals and biofuels. Enzymes that are more thermostable (up to 70°C) use shorter reaction times for the complete saccharification of plant polysaccharides compared to hydrolytic enzymes of mesophilic fungi such asTrichodermaandAspergillusspecies. The genusMyceliophthoracontains four thermophilic fungi producing industrially relevant thermostable enzymes. Within this genus, isolates belonging toM. heterothallicawere recently separated from the well-described speciesM. thermophila. We evaluate here the potential ofM. heterothallicaisolates to produce efficient enzyme mixtures for biomass degradation. Compared to the other thermophilicMyceliophthoraspecies, isolates belonging toM. heterothallicaandM. thermophilagrew faster on pretreated spruce, wheat straw, and giant reed. According to their protein profiles andin vitroassays after growth on wheat straw, (hemi-)cellulolytic activities differed strongly betweenM. thermophilaandM. heterothallicaisolates. Compared toM. thermophila,M. heterothallicaisolates were better in releasing sugars from mildly pretreated wheat straw (with 5% HCl) with a high content of xylan. The high levels of residual xylobiose revealed that enzyme mixtures ofMyceliophthoraspecies lack sufficient β-xylosidase activity. Sexual crossing of twoM. heterothallicashowed that progenies had a large genetic and physiological diversity. In the future, this will allow further improvement of the plant biomass-degrading enzyme mixtures ofM. heterothallica.

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Zhang, Dongcheng, Amy L. VanFossen, Ryan M. Pagano, et al. "Consolidated Pretreatment and Hydrolysis of Plant Biomass Expressing Cell Wall Degrading Enzymes." BioEnergy Research 4, no. 4 (2011): 276–86. http://dx.doi.org/10.1007/s12155-011-9138-2.

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Ma, Hongyan, Daniel G. Delafield, Zhe Wang, Jianlan You, and Si Wu. "Finding Biomass Degrading Enzymes Through an Activity-Correlated Quantitative Proteomics Platform (ACPP)." Journal of The American Society for Mass Spectrometry 28, no. 4 (2017): 655–63. http://dx.doi.org/10.1007/s13361-016-1569-8.

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Lange, Lene, Bo Pilgaard, Florian-Alexander Herbst, Peter Kamp Busk, Frank Gleason, and Anders Gorm Pedersen. "Origin of fungal biomass degrading enzymes: Evolution, diversity and function of enzymes of early lineage fungi." Fungal Biology Reviews 33, no. 1 (2019): 82–97. http://dx.doi.org/10.1016/j.fbr.2018.09.001.

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Rohman, Ali, Bauke W. Dijkstra та Ni Nyoman Tri Puspaningsih. "β-Xylosidases: Structural Diversity, Catalytic Mechanism, and Inhibition by Monosaccharides". International Journal of Molecular Sciences 20, № 22 (2019): 5524. http://dx.doi.org/10.3390/ijms20225524.

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Xylan, a prominent component of cellulosic biomass, has a high potential for degradation into reducing sugars, and subsequent conversion into bioethanol. This process requires a range of xylanolytic enzymes. Among them, β-xylosidases are crucial, because they hydrolyze more glycosidic bonds than any of the other xylanolytic enzymes. They also enhance the efficiency of the process by degrading xylooligosaccharides, which are potent inhibitors of other hemicellulose-/xylan-converting enzymes. On the other hand, the β-xylosidase itself is also inhibited by monosaccharides that may be generated in high concentrations during the saccharification process. Structurally, β-xylosidases are diverse enzymes with different substrate specificities and enzyme mechanisms. Here, we review the structural diversity and catalytic mechanisms of β-xylosidases, and discuss their inhibition by monosaccharides.

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Jung, Sang-Kyu, Vinuselvi Parisutham, Seong Hun Jeong, and Sung Kuk Lee. "Heterologous Expression of Plant Cell Wall Degrading Enzymes for Effective Production of Cellulosic Biofuels." Journal of Biomedicine and Biotechnology 2012 (2012): 1–10. http://dx.doi.org/10.1155/2012/405842.

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A major technical challenge in the cost-effective production of cellulosic biofuel is the need to lower the cost of plant cell wall degrading enzymes (PCDE), which is required for the production of sugars from biomass. Several competitive, low-cost technologies have been developed to produce PCDE in different host organisms such asEscherichia coli, Zymomonas mobilis, and plant. Selection of an ideal host organism is very important, because each host organism has its own unique features. Synthetic biology-aided tools enable heterologous expression of PCDE in recombinantE. coliorZ. mobilisand allow successful consolidated bioprocessing (CBP) in these microorganisms.In-plantaexpression provides an opportunity to simplify the process of enzyme production and plant biomass processing and leads to self-deconstruction of plant cell walls. Although the future of currently available technologies is difficult to predict, a complete and viable platform will most likely be available through the integration of the existing approaches with the development of breakthrough technologies.

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Vitcosque, Gabriela L., Rafael F. Fonseca, Ursula Fabiola Rodríguez-Zúñiga, Victor Bertucci Neto, Sonia Couri, and Cristiane S. Farinas. "Production of Biomass-Degrading Multienzyme Complexes under Solid-State Fermentation of Soybean Meal Using a Bioreactor." Enzyme Research 2012 (December 29, 2012): 1–9. http://dx.doi.org/10.1155/2012/248983.

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Biomass-degrading enzymes are one of the most costly inputs affecting the economic viability of the biochemical route for biomass conversion into biofuels. This work evaluates the effects of operational conditions on biomass-degrading multienzyme production by a selected strain of Aspergillus niger. The fungus was cultivated under solid-state fermentation (SSF) of soybean meal, using an instrumented lab-scale bioreactor equipped with an on-line automated monitoring and control system. The effects of air flow rate, inlet air relative humidity, and initial substrate moisture content on multienzyme (FPase, endoglucanase, and xylanase) production were evaluated using a statistical design methodology. Highest production of FPase (0.55 IU/g), endoglucanase (35.1 IU/g), and xylanase (47.7 IU/g) was achieved using an initial substrate moisture content of 84%, an inlet air humidity of 70%, and a flow rate of 24 mL/min. The enzymatic complex was then used to hydrolyze a lignocellulosic biomass, releasing 4.4 g/L of glucose after 36 hours of saccharification of 50 g/L pretreated sugar cane bagasse. These results demonstrate the potential application of enzymes produced under SSF, thus contributing to generate the necessary technological advances to increase the efficiency of the use of biomass as a renewable energy source.

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Singh, K. M., Bhaskar Reddy, Dishita Patel, et al. "High Potential Source for Biomass Degradation Enzyme Discovery and Environmental Aspects Revealed through Metagenomics of Indian Buffalo Rumen." BioMed Research International 2014 (2014): 1–10. http://dx.doi.org/10.1155/2014/267189.

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The complex microbiomes of the rumen functions as an effective system for plant cell wall degradation, and biomass utilization provide genetic resource for degrading microbial enzymes that could be used in the production of biofuel. Therefore the buffalo rumen microbiota was surveyed using shot gun sequencing. This metagenomic sequencing generated 3.9 GB of sequences and data were assembled into 137270 contiguous sequences (contigs). We identified potential 2614 contigs encoding biomass degrading enzymes including glycoside hydrolases (GH: 1943 contigs), carbohydrate binding module (CBM: 23 contigs), glycosyl transferase (GT: 373 contigs), carbohydrate esterases (CE: 259 contigs), and polysaccharide lyases (PE: 16 contigs). The hierarchical clustering of buffalo metagenomes demonstrated the similarities and dissimilarity in microbial community structures and functional capacity. This demonstrates that buffalo rumen microbiome was considerably enriched in functional genes involved in polysaccharide degradation with great prospects to obtain new molecules that may be applied in the biofuel industry.

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Frandsen, Kristian E. H., and Leila Lo Leggio. "Lytic polysaccharide monooxygenases: a crystallographer's view on a new class of biomass-degrading enzymes." IUCrJ 3, no. 6 (2016): 448–67. http://dx.doi.org/10.1107/s2052252516014147.

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Lytic polysaccharide monooxygenases (LPMOs) are a new class of microbial copper enzymes involved in the degradation of recalcitrant polysaccharides. They have only been discovered and characterized in the last 5–10 years and have stimulated strong interest both in biotechnology and in bioinorganic chemistry. In biotechnology, the hope is that these enzymes will finally help to make enzymatic biomass conversion, especially of lignocellulosic plant waste, economically attractive. Here, the role of LPMOs is likely to be in attacking bonds that are not accessible to other enzymes. LPMOs have attracted enormous interest since their discovery. The emphasis in this review is on the past and present contribution of crystallographic studies as a guide to functional understanding, with a final look towards the future.

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Ayeronfe, Fadilah, Angzzas Kassim, Patricia Hung, Nadiah Ishak, Sharfina Syarifah, and Ashuvila Aripin. "Production of Ligninolytic Enzymes by Coptotermes curvignathus Gut Bacteria." Environmental and Climate Technologies 23, no. 1 (2019): 111–21. http://dx.doi.org/10.2478/rtuect-2019-0008.

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Abstract Maximum utilization of lignocellulosic biomass is contingent upon degrading the recalcitrant lignin polymer. Conventional methods employed in delignification require high inputs of energy and chemicals, resulting in the release of highly toxic effluents. The ability of gut flora of Coptotermes curvignathus in lignin degradation was investigated in this study. Production of ligninolytic enzymes was done in an aerated submerged fermentation system with kraft lignin as sole carbon source. The degradation experiment was carried out for 7 days at 30 °C, pH 7. Three potential lignin degraders identified as Bacillus sp., Lysinibacillus sp. and Acinetobacter sp. were successfully isolated. The bacterial growth and secretion of extracellular ligninolytic enzymes confirmed metabolism of kraft lignin by the identified strains. Lysinibacillus sp., a novel lignin degrader showed highest manganese peroxidase (76.36 ± 15.74 U/L) and laccase activity (70.67 ± 16.82 U/L) after 7 and 6 days of incubation respectively, while maximal activity of lignin peroxidase (262.49 ± 0.92 U/L) was recorded after 7 days in culture supernatants of Bacillus sp. With respect to the activity of the secreted enzymes, the lignin degrading potential of these bacterial strains can be explored in the valorisations of lignocellulosic biomass in industrial processes such as pulping, bioethanol production, fine chemicals and materials synthesis.

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Bernardi, Aline Vianna, Luis Eduardo Gerolamo, Paula Fagundes de Gouvêa, et al. "LPMO AfAA9_B and Cellobiohydrolase AfCel6A from A. fumigatus Boost Enzymatic Saccharification Activity of Cellulase Cocktail." International Journal of Molecular Sciences 22, no. 1 (2020): 276. http://dx.doi.org/10.3390/ijms22010276.

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Cellulose is the most abundant polysaccharide in lignocellulosic biomass, where it is interlinked with lignin and hemicellulose. Bioethanol can be produced from biomass. Since breaking down biomass is difficult, cellulose-active enzymes secreted by filamentous fungi play an important role in degrading recalcitrant lignocellulosic biomass. We characterized a cellobiohydrolase (AfCel6A) and lytic polysaccharide monooxygenase LPMO (AfAA9_B) from Aspergillus fumigatus after they were expressed in Pichia pastoris and purified. The biochemical parameters suggested that the enzymes were stable; the optimal temperature was ~60 °C. Further characterization revealed high turnover numbers (kcat of 147.9 s−1 and 0.64 s−1, respectively). Surprisingly, when combined, AfCel6A and AfAA9_B did not act synergistically. AfCel6A and AfAA9_B association inhibited AfCel6A activity, an outcome that needs to be further investigated. However, AfCel6A or AfAA9_B addition boosted the enzymatic saccharification activity of a cellulase cocktail and the activity of cellulase Af-EGL7. Enzymatic cocktail supplementation with AfCel6A or AfAA9_B boosted the yield of fermentable sugars from complex substrates, especially sugarcane exploded bagasse, by up to 95%. The synergism between the cellulase cocktail and AfAA9_B was enzyme- and substrate-specific, which suggests a specific enzymatic cocktail for each biomass by up to 95%. The synergism between the cellulase cocktail and AfAA9_B was enzyme- and substrate-specific, which suggests a specific enzymatic cocktail for each biomass.

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Gladden, John M., Martin Allgaier, Christopher S. Miller, et al. "Glycoside Hydrolase Activities of Thermophilic Bacterial Consortia Adapted to Switchgrass." Applied and Environmental Microbiology 77, no. 16 (2011): 5804–12. http://dx.doi.org/10.1128/aem.00032-11.

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ABSTRACTIndustrial-scale biofuel production requires robust enzymatic cocktails to produce fermentable sugars from lignocellulosic biomass. Thermophilic bacterial consortia are a potential source of cellulases and hemicellulases adapted to harsher reaction conditions than commercial fungal enzymes. Compost-derived microbial consortia were adapted to switchgrass at 60°C to develop thermophilic biomass-degrading consortia for detailed studies. Microbial community analysis using small-subunit rRNA gene amplicon pyrosequencing and short-read metagenomic sequencing demonstrated that thermophilic adaptation to switchgrass resulted in low-diversity bacterial consortia with a high abundance of bacteria related to thermophilic paenibacilli,Rhodothermus marinus, andThermus thermophilus. At lower abundance, thermophilicChloroflexiand an uncultivated lineage of theGemmatimonadetesphylum were observed. Supernatants isolated from these consortia had high levels of xylanase and endoglucanase activities. Compared to commercial enzyme preparations, the endoglucanase enzymes had a higher thermotolerance and were more stable in the presence of 1-ethyl-3-methylimidazolium acetate ([C2mim][OAc]), an ionic liquid used for biomass pretreatment. The supernatants were used to saccharify [C2mim][OAc]-pretreated switchgrass at elevated temperatures (up to 80°C), demonstrating that these consortia are an excellent source of enzymes for the development of enzymatic cocktails tailored to more extreme reaction conditions.

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Solomon, Kevin V., Charles H. Haitjema, John K. Henske, et al. "Early-branching gut fungi possess a large, comprehensive array of biomass-degrading enzymes." Science 351, no. 6278 (2016): 1192–95. http://dx.doi.org/10.1126/science.aad1431.

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Freitag, Michael, and Jeffrey J. Morrel. "Changes in selected enzyme activities during growth of pure and mixed cultures of the white-rot decay fungus Trametes versicolor and the potential biocontrol fungus Trichoderma harzianum." Canadian Journal of Microbiology 38, no. 4 (1992): 317–23. http://dx.doi.org/10.1139/m92-053.

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Two filamentous fungi, the white-rot fungus Trametes versicolor and the soil fungus and potential biocontrol organismTrichoderma harzianum, have been grown in pure and mixed cultures on low-N (0.4 mM) and high-N (4 mM) defined synthetic media to determine the activities of selected wood-degrading enzymes such as cellobiase, cellulase, laccase,and peroxidases. Growth characteristics and enzyme activities were examined for potential correlations. Such correlations would allow the use of simple enzyme assays for measuring biomass development and would facilitate predictions about competitiveness of species in mixed fungal cultures. Our results show that while laccase and Poly Red-478 peroxidase activities indicate survival of the decay fungus, none of the monitored extracellular enzymes can serve as a quantitative indicator for biomass accumulation. As expected, the level of available nitrogen affected the production of the enzymes monitored: in low-N media, specific cellobiase, specific cellulase, and peroxidase activities were enhanced, while laccase activities were reduced. Most importantly, laccase activities of Trametes versicolor, and to a smaller extent, cellobiase activities of both fungi, were significantly induced in mixed cultures of Trametes versicolor and Trichoderma harzianum. Key words: biocontrol, wood decay, laccase, peroxidases.

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Couturier, Marie, Mireille Haon, Pedro M. Coutinho, Bernard Henrissat, Laurence Lesage-Meessen, and Jean-Guy Berrin. "Podospora anserinaHemicellulases Potentiate theTrichoderma reeseiSecretome for Saccharification of Lignocellulosic Biomass." Applied and Environmental Microbiology 77, no. 1 (2010): 237–46. http://dx.doi.org/10.1128/aem.01761-10.

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ABSTRACTTo improve the enzymatic hydrolysis (saccharification) of lignocellulosic biomass byTrichoderma reesei, a set of genes encoding putative polysaccharide-degrading enzymes were selected from the coprophilic fungusPodospora anserinausing comparative genomics. Five hemicellulase-encoding genes were successfully cloned and expressed as secreted functional proteins in the yeastPichia pastoris. These novel fungal CAZymes belonging to different glycoside hydrolase families (PaMan5A andPaMan26A mannanases,PaXyn11A xylanase, andPaAbf51A andPaAbf62A arabinofuranosidases) were able to break down their predicted cognate substrates. AlthoughPaMan5A andPaMan26A displayed similar specificities toward a range of mannan substrates, they differed in their end products, suggesting differences in substrate binding. The N-terminal CBM35 module ofPaMan26A displayed dual binding specificity toward xylan and mannan.PaXyn11A harboring a C-terminal CBM1 module efficiently degraded wheat arabinoxylan, releasing mainly xylobiose as end product.PaAbf51A andPaAbf62A arabinose-debranching enzymes exhibited differences in activity toward arabinose-containing substrates. Further investigation of the contribution made by eachP. anserinaauxiliary enzyme to the saccharification of wheat straw and spruce demonstrated that the endo-acting hemicellulases (PaXyn11A,PaMan5A, andPaMan26A) individually supplemented the secretome of the industrialT. reeseiCL847 strain. The most striking effect was obtained withPaMan5A that improved the release of total sugars by 28% and of glucose by 18%, using spruce as lignocellulosic substrate.

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Henske, John K., Stephen D. Springer, Michelle A. O'Malley, and Alison Butler. "Substrate-based differential expression analysis reveals control of biomass degrading enzymes in Pycnoporus cinnabarinus." Biochemical Engineering Journal 130 (February 2018): 83–89. http://dx.doi.org/10.1016/j.bej.2017.11.015.

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Jadhav, Rajesh Khanduji. "IN VITRO SCREENING OF CELL WALL DEGRADING ENZYME PRODUCTIVITY FROM FUNGAL CULTURE FILTRATES ON DEPROTEINISED PLANT FLUID BY CUP PLATE ASSAY." Fungal Territory 1, no. 2 (2018): 5–9. http://dx.doi.org/10.36547/ft.2018.1.2.5-9.

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The present study purpose is to evaluate the potentiality of the Deproteinised juice made from selected plants to induce the enzyme productivity by growing the fungi on it. It is because, in earlier findings, the DPJ was found potential in enhancing fungi and the plant growth when used as the medium. The internal factors are responsible in DPJ which induces plants and fungi growth. During the process of Green Crop Fractionation (GCF), the deproteinised (DPJ) obtained from tissues of cabbage, beet, lucerne (Alfalfa), carrot and Anathum (Dill) forages left after leaf protein extraction employed as a medium for the cultivation of mycelial biomass of Penicillium and Aspergillus fungi. The mycelial growth in vitro was compared with the glucose nitrate medium. The culture filtrates were used to screen different secreted hydrolytic or cell wall degrading enzymes.. The agar ‘cup‐plate’ diffusion technique has been applied to the quantitative determination of enzyme activity, principally to amylase, cellulase and protease. With all enzymes so far examined, the relationship between diameter of zone over a wide range secreted quantitatively was examined. All fungi grew well on DPJ in comparison to their growth on glucose nitrate (GN) medium. Comparatively with GN medium, lucerne DPJ was found having more mycelial cellular proliferation. When the fungi grown on different concentrations of substrates, enriched with carboxymethyl cellulose, casein and starch in deproteinised leaf extracts and GN medium, it was found that there was the enhancement in the mycelial dry weight grown on DPJ as compared with glucose nitrate medium. Penicillium showed more yield of enzyme activities especially of cellulases and amylases as compared to protease by cup plate method. There was enhancement of mycelial biomass when the concentrations of substrates increased from 1% to 2%, while there was no change in the activity of all enzymes by increasing the concentrations of substrates. Activities of the enzymes in vitro can be indicative of the pattern of organogenesis in callus cultures in further studies by fungal culture filtrates cultured on deproteinised fluid medium.

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Yao, Bo, Qiwu Hu, Guihua Zhang, Yafeng Yi, Meijuan Xiao, and Dazhi Wen. "Effects of Elevated CO2 Concentration and Nitrogen Addition on Soil Respiration in a Cd-Contaminated Experimental Forest Microcosm." Forests 11, no. 3 (2020): 260. http://dx.doi.org/10.3390/f11030260.

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Forests near rapidly industrialized and urbanized regions are often exposed to elevated CO2, increased N deposition, and heavy metal pollution. To date, the effects of elevated CO2 and/or increased N deposition on soil respiration (Rs) under heavy metal contamination are unclear. In this study, we firstly investigated Rs in Cd-contaminated model forests with CO2 enrichment and N addition in subtropical China. Results showed that Rs in all treatments exhibited similar clear seasonal patterns, with soil temperature being a dominant control. Cadmium addition significantly decreased cumulative soil CO2 efflux by 19% compared to the control. The inhibition of Rs caused by Cd addition was increased by N addition (decreased by 34%) was partially offset by elevated CO2 (decreased by 15%), and was not significantly altered by the combined N addition and rising CO2. Soil pH, microbial biomass carbon, carbon-degrading hydrolytic enzymes, and fine root biomass were also significantly altered by the treatments. A structural equation model revealed that the responses of Rs to Cd stress, elevated CO2, and N addition were mainly mediated by soil carbon-degrading hydrolytic enzymes and fine root biomass. Overall, our findings indicate that N deposition may exacerbate the negative effect of Cd on Rs in Cd-contaminated forests and benefit soil carbon sequestration in the future at increasing atmospheric CO2 levels.

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Anderson, Timothy D., J. Izaak Miller, Henri-Pierre Fierobe, and Robert T. Clubb. "Recombinant Bacillus subtilis That Grows on Untreated Plant Biomass." Applied and Environmental Microbiology 79, no. 3 (2012): 867–76. http://dx.doi.org/10.1128/aem.02433-12.

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ABSTRACTLignocellulosic biomass is a promising feedstock to produce biofuels and other valuable biocommodities. A major obstacle to its commercialization is the high cost of degrading biomass into fermentable sugars, which is typically achieved using cellulolytic enzymes fromTrichoderma reesei. Here, we explore the use of microbes to break down biomass.Bacillus subtiliswas engineered to display a multicellulase-containing minicellulosome. The complex contains a miniscaffoldin protein that is covalently attached to the cell wall and three noncovalently associated cellulase enzymes derived fromClostridium cellulolyticum(Cel48F, Cel9E, and Cel5A). The minicellulosome spontaneously assembles, thus increasing the practicality of the cells. The recombinant bacteria are highly cellulolytic and grew in minimal medium containing industrially relevant forms of biomass as the primary nutrient source (corn stover, hatched straw, and switch grass). Notably, growth did not require dilute acid pretreatment of the biomass and the cells achieved densities approaching those of cells cultured with glucose. An analysis of the sugars released from acid-pretreated corn stover indicates that the cells have stable cellulolytic activity that enables them to break down 62.3% ± 2.6% of the biomass. When supplemented with beta-glucosidase, the cells liberated 21% and 33% of the total available glucose and xylose in the biomass, respectively. As the cells display only three types of enzymes, increasing the number of displayed enzymes should lead to even more potent cellulolytic microbes. This work has important implications for the efficient conversion of lignocellulose to value-added biocommodities.

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Geiser, Elena, Michèle Reindl, Lars M. Blank, Michael Feldbrügge, Nick Wierckx, and Kerstin Schipper. "Activating Intrinsic Carbohydrate-Active Enzymes of the Smut Fungus Ustilago maydis for the Degradation of Plant Cell Wall Components." Applied and Environmental Microbiology 82, no. 17 (2016): 5174–85. http://dx.doi.org/10.1128/aem.00713-16.

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ABSTRACTThe microbial conversion of plant biomass to valuable products in a consolidated bioprocess could greatly increase the ecologic and economic impact of a biorefinery. Current strategies for hydrolyzing plant material mostly rely on the external application of carbohydrate-active enzymes (CAZymes). Alternatively, production organisms can be engineered to secrete CAZymes to reduce the reliance on externally added enzymes. Plant-pathogenic fungi have a vast repertoire of hydrolytic enzymes to sustain their lifestyle, but expression of the corresponding genes is usually highly regulated and restricted to the pathogenic phase. Here, we present a new strategy in using the biotrophic smut fungusUstilago maydisfor the degradation of plant cell wall components by activating its intrinsic enzyme potential during axenic growth. This fungal model organism is fully equipped with hydrolytic enzymes, and moreover, it naturally produces value-added substances, such as organic acids and biosurfactants. To achieve the deregulated expression of hydrolytic enzymes during the industrially relevant yeast-like growth in axenic culture, the native promoters of the respective genes were replaced by constitutively active synthetic promoters. This led to an enhanced conversion of xylan, cellobiose, and carboxymethyl cellulose to fermentable sugars. Moreover, a combination of strains with activated endoglucanase and β-glucanase increased the release of glucose from carboxymethyl cellulose and regenerated amorphous cellulose, suggesting that mixed cultivations could be a means for degrading more complex substrates in the future. In summary, this proof of principle demonstrates the potential applicability of activating the expression of native CAZymes from phytopathogens in a biocatalytic process.IMPORTANCEThis study describes basic experiments that aim at the degradation of plant cell wall components by the smut fungusUstilago maydis. As a plant pathogen, this fungus contains a set of lignocellulose-degrading enzymes that may be suited for biomass degradation. However, its hydrolytic enzymes are specifically expressed only during plant infection. Here, we provide the proof of principle that these intrinsic enzymes can be synthetically activated during the industrially relevant yeast-like growth. The fungus is known to naturally synthesize valuable compounds, such as itaconate or glycolipids. Therefore, it could be suited for use in a consolidated bioprocess in which more complex and natural substrates are simultaneously converted to fermentable sugars and to value-added compounds in the future.

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Lynd, Lee R., Paul J. Weimer, Willem H. van Zyl, and Isak S. Pretorius. "Microbial Cellulose Utilization: Fundamentals and Biotechnology." Microbiology and Molecular Biology Reviews 66, no. 3 (2002): 506–77. http://dx.doi.org/10.1128/mmbr.66.3.506-577.2002.

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SUMMARY Fundamental features of microbial cellulose utilization are examined at successively higher levels of aggregation encompassing the structure and composition of cellulosic biomass, taxonomic diversity, cellulase enzyme systems, molecular biology of cellulase enzymes, physiology of cellulolytic microorganisms, ecological aspects of cellulase-degrading communities, and rate-limiting factors in nature. The methodological basis for studying microbial cellulose utilization is considered relative to quantification of cells and enzymes in the presence of solid substrates as well as apparatus and analysis for cellulose-grown continuous cultures. Quantitative description of cellulose hydrolysis is addressed with respect to adsorption of cellulase enzymes, rates of enzymatic hydrolysis, bioenergetics of microbial cellulose utilization, kinetics of microbial cellulose utilization, and contrasting features compared to soluble substrate kinetics. A biological perspective on processing cellulosic biomass is presented, including features of pretreated substrates and alternative process configurations. Organism development is considered for “consolidated bioprocessing” (CBP), in which the production of cellulolytic enzymes, hydrolysis of biomass, and fermentation of resulting sugars to desired products occur in one step. Two organism development strategies for CBP are examined: (i) improve product yield and tolerance in microorganisms able to utilize cellulose, or (ii) express a heterologous system for cellulose hydrolysis and utilization in microorganisms that exhibit high product yield and tolerance. A concluding discussion identifies unresolved issues pertaining to microbial cellulose utilization, suggests approaches by which such issues might be resolved, and contrasts a microbially oriented cellulose hydrolysis paradigm to the more conventional enzymatically oriented paradigm in both fundamental and applied contexts.

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Metz, Benjamin, Verena Seidl-Seiboth, Thomas Haarmann, et al. "Expression of Biomass-Degrading Enzymes Is a Major Event during Conidium Development in Trichoderma reesei." Eukaryotic Cell 10, no. 11 (2011): 1527–35. http://dx.doi.org/10.1128/ec.05014-11.

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ABSTRACTThe conidium plays a critical role in the life cycle of many filamentous fungi, being the primary means for survival under unfavorable conditions. To investigate the transcriptional changes taking place during the transition from growing hyphae to conidia inTrichoderma reesei, microarray experiments were performed. A total of 900 distinct genes were classified as differentially expressed, relative to their expression at time zero of conidiation, at least at one of the time points analyzed. The main functional categories (FunCat) overrepresented among the upregulated genes were those involving solute transport, metabolism, transcriptional regulation, secondary metabolite synthesis, lipases, proteases, and, particularly, cellulases and hemicellulases. Categories overrepresented among the downregulated genes were especially those associated with ribosomal and mitochondrial functions. The upregulation of cellulase and hemicellulase genes was dependent on the function of the positive transcriptional regulator XYR1, but XYR1 exerted no influence on conidiation itself. At least 20% of the significantly regulated genes were nonrandomly distributed within theT. reeseigenome, suggesting an epigenetic component in the regulation of conidiation. The significant upregulation of cellulases and hemicellulases during this process, and thus cellulase and hemicellulase content in the spores ofT. reesei, contributes to the hypothesis that the ability to hydrolyze plant biomass is a major trait of this fungus enabling it to break dormancy and reinitiate vegetative growth after a period of facing unfavorable conditions.

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Ludwig, Roland. "OXIDISE - Interaction and Kinetics of Oxidative Biomass Degrading Enzymes Resolved by High-Resolution Techniques - ERC." Impact 2019, no. 5 (2019): 9–11. http://dx.doi.org/10.21820/23987073.2019.5.9.

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Longoni, Paolo, Sadhu Leelavathi, Enrico Doria, Vanga Siva Reddy, and Rino Cella. "Production by Tobacco Transplastomic Plants of Recombinant Fungal and Bacterial Cell-Wall Degrading Enzymes to Be Used for Cellulosic Biomass Saccharification." BioMed Research International 2015 (2015): 1–10. http://dx.doi.org/10.1155/2015/289759.

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Biofuels from renewable plant biomass are gaining momentum due to climate change related to atmospheric CO2increase. However, the production cost of enzymes required for cellulosic biomass saccharification is a major limiting step in this process. Low-cost production of large amounts of recombinant enzymes by transgenic plants was proposed as an alternative to the conventional microbial based fermentation. A number of studies have shown that chloroplast-based gene expression offers several advantages over nuclear transformation due to efficient transcription and translation systems and high copy number of the transgene. In this study, we expressed in tobacco chloroplasts microbial genes encoding five cellulases and a polygalacturonase. Leaf extracts containing the recombinant enzymes showed the ability to degrade various cell-wall components under different conditions, singly and in combinations. In addition, our group also tested a previously described thermostable xylanase in combination with a cellulase and a polygalacturonase to study the cumulative effect on the depolymerization of a complex plant substrate. Our results demonstrate the feasibility of using transplastomic tobacco leaf extracts to convert cell-wall polysaccharides into reducing sugars, fulfilling a major prerequisite of large scale availability of a variety of cell-wall degrading enzymes for biofuel industry.

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Langston, James A., Tarana Shaghasi, Eric Abbate, Feng Xu, Elena Vlasenko, and Matt D. Sweeney. "Oxidoreductive Cellulose Depolymerization by the Enzymes Cellobiose Dehydrogenase and Glycoside Hydrolase 61." Applied and Environmental Microbiology 77, no. 19 (2011): 7007–15. http://dx.doi.org/10.1128/aem.05815-11.

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ABSTRACTSeveral members of the glycoside hydrolase 61 (GH61) family of proteins have recently been shown to dramatically increase the breakdown of lignocellulosic biomass by microbial hydrolytic cellulases. However, purified GH61 proteins have neither demonstrable direct hydrolase activity on various polysaccharide or lignacious components of biomass nor an apparent hydrolase active site. Cellobiose dehydrogenase (CDH) is a secreted flavocytochrome produced by many cellulose-degrading fungi with no well-understood biological function. Here we demonstrate that the binary combination ofThermoascus aurantiacusGH61A (TaGH61A) andHumicola insolensCDH (HiCDH) cleaves cellulose into soluble, oxidized oligosaccharides. TaGH61A-HiCDH activity on cellulose is shown to be nonredundant with the activities of canonical endocellulase and exocellulase enzymes in microcrystalline cellulose cleavage, and while the combination of TaGH61A and HiCDH cleaves highly crystalline bacterial cellulose, it does not cleave soluble cellodextrins. GH61 and CDH proteins are coexpressed and secreted by the thermophilic ascomyceteThielavia terrestrisin response to environmental cellulose, and the combined activities ofT. terrestrisGH61 andT. terrestrisCDH are shown to synergize withT. terrestriscellulose hydrolases in the breakdown of cellulose. The action of GH61 and CDH on cellulose may constitute an important, but overlooked, biological oxidoreductive system that functions in microbial lignocellulose degradation and has applications in industrial biomass utilization.

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Mekasha, Sophanit, Tina Rise Tuveng, Fatemeh Askarian, et al. "A trimodular bacterial enzyme combining hydrolytic activity with oxidative glycosidic bond cleavage efficiently degrades chitin." Journal of Biological Chemistry 295, no. 27 (2020): 9134–46. http://dx.doi.org/10.1074/jbc.ra120.013040.

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Findings from recent studies have indicated that enzymes containing more than one catalytic domain may be particularly powerful in the degradation of recalcitrant polysaccharides such as chitin and cellulose. Some known multicatalytic enzymes contain several glycoside hydrolase domains and one or more carbohydrate-binding modules (CBMs). Here, using bioinformatics and biochemical analyses, we identified an enzyme, Jd1381 from the actinobacterium Jonesia denitrificans, that uniquely combines two different polysaccharide-degrading activities. We found that Jd1381 contains an N-terminal family AA10 lytic polysaccharide monooxygenase (LPMO), a family 5 chitin-binding domain (CBM5), and a family 18 chitinase (Chi18) domain. The full-length enzyme, which seems to be the only chitinase produced by J. denitrificans, degraded both α- and β-chitin. Both the chitinase and the LPMO activities of Jd1381 were similar to those of other individual chitinases and LPMOs, and the overall efficiency of chitin degradation by full-length Jd1381 depended on its chitinase and LPMO activities. Of note, the chitin-degrading activity of Jd1381 was comparable with or exceeded the activities of combinations of well-known chitinases and an LPMO from Serratia marcescens. Importantly, comparison of the chitinolytic efficiency of Jd1381 with the efficiencies of combinations of truncated variants—JdLPMO10 and JdCBM5-Chi18 or JdLPMO10-CBM5 and JdChi18—indicated that optimal Jd1381 activity requires close spatial proximity of the LPMO10 and the Chi18 domains. The demonstration of intramolecular synergy between LPMOs and hydrolytic enzymes reported here opens new avenues toward the development of efficient catalysts for biomass conversion.

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Adlakha, Nidhi, Raman Rajagopal, Saravanan Kumar, Vanga Siva Reddy, and Syed Shams Yazdani. "Synthesis and Characterization of Chimeric Proteins Based on Cellulase and Xylanase from an Insect Gut Bacterium." Applied and Environmental Microbiology 77, no. 14 (2011): 4859–66. http://dx.doi.org/10.1128/aem.02808-10.

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ABSTRACTInsects living on wood and plants harbor a large variety of bacterial flora in their guts for degrading biomass. We isolated aPaenibacillusstrain, designated ICGEB2008, from the gut of a cotton bollworm on the basis of its ability to secrete a variety of plant-hydrolyzing enzymes. In this study, we cloned, expressed, and characterized two enzymes, β-1,4-endoglucanase (Endo5A) and β-1,4-endoxylanase (Xyl11D), from the ICGEB2008 strain and synthesized recombinant bifunctional enzymes based on Endo5A and Xyl11D. The gene encoding Endo5A was obtained from the genome of the ICGEB2008 strain by shotgun cloning. The gene encoding Xyl11D was obtained using primers for conserved xylanase sequences, which were identified by aligning xylanase sequences in other species ofPaenibacillus. Endo5A and Xyl11D were overexpressed inEscherichia coli, and their optimal activities were characterized. Both Endo5A and Xyl11D exhibited maximum specific activity at 50°C and pH 6 to 7. To take advantage of this feature, we constructed four bifunctional chimeric models of Endo5A and Xyl11D by fusing the encoding genes either end to end or through a glycine-serine (GS) linker. We predicted three-dimensional structures of the four models using the I-TASSER server and analyzed their secondary structures using circular dichroism (CD) spectroscopy. The chimeric model Endo5A-GS-Xyl11D, in which a linker separated the two enzymes, yielded the highest C-score on the I-TASSER server, exhibited secondary structure properties closest to the native enzymes, and demonstrated 1.6-fold and 2.3-fold higher enzyme activity than Endo5A and Xyl11D, respectively. This bifunctional enzyme could be effective for hydrolyzing plant biomass owing to its broad substrate range.

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Saxena, Hirak, Bryan Hsu, Marc de Asis, et al. "Characterization of a thermostable endoglucanase from Cellulomonas fimi ATCC484." Biochemistry and Cell Biology 96, no. 1 (2018): 68–76. http://dx.doi.org/10.1139/bcb-2017-0150.

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Bacteria in the genus Cellulomonas are well known as secretors of a variety of mesophilic carbohydrate degrading enzymes (e.g., cellulases and hemicellulases), active against plant cell wall polysaccharides. Recent proteomic analysis of the mesophilic bacterium Cellulomonas fimi ATCC484 revealed uncharacterized enzymes for the hydrolysis of plant cell wall biomass. Celf_1230 (CfCel6C), a secreted protein of Cellulomonas fimi ATCC484, is a novel member of the GH6 family of cellulases that could be successfully expressed in Escherichia coli. This enzyme displayed very little enzymatic/hydrolytic activity at 30 °C, but showed an optimal activity around 65 °C, and exhibited a thermal denaturation temperature of 74 °C. In addition, it also strongly bound to filter paper despite having no recognizable carbohydrate binding module. Our experiments show that CfCel6C is a thermostable endoglucanase with activity on a variety of β-glucans produced by an organism that struggles to grow above 30 °C.

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Scott, Israel M., Gabe M. Rubinstein, Gina L. Lipscomb, et al. "A New Class of Tungsten-Containing Oxidoreductase in Caldicellulosiruptor, a Genus of Plant Biomass-Degrading Thermophilic Bacteria." Applied and Environmental Microbiology 81, no. 20 (2015): 7339–47. http://dx.doi.org/10.1128/aem.01634-15.

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ABSTRACTCaldicellulosiruptor besciigrows optimally at 78°C and is able to decompose high concentrations of lignocellulosic plant biomass without the need for thermochemical pretreatment.C. besciiferments both C5and C6sugars primarily to hydrogen gas, lactate, acetate, and CO2and is of particular interest for metabolic engineering applications given the recent availability of a genetic system. Developing optimal strains for technological use requires a detailed understanding of primary metabolism, particularly when the goal is to divert all available reductant (electrons) toward highly reduced products such as biofuels. During an analysis of theC. besciigenome sequence for oxidoreductase-type enzymes, evidence was uncovered to suggest that the primary redox metabolism ofC. besciihas a completely uncharacterized aspect involving tungsten, a rarely used element in biology. An active tungsten utilization pathway inC. besciiwas demonstrated by the heterologous production of a tungsten-requiring, aldehyde-oxidizing enzyme (AOR) from the hyperthermophilic archaeonPyrococcus furiosus. Furthermore,C. besciialso contains a tungsten-based AOR-type enzyme, here termed XOR, which is phylogenetically unique, representing a completely new member of the AOR tungstoenzyme family. Moreover, inC. bescii, XOR represents ca. 2% of the cytoplasmic protein. XOR is proposed to play a key, but as yet undetermined, role in the primary redox metabolism of this cellulolytic microorganism.

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B, Thamilmaraiselvi, Steffi PF, Sathammaipriya N, and Sangeetha K. "Low cost pretreatment of lignocellulosic waste by white rot fungi for ethanol production using Saccharomyces cerevisiae." International Journal of Research in Pharmaceutical Sciences 9, no. 1 (2018): 18. http://dx.doi.org/10.26452/ijrps.v9i1.1152.

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Saccharomyces cerevisiae is a species of yeast. It has been instrumental in winemaking, baking, and brewing since ancient times. The present study was performed to produce lignin degrading enzymes to degrade lignocellulosic substrates and to produce ethanol using Saccharomyces cerevisiae by performing FTIR method. The yeast culture Saccharomyces cerevisiae was isolated and screened for the production of lignolytic enzymes. Then it was pretreated to produce lignocellulosic substrates. Lignocellulosic materials are considered the most abundant renewable resource available for the production of ethanol by FTIR method. The present study concluded the utilization of lignocellulosic biomass for ethanol production in future. Keywords: Saccharomyces cerevisiae; Lignocellulosic; Ethanol; FTIR

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Farinas, Cristiane S. "Developments in solid-state fermentation for the production of biomass-degrading enzymes for the bioenergy sector." Renewable and Sustainable Energy Reviews 52 (December 2015): 179–88. http://dx.doi.org/10.1016/j.rser.2015.07.092.

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Guo, Haipeng, Houming Chen, Lu Fan, et al. "Enzymes produced by biomass-degrading bacteria can efficiently hydrolyze algal cell walls and facilitate lipid extraction." Renewable Energy 109 (August 2017): 195–201. http://dx.doi.org/10.1016/j.renene.2017.03.025.

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Rizk, Mazen, Garabed Antranikian, and Skander Elleuche. "End-to-end gene fusions and their impact on the production of multifunctional biomass degrading enzymes." Biochemical and Biophysical Research Communications 428, no. 1 (2012): 1–5. http://dx.doi.org/10.1016/j.bbrc.2012.09.142.

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Ontañon, Ornella M., Soma Bedő, Silvina Ghio, et al. "Optimisation of xylanases production by two Cellulomonas strains and their use for biomass deconstruction." Applied Microbiology and Biotechnology 105, no. 11 (2021): 4577–88. http://dx.doi.org/10.1007/s00253-021-11305-y.

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Abstract One of the main distinguishing features of bacteria belonging to the Cellulomonas genus is their ability to secrete multiple polysaccharide degrading enzymes. However, their application in biomass deconstruction still constitutes a challenge. We addressed the optimisation of the xylanolytic activities in extracellular enzymatic extracts of Cellulomonas sp. B6 and Cellulomonas fimi B-402 for their subsequent application in lignocellulosic biomass hydrolysis by culture in several substrates. As demonstrated by secretomic profiling, wheat bran and waste paper resulted to be suitable inducers for the secretion of xylanases of Cellulomonas sp. B6 and C. fimi B-402, respectively. Both strains showed high xylanolytic activity in culture supernatant although Cellulomonas sp. B6 was the most efficient xylanolytic strain. Upscaling from flasks to fermentation in a bench scale bioreactor resulted in equivalent production of extracellular xylanolytic enzymatic extracts and freeze drying was a successful method for concentration and conservation of the extracellular enzymes, retaining 80% activity. Moreover, enzymatic cocktails composed of combined extra and intracellular extracts effectively hydrolysed the hemicellulose fraction of extruded barley straw into xylose and xylooligosaccharides. Key points • Secreted xylanase activity of Cellulomonas sp. B6 and C. fimi was maximised. • Biomass-induced extracellular enzymes were identified by proteomic profiling. • Combinations of extra and intracellular extracts were used for barley straw hydrolysis.

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Journal articles on the topic 'Biomass degrading enzymes'

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