scholarly journals A Putative Lignin Copper Oxidase from Trichoderma reesei

2021 ◽  
Vol 7 (8) ◽  
pp. 643
Author(s):  
Mariane Daou ◽  
Alexandra Bisotto ◽  
Mireille Haon ◽  
Lydie Oliveira Correia ◽  
Betty Cottyn ◽  
...  
Keyword(s):  
Trichoderma Reesei ◽  
Catalytic Properties ◽  
Oxidative Conversion ◽  
Alcohol Group ◽  
Phylogenetic Characterization ◽  
Synergistic Mechanism ◽  
Simple Carbohydrates ◽  
Soda Lignin ◽  
Copper Oxidase ◽  
Soluble Lignin

The ability of Trichoderma reesei, a fungus widely used for the commercial production of hemicellulases and cellulases, to grow and modify technical soda lignin was investigated. By quantifying fungal genomic DNA, T. reesei showed growth and sporulation in solid and liquid cultures containing lignin alone. The analysis of released soluble lignin and residual insoluble lignin was indicative of enzymatic oxidative conversion of phenolic lignin side chains and the modification of lignin structure by cleaving the β-O-4 linkages. The results also showed that polymerization reactions were taking place. A proteomic analysis conducted to investigate secreted proteins at days 3, 7, and 14 of growth revealed the presence of five auxiliary activity (AA) enzymes in the secretome: AA6, AA9, two AA3 enzymes), and the only copper radical oxidase encoded in the genome of T. reesei. This enzyme was heterologously produced and characterized, and its activity on lignin-derived molecules was investigated. Phylogenetic characterization demonstrated that this enzyme belonged to the AA5_1 family, which includes characterized glyoxal oxidases. However, the enzyme displayed overlapping physicochemical and catalytic properties across the AA5 family. The enzyme was remarkably stable at high pH and oxidized both, alcohols and aldehydes with preference to the alcohol group. It was also active on lignin-derived phenolic molecules as well as simple carbohydrates. HPSEC and LC-MS analyses on the reactions of the produced protein on lignin dimers (SS ββ, SS βO4 and GG β5) uncovered the polymerizing activity of this enzyme, which was accordingly named lignin copper oxidase (TrLOx). Polymers of up 10 units were formed by hydroxy group oxidation and radical formation. The activations of lignin molecules by TrLOx along with the co-secretion of this enzyme with reductases and FAD flavoproteins oxidoreductases during growth on lignin suggest a synergistic mechanism for lignin breakdown.

Comparison of catalytic properties of multiple β-glucosidases of Trichoderma reesei

2016 ◽  
Vol 100 (11) ◽  
pp. 4959-4968 ◽  
Author(s):  
Boyang Guo ◽  
Nobuaki Sato ◽  
Peter Biely ◽  
Yoshihiko Amano ◽  
Kouichi Nozaki
Keyword(s):  
Trichoderma Reesei ◽  
Catalytic Properties

Effect of SiO2 on the physicochemical and catalytic properties of VMoTeNbО catalyst in oxidative conversion of ethane

2016 ◽  
Vol 89 (8) ◽  
pp. 1279-1285 ◽  
Author(s):  
V. M. Bondareva ◽  
E. V. Ishchenko ◽  
T. Yu. Kardash ◽  
A. V. Ishchenko ◽  
V. I. Sobolev
Keyword(s):  
Catalytic Properties ◽  
Oxidative Conversion

scholarly journals 1,3-butadiene and methacrylonitrile obtaining using oxidative conversion of C4 olefins over Fe-Te-Mo-Ox catalyst promoted with BaCl2

2007 ◽  
Vol 1 (1) ◽  
pp. 31-34
Author(s):  
Volodymyr Gumenetskiy ◽  
◽  
Svitlana Maikova ◽  
Vyacheslav Zhyznevskiy ◽  
◽  
...  
Keyword(s):  
Catalytic Properties ◽  
Optimal Composition ◽  
Oxidative Conversion ◽  
Process Kinetics ◽  
Oxidative Dehydration

The effect of BaCl2 promotor on the catalytic properties of Fe-Te-Mo-Ox catalyst of joint oxidative dehydration and oxidative amonolysis of C4 olefins has been examined. The optimal composition of promoted catalyst has been established taking into consideration methacrylonitrile and butadiene yields. The process kinetics has been investigated

scholarly journals Heterologous Expression of Phanerochaete Chrysosporium Cellobiose Dehydrogenase in Trichoderma Reesei

2020 ◽  
Author(s):  
Lena Wohlschlager ◽  
Florian Csarman ◽  
Hucheng Chang ◽  
Elisabeth Fitz ◽  
Bernhard Seiboth ◽  
...  
Keyword(s):  
Electrochemical Properties ◽  
Trichoderma Reesei ◽  
Phanerochaete Chrysosporium ◽  
Catalytic Properties ◽  
Detailed Comparison ◽  
Biofuel Cells ◽  
Cellobiose Dehydrogenase ◽  
Efficient Production ◽  
Homologous Expression ◽  
High Mannose

Abstract Background: Cellobiose dehydrogenase from Phanerochaete chrysosporium (PcCDH) is a key enzyme in lignocellulose depolymerization, biosensors and biofuel cells. For these applications, it should retain important molecular and catalytic properties when recombinantly expressed. While homologous expression is time-consuming and the prokaryote Escherichia coli is not suitable for expression of the two-domain flavocytochrome, the yeast Pichia pastoris is hyperglycosylating the enzyme. Fungal expression hosts like Aspergillus niger and Trichoderma reesei were successfully used to express CDH from the ascomycete Corynascus thermophilus. This study describes the expression of basidiomycetous PcCDH in T. reesei (PcCDHTr) and the detailed comparison of its molecular, catalytic and electrochemical properties in comparison with PcCDH expressed by P. chrysosporium and P. pastoris (PcCDHPp). Results: PcCDHTr was recombinantly produced with a yield of 600 U L-1 after 4 days, which is fast compared to the secretion of the enzyme by P. chrysosporium. PcCDHTr and PcCDH were purified to homogeneity by two chromatographic steps. Both enzymes were comparatively characterized in terms of molecular and catalytic properties. The pH optima for electron acceptors are identical for PcCDHTr and PcCDH. The determined FAD cofactor occupancy of 70% for PcCDHTr is higher than for other recombinantly produced CDHs and its catalytic constants are in good accordance with those of PcCDH. Mass spectrometry showed high mannose-type N-glycans on PcCDH, but only single N-acetyl-d-glucosamine additions at the six potential N-glycosylation sites of PcCDHTr, which indicates the presence of an endo-N-acetyl-b-d-glucosaminidase in the supernatant.Conclusions: Heterologous production of PcCDHTr is faster and the yield higher than secretion by P. chrysosporium. It also does not need a cellulose-based medium that impedes efficient production and purification of CDH by binding to the polysaccharide. The obtained high uniformity of PcCDHTr glycoforms will be very useful to investigate electron transfer characteristics in biosensors and biofuel cells, which are depending on the spatial restrictions inflicted by high-mannose N-glycan trees. The determined catalytic and electrochemical properties of PcCDHTr are very similar to those of PcCDH and the FAD cofactor occupancy is good, which advocates T. reesei as expression host for engineered PcCDH for biosensors and biofuel cells.

scholarly journals Heterologous expression of Phanerochaete chrysosporium cellobiose dehydrogenase in Trichoderma reesei

2021 ◽  
Vol 20 (1) ◽  
Author(s):  
Lena Wohlschlager ◽  
Florian Csarman ◽  
Hucheng Chang ◽  
Elisabeth Fitz ◽  
Bernhard Seiboth ◽  
...  
Keyword(s):  
Electrochemical Properties ◽  
Trichoderma Reesei ◽  
Phanerochaete Chrysosporium ◽  
Catalytic Properties ◽  
Detailed Comparison ◽  
Biofuel Cells ◽  
Cellobiose Dehydrogenase ◽  
Efficient Production ◽  
Homologous Expression ◽  
High Mannose

Abstract Background Cellobiose dehydrogenase from Phanerochaete chrysosporium (PcCDH) is a key enzyme in lignocellulose depolymerization, biosensors and biofuel cells. For these applications, it should retain important molecular and catalytic properties when recombinantly expressed. While homologous expression is time-consuming and the prokaryote Escherichia coli is not suitable for expression of the two-domain flavocytochrome, the yeast Pichia pastoris is hyperglycosylating the enzyme. Fungal expression hosts like Aspergillus niger and Trichoderma reesei were successfully used to express CDH from the ascomycete Corynascus thermophilus. This study describes the expression of basidiomycetes PcCDH in T. reesei (PcCDHTr) and the detailed comparison of its molecular, catalytic and electrochemical properties in comparison with PcCDH expressed by P. chrysosporium and P. pastoris (PcCDHPp). Results PcCDHTr was recombinantly produced with a yield of 600 U L−1 after 4 days, which is fast compared to the secretion of the enzyme by P. chrysosporium. PcCDHTr and PcCDH were purified to homogeneity by two chromatographic steps. Both enzymes were comparatively characterized in terms of molecular and catalytic properties. The pH optima for electron acceptors are identical for PcCDHTr and PcCDH. The determined FAD cofactor occupancy of 70% for PcCDHTr is higher than for other recombinantly produced CDHs and its catalytic constants are in good accordance with those of PcCDH. Mass spectrometry showed high mannose-type N-glycans on PcCDH, but only single N-acetyl-d-glucosamine additions at the six potential N-glycosylation sites of PcCDHTr, which indicates the presence of an endo-N-acetyl-β-d-glucosaminidase in the supernatant. Conclusions Heterologous production of PcCDHTr is faster and the yield higher than secretion by P. chrysosporium. It also does not need a cellulose-based medium that impedes efficient production and purification of CDH by binding to the polysaccharide. The obtained high uniformity of PcCDHTr glycoforms will be very useful to investigate electron transfer characteristics in biosensors and biofuel cells, which are depending on the spatial restrictions inflicted by high-mannose N-glycan trees. The determined catalytic and electrochemical properties of PcCDHTr are very similar to those of PcCDH and the FAD cofactor occupancy is good, which advocates T. reesei as expression host for engineered PcCDH for biosensors and biofuel cells.

Ultrastructural Lesions Produced by Alcohol and Sucrose in the Heart and Liver of C57BL Mice

1970 ◽  
Vol 28 ◽  
pp. 208-209
Author(s):  
K.K. SEKHRI ◽  
C.S. ALEXANDER ◽  
H.T. NAGASAWA
Keyword(s):  
Osmium Tetroxide ◽  
Male Mice ◽  
Alcohol Group ◽  
Group Iii ◽  
Group I ◽  
C57bl Mice ◽  
Group Ii

C57BL male mice (Jackson Lab., Bar Harbor, Maine) weighing about 18 gms were randomly divided into three groups: group I was fed sweetened liquid alcohol diet (modified Schenkl) in which 36% of the calories were derived from alcohol; group II was maintained on a similar diet but alcohol was isocalorically substituted by sucrose; group III was fed regular mouse chow ad lib for five months. Liver and heart tissues were fixed in 2.5% cacodylate buffered glutaraldehyde, post-fixed in 2% osmium tetroxide and embedded in Epon-araldite.

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