Optimization of the catalytic process and increase of the Irpex lacteus cellulases yield for saccharification

2021 ◽  
pp. 100780
Author(s):  
Sergiy Boiko
Keyword(s):  
Catalytic Process ◽  
Irpex Lacteus

Crystal structures of Magnaporthe oryzae trehalose-6-phosphate synthase (MoTps1) suggest a model for catalytic process of Tps1

2019 ◽  
Vol 476 (21) ◽  
pp. 3227-3240 ◽  
Author(s):  
Shanshan Wang ◽  
Yanxiang Zhao ◽  
Long Yi ◽  
Minghe Shen ◽  
Chao Wang ◽  
...  
Keyword(s):  
Crystal Structures ◽  
Conformational Changes ◽  
Magnaporthe Oryzae ◽  
Structural Information ◽  
Complex Structure ◽  
Critical Role ◽  
Catalytic Process ◽  
Structural Basis ◽  
Salt Bridges ◽  
Terminal Domain

Trehalose-6-phosphate (T6P) synthase (Tps1) catalyzes the formation of T6P from UDP-glucose (UDPG) (or GDPG, etc.) and glucose-6-phosphate (G6P), and structural basis of this process has not been well studied. MoTps1 (Magnaporthe oryzae Tps1) plays a critical role in carbon and nitrogen metabolism, but its structural information is unknown. Here we present the crystal structures of MoTps1 apo, binary (with UDPG) and ternary (with UDPG/G6P or UDP/T6P) complexes. MoTps1 consists of two modified Rossmann-fold domains and a catalytic center in-between. Unlike Escherichia coli OtsA (EcOtsA, the Tps1 of E. coli), MoTps1 exists as a mixture of monomer, dimer, and oligomer in solution. Inter-chain salt bridges, which are not fully conserved in EcOtsA, play primary roles in MoTps1 oligomerization. Binding of UDPG by MoTps1 C-terminal domain modifies the substrate pocket of MoTps1. In the MoTps1 ternary complex structure, UDP and T6P, the products of UDPG and G6P, are detected, and substantial conformational rearrangements of N-terminal domain, including structural reshuffling (β3–β4 loop to α0 helix) and movement of a ‘shift region' towards the catalytic centre, are observed. These conformational changes render MoTps1 to a ‘closed' state compared with its ‘open' state in apo or UDPG complex structures. By solving the EcOtsA apo structure, we confirmed that similar ligand binding induced conformational changes also exist in EcOtsA, although no structural reshuffling involved. Based on our research and previous studies, we present a model for the catalytic process of Tps1. Our research provides novel information on MoTps1, Tps1 family, and structure-based antifungal drug design.

scholarly journals Degradation Products of Polychlorinated Biphenyls and Their In Vitro Transformation by Ligninolytic Fungi

Toxics ◽  
2021 ◽  
Vol 9 (4) ◽  
pp. 81
Author(s):  
Kamila Šrédlová ◽  
Kateřina Šírová ◽  
Tatiana Stella ◽  
Tomáš Cajthaml
Keyword(s):  
Polychlorinated Biphenyls ◽  
Extracellular Enzymes ◽  
Degradation Products ◽  
Transformation Products ◽  
Irpex Lacteus ◽  
Chlorobenzoic Acid ◽  
Ligninolytic Fungi ◽  
Wide Range ◽  
Pcb Metabolites

Metabolites of polychlorinated biphenyls (PCBs)—hydroxylated PCBs (OH‑PCBs), chlorobenzyl alcohols (CB‑OHs), and chlorobenzaldehydes (CB‑CHOs)—were incubated in vitro with the extracellular liquid of Pleurotus ostreatus, which contains mainly laccase and low manganese-dependent peroxidase (MnP) activity. The enzymes were able to decrease the amount of most of the tested OH‑PCBs by > 80% within 1 h; the removal of more recalcitrant OH‑PCBs was greatly enhanced by the addition of the laccase mediator syringaldehyde. Conversely, glutathione substantially hindered the reaction, suggesting that it acted as a laccase inhibitor. Hydroxylated dibenzofuran and chlorobenzoic acid were identified as transformation products of OH‑PCBs. The extracellular enzymes also oxidized the CB‑OHs to the corresponding CB‑CHOs on the order of hours to days; however, the mediated and nonmediated setups exhibited only slight differences, and the participating enzymes could not be determined. When CB‑CHOs were used as the substrates, only partial transformation was observed. In an additional experiment, the extracellular liquid of Irpex lacteus, which contains predominantly MnP, was able to efficiently transform CB‑CHOs with the aid of glutathione; mono‑ and di-chloroacetophenones were detected as transformation products. These results demonstrate that extracellular enzymes of ligninolytic fungi can act on a wide range of PCB metabolites, emphasizing their potential for bioremediation.

Triggering photocatalytic activity of carbon dot-based nanocomposites by self-supplying peroxide

2021 ◽  
Author(s):  
Tingting Cai ◽  
Qing Chang ◽  
Bin Liu ◽  
Caihong Hao ◽  
Jinlong Yang ◽  
...  
Keyword(s):  
Photocatalytic Activity ◽  
Electric Field ◽  
Catalytic Process ◽  
Charge Accumulation ◽  
Carbon Dot ◽  
Carrier Transfer ◽  
Polarization Electric Field

The photocatalyst performance highly relies on the quantity of carrier transfer from the bulk to surface during the catalytic process. However, the polarization electric field induced by charge accumulation at...

Treating crude oil storage tank sludge by catalytic process and recovering valuable hydrocarbons

2021 ◽  
Author(s):  
Kamalesh Gupta ◽  
Arun Kumar Jana ◽  
Mousumi Chakraborty ◽  
Parimal A. Parikh
Keyword(s):  
Crude Oil ◽  
Storage Tank ◽  
Catalytic Process ◽  
Oil Storage ◽  
Oil Storage Tank

scholarly journals Characterization of a Dye-Decolorizing Peroxidase from Irpex lacteus Expressed in Escherichia coli: An Enzyme with Wide Substrate Specificity Able to Transform Lignosulfonates

2021 ◽  
Vol 7 (5) ◽  
pp. 325
Author(s):  
Laura Isabel de de Eugenio ◽  
Rosa Peces-Pérez ◽  
Dolores Linde ◽  
Alicia Prieto ◽  
Jorge Barriuso ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Inclusion Bodies ◽  
Veratryl Alcohol ◽  
Dye Decolorization ◽  
Irpex Lacteus ◽  
Type D ◽  
Lignin Peroxidases

A dye-decolorizing peroxidase (DyP) from Irpex lacteus was cloned and heterologously expressed as inclusion bodies in Escherichia coli. The protein was purified in one chromatographic step after its in vitro activation. It was active on ABTS, 2,6-dimethoxyphenol (DMP), and anthraquinoid and azo dyes as reported for other fungal DyPs, but it was also able to oxidize Mn2+ (as manganese peroxidases and versatile peroxidases) and veratryl alcohol (VA) (as lignin peroxidases and versatile peroxidases). This corroborated that I. lacteus DyPs are the only enzymes able to oxidize high redox potential dyes, VA and Mn+2. Phylogenetic analysis grouped this enzyme with other type D-DyPs from basidiomycetes. In addition to its interest for dye decolorization, the results of the transformation of softwood and hardwood lignosulfonates suggest a putative biological role of this enzyme in the degradation of phenolic lignin.

scholarly journals Gold(I)-catalyzed synthesis of γ-vinylbutyrolactones by intramolecular oxaallylic alkylation with alcohols

2011 ◽  
Vol 7 ◽  
pp. 1198-1204 ◽  
Author(s):  
Michel Chiarucci ◽  
Mirko Locritani ◽  
Gianpiero Cera ◽  
Marco Bandini
Keyword(s):  
Catalytic System ◽  
Functional Group ◽  
Direct Synthesis ◽  
Catalytic Process ◽  
Primary Alcohols

Gold(I)-N-heterocyclic carbene (NHC) complexes proved to be a reliable catalytic system for the direct synthesis of functionalized γ-vinylbutyrolactones by intramolecular oxaallylic alkylation with primary alcohols. Good isolated chemical yields were obtained for a range of malonyl and acetate derivatives. The good performance in reagent-grade solvents and the functional group/moisture tolerance make this catalytic process a promising route for the synthesis of architecturally complex polycyclic structures.

scholarly journals Ethane‐Based Catalytic Process for Vinyl Chloride Manufacture

2021 ◽  
Author(s):  
Guido Zichittella ◽  
Javier Pérez‐Ramírez
Keyword(s):  
Vinyl Chloride ◽  
Catalytic Process
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