scholarly journals Ancestral amino acid substitution improves the thermal stability of recombinant lignin-peroxidase from white-rot fungi, Phanerochaete chrysosporium strain UAMH 3641

2015 ◽  
Vol 28 (7) ◽  
pp. 221-230 ◽  
Author(s):  
Yasuyuki Semba ◽  
Manabu Ishida ◽  
Shin-ichi Yokobori ◽  
Akihiko Yamagishi
Keyword(s):  
Thermal Stability ◽  
Amino Acid ◽  
Phanerochaete Chrysosporium ◽  
Amino Acid Substitution ◽  
Lignin Peroxidase ◽  
White Rot Fungi ◽  
White Rot ◽  
Thermal Stability Of ◽  
Ancestral Amino Acid

scholarly journals Effect of position-specific single-point mutations and biophysical characterization of amyloidogenic peptide fragments identified from lattice corneal dystrophy patients

2017 ◽  
Vol 474 (10) ◽  
pp. 1705-1725 ◽  
Author(s):  
Venkatraman Anandalakshmi ◽  
Elavazhagan Murugan ◽  
Eunice Goh Tze Leng ◽  
Lim Wei Ting ◽  
Shyam S. Chaurasia ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Amino Acid ◽  
Growth Factor ◽  
Amino Acid Substitution ◽  
Amyloid Fibrils ◽  
Transforming Growth Factor ◽  
Transforming Growth Factor Β ◽  
Proteolytic Processing ◽  
Mutant Proteins ◽  
Thermal Stability Of

Corneal stromal dystrophies are a group of genetic disorders that may be caused by mutations in the transforming growth factor β-induced (TGFBI) gene which results in the aggregation and deposition of mutant proteins in various layers of the cornea. The type of amino acid substitution dictates the age of onset, anatomical location of the deposits, morphological features of deposits (amyloid, amorphous powder or a mixture of both forms) and the severity of disease presentation. It has been suggested that abnormal turnover and aberrant proteolytic processing of the mutant proteins result in the accumulation of insoluble protein deposits. Using mass spectrometry, we identified increased abundance of a 32 amino acid-long peptide in the 4th fasciclin-like domain-1 (FAS-1) domain of transforming growth factor β-induced protein (amino acid 611–642) in the amyloid deposits of the patients with lattice corneal dystrophies (LCD). In vitro studies demonstrated that the peptide readily formed amyloid fibrils under physiological conditions. Clinically relevant substitution (M619K, N622K, N622H, G623R and H626R) of the truncated peptide resulted in profound changes in the kinetics of amyloid formation, thermal stability of the amyloid fibrils and cytotoxicity of fibrillar aggregates, depending on the position and the type of the amino acid substitution. The results suggest that reduction in the overall net charge, nature and position of cationic residue substitution determines the amyloid aggregation propensity and thermal stability of amyloid fibrils.

The Onset of Lignin-Modifying Enzymes, Decrease of AOX and Color Removal by White-Rot Fungi Grown on Bleach Plant Effluents

1991 ◽  
Vol 24 (3-4) ◽  
pp. 189-198 ◽  
Author(s):  
V. P. Lankinen ◽  
M. M. Inkeröinen ◽  
J. Pellinen ◽  
A. I. Hatakka
Keyword(s):  
Lignin Peroxidase ◽  
Active Form ◽  
White Rot Fungi ◽  
Pulp Mill ◽  
Color Removal ◽  
Effluent Treatment ◽  
White Rot ◽  
White Rot Fungus ◽  
Lignin Peroxidases ◽  
Pulp Mill Effluents

Decrease of adsorbable organic chlorine (AOX) is becoming the most important criterion for the efficiency of pulp mill effluent treatment in the 1990s. Two methods, designated MYCOR and MYCOPOR which utilize the white-rot fungus Phanerochaete chrysosporium have earlier been developed for the color removal of pulp mill effluents, but the processes have also a capacity to decrease the amount of chlorinated organic compounds. Lignin peroxidases (ligninases) produced by P. chrvsosporium may dechlorinate chlorinated phenols. In this work possibilities to use selected white-rot fungi in the treatment of E1-stage bleach plant effluent were studied. Phlebia radiata. Phanerochaete chrvsosporium and Merulius (Phlebia) tremellosus were compared in shake flasks for their ability to produce laccase, lignin peroxidase(s) and manganese-dependent peroxidase(s) and to remove color from a medium containing effluent. Softwood bleaching effluents were treated by carrier-immobilized P. radiata in 2 1 bioreactors and a 10 1 BiostatR -fermentor. Dechlorination was followed using Cl ion and AOX determinations. All fungi removed the color of the effluent. In P. radiata cultivations AOX decrease was ca. 4 mg l−1 in one day. Apparent lignin peroxidase activities as determined by veratryl alcohol oxidation method were negligible or zero in a medium with AOX content of ca. 60 mg l−1, prepared using about 20 % (v/v) of softwood effluent. However, the purification of extracellular enzymes implied that large amounts of lignin peroxidases were present in the medium and, after the purification, in active form. Enzyme proteins were separated using anion exchange chromatography, and they were further characterized by electrophoresis (SDS-PAGE) to reveal the kind of enzymes that were present during AOX decrease and color removal. The most characteristic lignin peroxidase isoenzymes in effluent media were LiP2 and LiP3.

scholarly journals Lignin peroxidase-negative mutant of the white-rot basidiomycete Phanerochaete chrysosporium.

1990 ◽  
Vol 172 (1) ◽  
pp. 260-265 ◽  
Author(s):  
K Boominathan ◽  
S B Dass ◽  
T A Randall ◽  
R L Kelley ◽  
C A Reddy
Keyword(s):  
Phanerochaete Chrysosporium ◽  
Lignin Peroxidase ◽  
White Rot ◽  
Negative Mutant

Establishing molecular genetics for Phanerochaete chrysosporium

1987 ◽  
Vol 321 (1561) ◽  
pp. 475-483 ◽  
Keyword(s):  
Phanerochaete Chrysosporium ◽  
Complex Function ◽  
Strain Improvement ◽  
White Rot Fungi ◽  
Point Of View ◽  
Site Directed Mutagenesis ◽  
White Rot ◽  
General Strategy ◽  
Lignin Biodegradation ◽  
Control Of Expression

Genetics provides an approach to the analysis of the complex function of lignin biodegradation, through the isolation of mutants and the creation of gene libraries for the identification of genes and their products. However, white-rot fungi (for example, Phanerochaete chrysosporium ) have not so far been analysed from this point of view, and there is the challenge of establishing such genetics. P. chrysosporium is convenient experimentally because relatively few genes are switched on at the onset of ligninolytic activity. We describe the isolation of clones carrying genes expressed specifically in the ligninolytic phase, the development of a general strategy for mapping such clones, and the elucidation of the mating system of this organism. Another objective is the development of methods for transforming DNA into P. chrysosporium . This would allow the use of site-directed mutagenesis to analyse the functioning of ligninases, and the control of expression of the corresponding genes. The use of genetic crosses for strain improvement and the identification of components of the system are also discussed.

scholarly journals Identification of white rot fungus CP9 and its potential application in biopulping

2018 ◽  
Vol 14 (4) ◽  
pp. 721-726
Author(s):  
Nguyen Thi Hong Lien ◽  
Nguyen Van Hieu ◽  
Luong Thi Hong ◽  
Hy Tuan Anh ◽  
Phan Thi Hong Thao
Keyword(s):  
Rice Straw ◽  
Lignin Peroxidase ◽  
Paper Industry ◽  
Morphological Characteristics ◽  
White Rot Fungi ◽  
White Rot ◽  
White Rot Fungus ◽  
Wood Block ◽  
New Production ◽  
Cellulosic Fibers

Wood-rotting fungi represent an important component of forest ecosystems. Among them, white-rot fungi are the most efficient lignin degraders. Biopulping using white-rot fungi in pretreatment of the materials, is one of the solutions to overcome disadvantages of traditional production methods. Today, the isolation and screening of lignin degrading fungi capable for application in biopulping are of keen interest in Vietnam. The use of non–wood, plant fibres in pulp and paper industry, special, agricultural residuces such as rice and wheat straw, sugarcane baggase, cornstalks etc is the new production toward, potential, serving sustainable development. The fungus CP9, which possessed high ligninolytic activity, was identified and studied in pretreatment of rice straw for biopulping. The fruiting bodies of strain CP9 were effuse on trunk. The hymenium was porous and brown white with short tubes, the white mycelia penetrated wood block. The colony was off-white, blossom, irregularly circular. The mycelia were thick and closely bound together. Beside lignin, this fungus could degrade other substrates such as casein, carboxymethyl cellulose and starch. Biological and morphological characteristics of the fungus CP9 suggested its placement in subdivision Basidiomycota. Combined with the results of phylogenetic analysis, which showed 99% similarity of the fungus with species Leiotrametes lactinea, our strain was named as Leiotrametes lactinea CP9. This fungus could grow well on rice straw under solid state fermentation. Pretreatment of rice straw using L. lactinea CP9 was based on the activity of fungal lignin peroxidase and laccase. After 20 days, the residual enzyme activity was of 21.6 and 18.4 nkat/g material for lignin peroxidase and laccase, respectively. Pretreatment significantly improved the quality of straw, as lignin loss of 38% while cellulosic fibers were comparatively well preserved.

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