scholarly journals Effect of Physisporinus vitreus on wood properties of Norway spruce. Part 2: Aspects of microtensile strength and chemical changes

Holzforschung ◽  
2011 ◽  
Vol 65 (5) ◽  
Author(s):  
Christian Lehringer ◽  
Bodo Saake ◽  
Vjekoslav Živković ◽  
Klaus Richter ◽  
Holger Militz
Keyword(s):  
Norway Spruce ◽  
Lignin Content ◽  
Anion Exchange Chromatography ◽  
Exchange Chromatography ◽  
White Rot ◽  
White Rot Fungus ◽  
Wall Structure ◽  
Fungal Activity ◽  
Selective Delignification ◽  
Simultaneous Degradation

AbstractThe biotechnological application of the white rot fungusPhysisporinus vitreusnamed “bioincising” is currently being investigated for permeability improvement of Norway spruce (Picea abies(L.) Karst.) wood. During short-term (<9 weeks) incubation, fungal activity induces degradation of pit membranes and a simultaneous alteration of the tracheid cell wall structure. In Part 1 of this article series, the occurrence of selective delignification and simultaneous degradation was shown by UV-microspectrophotometry (UMSP). Moreover, significant reduction of Brinell hardness was recorded after 7 and 9 weeks incubation. For a better understanding of the chemical alterations in the wood constituents and the corresponding changes of mechanical properties due to fungal activity, we applied microtensile tests on thin strips that were prepared from the surface of incubated Norway spruce wood. Indications for the occurrence of selective delignification and simultaneous degradation were evident. Determination of lignin content and carbohydrate analysis by borate anion exchange chromatography confirmed the results. The present study verifies the findings from Part 1 of this article series and from previously conducted microscopic investigations. Now, the degradation characteristics ofP. vitreusare established and the bioincising process can be further optimized with higher reliability.

scholarly journals A New Laccase of Lac 2 from the White Rot Fungus Cerrena unicolor 6884 and Lac 2-Mediated Degradation of Aflatoxin B1

Toxins ◽  
2020 ◽  
Vol 12 (8) ◽  
pp. 476 ◽  
Author(s):  
Zhimin Zhou ◽  
Renkuan Li ◽  
Tzi Bun Ng ◽  
Yunyun Lai ◽  
Jie Yang ◽  
...  
Keyword(s):  
Aflatoxin B1 ◽  
Environmental Pollutants ◽  
Anion Exchange Chromatography ◽  
Exchange Chromatography ◽  
Mass Spectrometry Data ◽  
White Rot ◽  
White Rot Fungus ◽  
Multicopper Oxidases ◽  
Cerrena Unicolor

Aflatoxin B1 (AFB1) is a known toxic human carcinogen and can be detoxified by laccases, which are multicopper oxidases that convert several environmental pollutants and toxins. In this study, a new laccase that could catalyze AFB1 degradation was purified and identified from the white-rot fungus Cerrena unicolor 6884. The laccase was purified using (NH4)2SO4 precipitation and anion exchange chromatography, and then identified as Lac 2 through zymogram and UHPLC-MS/MS based on the Illumina transcriptome analysis of C. unicolor 6884. Six putative laccase protein sequences were obtained via functional annotation. The lac 2 cDNA encoding a full-length protein of 512 amino acids was cloned and sequenced to expand the fungus laccase gene library for AFB1 detoxification. AFB1 degradation by Lac 2 was conducted in vitro at pH 7.0 and 45 °C for 24 h. The half-life of AFB1 degradation catalyzed by Lac 2 was 5.16 h. Acetosyringone (AS), Syrinagaldehyde (SA) and [2,2′ -azino-bis-(3-ethylbenzothiazoline-6-sulfonic acid)] (ABTS) at 1 mM concentration seemed to be similar mediators for strongly enhancing AFB1 degradation by Lac 2. The product of AFB1 degradation catalyzed by Lac 2 was traced and identified to be Aflatoxin Q1 (AFQ1) based on mass spectrometry data. These findings are promising for a possible application of Lac 2 as a new aflatoxin oxidase in degrading AFB1 present in food and feeds.

Isolation of a new laccase isoform from the white-rot fungiPycnoporus cinnabarinusstrain ss3

2000 ◽  
Vol 46 (8) ◽  
pp. 759-763 ◽  
Author(s):  
Ludovic Otterbein ◽  
Eric Record ◽  
David Chereau ◽  
Isabelle Herpoël ◽  
Marcel Asther ◽  
...  
Keyword(s):  
First Generation ◽  
Polyacrylamide Gel Electrophoresis ◽  
Anion Exchange Chromatography ◽  
Exchange Chromatography ◽  
Amino Acid Sequences ◽  
White Rot ◽  
White Rot Fungus ◽  
Pycnoporus Cinnabarinus ◽  
Ammonium Sulphate Precipitation ◽  
Liquid Culture Medium

Two extracellular laccase isoforms (Lac I and Lac II) produced by the white-rot fungus Pycnoporus cinnabarinus from the monokaryotic strain ss3 were purified from ferulic-acid-induced liquid culture medium using ammonium sulphate precipitation, followed by anion-exchange chromatography on a Mono Q column. Strain ss3 is the first generation of the parental strain P. cinnabarinus I-937. The new isolated isoform, Lac II, consists of an 86 000 molecular weight protein as determined by SDS polyacrylamide gel electrophoresis. The N-terminal amino acid sequences of both isoforms were determined, and compared to known laccase protein sequences of other organisms.Key words: oxydo-reductase, filamentous fungi, purification.

scholarly journals Effect of Physisporinus vitreus on wood properties of Norway spruce. Part 1: Aspects of delignification and surface hardness

Holzforschung ◽  
2011 ◽  
Vol 65 (5) ◽  
Author(s):  
Christian Lehringer ◽  
Gerald Koch ◽  
Ramesh-Babu Adusumalli ◽  
William M. Mook ◽  
Klaus Richter ◽  
...  
Keyword(s):  
Cell Wall ◽  
Norway Spruce ◽  
Brinell Hardness ◽  
Surface Hardness ◽  
Hardness Test ◽  
Wood Properties ◽  
Acoustic Properties ◽  
White Rot ◽  
White Rot Fungus ◽  
Wall Structure

Abstract The white rot fungus Physisporinus vitreus is currently tested for several biotechnological applications such as permeability improvement of refractory wood species or the optimization of the acoustic properties of wood for violins. The enzymatic activity of P. vitreus results in the degradation of pit membranes and simultaneous alterations of the tracheid cell wall structure in wood of Norway spruce [Picea abies (L.) Karst]. By this means, selective delignification and simultaneous degradation occur in the latewood tracheids at short incubation times. To study the delignification of individual cell wall layers in latewood tracheids, cellular UV-microspectrophotometry was applied to wood of Norway spruce that had been incubated for between 3 and 9 weeks. By means of this technique, the progressing delignification was demonstrated in the latewood tracheid secondary walls. Moreover, local delignification in close proximity to hyphal tunneling, cavities, and notches was evident. Additionally, the mechanical changes were measured (a) at the macroscopic level by Brinell hardness test and (b) at the cellular level by nanoindentation. Brinell hardness was significantly reduced with increasing incubation time which was attributed to the partial delignification. Unlike Brinell tests, results from nanoindentation tests did not show a clear effect of fungal activity because of the material heterogeneity and the high spatial resolution of this technique. The present study provides methodological approaches for the investigation of wood-fungus interactions and contributes to a better understanding of the characteristics of wood decay at the subcellular level caused by the white rot fungus P. vitreus. Moreover, it establishes the basis for a subsequent chemical analysis, for which the results will be the topic of a second paper in this series.

Xylem defense wood of Norway spruce compromised by the pathogenic white-rot fungus Heterobasidion parviporum shows a prolonged period of selective decay

Planta ◽  
2012 ◽  
Vol 236 (4) ◽  
pp. 1125-1133 ◽  
Author(s):  
Nina Elisabeth Nagy ◽  
Simon Ballance ◽  
Harald Kvaalen ◽  
Carl Gunnar Fossdal ◽  
Halvor Solheim ◽  
...  
Keyword(s):  
Norway Spruce ◽  
White Rot ◽  
White Rot Fungus ◽  
Selective Decay

scholarly journals The pathogenic white-rot fungus Heterobasidion parviporum triggers non-specific defence responses in the bark of Norway spruce

2011 ◽  
Vol 31 (11) ◽  
pp. 1262-1272 ◽  
Author(s):  
J. Arnerup ◽  
M. Lind ◽  
A. Olson ◽  
J. Stenlid ◽  
M. Elfstrand
Keyword(s):  
Norway Spruce ◽  
White Rot ◽  
White Rot Fungus ◽  
Defence Responses

Effects of White-Rot Fungus Trametes Sp.lg-9 Treatment on Properties of Chlorine-Containing Bleaching Wastewater

2012 ◽  
Vol 550-553 ◽  
pp. 2241-2245
Author(s):  
Zhi Qiang Pang ◽  
Chao Yang ◽  
Jia Chuan Chen ◽  
Gui Hua Yang
Keyword(s):  
Ph Value ◽  
Lignin Content ◽  
Optimal Growth ◽  
Growth Conditions ◽  
Crude Enzyme ◽  
White Rot ◽  
Enzyme Treatment ◽  
White Rot Fungus ◽  
Short Time ◽  
Low Dosage

Effects of white-rot fungus Trametes sp.lg-9 treatment on properties of chlorine-containing bleaching wastewater were investigated. Trametes sp.lg-9 was cultured in chlorine-containing bleaching wastewater under optimal growth conditions, COD sharply decreased from 10740mg/l to 7811mg/l after 5 days; chroma firstly increased from 6212 degree to 7272 degree at 5 days and then declined to 5303 degree; lignin content firstly increased to 0.33 g/l and then decreased to 0.323 g/l. Separating the crude enzyme solution to treat chlorine-containing bleaching wastewater, demonstrating the suitable temperature of the crude enzyme treatment is 40 °C and the optimum pH value is 5.6. COD, chroma and lignin content of chlorine-containing bleaching wastewater can be significantly reduced by crude enzyme treatment on conditions of low dosage and short time.

scholarly journals Biotransformation of Aromatic Methyl Groups to Aldehyde Groups Using Laccase of Gloephyllum Stratum MTCC-1117

2020 ◽  
Author(s):  
RAM SAHAY
Keyword(s):  
White Rot Fungi ◽  
Anion Exchange Chromatography ◽  
Exchange Chromatography ◽  
White Rot ◽  
Show Absorption Band ◽  
Yellow Colour ◽  
Sds Page ◽  
Coir Dust ◽  
Laccase Enzyme ◽  
Aldehyde Groups

Abstract Laccases has been produced by white rot fungi are involved in lignin containing natural substrates wheat-straw, bagasse, saw-dust, corn cob and coir dust particle on the production of laccase enzyme in the aqueous cultivation medium of Gloephyllum stratum MTCC1117. The approach involved concentration of aqueous filtrate by ultrafiltration and anion exchange chromatography on DEAE (diethyl aminoethyl cellulose). From SDS-PAGE analysis the molecular mass of the purified enzyme is 57 kDa. The Km and kcat values of the laccase are found to be 18 μM and 0.34 s-1 using 2,6-dimethoxyphenol as the substrate, giving a kcat/Km value is 1.70 x 103 M-1 s-1. The pH and temperature optimum were 4.5 and 40 °C respectively. The purified enzyme has yellow colour and does not show absorption band around 610 nm found in blue laccases. Moreover the conversion of methylbenzene to benzaldehyde in the lack of mediator molecules, property exhibited by yellow laccases.

scholarly journals Purification and Characterization of a Nylon-Degrading Enzyme

1998 ◽  
Vol 64 (4) ◽  
pp. 1366-1371 ◽  
Author(s):  
Tetsuya Deguchi ◽  
Yoshihisa Kitaoka ◽  
Masaaki Kakezawa ◽  
Tomoaki Nishida
Keyword(s):  
Reaction Mechanism ◽  
Manganese Peroxidase ◽  
Gel Filtration ◽  
White Rot Fungi ◽  
Exchange Chromatography ◽  
White Rot ◽  
White Rot Fungus ◽  
Extracellular Medium ◽  
Degrading Enzyme ◽  
Key Enzyme

ABSTRACT A nylon-degrading enzyme found in the extracellular medium of a ligninolytic culture of the white rot fungus strain IZU-154 was purified by ion-exchange chromatography, gel filtration chromatography, and hydrophobic chromatography. The characteristics of the purified protein (i.e., molecular weight, absorption spectrum, and requirements for 2,6-dimethoxyphenol oxidation) were identical to those of manganese peroxidase, which was previously characterized as a key enzyme in the ligninolytic systems of many white rot fungi, and this result led us to conclude that nylon degradation is catalyzed by manganese peroxidase. However, the reaction mechanism for nylon degradation differed significantly from the reaction mechanism reported for manganese peroxidase. The nylon-degrading activity did not depend on exogenous H2O2 but nevertheless was inhibited by catalase, and superoxide dismutase inhibited the nylon-degrading activity strongly. These features are identical to those of the peroxidase-oxidase reaction catalyzed by horseradish peroxidase. In addition, α-hydroxy acids which are known to accelerate the manganese peroxidase reaction inhibited the nylon-degrading activity strongly. Degradation of nylon-6 fiber was also investigated. Drastic and regular erosion in the nylon surface was observed, suggesting that nylon is degraded to soluble oligomers and that nylon is degraded selectively.

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