scholarly journals Coupling structural characterization with secretomic analysis reveals mechanism of the disruption of cross-linked structure in bamboo culms by Echinodontium taxodii

2019 ◽  
Author(s):  
Wen Kong ◽  
Jialong Zhang ◽  
Qiuyun Xiao ◽  
Jiashu Liu ◽  
Zhixiang Cao ◽  
...  
Keyword(s):  
Lignocellulosic Biomass ◽  
Extracellular Enzymes ◽  
Early Stage ◽  
White Rot Fungi ◽  
White Rot ◽  
Biomass Recalcitrance ◽  
Lignocellulose Conversion ◽  
Fungal Pretreatment ◽  
Insight Into

Abstract Background: Overcoming the biomass recalcitrance is essential for efficient utilization of lignocellulosic biomass in industrial bio-refining. White-rot fungi can overcome the biomass recalcitrance and accelerate the conversion of lignocellulose to biofuels via a large number of special extracellular lignocellulolytic enzymes. Previous studies try to dissect the function of extracellular enzymes on biomass resistant cross-linked structures by secretome analysis, but the bio-alteration of cross-linked structures is ignored usually. A deeper and detailed understanding of relationship between secretome and bio-alteration of cross-linked structure in lignocellulosic biomass is still lack. Results: As an efficient wood-decaying fungus, Echinodontium taxodii could improve the conversion efficiency of lignocellulose to biofuels. This study coupled comparative analysis of fungal secretomes and 2D HSQC NMR analysis of lignocellulose fractions, aiming to elucidate the role of extracellular enzymes from Echinodontium taxodii 2538 in the disruption of resistant cross-linked structure of bamboo culms. Carboxylesterases, alcohol oxidases and Class-II peroxidases showed importance in the cleavage of cross-linked structures, including ester and ether linkages of lignin-carbohydrate complexes (LCCs) and inter-unit linkages of lignin, which contributed to biomass resistance removal and cellulose exposure during the early stage of fungal decay. Moreover, the rapid oxidation of Cα-OH was found to contribute to the lignin bio-depolymerization. Conclusions: These findings revealed the detailed mechanisms of biomass recalcitrance reduction by fungal pretreatment, and provide insight into efficient strategy of lignocellulose conversion. It will advance the development in design of enzyme cocktail for efficient lignocellulose bio-refinery.

scholarly journals A comprehensive study of the promoting effect of manganese on white rot fungal treatment for enzymatic hydrolysis of woody and grass lignocellulose

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Xiao Fu ◽  
Jialong Zhang ◽  
Xiangyu Gu ◽  
Hongbo Yu ◽  
Shulin Chen
Keyword(s):  
Wheat Straw ◽  
Lignocellulosic Biomass ◽  
Quantum Coherence ◽  
Plant Cell Wall ◽  
White Rot ◽  
Yield Enhancement ◽  
Biomass Recalcitrance ◽  
Fungal Treatment ◽  
Ether Linkage ◽  
Glucose Yield

Abstract Background The efficiency of biological systems as an option for pretreating lignocellulosic biomass has to be improved to make the process practical. Fungal treatment with manganese (Mn) addition for improving lignocellulosic biomass fractionation and enzyme accessibility were investigated in this study. The broad-spectrum effect was tested on two different types of feedstocks with three fungal species. Since the physicochemical and structural properties of biomass were the main changes caused by fungal degradation, detailed characterization of biomass structural features was conducted to understand the mechanism of Mn-enhanced biomass saccharification. Results The glucose yields of fungal-treated poplar and wheat straw increased by 2.97- and 5.71-fold, respectively, after Mn addition. Particularly, over 90% of glucose yield was achieved in Mn-assisted Pleurotus ostreatus-treated wheat straw. A comparison study using pyrolysis gas chromatography mass spectrometry (Py-GC/MS) and two-dimensional 1H–13C heteronuclear single quantum coherence (2D HSQC) nuclear magnetic resonance (NMR) spectroscopy was conducted to elucidate the role of Mn addition on fungal disruption of the cross-linked structure of whole plant cell wall. The increased Cα-oxidized products was consistent with the enhanced cleavage of the major β-O-4 ether linkages in poplar and wheat straw lignin or in the wheat straw lignin–carbohydrate complexes (LCCs), which led to the reduced condensation degree in lignin and decreased lignin content in Mn-assisted fungal-treated biomass. The correlation analysis and principal component analysis (PCA) further demonstrated that Mn addition to fungal treatment enhanced bond cleavage in lignin, especially the β-O-4 ether linkage cleavage played the dominant role in removing the biomass recalcitrance and contributing to the glucose yield enhancement. Meanwhile, enhanced deconstruction of LCCs was important in reducing wheat straw recalcitrance. The findings provided not only mechanistic insights into the Mn-enhanced biomass digestibility by fungus, but also a strategy for improving biological pretreatment efficiency of lignocellulose. Conclusion The mechanism of enhanced saccharification of biomass by Mn-assisted fungal treatment mainly through Cα-oxidative cleavage of β-O-4 ether linkages further led to the decreased condensation degree in lignin, as a result, biomass recalcitrance was significantly reduced by Mn addition. Graphic abstract

scholarly journals The attraction of Tremex apicalis (Hymenoptera, Siricidae, Tremecinae) and its parasitoid Ibalia japonica (Hymenoptera, Ibaliidae) to the fungus Cerrena unicolor

2019 ◽  
Vol 68 ◽  
pp. 37-48 ◽  
Author(s):  
Kazumu Kuramitsu ◽  
Teruhito Ishihara ◽  
Aki Sugita ◽  
Thitaree Yooboon ◽  
Barry Lustig ◽  
...  
Keyword(s):  
Volatile Compounds ◽  
Dna Barcode ◽  
White Rot Fungi ◽  
White Rot ◽  
Searching Behavior ◽  
Host Searching ◽  
Additional Species ◽  
Saproxylic Insects ◽  
Symbiotic Fungi

Woodwasps (Hymenoptera: Siricidae) are saproxylic insects and a common forest pest. Siricid woodwasps are classified into two subfamilies: Siricinae and Tremecinae. All known symbiotic fungi of Siricinae are in the genusAmylostereumBoidin while some species of Tremecinae have been observed to have a relationship with the fungusCerrenaunicolor(Bull.) Murrill. Previous studies about the host searching behavior of woodwasps and their parasitoids have focused primarily on the subfamily Siricinae.We analyzed the role ofC.unicolorvolatiles on the host searching behavior ofTremexapicalisMatsumura (Hymenoptera: Siricidae: Tremecinae) and its parasitoid Ibalia (Tremibalia) japonica Matsumura (Hymenoptera: Ibaliidae). The results of an olfactory response experiment indicated that the females ofT.apicalisand its parasitoid find their respective hosts using volatiles fromC.unicolor. Using DNA barcode, we identified basidiocarps on the trees infested withT.apicalis.The basidiocarps were all white-rot fungi that cause sapwood decay, includingC.unicolor. Two additional species that we identified belonged to genera closely related toC.unicolor.Woodwasp species are known to carry symbiotic fungi in a pair of specialized sacs called mycangia. Notably we found that mycangia-like structures were absent in the abdomens ofT.apicalisfemales. To the best of our knowledge,Xerisspectrum(Linnaeus) (Hymenoptera: Siricidae) is the only reported example of woodwasp species that do not contain symbiotic fungi in their bodies.Our results suggested that: (1)T.apicalisfemales search for host wood that is already infected with sapwood decaying fungus using volatile compounds; (2)T.apicalis’ female parasitoid also uses volatile compounds from fungus to locate wood that is infested with its potential host.

scholarly journals Evaluation of Compressive Strength of Decayed Wood in Magnolia obovata

2010 ◽  
Vol 36 (2) ◽  
pp. 81-85
Author(s):  
Kahoru Matsumoto ◽  
Futoshi Ishiguri ◽  
Kazuya Iizuka ◽  
Shinso Yokota ◽  
Naoto Habu ◽  
...  
Keyword(s):  
Compressive Strength ◽  
Early Stage ◽  
White Rot Fungi ◽  
Brown Rot ◽  
Soft Rot ◽  
White Rot ◽  
Chemical Components ◽  
Cellulose Content ◽  
Magnolia Obovata ◽  
Weight Loss Ratio

To obtain the basic information needed to estimate the degree of decay from compressive strength measured using a Fractometer (CS), relationships between CS and the contents of chemical components were analyzed for Magnolia wood decayed by three types fungi (brown rot, white rot, and soft rot fungi) at various decay levels. Weight loss ratio was significantly, negatively correlated with CS in woods decayed by brown rot and white rot fungi. In addition, a relatively high correlation coefficient was recognized between CS and holocellulose or α-cellulose content, except for wood decayed by soft rot fungus. The results obtained showed that Fractometer can detect the decrease of CS at relatively early stage of decay.

Extracellular Enzymes of the White Rot Fungi

2001 ◽  
Vol 3 (2-3) ◽  
pp. 1
Author(s):  
Cristina N. Dumitrache-Anghel ◽  
Danielle Tilmanis ◽  
Lyndal Roberts ◽  
Warren L. Baker ◽  
Greg T. Lonergan
Keyword(s):  
Extracellular Enzymes ◽  
White Rot Fungi ◽  
White Rot

scholarly journals Role of ligninolytic enzymes of white rot fungi (Pleurotus spp.) grown with azo dyes

SpringerPlus ◽  
2016 ◽  
Vol 5 (1) ◽  
Author(s):  
Prashant D. Kunjadia ◽  
Gaurav V. Sanghvi ◽  
Anju P. Kunjadia ◽  
Pratap N. Mukhopadhyay ◽  
Gaurav S. Dave
Keyword(s):  
Azo Dyes ◽  
White Rot Fungi ◽  
Ligninolytic Enzymes ◽  
White Rot

scholarly journals Biological pretreatment of wheat straw: Effect of fungal culturing on enzymatic hydrolysis of carbohydrate polymers

2021 ◽  
Author(s):  
Aleksandar Knežević ◽  
Ivana Đokić ◽  
Tomislav Tosti ◽  
Slađana Popović ◽  
Dušanka Milojković-Opsenica ◽  
...  
Keyword(s):  
Enzymatic Hydrolysis ◽  
Wheat Straw ◽  
Lignin Degradation ◽  
Enzymatic Saccharification ◽  
White Rot Fungi ◽  
Fungal Species ◽  
White Rot ◽  
Irpex Lacteus ◽  
Fungal Pretreatment ◽  
Hydrolysis Of

Abstract The aim of the study was comparative analysis of degradation of wheat straw lignin by white-rot fungi and its implications on the efficiency of enzymatic hydrolysis of holocellulose. Cyclocybe cylindracea, Ganoderma resinaceum, Irpex lacteus, Pleurotus ostreatus and Trametes versicolor were the species studied. Peroxidases were predominantly responsible for lignin degradation even though high laccase activities were detected, except in the case of Irpex lacteus where laccase activity was not detected. Studied fungal species showed various ability to degrade lignin in wheat straw which further affected release of reducing sugars during enzymatic saccharification. The highest rate of lignin degradation was noticed in sample pretreated with Irpex lacteus (50.9 ± 4.1%). Among all tested species only Ganoderma resinaceum was suitable lignin degrader with the 2-fold higher hydrolysis yield (51.1 ± 4.7%) than in the control, and could have significant biotechnological application due to lower cellulose loss. A key mechanism of carbohydrate component convertibility enhancement was lignin removal in the biomass. Long time consumption, the low sugar yields and unpredictable fungal response still remain the challenge of the fungal pretreatment process.

scholarly journals Comparative Study on Quality of Fuel Pellets from Switchgrass Treated with Different White-Rot Fungi

Energies ◽  
2021 ◽  
Vol 14 (22) ◽  
pp. 7670
Author(s):  
Onu Onu Olughu ◽  
Lope G. Tabil ◽  
Tim Dumonceaux ◽  
Edmund Mupondwa ◽  
Duncan Cree
Keyword(s):  
Tensile Strength ◽  
Trametes Versicolor ◽  
Positive Impact ◽  
White Rot Fungi ◽  
Fold Increase ◽  
White Rot ◽  
Fermentation Time ◽  
Fungal Strains ◽  
Particle Bonding ◽  
Fungal Pretreatment

Fungal pretreatment of switchgrass using Phanerochaete chrysosporium (PC), Trametes versicolor 52J (TV52J), and the Trametes versicolor mutant strain (m4D) under solid-state fermentation was conducted to improve its pellet quality. For all three fungal strains, the fermentation temperature had a significant effect (p < 0.05) on pellet unit density and tensile strength. The p-values of the quadratic models for all the response variables showed highly significant regression models (p < 0.01) except for dimensional stability. In addition, 3.1-fold and 2.8-fold increase in pellet tensile strength were obtained from P. chrysosporium- and T. versicolor 52J-treated materials, respectively. Microstructural examination showed that fungal pretreatment reduced pores in the pellets and enhanced pellet particle bonding. Among the fungal strains, PC had the shortest optimum fermentation time (21 d) and most positive impact on the pellet tensile strength and hydrophobicity. Therefore, switchgrass pretreatment using PC has the potential for resolving the challenges of switchgrass pellet transportation and storage and reducing the overall pelletization cost. However, a detailed comparative technoeconomic analysis would be required to make definitive cost comparisons.

scholarly journals The Manganese Peroxidase Gene Family of Trametes trogii: Gene Identification and Expression Patterns Using Various Metal Ions under Different Culture Conditions

2021 ◽  
Vol 9 (12) ◽  
pp. 2595
Author(s):  
Yu Zhang ◽  
Zhongqi Dong ◽  
Yuan Luo ◽  
En Yang ◽  
Huini Xu ◽  
...  
Keyword(s):  
Metal Ions ◽  
Gene Family ◽  
Liquid Culture ◽  
Extracellular Enzymes ◽  
Expression Patterns ◽  
White Rot Fungi ◽  
Culture Conditions ◽  
White Rot ◽  
Type I ◽  
Group I

Manganese peroxidases (MnPs), gene family members of white-rot fungi, are necessary extracellular enzymes that degrade lignocellulose and xenobiotic aromatic pollutants. However, very little is known about the diversity and expression patterns of the MnP gene family in white-rot fungi, especially in contrast to laccases. Here, the gene and protein sequences of eight unique MnP genes of T. trogii S0301 were characterized. Based on the characteristics of gene sequence, all TtMnPs here belong to short-type hybrid MnP (type I) with an average protein length of 363 amino acids, 5–6 introns, and the presence of conserved cysteine residues. Furthermore, analysis of MnP activity showed that metal ions (Mn2+ and Cu2+) and static liquid culture significantly influenced MnP activity. A maximum MnP activity (>14.0 U/mL) toward 2,6-DMP was observed in static liquid culture after the addition of Mn2+ (1 mM) or Cu2+ (0.2 or 2 mM). Moreover, qPCR analysis showed that Mn2+ obviously upregulated the Group I MnP subfamily (T_trogii_09901, 09904, 09903, and 09906), while Cu2+ and H2O2, along with changing temperatures, mainly induced the Group II MnP subfamily (T_trogii_11984, 11971, 11985, and 11983), suggesting diverse functions of fungal MnPs in growth and development, stress response, etc. Our studies here systematically analyzed the gene structure, expression, and regulation of the TtMnP gene family in T. trogii, one of the important lignocellulose-degrading fungi, and these results extended our understanding of the diversity of the MnP gene family and helped to improve MnP production and appilications of Trametes strains and other white-rot fungi.

scholarly journals Comparison of the Ability of Several White-rot Fungi to Biobleach Acacia Oxygen-delignified Kraft Pulp

2019 ◽  
pp. 1-10
Author(s):  
Sitompul Afrida ◽  
Toshihiro Watanabe ◽  
Yutaka Tamai
Keyword(s):  
Kraft Pulp ◽  
Extracellular Enzymes ◽  
Low Cost ◽  
White Rot Fungi ◽  
Acacia Mangium ◽  
White Rot ◽  
Irpex Lacteus ◽  
Lentinus Tigrinus

Previous screening analyses demonstrated that the in vivo biobleaching activities of the white-rot fungi Irpex lacteus KB-1.1 and Lentinus tigrinus LP-7 are higher than those of Phanerochaete chrysosporium and Trametes versicolor. The purpose of the current study was to examine the production of extracellular enzymes of these four white-rot fungi grown on three types of low-cost media containing agricultural and forestry waste, and to evaluate the ability of the produced extracellular enzymes to biobleach Acacia oxygen-delignified kraft pulp (A-OKP). The biobleaching activity of extracellular fractions of I. lacteus, L. tigrinus, T. versicolor, and P. chrysosporium cultures was the most pronounced after 3 days of incubation with Acacia mangium wood powder supplemented with rice bran and 1% glucose (WRBG) with resultant Kappa number reduction of 4.4%, 6.7%, 3.3%, and 3.3%, respectively. Therefore, biobleaching ability of I. lacteus and L. tigrinus have been shown to be higher than of T. versicolor and P. chrysosporium, both in vivo and in vitro.

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