scholarly journals Assessing the Biodegradation of Vulcanised Rubber Particles by Fungi Using Genetic, Molecular and Surface Analysis

2021 ◽  
Vol 9 ◽  
Author(s):  
R. Andler ◽  
V. D’Afonseca ◽  
J. Pino ◽  
C. Valdés ◽  
M. Salazar-Viedma
Keyword(s):  
Extracellular Enzymes ◽  
Degradation Products ◽  
White Rot Fungi ◽  
Fungal Species ◽  
White Rot ◽  
Great Resistance ◽  
Rubber Particles ◽  
Tyre Waste ◽  
Public Repositories ◽  
Highly Hydrophobic

Millions of tonnes of tyre waste are discarded annually and are considered one of the most difficult solid wastes to recycle. A sustainable alternative for the treatment of vulcanised rubber is the use of microorganisms that can biotransform polymers and aromatic compounds and then assimilate and mineralise some of the degradation products. However, vulcanised rubber materials present great resistance to biodegradation due to the presence of highly hydrophobic cross-linked structures that are provided by the additives they contain and the vulcanisation process itself. In this work, the biodegradation capabilities of 10 fungal strains cultivated in PDA and EM solid medium were studied over a period of 4 weeks. The growth of the strains, the mass loss of the vulcanised rubber particles and the surface structure were analysed after the incubation period. With the white rot fungi Trametes versicolor and Pleurotus ostreatus, biodegradation percentages of 7.5 and 6.1%, respectively, were achieved. The FTIR and SEM-EDS analyses confirmed a modification of the abundance of functional groups and elements arranged on the rubber surface, such as C, O, S, Si, and Zn, due to the biological treatment employed. The availability of genomic sequences of P. ostreatus and T. versicolor in public repositories allowed the analysis of the genetic content, genomic characteristics and specific components of both fungal species, determining some similarities between both species and their relationship with rubber biodegradation. Both fungi presented a higher number of sequences for laccases and manganese peroxidases, two extracellular enzymes responsible for many of the oxidative reactions reported in the literature. This was confirmed by measuring the laccase and peroxidase activity in cultures of T. versicolor and P. ostreatus with rubber particles, reaching between 2.8 and 3.3-times higher enzyme activity than in the absence of rubber. The integrative analysis of the results, supported by genetic and bioinformatics tools, allowed a deeper analysis of the biodegradation processes of vulcanised rubber. It is expected that this type of analysis can be used to find more efficient biotechnological solutions in the future.

scholarly journals Assessing The Biodegradation of Vulcanised Rubber Particles by Fungi Using Genetic, Molecular and Surface Analysis

2021 ◽  
Author(s):  
Rodrigo Andler ◽  
Vivian D’Afonseca ◽  
Javiera Pino ◽  
Cristian Valdés ◽  
Marcela Salazar-Viedma
Keyword(s):  
Extracellular Enzymes ◽  
Degradation Products ◽  
White Rot Fungi ◽  
Fungal Species ◽  
White Rot ◽  
Great Resistance ◽  
Rubber Particles ◽  
Tyre Waste ◽  
Public Repositories ◽  
Highly Hydrophobic

Abstract Millions of tonnes of tyre waste are discarded annually and are considered one of the most difficult solid wastes to recycle. A sustainable alternative for the treatment of vulcanised rubber is the use of microorganisms that can biotransform polymers and aromatic compounds and then assimilate and mineralise some of the degradation products. However, vulcanised rubber materials present great resistance to biodegradation due to the presence of highly hydrophobic cross-linked structures that are provided by the additives they contain and the vulcanisation process itself. In this work, the biodegradation capabilities of 10 fungal strains cultivated in PDA and EM solid medium were studied over a period of 4 weeks. The growth of the strains, the mass loss of the vulcanised rubber particles and the surface structure were analysed after the incubation period. With the white rot fungi Trametes versicolor and Pleurotus ostreatus, biodegradation percentages of 7.5 and 6.1%, respectively, were achieved. The FTIR and SEM-EDS analyses confirmed a modification of the abundance of functional groups and elements arranged on the rubber surface, such as C, O, S, Si and Zn, due to the biological treatment employed. The availability of genomic sequences of P. ostreatus and T. versicolor in public repositories allowed the analysis of the genetic content, genomic characteristics and specific components of both fungal species, determining some similarities between both species and their relationship with rubber biodegradation. Both fungi presented a higher number of sequences for laccases and manganese peroxidases, two extracellular enzymes responsible for many of the oxidative reactions reported in the literature. The integrative analysis of the results, supported by genetic and bioinformatics tools, allowed a deeper analysis of the biodegradation processes of vulcanised rubber. It is expected that this type of analysis can be used to find more efficient biotechnological solutions in the future.

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

Ability of white-rot fungi to remove selected pharmaceuticals and identification of degradation products of ibuprofen by Trametes versicolor

Chemosphere ◽  
2009 ◽  
Vol 74 (6) ◽  
pp. 765-772 ◽  
Author(s):  
Ernest Marco-Urrea ◽  
Miriam Pérez-Trujillo ◽  
Teresa Vicent ◽  
Gloria Caminal
Keyword(s):  
Trametes Versicolor ◽  
Degradation Products ◽  
White Rot Fungi ◽  
White Rot

Decay resistance of softwoods and hardwoods thermally modified by the Thermovouto type thermo-vacuum process to brown rot and white rot fungi

Holzforschung ◽  
2016 ◽  
Vol 70 (9) ◽  
pp. 877-884 ◽  
Author(s):  
Jie Gao ◽  
Jong Sik Kim ◽  
Nasko Terziev ◽  
Geoffrey Daniel
Keyword(s):  
White Rot Fungi ◽  
Brown Rot ◽  
Decay Resistance ◽  
Fungal Species ◽  
White Rot ◽  
Agar Block ◽  
Pycnoporus Sanguineus ◽  
Postia Placenta ◽  
Soil Block ◽  
Class 1

Abstract Softwoods (SW, spruce and fir) and hardwoods (HW, ash and beech) were thermally modified by the thermo-vacuum (Termovuoto) process for 3–4 h in the temperature range 160–220°C (TMW160–220°C) and their fungal durability were examined in soil-block tests with two brown rot (BR, Postia placenta, Gloeophyllum trabeum) and two white rot (WR, Pycnoporus sanguineus, Phlebia radiata) fungi. SW-TMW160–220°C were exposed to P. placenta and P. sanguineus and HW-TMW190–220°C to all fungal species. Considerable improvement (durability class 1–3) in decay resistance was only achieved for SW- and HW-TMW220°C. Thermal modification (TM) below 200°C influenced decay resistance negatively in case of some fungal species applied for both SW and HW. Judged by the durability class, decay resistance was higher in HW- than in SW-TMW at high TM temperature. Behavior of TM differed significantly between ash (ring-porous HW) and beech (diffuse-porous HW). A comparison between results of soil- and agar-block tests on Termovouoto wood demonstrated that the influence of testing method in terms of assignment to durability classes is not significant.

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 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.

scholarly journals Lignin-degrading activity and ligninolytic enzymes of different white-rot fungi: effects of manganese and malonate

1997 ◽  
Vol 75 (1) ◽  
pp. 61-71 ◽  
Author(s):  
Tamara Vares ◽  
Annele Hatakka
Keyword(s):  
Lignin Peroxidase ◽  
Manganese Peroxidase ◽  
White Rot Fungi ◽  
Ligninolytic Enzymes ◽  
Growth Conditions ◽  
Fungal Species ◽  
White Rot ◽  
Trametes Hirsuta ◽  
Air Atmosphere ◽  
Trametes Trogii

Ten species of white-rot fungi, mainly belonging to the family Polyporaceae (Basidiomycotina), were studied in terms of their ability to degrade14C-ring labelled synthetic lignin and secrete ligninolytic enzymes in liquid cultures under varying growth conditions. Lignin mineralization by the fungi in an air atmosphere did not exceed 14% within 29 days. Different responses to the elevated Mn2+concentration and the addition of a manganese chelator (sodium malonate) were observed among various fungal species. This could be related with the utilization of either lignin peroxidase (LiP) or manganese peroxidase (MnP) for lignin depolymerization, i.e., some fungi apparently had an LiP-dominating ligninolytic system and others an MnP-dominating ligninolytic system. The LiP isoforms were purified from Trametes gibbosa and Trametes trogii. Isoelectric focusing of purified ligninolytic enzymes revealed the expression of numerous MnP isoforms in Trametes gibbosa, Trametes hirsuta, Trametes trogii, and Abortiporus biennis grown under a high (50-fold) Mn2+level (120 μM) with the addition of the chelator. In addition, two to three laccase isoforms were detected. Key words: white-rot fungi, lignin degradation, lignin peroxidase, manganese peroxidase, manganese, malonate.

scholarly journals Evolution and enrichment of CYP5035 in Polyporales: functionality of an understudied P450 family

2021 ◽  
Vol 105 (18) ◽  
pp. 6779-6792
Author(s):  
Nico D. Fessner ◽  
David R. Nelson ◽  
Anton Glieder
Keyword(s):  
White Rot Fungi ◽  
Fungal Species ◽  
White Rot ◽  
Functional Screening ◽  
Cytochrome P450 Enzymes ◽  
Lentinus Tigrinus ◽  
Detoxification Mechanism ◽  
Key Points ◽  
Functional Profiling ◽  
Polyporus Brumalis

Abstract Bioprospecting for innovative basidiomycete cytochrome P450 enzymes (P450s) is highly desirable due to the fungi’s enormous enzymatic repertoire and outstanding ability to degrade lignin and detoxify various xenobiotics. While fungal metagenomics is progressing rapidly, the biocatalytic potential of the majority of these annotated P450 sequences usually remains concealed, although functional profiling identified several P450 families with versatile substrate scopes towards various natural products. Functional knowledge about the CYP5035 family, for example, is largely insufficient. In this study, the families of the putative P450 sequences of the four white-rot fungi Polyporus arcularius, Polyporus brumalis, Polyporus squamosus and Lentinus tigrinus were assigned, and the CYPomes revealed an unusual enrichment of CYP5035, CYP5136 and CYP5150. By computational analysis of the phylogeny of the former two P450 families, the evolution of their enrichment could be traced back to the Ganoderma macrofungus, indicating their evolutionary benefit. In order to address the knowledge gap on CYP5035 functionality, a representative subgroup of this P450 family of P. arcularius was expressed and screened against a test set of substrates. Thereby, the multifunctional enzyme CYP5035S7 converting several plant natural product classes was discovered. Aligning CYP5035S7 to 102,000 putative P450 sequences of 36 fungal species from Joint Genome Institute-provided genomes located hundreds of further CYP5035 family members, which subfamilies were classified if possible. Exemplified by these specific enzyme analyses, this study gives valuable hints for future bioprospecting of such xenobiotic-detoxifying P450s and for the identification of their biocatalytic potential. Graphical abstract Key points • The P450 families CYP5035 and CYP5136 are unusually enriched in P. arcularius. • Functional screening shows CYP5035 assisting in the fungal detoxification mechanism. • Some Polyporales encompass an unusually large repertoire of detoxification P450s.

Biodegradation of lignin

1995 ◽  
Vol 73 (S1) ◽  
pp. 1011-1018 ◽  
Author(s):  
Ian D. Reid
Keyword(s):  
Lignin Peroxidase ◽  
Manganese Peroxidase ◽  
Extracellular Enzymes ◽  
White Rot Fungi ◽  
Wood Decay ◽  
Brown Rot ◽  
Economic Consequences ◽  
White Rot ◽  
Lignin Biodegradation ◽  
Pulp Bleaching

Lignin is an aromatic polymer forming up to 30% of woody plant tissues, providing rigidity and resistance to biological attack. Because it is insoluble, chemically complex, and lacking in hydrolysable linkages, lignin is a difficult substrate for enzymatic depolymerization. Certain fungi, mostly basidiomycetes, are the only organisms able to extensively biodegrade it; white-rot fungi can completely mineralize lignin, whereas brown-rot fungi merely modify lignin while removing the carbohydrates in wood. Several oxidative and reductive extracellular enzymes (lignin peroxidase, manganese peroxidase, laccase, and cellobiose:quinone oxidoreductase) have been isolated from ligninolytic fungi; the role of these enzymes in lignin biodegradation is being intensively studied. Enzymatic combustion, a process wherein enzymes generate reactive intermediates, but do not directly control the reactions leading to lignin breakdown, has been proposed as the mechanism of lignin biodegradation. The economic consequences of lignin biodegradation include wood decay and the biogeochemical cycling of woody biomass. Efforts are being made to harness the delignifying abilities of white-rot fungi to aid wood and straw pulping and pulp bleaching. These fungi can also be used to degrade a variety of pollutants in wastewaters and soils, to increase the digestibility of lignocellulosics, and possibly to bioconvert lignins to higher value products. Key words: delignification, white-rot fungi, biobleaching, lignin peroxidase, manganese peroxidase, laccase.

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