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1.
Heliyon ; 10(7): e28449, 2024 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-38689961

RESUMO

Trametes villosa is a remarkable white-rot fungus (WRF) with the potential to be applied in lignocellulose conversion to obtain chemical compounds and biofuels. Lignocellulose breakdown by WRF is carried out through the secretion of oxidative and hydrolytic enzymes. Despite the existing knowledge about this process, the complete molecular mechanisms involved in the regulation of this metabolic system have not yet been elucidated. Therefore, in order to understand the genes and metabolic pathways regulated during lignocellulose degradation, the strain T. villosa CCMB561 was cultured in media with different carbon sources (lignin, sugarcane bagasse, and malt extract). Subsequently, biochemical assays and differential gene expression analysis by qPCR and high-throughput RNA sequencing were carried out. Our results revealed the ability of T. villosa CCMB561 to grow on lignin (AL medium) as the unique carbon source. An overexpression of Cytochrome P450 was detected in this medium, which may be associated with the lignin O-demethylation pathway. Clusters of up-regulated CAZymes-encoding genes were identified in lignin and sugarcane bagasse, revealing that T. villosa CCMB561 acts simultaneously in the depolymerization of lignin, cellulose, hemicellulose, and pectin. Furthermore, genes encoding nitroreductases and homogentisate-1,2-dioxygenase that act in the degradation of organic pollutants were up-regulated in the lignin medium. Altogether, these findings provide new insights into the mechanisms of lignocellulose degradation by T. villosa and confirm the ability of this fungal species to be applied in biorefineries and in the bioremediation of organic pollutants.

2.
J Fungi (Basel) ; 10(3)2024 Feb 21.
Artigo em Inglês | MEDLINE | ID: mdl-38535176

RESUMO

Industrial development has enhanced the release into the environment of large quantities of chemical compounds with high toxicity and limited prospects of degradation. The pollution of soil and water with xenobiotic chemicals has become a major ecological issue; therefore, innovative treatment technologies need to be explored. Fungal bioremediation is a promising technology exploiting their metabolic potential to remove or lower the concentrations of xenobiotics. In particular, white rot fungi (WRF) are unique microorganisms that show high capacities to degrade a wide range of toxic xenobiotic compounds such as synthetic dyes, chlorophenols, polychlorinated biphenyls, organophosphate pesticides, explosives and polycyclic aromatic hydrocarbons (PAHs). In this review, we address the main classes of enzymes involved in the fungal degradation of organic pollutants, the main mechanisms used by fungi to degrade these chemicals and the suitability of fungal biomass or extracellular enzymes for bioremediation. We also exemplify the role of several fungi in degrading pollutants such as synthetic dyes, PAHs and emerging pollutants such as pharmaceuticals and perfluoroalkyl/polyfluoroalkyl substances (PFASs). Finally, we discuss the existing current limitations of using WRF for the bioremediation of polluted environments and future strategies to improve biodegradation processes.

3.
Braz J Microbiol ; 55(1): 111-116, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38231377

RESUMO

The white-rot fungus Pleurotus eryngii secretes various laccases involved in the degradation of a wide range of chemical compounds. Since the laccase production is relatively low in fungi, many efforts have been focused on finding ways to increase it, so in this study, we investigated the effect of copper on the transcription of the pel3 laccase gene and extracellular laccase activity. The results indicate that adding 0.5 to 2 mM copper to liquid cultures of P. eryngii KS004 increased both pel3 gene transcription and extracellular laccase activity in a concentration-dependent manner. The most significant increase in enzyme activity occurred at 1 mM Cu2+, where the peak activity was 4.6 times higher than in control flasks. Copper also induced the transcription of the laccase gene pel3. The addition of 1.5 and 2 mM Cu2+ to fungal culture media elevated pel3 transcript levels to more than 13-fold, although the rate of induction slowed down at Cu2+ concentrations higher than 1.5 mM. Our findings suggest that copper acts as an inducer in the regulation of laccase gene expression in P. eryngii KS004. Despite its inhibitory effect on fungal growth, supplementing cultures with copper can lead to an increased extracellular laccase production in P. eryngii.


Assuntos
Lacase , Pleurotus , Lacase/metabolismo , Cobre/farmacologia , Cobre/metabolismo , Pleurotus/genética , Pleurotus/metabolismo , Transcrição Gênica
4.
Sci Total Environ ; 901: 165950, 2023 Nov 25.
Artigo em Inglês | MEDLINE | ID: mdl-37536592

RESUMO

Plastic pollution is one of the most environmental problems in the last two centuries, because of their excessive usage and their rapidly increasing production, which overcome the ability of natural degradation. Moreover, this problem become an escalating environmental issue caused by inadequate disposal, ineffective or nonexistent waste collection methods, and a lack of appropriate measures to deal with the problem, such as incineration and landfilling. Consequently, plastic wastes have become so ubiquitous and have accumulated in the environment impacting ecosystems and wildlife. The above, enhances the urgent need to explore alternative approaches that can effectively reduce waste without causing harsh environmental consequences. For example, white-rot fungi are a promising alternative to deal with the problem. These fungi produce ligninolytic enzymes able to break down the molecular structures of plastics, making them more bioavailable and allowing their degradation process, thereby mitigating waste accumulation. Over the years, several research studies have focused on the utilization of white-rot fungi to degrade plastics. This review presents a summary of plastic degradation biochemistry by white-rot fungi and the function of their ligninolytic enzymes. It also includes a collection of different research studies involving white-rot fungi to degrade plastic, their enzymes, the techniques used and the obtained results. Also, this highlights the significance of pre-treatments and the study of plastic blends with natural fibers or metallic ions, which have shown higher levels of degradation. Finally, it raises the limitations of the biotechnological processes and the prospects for future studies.

5.
Chem Biodivers ; 20(9): e202300346, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37503864

RESUMO

Pleurotus ostreatus is an edible fungus with high nutritional value that uses industrial and agricultural lignocellulosic residues as substrates for growth and reproduction. Understanding their growth metabolic dynamics on agro-industrial wastes would help to develop economically viable and eco-friendly biotechnological strategies for food production. Thus, we used UHPLC/MS/MS and GNPS as an innovative approach to investigate the chemical composition of two strains of P. ostreatus, coded as BH (Black Hirataki) and WH (White Hirataki), grown on sisal waste mixture (SW) supplemented with 20 % cocoa almond tegument (CAT) or 20 % of wheat bran (WB). Metabolite dereplication allowed the identification of 53 metabolites, which included glycerophospholipids, fatty acids, monoacylglycerols, steroids, carbohydrates, amino acids, and flavonoids. This is the first report of the identification of these compounds in P. ostreatus, except for the steroid ergosterol. Most of the metabolites described in this work possess potential biological activities, which support the nutraceutical properties of P. ostreatus. Thus, the results of this study provide essential leads to the understanding of white-rot fungi chemical plasticity aiming at developing alternative biotechnologies strategies for waste recycling.


Assuntos
Pleurotus , Prunus dulcis , Pleurotus/química , Pleurotus/metabolismo , Resíduos Industriais , Fibras na Dieta/metabolismo , Espectrometria de Massas em Tandem , Suplementos Nutricionais
6.
Front Microbiol ; 14: 1148750, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37362943

RESUMO

Soil organic matter (SOM) decomposition mechanisms in rainforest ecosystems are governed by biotic and abiotic procedures which depend on available oxygen in the soil. White-rot fungi (WRF) play an important role in the primary decomposition of SOM via enzymatic mechanisms (biotic mechanism), which are linked to abiotic oxidative reactions (e.g., Fenton reaction), where both processes are dependent on reactive oxygen species (ROS) and soil pH variation, which has yet been studied. In humid temperate forest soils, we hypothesize that soil pH is a determining factor that regulates the production and consumption of ROS during biotic and abiotic SOM decomposition. Three soils from different parent materials and WRF inoculum were considered for this study: granitic (Nahuelbuta, Schizophyllum commune), metamorphic (Alerce Costero, Stereum hirsutum), and volcanic-allophanic (Puyehue, Galerina patagonica). CO2 fluxes, lignin peroxidase, manganese peroxidase, and dye-decolorizing peroxidase levels were all determined. Likewise, the production of superoxide anion (O2•-), hydrogen peroxide (H2O2), and hydroxyl radicals (•OH) were assessed in soils microcosms after 36 days of anaerobic incubation with WRF inoculum and induced Fenton reaction under pH variations ranging from 2.5 to 5.1. ROS significantly increased biotic and abiotic CO2 emissions in all tested soils, according to the findings. The highest values (217.45 mg C kg-1) were found during the anaerobic incubation of sterilized and inoculated soils with WRF at a natural pH of 4.5. At pH 4.0, the lowest levels of C mineralization (82 mg C kg-1) were found in Nahuelbuta soil. Enzyme activities showed different trends as pH changed. The Fenton reaction consumed more H2O2 between pH 3 and 4, but less between pH 4.5 and 2.5. The mechanisms that oxidized SOM are extremely sensitive to variations in soil pH and the stability of oxidant radical and non-radical compounds, according to our findings.

7.
Prep Biochem Biotechnol ; 53(5): 488-499, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-35980820

RESUMO

The purpose of the study was to evaluate the production of lignin-modifying enzyme extracts and delignified biomass from agro-industrial wastes using white rot fungi (Inonotus sp. Sp2, Stereum hirsutum Ru-104, Bjerkandera sp. BOS55, Pleurotus eryngii IJFM 169 and Phanerochaete chrysosporium BKM-F-1767). These were screened based on their adaptability and colonization ability on different substrates, as well as by the Laccase, Manganese peroxidase, and Lignin peroxidase enzymatic production. Native strains (Inonotus sp. Sp2 and S. hirsutum Ru-104) showed the highest growth kinetics under the solid-substrate fermentation conditions and the growth rate parameters of the kinetic logistic model for the different substrates were between 0.39-0.81 (1/d) and 0.42-0.83 (1/d), respectively; the determination coefficients were ≥0.99. Inonotus sp. Sp2 was subsequently cultured in static flasks to produce crude enzyme extracts, obtaining manganese peroxidase activity levels of 18.5 and 31.3 (U/g) when growing in corn cob husk and spent tea leaves, respectively. Besides, it was to establish that the best conditions for lignin-modifying enzymes production using corn cob husk are 70% of initial moisture and 2.12 mm of particle size; reaching after 30 incubation days a manganese peroxidase activity of 21 ± 6 (U/g) under these conditions; enzyme that showed a suitable thermostability.


Assuntos
Resíduos Industriais , Lignina , Lignina/metabolismo , Fermentação , Peroxidases/metabolismo , Lacase/metabolismo , Extratos Vegetais
8.
Foods ; 11(11)2022 May 28.
Artigo em Inglês | MEDLINE | ID: mdl-35681337

RESUMO

This study evaluated the use of the white-rot fungi (WRF) Anthracophyllum discolor and Stereum hirsutum as a biological pretreatment for olive mill solid mill waste (OMSW). The WRF strains proposed were added directly to OMSW. The assays consisted of determining the need to add supplementary nutrients, an exogenous carbon source or use agitation systems, and evaluating WRF growth, enzyme activity, phenolic compound removal and lignin degradation. The highest ligninolytic enzyme activity was found at day 10, reaching 176.7 U/L of manganese-independent peroxidase (MniP) produced by A. discolor, and the highest phenolic removal (more than 80% with both strains) was reached after 24 days of incubation. The confocal laser scanning microscopy analysis (CLSM) confirmed lignin degradation through the drop in lignin relative fluorescence units (RFU) from 3967 for untreated OMSW to 235 and 221 RFU, showing a lignin relative degradation of 94.1% and 94.4% after 24 days of treatment by A. discolor and S. hirsutum, respectively. The results demonstrate for the first time that A. discolor and S. hirsutum were able to degrade lignin and remove phenolic compounds from OMSW using this as the sole substrate without adding other nutrients or using agitation systems. This work indicates that it could be possible to design an in situ pretreatment of the valorization of OMSW, avoiding complex systems or transportation. In this sense, future research under non-sterile conditions is needed to evaluate the competition of WRF with other microorganisms present in the OMSW. The main drawbacks of this work are associated with both the low reaction time and the water addition. However, OMSW is seasonal waste produced in one season per year, being stored for a long time. In terms of water addition, the necessary optimization will be addressed in future research.

9.
Braz J Microbiol ; 53(3): 1425-1437, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-35446011

RESUMO

This study explores the biotechnological potential of lignocellulolytic fungi collected in an oak forest. Fungal collections were obtained from natural reserves located in Boyacá-Colombia, ranging from 2700 to 3000 m.a.s.l. Twenty-three strains were isolated on malt agar, molecular characterization was performed, and ligninolytic and cellulolytic enzymatic activities were screened. Several white-rot fungi of biotechnological importance were identified as follows: Trametes sp., Trametes versicolor, Trametes villosa, Pycnoporus sanguineus, Bjerkandera adjusta, Lentinula boryana, Panus conchatus, Antrodia neotropica, Brunneoporus malicola, Laetiporus gilbertsonii, Stereum sp., Ganoderma sp., and Dichomitus sp. The strains T. versicolor 0554 and 0583, T. villosa 0562, and B. adusta 0556 showed the highest response in the qualitative enzymatic assays. These strains were used to determine their ability to decolorate the dyes aniline blue and Congo red, and it was found that T. villosa 0562 reached a level of decolorization close to 90% after 48 h of submerged culture. The fungal strains obtained here could offer alternatives to develop a process to accomplish sustainable development objectives.


Assuntos
Trametes , Madeira , Colômbia , Corantes , Florestas , Madeira/microbiologia
10.
J Environ Sci Health B ; 57(2): 90-101, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35103576

RESUMO

The main purpose of this work was to use pineapple crowns as substrate for optimizing laccase production by Trametes versicolor in lab-scale experiments. One-factor-at-the-time analysis and response surface methodology were used to optimize production. A single laccase with molecular weight of 45 kDa was the main protein produced. A maximal laccase activity of 60.73 ± 1.01 U/g was obtained in 7-day cultures, representing a 6.7-fold increase compared to non-optimized conditions. The optimized conditions were temperature: 28 °C; initial moisture: 90%; glucose: 8.38%; yeast extract: 2.86%. Combining activity and stability, the best conditions for using this laccase during the long periods required by large-scale processes are pH 4.0-5.0 and temperature of 40-50 °C. Under these conditions, the crude laccase was efficient in detoxifying the dye malachite green with a KM of 14.33 ± 1.94 µM and a Vmax of 0.482 ± 0.029 µM/min with 0.1 units/mL. It can be concluded that pineapple crown leaves can be effectively used as substrate by T. versicolor for producing laccase under solid-state culture conditions. Laccase is an industrially relevant enzyme and its production with concomitant valorization of pineapple crowns as substrate offers highly interesting perspectives.


Assuntos
Ananas , Lacase , Ananas/metabolismo , Lacase/metabolismo , Corantes de Rosanilina , Trametes/metabolismo
11.
Mycologia ; 113(5): 877-890, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34251997

RESUMO

C4 grasses are common species in rangelands around the world and represent an attractive option for second-generation biofuel production. Although they display high polysaccharide content and reach great levels of biomass accumulation, there is a major technical issue to be addressed before they can be used for bioethanol industrial production: lignin removal. Concerning this, Pycnoporus and Ganoderma fungal genera have been highlighted due to their ability to hydrolyze lignocellulose in biological pretreatments. Our goals here were to evaluate the pretreatment efficiency using the secretome of species from Pycnoporus and Ganoderma spp. harvested from a glucose-free inductive medium (using a C4 grass) and to identify the fungal enzymatic activities responsible for the lignin degradation and glucose release. Our results show that P. sanguineus secretome exhibits a higher activity of lignocellulolytic enzymes such as cellulases, xylanases, laccases, and manganese peroxidases compared with that from G. resinaceum. Interestingly, zymograms in the presence of 2 M glucose suggest that a ß-glucosidase isoform from P. sanguineus could be glucose tolerant. The proteomic approach carried out allowed the identification of 73 and 180 different proteins in G. resinaceum and P. sanguineus secretomes, respectively, which were functionally classified in five main categories and a miscellaneous group. These results open new avenues for future experimental work that lead to a deeper comprehension and a greater application of the mechanisms underlying lignocellulosic biomass degradation.


Assuntos
Ganoderma , Panicum , Biomassa , Celulose , Proteínas Fúngicas , Fungos , Lignina , Polyporaceae , Proteômica
12.
Artigo em Inglês | MEDLINE | ID: mdl-32766234

RESUMO

The ability of white-rot fungi to degrade polysaccharides in lignified plant cell walls makes them a suitable reservoir for CAZyme prospects. However, to date, CAZymes from these species are barely studied, which limits their use in the set of choices for biomass conversion in modern biorefineries. The current work joined secretome studies of two representative white-rot fungi, Phanerochaete chrysosporium and Trametes versicolor, with expression analysis of cellobiohydrolase (CBH) genes, and use of the secretomes to evaluate enzymatic conversion of simple and complex sugarcane-derived substrates. Avicel was used to induce secretion of high levels of CBHs in the extracellular medium. A total of 56 and 58 proteins were identified in cultures of P. chrysosporium and T. versicolor, respectively, with 78-86% of these proteins corresponding to plant cell wall degrading enzymes (cellulolytic, hemicellulolytic, pectinolytic, esterase, and auxiliary activity). CBHI predominated among the plant cell wall degrading enzymes, corresponding to 47 and 34% of the detected proteins in P. chrysosporium and T. versicolor, respectively, which confirms that Avicel is an efficient CBH inducer in white-rot fungi. The induction by Avicel of genes encoding CBHs (cel) was supported by high expression levels of cel7D and cel7C in P. chrysosporium and T. versicolor, respectively. Both white-rot fungi secretomes enabled hydrolysis experiments at 10 FPU/g substrate, despite the varied proportions of CBHs and other enzymes present in each case. When low recalcitrance sugarcane pith was used as a substrate, P. chrysosporium and T. versicolor secretomes performed similarly to Cellic® CTec2. However, the white-rot fungi secretomes were less efficient than Cellic® CTec2 during hydrolysis of more recalcitrant substrates, such as acid or alkaline sulfite-pretreated sugarcane bagasse, likely because Cellic® CTec2 contains an excess of CBHs compared with the white-rot fungi secretomes. General comparison of the white-rot fungi secretomes highlighted T. versicolor enzymes for providing high glucan conversions, even at lower proportion of CBHs, probably because the other enzymes present in this secretome and CBHs lacking carbohydrate-binding modules compensate for problems associated with unproductive binding to lignin.

13.
Biosci. j. (Online) ; 36(3): 924-931, 01-05-2020. tab
Artigo em Inglês | LILACS | ID: biblio-1146988

RESUMO

Fungi are capable of sensing light from ultraviolet to far-red and they use light as a source of information about the environment anticipating stress and adverse conditions. Lentinus crinitus is a lignin-degrading fungus which produces laccase and other enzymes of biotechnological interest. The effect of blue light on fungal enzymatic activity has been studied; however, it has not been found studies on the effect of the blue light on carbohydrate-active enzymes and on mycelial biomass production of L. crinitus. We aimed to investigate carbohydrate-active enzymes activity and mycelial biomass production of L. crinitus cultivated under continuous illumination with blue light. L. crinitus was cultivated in malt extract medium in the dark, without agitation, and under continuous illumination with blue light-emitting diodes. The blue light reduced the total cellulase, pectinase and xylanase activities but increased the endoglucanase activity. Blue light reduced the mycelial growth of L. crinitus in 26% and the enzymatic activity-to-mycelial biomass ratio (U mg-1 dry basis) increased in 10% total cellulase, 33% endoglucanase, and 16% pectinase activities. Also, it is suggested that L. crinitus has a photosensory system and it could lead to new process of obtaining enzymes of biotechnological interest.


Fungos são capazes de sentir a luz com comprimentos de onda que variam do ultravioleta ao infravermelho e usam a luz como fonte de informação sobre o ambiente, antecipando condições adversas e de estresse. Lentinus crinitus é um fungo ligninolítico que produz lacase e outras enzimas de interesse biotecnológico. O efeito da luz azul na atividade enzimática de fungos já foi estudado, contudo, ainda não há estudos sobre o efeito da luz azul na produção de enzimas ativas sobre carboidratos (CAZymes, carbohydrate-active enzymes) e de biomassa micelial de L. crinitus. O objetivo deste estudo foi investigar a avitivade de CAZymes e a produção de biomassa micelial de L. crinitus cultivado sob iluminação continua com luz azul. L. crinitus foi cultivado em meio extrato de malte, sem agitação, na ausência de luz e sob luz continua fornecida por diodos emissores de luz azul. A luz azul reduziu a atividade de cellulase total, pectinase e xilanase, mas aumentou a atividade de endoglucanase. A luz azul reduziu o crescimento micelial de L. crinitus em 26% e aumentou a razão atividade enzimática/biomassa micelial (U mg-1 em base seca) de cellulase total em 10%, endoglucanase em 33% e pectinase em 16%. Além disso, sugere-se que L. crinitus possua um sistema fotossensorial que poderia ser explorado para a otimização de bioprocessos que visam a obtenção de enzimas de interesse biotecnológico.


Assuntos
Poligalacturonase , Lentinula , Celulases , Luz
14.
Appl Microbiol Biotechnol ; 104(1): 23-31, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31745575

RESUMO

Anticancer drugs are a class of pharmaceutical compounds that have been found in hospital, domestic, and industrial wastewaters and also in surface waters. They have been showing recalcitrance to conventional wastewater treatment technologies and present a potential risk to environment and human health, since they exhibit cytotoxic, teratogenic, and carcinogenic among other effects in higher organisms, even at low concentrations. The presence of these compounds in the environment is a recent challenge for wastewater treatment and some alternative strategies to remove them were already studied, such as white-rot fungi (WRF) technologies. Despite promising results, processes involving fungi are complex, have high reaction times, and require nutrient addition for fungus growth and maintenance. Due to this potential, strategies to make the technology feasible were studied, such as the possibility for direct application of enzymes secreted by WRF. Enzymatic processes were studied in the removal of other pharmaceuticals such as antibiotics, anti-inflammatory, and steroid hormones; however, to the best of our knowledge, there is a gap on literature about their direct action on anticancer drugs.


Assuntos
Antineoplásicos/metabolismo , Lacase/metabolismo , Águas Residuárias/análise , Poluentes Químicos da Água/metabolismo , Purificação da Água/métodos , Biodegradação Ambiental , Ativação Enzimática , Eliminação de Resíduos Líquidos/métodos
15.
Microorganisms ; 7(11)2019 Oct 23.
Artigo em Inglês | MEDLINE | ID: mdl-31652874

RESUMO

Consolidated bioprocessing (CBP), which integrates biological pretreatment, enzyme production, saccharification, and fermentation, is a promising operational strategy for cost-effective ethanol production from biomass. In this study, the use of a native strain of Trametes hirsuta (Bm-2) was evaluated for bioethanol production from Brosimum alicastrum in a CBP. The raw seed flour obtained from the ramon tree contained 61% of starch, indicating its potential as a raw material for bioethanol production. Quantitative assays revealed that the Bm-2 strain produced the amylase enzyme with activity of 193.85 U/mL. The Bm-2 strain showed high tolerance to ethanol stress and was capable of directly producing ethanol from raw flour at a concentration of 13 g/L, with a production yield of 123.4 mL/kg flour. This study demonstrates the potential of T. hirsuta Bm-2 for starch-based ethanol production in a consolidated bioprocess to be implemented in the biofuel industry. The residual biomass after fermentation showed an average protein content of 22.5%, suggesting that it could also be considered as a valuable biorefinery co-product for animal feeding.

16.
Bioresour Technol ; 289: 121655, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31247524

RESUMO

A single laccase with molecular weight of 41 kDa was produced by the white-rot fungus Oudemansiella canarii cultured on solid state fermentation using a mixture of sugarcane bagasse-wheat bran as substrate. The enzyme (5 U) was able to decolourize 80% of 50 mg/L Congo red within 24 h at 30 °C and pH 5.5. The relationship between the decolorization rate and dye concentration obeyed Michaelis-Menten kinetics, with KM and Vmax values of 46.180 ±â€¯6.245 µM and 1.840 ±â€¯0.101 µmol/min, respectively. Fourier transform infrared spectroscopy (FTIR) and mass spectrometry allowed to conclude that the laccase acts not only on the dye chromophore group, but also that it cleaves different covalent bonds, causing an effective fragmentation of the molecule. The action of the laccase caused a significant reduction in toxicity, as indicated by the Microtox test. In conclusion, O. canarii laccase could be useful in future biological strategies aiming at degrading azo dyes.


Assuntos
Basidiomycota , Vermelho Congo , Compostos Azo , Corantes , Lacase
17.
Appl Microbiol Biotechnol ; 103(13): 5065-5078, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31044311

RESUMO

Phenoxy herbicides are the most widely used family of herbicides worldwide. The dichlorophenoxyacetic acid (2,4-D) is extensively used as a weed killer on cereal crops and pastures. This herbicide is highly water-soluble, and even after a long period of disuse, considerable amounts of both 2,4-D and its main product of degradation, 2,4 dichlorophenol (2,4-DCP), might be found in nature. Biological decomposition of pesticides is an expressive and effective way for the removal of these compounds from the environment. The role of bacteria as well as the enzymes and genes that regulate the 2,4-D degradation has been widely studied, but the 2,4-D degradation by fungi, especially regarding the ability of white-rot basidiomycetes as agent for its bioconversion, has been not extensively considered. This review discusses the current knowledge about the biochemical mechanisms of 2,4-D biodegradation, focused on the role of white-rot fungi in this process. Finally, the cultivation conditions and medium composition for the growth of 2,4-D-degrading microorganisms are also addressed.


Assuntos
Ácido 2,4-Diclorofenoxiacético/metabolismo , Biodegradação Ambiental , Fungos/metabolismo , Herbicidas/metabolismo , Bactérias/metabolismo , Meios de Cultura , Fungos/crescimento & desenvolvimento , Redes e Vias Metabólicas , Técnicas Microbiológicas , Água
18.
Saudi J Biol Sci ; 26(4): 633-646, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-31048986

RESUMO

Pleurotus genus is one of most extensively studied white-rot fungi due to its exceptional ligninolytic properties. It is an edible mushroom and it also has several biological effects, as it contains important bioactive molecules. In basidiomycete fungi, lignocellulolytic enzymes are affected by many typical fermentation factors, such as medium composition, ratio of carbon to nitrogen, pH, temperature, air composition, etc. The survival and multiplication of mushrooms is related to a number of factors, which may act separately or have interactive effects among them. Out that understanding challenges in handling Pleurotus species mushroom requires a fundamental understanding of their physical, chemical, biological and enzymatic properties. This review presents a practical checklist of available intrinsic and extrinsic factors, providing useful synthetic information that may help different users. An in-depth understanding of the technical features is needed for an appropriate and efficient production of Pleurotus spp.

19.
Sci Total Environ ; 646: 1536-1545, 2019 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-30235638

RESUMO

This work investigated fungal co-culture as inducer of ligninolytic enzymes and decolourising activity in the Colombian strain Leptosphaerulina sp., an ascomycete white-rot fungus isolated from lignocellulosic material. Aspergillus niger, Aspergillus fumigatus, Aspergillus terreus, Trichoderma viride, Fusarium sp. and Penicillium chrysogenum were tested as Leptosphaerulina sp. inducers. The best fungal combinations in terms of enzyme production, fungal growth and decolourising activity were selected from solid media experiments. Response surface methodology (RSM) was utilised to optimise enzyme production and decolourising activity in liquid media. Solid media assays evidenced T. viride and A. terreus as the best Leptosphaerulina sp. inducers. The RSM identified a triple co-culture inoculated with T. viride (1000 µL) and A. terreus (1000 µL) into a 7-day culture of Leptosphaerulina sp. as the best treatment. This triple combination significantly improved ligninolytic enzymes production and Reactive Black 5 dye removal when compared to the Leptosphaerulina sp. monoculture and previously used chemical inducers. These results demonstrated the potential of fungal co-culture as an environmentally-friendly method to enhance Leptosphaerulina sp. enzymes production and decolourising activity.


Assuntos
Aspergillus/fisiologia , Lignina/metabolismo , Trichoderma/fisiologia , Ascomicetos , Basidiomycota , Eliminação de Resíduos Líquidos/métodos
20.
Mycology ; 9(4): 239-249, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30533250

RESUMO

The aim of the present study was to assess the ability of different white-rot fungi to tolerate polychlorinated biphenyls (PCBs) using predictive mycology, by relating fungal growth inhibition to ligninolityc enzyme secretion. Fungal strains were grown in the presence of PCBs in solid media and their radial growth values were modelled through the Dantigny-logistic like function in order to estimate the time required by the fungal colonies to attain half their maximum diameter. The principal component analysis (PCA) revealed an inverse correlation between strain tolerance to PCBs and the laccase secretion over time, being laccase production closely associated with fungal growth capacity. Finally, a PCA was run to regroup and split between resistant and sensitive fungi. Simultaneously, a function associated with a model predicting the tolerance to PCBs was developed. Some of the assayed isolates showed a promising capacity to be applied in PCB bioremediation. Abbreviations: Polychlorinated biphenyls (PCBs), white-rot fungi (WRF).

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