The objective of this work was to evaluate the post-treatment of an anaerobic recalcitrant effluent (anaerobically-treated weak black liquor, AnE) in an aerobic, upflow reactor packed with "biocubes" ...of Trametes versicolor immobilized onto small cubes of holm oak wood. The treated effluent (named anaerobic effluent; AnE) from an anaerobic fluidized bed reactor was fed to an up-flow aerobic fungal packed bed reactor (PBR). Two HRT were tested in this unit, namely 5 and 2.5 days; the PBR operated 60 days at 5-day HRT and 35 days at 2.5-day HRT. The aerobic packed bench scale reactor was a glass column 1.5 L total geometric volume containing 0.75 L biocubes of T. versicolor immobilized onto holm oak wood small cubes of 5 mm side. The reactor was operated at 25 C. The pH of the AnE was adjusted to 4.5 before feeding; no carbohydrates or other soluble carbon source was supplemented. The fungal packed bed bioreactor averaged organic matter removals of 30% and 32% COD basis, during an experimental run of 60 days at 5-day HRT and 35 days at 2.5-day HRT, respectively. Colour and ligninoids contents were removed at higher percentages (69% and 54% respectively, average of both HRT). There was no significant difference between reactor performance at 5- and 2.5-day HRT, so, operation at 2.5-day HRT is recommended since reactor throughput is double. Activity of manganese peroxidase and laccase was found during the entire operation of the fungal PBR whereas lignin peroxidase activity practically disappeared in the second operation period. In general, enzyme activities were higher in the first period of operation (5-day HRT) than at 2.5-day HRT. To the best of our knowledge, this is one of the few works that demonstrated extended performance (3 months) of a fungal bioreactor for the treatment of a recalcitrant wastewater with no supplementation of glucose or other expensive, soluble carbohydrate.
This work evaluates the potential of polyacrylonitrile particles (PAN) as support for laccase from Trametes versicolor immobilization. The slurry polymerization method forms mesoporous particles with ...low surface area and low maximum pore volume in desorption. The particles were chemically modified by consecutive alkaline and acid hydrolysis, followed by amination and activation with glutaraldehyde to enzyme immobilization. The laccase immobilization yield was 99.48% and 14.29% using the functionalized and non‐functionalized particles, respectively. The enzyme activity was measured by the oxidation of 2,2′‐azino‐bis(3‐ethylbenzthiazoline‐6‐sulfonic acid) at different pHs and temperatures. The PAN/laccase derivative was hyperactivated at pH 3, up to 3 times higher than the free enzyme, and performed better at 50°C after 6 h of incubation, with relative activity up to 33% higher than the free enzyme. However, both enzymes denatured when the conditions reached pH 8 and 70°C. The PAN/laccase retained 89% of the initial activity after 30 days of storage at 5°C. It was possible to reuse the enzymatic derivative for 5 cycles, with up to 50% residual activity, under 50°C and pH 3. These results show the potential of this new support for laccase immobilization and further applications of industrial interest.
Functionalization of polyacrylonitrile particles for laccase immobilization.
This study delved into the feasibility of fermenting Rosa roxburghii Tratt and coix seed beverage (RRTCSB) using dual-strain fermentation. The impact of Trametes versicolor and Lactiplantibacillus ...plantarum LB12 fermentation on RRTCSB's physicochemical properties was investigated. Post-fermentation, the beverage's color clarified and brightened, displaying an appealing hue. Even the concentrated malic acid, which contributes both sourness and astringency, decreased from 21.227 ± 0.151 mg/mL before fermentation to 14.067 ± 0.090 mg/mL after fermentation, indicating a reduction of approximately 30%. Regarding the beverage's characteristics, the retention rate of vitamin C was about 75%, resulting in a final content of 2.9 mg/mL. Additionally, the polysaccharide content consistently increased. Specifically, during T. versicolor fermentation, the polysaccharide content experienced an approximate 72% increase. The final polysaccharide content reached 2.85 mg/mL. Initially declining and then rising, γ-aminobutyric acid (GABA) increased by 17% during the dual-strain fermentation. The final content of GABA reached 5.12 mg/100 mL. Fermentation, particularly with T. versicolor, gradually enhanced the beverage's hypoglycemic activity. Ultimately, this study successfully demonstrated the feasibility of introducing T. versicolor and L. plantarum for fermenting RRTCSB, yielding an improved novel beverage.
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•Rosa roxburghii Tratt and coix seed beverage (RRTCSB) was produced with good luster.•RRTCSB hypoglycemic activity increased, especially in T. versicolor fermentation.•Polysaccharide content increased by about 72% during the T. versicolor fermentation.•GABA content increased by about 17% in the two-strains fermentation stage.•The malic acid content reduced by about 30% after fermentation.
Fungal laccases (EC 1.10.3.2) are multi-copper oxidases that oxidize a wide variety of substrates. Despite extensive studies, the molecular basis for their diverse activity is unclear. Notably, there ...is no current way to rationally predict the activity of a laccase toward a given substrate. Such knowledge would greatly facilitate the rational design of new laccases for technological purposes. We report a study of three datasets of experimental K
values and activities for Trametes versicolor and Cerrena unicolor laccase, using a range of protein modeling techniques. We identify diverse binding modes of the various substrates and confirm an important role of Asp-206 and His-458 (T. versicolor laccase numbering) in guiding substrate recognition. Importantly, we demonstrate that experimental K
values correlate with binding affinities computed by MMGBSA. This confirms the common assumption that the protein-substrate affinity is a major contributor to observed K
. From quantitative structure-activity relations (QSAR) we identify physicochemical properties that correlate with observed K
and activities. In particular, the ionization potential, shape, and binding affinity of the substrate largely determine the enzyme's K
for the particular substrate. Our results suggest that K
is not just a binding constant but also contains features of the enzymatic activity. In addition, we identify QSAR models with only a few descriptors showing that phenolic substrates employ optimal hydrophobic packing to reach the T1 site, but then require additional electronic properties to engage in the subsequent electron transfer. Our results advance our ability to model laccase activity and lend promise to future rational optimization of laccases toward phenolic substrates.
In this paper the antimicrobial activity of crude methanolic extracts obtained from Ganoderma lucidum and Trametes versicolor were investigated. The antimicrobial activities of the extracts against ...E. coli, P. aeruginosa, S. epidermis, E. raffinosus, S. cerevisiae and C. albicans were determined by the microbroth dillution method according by EUCAST in 96-well microplates. Microorganisms were obtained from Czech Collection of Microorganisms. Absorbances after and before the experiment were subtracted, converted to binary system and obtained values to Probit analysis were used. Of the two macromycetes extracts tested, not all extracts showed antimicrobial activity in tested MICs range. The highest antimicrobial activity showed the both extracts to Saccharomyces cerevisiae. The less antimicrobial effects had the both macromycetes extracts to Staphylococcus epidermis. Antimicrobial activity of macromycetes methanolic crude extracts to others tested microorganisms showed no effect or used concentration could be higher.
Abstract
Nanotechnology has increased the release of nanoparticles into the environment, which poses a risk to human health and the ecosystem. Therefore, finding ways to eliminate these hazardous ...particles from the environment is crucial. This research studied the ability of
Trametes versicolor
fungi to remove carboxylated multi-walled carbon nanotubes. The study analyzed the impact of pH, MWCNT-COOH concentration, and initial fungal growth time on the removal process. The properties of the adsorbent were measured before and after the biosorption process using SEM, FTIR, and EDS techniques. The results showed that the live biomass of
T. versicolor
was more effective in removing nanoparticles than dead biomass at 30 °C and pH 7. An increase in carbon nanotube concentration from 5 to 20 mg. mL
−1
decreased biosorption potential from 100% to 28.55 ± 1.7%. The study also found that an increase in initial fungal growth time led to higher biomass production and adsorption capacity, increasing biosorption ability for concentrations > 5mg. ml
−1
. The biosorption kinetics followed a pseudo-second-order model and corresponded most closely to the Freundlich isotherm model. The adsorption capacity of live fungal biomass to remove multi-walled carbon nanotubes was 945.17 mg. g
−1
, indicating that
T. versicolor
fungi have significant potential for removing carbon nanostructures from the environment.
Controlling the orientation of laccase on electrodes is crucial for the achievement of fast direct electron transfer. It is important to find a short pathway between the T1 copper site of laccase and ...a substrate during the laccase immobilization. In this work, we studied the adsorption orientation and conformation of Trametes versicolor laccase (TvL) on two kinds of charged self-assembled monolayers (SAMs), including NH2–SAM and COOH–SAM, by parallel tempering Monte Carlo and all-atom molecular dynamics simulations. TvL adsorbs on positively and negatively charged surface with “end-on” and “lying” orientation, respectively. On the positively charged surface, T1 copper site of TvL is closer to the surface. The orientation of TvL on positively charged surface is narrower than that on negatively charged surface. Thus, the positively charged surface is more conducive to the immobilization of TvL. The conformational changes of TvL on the charged surfaces are analyzed by RMSD, superimposed structures, dipole moment, gyration radius, and eccentricity. Results show that native structures of TvL are well preserved when it adsorbs on the charged surfaces. This work provides atomistic insight into the mechanism of TvL adsorption on charged surface and is helpful for the design and development of laccase-based electrodes.
Lignin is a biopolymer found in plant cell walls that accounts for 30% of the organic carbon in the biosphere. White-rot fungi (WRF) are considered the most efficient organisms at degrading lignin in ...nature. While lignin depolymerization by WRF has been extensively studied, the possibility that WRF are able to utilize lignin as a carbon source is still a matter of controversy. Here, we employ 13C-isotope labeling, systems biology approaches, and in vitro enzyme assays to demonstrate that two WRF, Trametes versicolor and Gelatoporia subvermispora, funnel carbon from lignin-derived aromatic compounds into central carbon metabolism via intracellular catabolic pathways. These results provide insights into global carbon cycling in soil ecosystems and furthermore establish a foundation for employing WRF in simultaneous lignin depolymerization and bioconversion to bioproducts—a key step toward enabling a sustainable bioeconomy.
Herawati E, Ramadhan R, Ariyani F, Marjenah, Kusuma IW, Suwinarti W, Mardji D, Amirta R, Arung ET. 2021. Phytochemical screening and antioxidant activity of wild mushrooms growing in tropical ...regions. Biodiversitas 22: 4716-4721. This study aims to determine the presence of secondary metabolites which generally have bioactivity that is antioxidant with phytochemical tests and antioxidant tests in Auricularia auricula, Schyzophyllum commune, Microporus xanthopus, and Trametes versicolor fungi that grow in the wild. Phytochemical analysis was carried out by testing color changes and modifications, while antioxidant tests were carried out by using a UV-Vis spectrophotometer and a DPPH solution (1,1-diphenyl-2-picrylhydrazyl). This research found that edible wood fungus that grows, wild such as A. auricula, contains secondary metabolites, namely flavonoids, triterpenoids, saponins, and tannins, but does not contain steroids, alkaloids, carotenoids, or coumarin, while S. commune contains secondary metabolites, namely flavonoids, steroids, tannins, and coumarin, but does not contain triterpenoids, alkaloids, carotenoids, or saponins and non-edible wood fungus, such as M. xanthopus, contains secondary metabolites, namely, flavonoids, saponins, tannins, coumarin, and steroids, but does not contain triterpenoids, alkaloids, or carotenoids, while T. versicolor contains compounds, secondary metabolites, flavonoids, saponin, tannins, coumarin, and triterpenoids, but does not contain steroids, alkaloids, or carotenoids. The antioxidant test results are based on IC50 calculations; it is known that the IC50 value of A. auricula is 499.25 g/mL, while S. commune is 121.37 g/mL, M. xanthopus is 251.20 g/mL, and T. versicolor is 493.04 g/mL. Based on the research results, edible and inedible wood mushroom extracts contain several phytochemicals and show potential for antioxidant activity.
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•Whole-plant corn silage was pretreated with Trametes versicolor.•Pilot-scale semi-continuous anaerobic co-digestion process was developed.•In the first phase, cow manure was ...co-digested with corn silage and corn grits.•In the second phase, cow manure was co-digested with pretreated corn silage.•Fungal pretreatment improved biogas and methane generation rates.
The objective of this research was to use white-rot fungus Trametes versicolor for corn silage pretreatment and to investigate the effect of pretreatment on biogas productivity. Semi-continuous pilot-scale experiment, comprised of two experimental phases, was carried out. In the first phase, operational conditions of the full-scale biogas plant were reproduced at pilot-scale. In that phase, the reactor was daily fed with the mixture of cow manure, digestate from industrial postfermentor, corn grits and ensiled corn silage, and the average methane generation rate was 0.167 m3CH4 kgVS−1. In the second phase, corn grits and ensiled corn silage were replaced with corn silage pretreated with T. versicolor, and the average methane generation rate increased up to 0.236 m3CH4 kgVS−1. The results of this study suggest that application of fungal-based solid-state pretreated corn silage has positive effect on pH stability and increase the biogas productivity.
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