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•Novel use of laccase coupled UlS technique to degrade antibiotics in wastewater.•UAL treatment achieved maximum degradation of CTC in lower time.•Degradation rate was increased by ...5.6 folds in UAL treatment.•Laccase at 0.5 U/L removed over 80% of 2 µg/L CTC in 2 h at pH 4.5 by UlS assistance.
Chlortetracycline (CTC) is widely used as a veterinary antibiotic and is considered as a recalcitrant pollutant. In this study, spiked CTC (2 mg L−1) in wastewater was degraded using laccase from the white rot fungi, Trametes Versicolor combined with ultrasonication (UlS). Over 60% of CTC was removed in 2 h by UlS assisted laccase (UAL) treatment where laccase treatment alone took 2 days to degrade 87% of CTC under similar CTC concentration (2 mg L−1), laccase dose (0.5 IU) and pH 6.0 conditions. UAL treatment showed 5.3 folds higher CTC degradation rate compared to laccase alone treatment at pH 6.0. Further, pH optimization of UAL treatment was done and pH 4.5 was found to be optimum wherein 80% of CTC degradation was obtained which is 2.6 folds higher compared to degradation at pH 6.0. The UAL treatment with optimized pH was not only increased CTC degradation efficiency (∼80%) but also reduced the degradation time to 2 h. The obtained results highlighted the enhanced degradation rate, efficiency and unaltered stability of laccase during UAL treatment which can be used for oxidizing other tetracycline groups of antibiotics. Moreover, laccase and UAL treatments showed similar degradation products and no estrogenic activity.
•Basis for utilization of konjac flying powder on wood protectors were provided.•The antifungal active fractions are mainly organic acids and plant essential oils.•Konjac flying powder might provide ...a natural alternative for wood preservatives.•Plant containing essential oils and organic acids might have antifungal potential.
Public concern for the environment has stimulated the development of natural wood preservatives. The antifungal activity of konjac (Amorphophallus konjac K. Koch) flying powder (a by-product produced during mechanical processing of konjac flour) ethanol extracts was evaluated against wood decay fungi in poplar (Populus nigra L.). Compounds associated with antifungal activity in the extracts were isolated and purified by silica gel column chromatography. The antifungal active fractions were identified by ultra-high-performance liquid chromatography-mass spectrometry (UHPLC-MS). The ethanol extracts showed better activity against the brown-rot fungus, Gloeophyllum trabeum (Pers.: Fr.) Murr. than the white-rot fungus, Trametes versicolor (L. ex Fr.) Quél. in poplar. The antifungal active fractions were mainly composed of organic acids and plant essential oils. Salicylic acid, 2,4,6-trichlorophenol, vanillin and cinnamaldehyde were present in the active fractions. These compounds showed high efficacy against both fungi in poplar. The results indicate that konjac extracts have potential as natural wood protectants and suggested that some fractions of konjak flying powder may be useful for protecting wood against fungal attack.
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•The prospects of T. versicolor in lignocellulose-based bioeconomy are encouraging.•Solid-state fermentation – a promising technology for lignocellulosic biorefineries.•T. versicolor ...and laccase crude extracts are both efficient in wastewater treatment.•Great potential for lignocellulose valorization to feed, biogas and biofertilizers.
Although Trametes versicolor is one of the most investigated white-rot fungi, the industrial application of this fungus and its metabolites is still far from reaching its full potential. This review aims to highlight the opportunities and challenges for the industrial use of T. versicolor according to the principles of circular bioeconomy. The use of this fungus can contribute significantly to the success of efforts to valorize lignocellulosic waste biomass and industrial lignocellulosic byproducts. Various techniques of T. versicolor cultivation for enzyme production, food and feed production, wastewater treatment, and biofuel production are listed and critically evaluated, highlighting bottlenecks and future perspectives. Applications of T. versicolor crude laccase extracts in wastewater treatment, removal of lignin from lignocellulose, and in various biotransformations are analyzed separately.
The potential application of fungal laccase-assisted bioremediation for estrogen elimination has caused tremendous attention. Herein, naturally-occurring Trametes versicolor laccase (Tvlac) was ...capable of significantly removing 17β-estradiol (E2) and 17α-ethynylestradiol (EE2) at pH 5. A lower (or higher) pH caused decline in the velocity constants (kprcs) by obstructing the single-electron oxidation of estrogen at Tvlac T1-Cu site (or intercepting the intramolecular-electron transfer between Tvlac T1-Cu and T2/T3-Cu sites). Humic acid (HA) and natural phenolic compounds (PCs) are omnipresent in water and can influence the conversion kinetics of estrogen in Tvlac-triggered reactions. Compared with HA-free, the kprcs values of E2 and EE2 in presence of HA respectively reduced 58.61%–83.72% and 69.72%–95.62% at different pH levels. Additionally, the kprcs values for estrogen were also hampered obviously by O-dihydroxyphenol structure of model PCs, owning to the created monomeric/polymeric O-quinones inverted estrogen phenoxy radicals. The generated carbon‑carbon/oxygen self-linking aggregates during Tvlac-mediated estrogen oxidative coupling were characterized, and the polymerization mechanisms were speculated. A fluid-bed reactor with cross-linked-entrapped Tvlac in Ca-alginate beads was established to treat E2 and EE2, respectively. Compared with free Tvlac, immobilized Tvlac prominently exhibited a higher pH and temperature stability. Especially, the fluid-bed reactor with immobilized Tvlac could be reused, keeping its high conversion efficiencies of E2 and EE2 in natural water, only changing from 99.2% to 73.6% and from 98.5% to 70.9% after 1 to 5 cycles, respectively. These findings present an alternative immobilized fungal laccase-based clean biotechnology for continuously handling estrogen-contaminated waterbodies at a large-scale.
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•Tvlac-assisted conversion kinetics of estrogen exhibited strong pH dependency.•HA evidently blocked removal of estrogen through quenching estrogen radicals.•Tvlac aided self/cross-linking of estrogen and PCs to create new polymeric species.•A fluid-bed reactor with cross-linked-entrapped Tvlac within Ca-AB was designed.•Immobilized Tvlac owned great reuse potential to continuously eliminate estrogen.
Trametes versicolor is a promising white-rot fungus for the biological pretreatment of lignocellulosic biomass. In the present work, T. versicolor ATCC 20869 was grown on Pinus taeda wood chips under ...solid-state fermentation conditions to examine the wood-degrading mechanisms employed by this fungus. Samples that were subjected to fungal pretreatment for one-, two- and four-week periods were investigated. The average mass loss ranged from 5 % to 8 % (m m super(-) super(1)). The polysaccharides were preferentially degraded: hemicellulose and glucan losses reached 13.4 % and 6.9 % (m m super(-) super(1)) after four weeks of cultivation, respectively. Crude enzyme extracts were obtained and assayed using specific substrates and their enzymatic activities were measured. Xylanases were the predominant enzymes, while cellobiohydrolase activities were marginally detected. Endoglucanase activity, beta -glucosidase activity, and wood glucan losses increased up to the second week of biodegradation and remained constant after that time. Although no lignin-degrading enzyme activity was detected, the lignin loss reached 7.5 % (m m super(-) super(1)). Soluble oxalic acid was detected in trace quantities. After the first week of biodegradation, the Fe super(3+)-reducing activity steadily increased with time, but the activity levels were always lower than those observed in the undecayed wood. The progressive wood polymer degradation appeared related to the secretion of hydrolytic enzymes, as well as to Fe super(3+)-reducing activity, which was restored in the cultures after the first week of biodegradation.
Genes in prokaryotic genomes are often arranged into clusters and co-transcribed into polycistronic RNAs. Isolated examples of polycistronic RNAs were also reported in some higher eukaryotes but ...their presence was generally considered rare. Here we developed a long-read sequencing strategy to identify polycistronic transcripts in several mushroom forming fungal species including Plicaturopsis crispa, Phanerochaete chrysosporium, Trametes versicolor, and Gloeophyllum trabeum. We found genome-wide prevalence of polycistronic transcription in these Agaricomycetes, involving up to 8% of the transcribed genes. Unlike polycistronic mRNAs in prokaryotes, these co-transcribed genes are also independently transcribed. We show that polycistronic transcription may interfere with expression of the downstream tandem gene. Further comparative genomic analysis indicates that polycistronic transcription is conserved among a wide range of mushroom forming fungi. In summary, our study revealed, for the first time, the genome prevalence of polycistronic transcription in a phylogenetic range of higher fungi. Furthermore, we systematically show that our long-read sequencing approach and combined bioinformatics pipeline is a generic powerful tool for precise characterization of complex transcriptomes that enables identification of mRNA isoforms not recovered via short-read assembly.
Microbial remediation of organically combined contaminated sites is currently facing technical challenges. White rot fungi possess broad-spectrum degradation capabilities, but most of the studies are ...conducted on polluted water bodies, and few research focus on the degradation of combined organically contaminated soils. This study aimed to investigate the physiological changes in
to enhance its simultaneous degradation ability towards benzo(a)pyrene (BaP) and TPH. The results demonstrated that
, when subjected to liquid fermentation, achieved an 88.08% degradation of individual BaP within 7 days. However, under the combined contamination conditions of BaP and TPH, the BaP degradation rate decreased to 69.25%, while the TPH degradation rate was only 16.95%. Furthermore, the degradation rate of BaP exhibited a significant correlation with the extracellular protein concentration and laccase activities. Conversely, the TPH degradation rate exhibited a significant and positive correlation with the intracellular protein concentration. Solid-state fermentation utilizing fungal agents proved to be the most effective method for removing BaP and TPH, yielding degradation rates of 56.16% and 15.73% respectively within 60 days. Overall,
demonstrated a commendable capability for degrading combined PAHs-TPH pollutants, thereby providing theoretical insights and technical support for the remediation of organically combined contaminated sites.
Fungal bioremediation emerges as an effective technology for pesticide treatment, but its successful implementation depends on overcoming the problem of microbial contamination. In this regard, ...fungal immobilization on wood seems to be a promising strategy, but there are two main drawbacks: the predominant removal of pesticides by sorption and fungal detachment. In this study, agricultural wastewater with pesticides was treated by Trametes versicolor immobilized on wood chips in a rotary drum bioreactor (RDB) for 225 days, achieving fungal consolidation and high pesticide biodegradation through two main improvements: the use of a more favorable substrate and the modification of operating conditions. Fungal community dynamic was assessed by denaturing gradient gel electrophoresis (DGGE) analysis and subsequent prominent band sequencing, showing a quite stable community in the RDB, mainly attributed to the presence of T. versicolor. Pesticide removals were up to 54 % diuron and 48 % bentazon throughout the treatment. Afterwards, pesticide-contaminated wood chips were treated by T. versicolor in a solid biopile-like system. Hence, these results demonstrate that the microbial contamination constraint has definitely been overcome, and fungal bioremediation technology is ready to be implemented on a larger scale.
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•A fungal bioremediation treatment was successfully operated for more than 7 months.•Using the suitable substrate and operating conditions improved biomass retention.•Inoculation of T. versicolor led to the establishment of a stable fungal consortium.•Fungal bioremediation technology is ready for full-scale application.
Reactive azo dyes are widely used as textile colorants, typically for cotton dyeing, due to their variety of color shades, and minimal energy consumption. In the present study, commercial laccase ...from Trametes versicolor was used for the biodecolorization of Reactive Black 5 (RB-5) dye using different redox mediators viz, N-hydroxybenzotriazole (HBT), 2,2'-azino-bis-(3-ethylbenzthiazoline- 6-sulfonic acid (ABTS), 2,6-dimethoxy phenol (DMP), syringaldehyde, vanillin, aceto-vanillone, p-coumaric acid and catechol. Commercial laccase alone did not show any considerable decolorization of RB-5. However, the laccase in the presence of syringaldehyde showed the strongest decolorization rate (98%), followed by vanillin (55.21%), aceto-vanillone (53.25%), ABTS (42.78%), p-coumaric acid (41.9%), DMP (39%), and catechol (36.33%); while least decolorization was observed with HBT at dye/mediator ratio of only 1:5 after 30 min. Therefore, syringaldehyde performance was evaluated at different mediator/dye ratios (1:1, 1:5 and 1:10) using commercial laccase and it was compared with that of synthetic mediator like HBT. It was found that the presence of syringaldehyde was essential for biodecolorization of RB-5. Moreover, it was observed that syringaldehyde was an effective natural redox mediator as compared to synthetic HBT. Enhanced decolorization (98%) of RB-5 by laccase was observed with 1:5 syringaldehyde and dye ratio for 30 min but maximum removal (22%) of RB-5 was recorded with HBT at 1:1 after 40 min. Thus, the study reveals that the phenolic compounds could be used as potential redox mediators for enhanced laccase-mediated decolorization of azo dyes.
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