The increase in the surface and groundwater contamination due to global population growth, industrialization, proliferation of pathogens, emerging pollutants, heavy metals, and scarcity of drinking ...water represents a critical problem. Because of this problem, particular emphasis will be placed on wastewater recycling. Conventional wastewater treatment methods may be limited due to high investment costs or, in some cases, poor treatment efficiency. To address these issues, it is necessary to continuously evaluate novel technologies that complement and improve these traditional wastewater treatment processes. In this regard, technologies based on nanomaterials are also being studied. These technologies improve wastewater management and constitute one of the main focuses of nanotechnology. The following review describes wastewater's primary biological, organic, and inorganic contaminants. Subsequently, it focuses on the potential of different nanomaterials (metal oxides, carbon-based nanomaterials, cellulose-based nanomaterials), membrane, and nanobioremediation processes for wastewater treatment. The above is evident from the review of various publications. However, nanomaterials' cost, toxicity, and biodegradability need to be addressed before their commercial distribution and scale-up. The development of nanomaterials and nanoproducts must be sustainable and safe throughout the nanoproduct life cycle to meet the requirements of the circular economy.
Azo dyes have been found in wastewater from textile industries. These compounds continuously persist in the environment for long periods of time and may be toxic for living beings. An alternative ...treatment for dye removal that has proven to be effective is aerobic treatment with fungi. In this study, Aspergillus niger was investigated as a mechanism to remove orange G (OG). Removal of 200 mg/L of OG by A. niger biomass was carried out in solid and liquid medium, which showed a positive correlation between A. niger growth and dye removal. In liquid media what was proved is that the efficiency of OG removal by A. niger depends on its concentration; at 200 mg/L of OG remove by degradation and at 400 mg/L by processes as sorption and degradation. During OG removal, the generation of organic acids by A. niger was modified compared to constitutive generation, one of the modifications was the increase of gluconic acid production and the decrease of acids involved in the Krebs cycle, as well as the null detection of oxalic acid. The monitoring of organic acids by high-performance liquid chromatography (HPLC) was important because some of them have been linked to dye removal.
Fungal laccases Rivera-Hoyos, Claudia M.; Morales-Álvarez, Edwin David; Poutou-Piñales, Raúl A. ...
Fungal biology reviews,
December 2013, 2013-12-00, 20131201, Letnik:
27, Številka:
3-4
Journal Article
Recenzirano
Laccases are enzymes widely distributed in plants, fungi, bacteria, and insects. They are multicopper oxidases that catalyze the transformation of aromatic and non-aromatic compounds with reduction ...of molecular oxygen to water. These enzymes participate in processes such as biosynthesis and lignin degradation, morphogenesis, and pigment biosynthesis, among others. In this review we discuss relevant aspects of fungal laccases regarding the existence of fungal laccases gene families, the growing interest in investigating mechanisms of their molecular regulation, and factors that influence the production of laccases, due to their potential biotechnological applications. In addition we comparatively analyzed some structural similarities and differences depicting general features of laccases' active site, demonstrating their frequency as monomeric proteins with highly conserved cupredoxine type domains. Although inter- and intra-specific differences have been determined, structural differences encountered between fungal laccases remain unclear based on Crystallography and X-ray diffraction.
•Exist several lacasses genes as a consequence of physiological function diversity.•Crystallography or X-ray resolutions influence the structural differences encountered.•Not all recombinant lacasses combines attributes to promote production processes.•There are intra-specific differences, among laccases of the same fungus.•We discuss the diversity of fungal laccases with crystallography structures.
Soil salinity and the indiscriminate use of agrochemicals has significantly reduced the productivity of the ‘Chinampas’ agroecosystem in Mexico City. Crop improvement under these stressful conditions ...may be achieved by soil bioremediation. In this study, we checked the effects of the organochlorine pesticide endosulfan and bioremediation with Penicillium crustosum or a citric waste on the growth of Phaseolus leptostachyus plants in saline soil from the Chinampas area. Biochemical markers associated with specific stress responses were also determined after one month of growth in the different substrates. Plant growth was stimulated by bioremediation of the soil. Both biostimulants reduced the degree of stress affecting the plants, as shown by the increase in photosynthetic pigments and the reduction of proline, malondialdehyde (MDA), and H2O2 contents, and the activation of antioxidant systems. However, the biostimulants appeared to mitigate oxidative stress through different mechanisms. Endosulfan contamination inhibited seed germination—which was reverted to control values in the presence of the biostimulants—and further decreased plant growth. No clear patterns of variation of biochemical stress markers were observed combining endosulfan and the biostimulants. In any case, bioremediation with P. crustosum and/or citric waste is recommended to improve the germination and growth of P. leptostachyus plants.
Lacasses are multicopper oxidases that can catalyze aromatic and non-aromatic compounds concomitantly with reduction of molecular oxygen to water. Fungal laccases have generated a growing interest ...due to their biotechnological potential applications, such as lignocellulosic material delignification, biopulping and biobleaching, wastewater treatment, and transformation of toxic organic pollutants. In this work we selected fungal genes encoding for laccase enzymes GlLCC1 in Ganoderma lucidum and POXA 1B in Pleurotus ostreatus. These genes were optimized for codon use, GC content, and regions generating secondary structures. Laccase proposed computational models, and their interaction with ABTS 2, 2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) substrate was evaluated by molecular docking. Synthetic genes were cloned under the control of Pichia pastoris glyceraldehyde-3-phosphate dehydrogenase (GAP) constitutive promoter. P. pastoris X-33 was transformed with pGAPZαA-LaccGluc-Stop and pGAPZαA-LaccPost-Stop constructs. Optimization reduced GC content by 47 and 49% for LaccGluc-Stop and LaccPost-Stop genes, respectively. A codon adaptation index of 0.84 was obtained for both genes. 3D structure analysis using SuperPose revealed LaccGluc-Stop is similar to the laccase crystallographic structure 1GYC of Trametes versicolor. Interaction analysis of the 3D models validated through ABTS, demonstrated higher substrate affinity for LaccPost-Stop, in agreement with our experimental results with enzymatic activities of 451.08 ± 6.46 UL-1 compared to activities of 0.13 ± 0.028 UL-1 for LaccGluc-Stop. This study demonstrated that G. lucidum GlLCC1 and P. ostreatus POXA 1B gene optimization resulted in constitutive gene expression under GAP promoter and α-factor leader in P. pastoris. These are important findings in light of recombinant enzyme expression system utility for environmentally friendly designed expression systems, because of the wide range of substrates that laccases can transform. This contributes to a great gamut of products in diverse settings: industry, clinical and chemical use, and environmental applications.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
In this research, selected catalytic activity conditions of nano Cu‐TiO2 films were evaluated through a 2IV4−1 Fractional Factorial Design for methylene blue discoloration. The following conditions ...were set at two levels: dye concentration (mg/L) (A) at 3.13 and 5.81; aeration (psi) (B) with and without; radiation (nm) (C) at 320 (UV) and 470 (Visible); and nano‐TiO2 films (D) without and with Cu‐doping. Films were prepared by the Sol‐Gel dip‐coating method and characterized using X‐ray diffraction, revealing an anatase phase in TiO2; and anatase, rutile, and brookite crystalline phases in Cu‐doped nano‐TiO2, with average band gap energies of 3.82 and 3.77 eV. The catalytic activity of films was significantly affected (p<0.05) by aeration (0.0002), radiation (0.001), and Cu‐doped nano‐TiO2 (0.004). Dye concentration did not have a significant effect; however, the AC interaction was significant (p=0.015). A discoloration efficiency of 46.23 % was obtained with 5.81 mg/L dye concentration using Cu‐doped TiO2, with UV radiation and without aeration, whereas a 52.32 % efficiency was achieved with 3.13 mg/L dye concentration using non Cu‐doped TiO2. Using factorial designs allows us to identify the main variables and their interactions to determine the optimal conditions for the catalytic activity of nano‐TiO2.
The catalytic activity conditions of nano Cu‐TiO2 films were assessed using a 2IV4−1 Fractional Factorial Design to study methylene blue discoloration in a photocatalytic reactor equipped with TiO2 films. Variables examined included dye concentration (mg/L), aeration (psi), radiation (nm), and the presence of Cu‐doped TiO2 films. Films were synthesized using the Sol‐Gel dip‐coating method, with X‐ray diffraction revealing anatase crystalline phase in non‐doped films, and anatase, rutile, and brookite phases in Cu‐doped TiO2 films. The catalytic activity was significantly influenced (p<0.05) by aeration, radiation, and Cu‐doped TiO2, while dye concentration showed no significant effect, except for its interaction with radiation. A discoloration efficiency of 46.23 % was achieved with 5.81 mg/L dye concentration using Cu‐doped TiO2 films under visible radiation and aeration. In contrast, 52.32 % discoloration was attained with 3.13 mg/L dye concentration using non Cu‐doped TiO2 films without aeration under visible light. This study aims to elucidate the main effects and interactions observed in FFD experiments to optimize catalytic conditions.
Arsenic (As) contamination of groundwater is widespread and significantly affects drinking water, posing a threat to public health due to its classification as a human carcinogen. Arsenic (As) can be ...removed from contaminated water using sustainable technologies (e.g., biotechnological processes). The process of removing Arsenic from water through reactions with iron under acidic and oxidizing conditions in a fungal broth has been proposed alongside the production of bioscorodite (FeAsO4·2H2O) crystals by Trichoderma atroviride culture. This ascomycete was selected based on tests with three other fungi (Aspergillus niger, and the basidiomycetes, Postia placenta, and Phanerochaete chrysosporium) because it decreased the pH to 2.2, raised the redox potential (Eh) to 207 mV, and was the quickest to produce 0.39 µg/L of H2O2 in a modified Wunder medium. The Eh was further increased to 324.80 mV under improved fungal culture conditions, selected using a 23−1 fractional factorial design (FFD). The fungal broth was then used for bioscorodite production by adding Fe(III)/As(III) salts and scorodite seeds at 92 °C for 21 h. Scorodite seeds and bioscorodite were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). Arsenic was determined in solution by atomic absorption spectrophotometry (AAS), and a 73% reduction in the initial As concentration (0.30 g/100 mL) was observed after bioscorodite production. Bioscorodite production under appropriate fungal culture conditions could be an option for sustainable As removal from water. The production of H2O2 by the fungus resulted in the oxidation of As(III) into As(V) and acidification of the culture broth, which created the necessary conditions for the production of bioscorodite without the need for chemical acids or oxidants. This approach is environmentally friendly and cost effective, making it a promising alternative for the treatment of arsenic-contaminated water.
Background: In the industrial biotechnology, ligninolytic enzymes are
produced by single fungal strains. Experimental evidence suggests that
co-culture of ligninolytic fungi and filamentous ...microfungi results in
an increase laccase activity. In this topic, only the ascomycete
Trichoderma spp. has been studied broadly. However, fungal
ligninolytic-filamentousmicrofungi biodiversity interaction in nature
is abundant and poorly studied. The enhancement of laccase and
manganese peroxidase (MnP) activities of Trametes maxima as a
function of time inoculation of Paecilomyces carneus and under
several culture conditions using Plackett-Burman experimental
design (PBED) were investigated. Results: The highest increases of
laccase (12,382.5 U/mg protein) and MnP (564.1 U/mg protein) activities
were seen in co-cultures I3 and I5, respectively, both at 10 d after
inoculation. This level of activity was significantly different from
the enzyme activity in non-inoculated T. maxima (4881.0 U/mg protein
and 291.8 U/mg protein for laccase and MnP, respectively). PBED results
showed that laccase was increased (P < 0.05) by high levels of
glucose, (NH4)2SO4 and MnSO4 and low levels of KH2PO4, FeSO4 and
inoculum (P < 0.05). In addition, MnP activity was increased (P <
0.05) by high yeast extract, MgSO4, CaCl2 and MnSO4 concentrations.
Conclusions: Interaction between indigenous fungi: T. maxima-P.
carneus improves laccase and MnP activities. The inoculation time of P.
carneus on T. maxima plays an important role in the laccase and MnP
enhancement. The nutritional requirements for enzyme improvement in a
co-culture system are different from those required for a monoculture
system.
The global environmental issue of arsenic (As) contamination in drinking water is a significant problem that requires attention. Therefore, the aim of this research was to address the application of ...a sustainable methodology for arsenic removal through mycoremediation aerated with micro-nanobubbles (MNBs), leading to bioscorodite (FeAsO4·2H2O) generation. To achieve this, the fungus Trichoderma atroviride was cultivated in a medium amended with 1 g/L of As(III) and 8.5 g/L of Fe(II) salts at 28 °C for 5 days in a tubular reactor equipped with an air MNBs diffuser (TR-MNBs). A control was performed using shaking flasks (SF) at 120 rpm. A reaction was conducted at 92 °C for 32 h for bioscorodite synthesis, followed by further characterization of crystals through Fourier–Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscopy (SEM), and X-ray diffraction (XRD) analyses. At the end of the fungal growth in the TR-MNBs, the pH decreased to 2.7–3.0, and the oxidation-reduction potential (ORP) reached a value of 306 mV at 5 days. Arsenic decreased by 70%, attributed to possible adsorption through rapid complexation of oxidized As(V) with the exchangeable ferrihydrite ((Fe(III))4-5(OH,O)12), sites, and the fungal biomass. This mineral might be produced under oxidizing and acidic conditions, with a high iron concentration (As:Fe molar ratio = 0.14). The crystals produced in the reaction using the TR-MNBs culture broth and characterized by SEM, XRD, and FTIR revealed the morphology, pattern, and As-O-Fe vibration bands typical of bioscorodite and römerite (Fe(II)(Fe(III))2(SO4)4·14H2O). Arsenic reduction in SF was 30%, with slight characteristics of bioscorodite. Consequently, further research should include integrating the TR-MNBs system into a pilot plant for arsenic removal from contaminated water.
Abstract The use of fungi to reduce dye removal in water from diverse industries can be an efficient option for solving environmental problems. However, the mycoremediation processes involved in ...color removal are unknown. In this article, Aspergillus niger CDBB‐H‐175 was applied for vat blue discoloration (DC). Hence, inactive biomass by two methods (metabolic inhibitor and heat) and active biomass were studied by scanning electron microscopy and enzyme activities to determine the vat blue DC. When using active biomass, 62% of DC, glucose oxidase (GOX) enzyme activity, 1.19 U/mL and 1.43 mg/L of H 2 O 2 were obtained. It was observed that 68% of DC was due to the degradation process and 32% was due to biomass sorption. When the biomass was inactivated with sodium azide, DC increased by 90% (1.45‐fold), low GOX activity (0.138 U/mL), and H 2 O 2 (0.25 mg/L) were detected. High DC might be due to a high dye sorption in hyphae, since an increase in the thickness and morphology of the hyphae were observed by SEM. Inactivated biomass through heating, showed a 69.5% of DC, where 0.01 U/mL GOX and 0.25 mg/L H 2 O 2 were reached, demonstrating that inactivation of A. niger biomass by sodium azide can be considered as an alternative treatment for colored wastewater.
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