Production of manganese-dependent peroxidase in a new solid-state bioreactor by Phanerochaete chrysosporium grown on wood shavings. Application to the decolorization of synthetic dyes

Stability of Selected Hydrogen Bonded Semiconductors in Organic Electronic Devices

The electronics era is flourishing and morphing itself into Internet of Everything, IoE. At the same time, questions arise on the issue of electronic materials employed: especially their natural availability and low-cost fabrication, their functional stability in devices, and finally their desired biodegradation at the end of their life cycle. Hydrogen bonded pigments and natural dyes like indigo, anthraquinone and acridone are not only biodegradable and of bio-origin but also have functionality robustness and offer versatility in designing electronics and sensors components. With this Perspective, we intend to coalesce all the scattered reports on the above-mentioned classes of hydrogen bonded semiconductors, spanning across several disciplines and many active research groups. The article will comprise both published and unpublished results, on stability during aging, upon electrical, chemical and thermal stress, and will finish with an outlook section related to biological degradation and biological stability of selected hydrogen bonded molecules employed as semiconductors in organic electronic devices. We demonstrate that when the purity, the long-range order and the strength of chemical bonds, are considered, then the Hydrogen bonded organic semiconductors are the privileged class of materials having the potential to compete with inorganic semiconductors. As an experimental historical study of stability, we fabricated and characterized organic transistors from a material batch synthesized in 1932 and compared the results to a fresh material batch.

Physical and enzymatic properties of a new manganese peroxidase from the white-rot fungus Trametes pubescens strain i8 for lignin biodegradation and textile-dyes biodecolorization

A new manganese peroxidase-producing white-rot basidiomycete fungus was isolated from symptomatic wood of the camphor trees Cinnamomum camphora (L.) at the Hamma Botanical Garden (Algeria) and identified as Trametes pubescens strain i8. The enzyme was purified (MnP TP55) to apparent electrophoretic homogeneity and biochemically characterized. The specific activity and Reinheitzahl value of the purified enzyme were 221 U/mg and 2.25, respectively. MALDI-TOF/MS analysis revealed that the purified enzyme was a monomer with a molecular mass of 55.2 kDa. The NH₂-terminal sequence of the first 26 amino acid residues of MnP TP55 showed high similarity with those of white-rot fungal peroxidases. It revealed optimal activity at pH 5 and 40 °C. This peroxidase was completely inhibited by sodium azide and potassium cyanide, suggesting the presence of heme-components in its tertiary structure. Interestingly, MnP TP55 showed higher catalytic efficiency, organic solvent-tolerance, dye-decolorization ability, and detergent-compatibility than that of horseradish peroxidase (HRP) from roots of Armoracia rustanica, manganese peroxidase from Bjerkandera adusta strain CX-9 (MnP BA30), and manganese peroxidase from Phanerochaete chrysosporium (MnP PC). Overall, the findings provide strong support for the potential candidacy of MnP TP55 for environmental applications, mainly the development of enzyme-based technologies for lignin biodegradation, textile-dyes biodecolorization, and detergent formulations.

Expression and characteristics of manganese peroxidase from Ganoderma lucidum in Pichia pastoris and its application in the degradation of four dyes and phenol

Background

Manganese peroxidase (MnP) of white rot basidiomycetes, an extracellular heme enzyme, is part of a peroxidase superfamily that is capable of degrading the different phenolic compounds. Ganoderma, a white rot basidiomycete widely distributed worldwide, could secrete lignin-modifying enzymes (LME), including laccase (Lac), lignin peroxidases (LiP) and MnP.

Results

After the selection of a G. lucidum strain from five Ganoderma strains, the 1092 bp full-length cDNA of the MnP gene, designated as G. lucidum MnP (GluMnP1), was cloned from the selected strain. We subsequently constructed an eukaryotic expression vector, pAO815:: GlMnP, and transferred it into Pichia pastoris SMD116. Recombinant GluMnP1 (rGluMnP1) was with a yield of 126 mg/L and a molecular weight of approximately 37.72 kDa and a specific enzyme activity of 524.61 U/L. The rGluMnP1 could be capable of the decolorization of four types of dyes and the degradation of phenol. Phenol and its principal degradation products including hydroquinone, pyrocatechol, resorcinol, benzoquinone, were detected successfully in the experiments.

Conclusions

The rGluMnP1 could be effectively expressed in Pichia pastoris and with a higher oxidation activity. We infer that, in the initial stages of the reaction, the catechol-mediated cycle should be the principal route of enzymatic degradation of phenol and its oxidation products. This study highlights the potential industrial applications associated with the production of MnP by genetic engineering methods, and the application of industrial wastewater treatment.

Electronic supplementary material

The online version of this article (doi:10.1186/s12896-017-0338-5) contains supplementary material, which is available to authorized users.

Implication of Dichomitus squalens manganese-dependent peroxidase in dye decolorization and cooperation of the enzyme with laccase

Three new chromatographic forms of Dichomitus squalens manganese-dependent peroxidase (MnP) were isolated from wheat-straw cultures using Mono Q and connective interaction media (CIM) fast protein liquid chromatography. Enzymes revealed identical molar mass of 50 kDa (estimated by SDS-PAGE) and pI values of 3.5, however, they varied in Km values obtained for Mn2+ oxidation. The addition of wood and straw methanol extracts to the cultures showed that the production of MnPs in wheat-straw cultures was influenced rather by the type of cultivation than by phenolic compounds from lignocellulosic material which induced laccase production. The purified CIM1 MnP was able to decolorize selected azo and anthraquinone dyes more rapidly than laccase Lc1. In vitro dye decolorization showed a synergistic cooperation of MnP and laccase. In the case of CSB degradation MnP prevented from the production of a differently colored substance that could be produced after CSB degradation by laccase-HBT system.

Dye removal by immobilised fungi

Dyes are widely used within the food, pharmaceutical, cosmetic, printing, textile and leather industries. This has resulted in the discharge of highly coloured effluents that affect water transparency and gas solubility in water bodies. Furthermore, they pose a problem because of their carcinogenicity and toxicity. Therefore, removal of such dyes before discharging them into natural water streams is essential. For this, appropriate treatment technologies are required. The treatment of recalcitrant and toxic dyes with traditional technologies is not always effective or may not be environmentally friendly. This has impelled the search for alternative technologies such as biodegradation with fungi. In particular, ligninolytic fungi and their non-specific oxidative enzymes have been reported to be responsible for the decolouration of different synthetic dyes. Thus, the use of such fungi is becoming a promising alternative to replace or complement the current technologies for dye removal. Processes using immobilised growing cells seem to be more promising than those with free cells, since the immobilisation allows using the microbial cells repeatedly and continuously. This paper reviews the application of fungal immobilisation to dye removal.

Conidia production ofBeauveria sp. by solid-state fermentation for biocontrol ofIlex paraguariensis caterpillars

Conidia production of Beauveria sp. strain LAG by solid-state fermentation (SSF) using blends of agro-industrial residues (residual potatoes and sugar-cane bagasse) was optimized with respect to cultivation conditions and the composition of substrate mixture in Erlenmeyer flasks and column-type bioreactor. With a blend of 60 % residual potatoes and 40 % sugar-cane bagasse the optimum conditions achieved were: incubation temperature 26 degrees C, initial substrate pH 6, inoculum concentration 10(7) conidia per g substrate; optimal initial moisture of the substrate was 70 % for Erlenmeyer flasks, in column-type bioreactor (with forced aeration) the optimal initial moisture of the substrate was 65 % with airflow of 60 mL/min. The highest production (1.07 x 10(10) conidia per g dry substrate) was achieved after a 10-d fermentation. The conidia were used in laboratory assays against Thelosia camina and Hylesia sp., caterpillars that are serious pests of mate plants. The mortality of T. camina was >90 % 10 d after spraying caterpillars with 1 mL conidia suspension at a concentration 10(5)-10(8)/mL. For Hylesia sp., the mortality was 70 %, 7 d after immersion in the conidia suspension containing 108 conidia per mL. Therefore, the Beauveria sp. LAG can be considered to be an important biocontrol instrument in the prospect of the Integrated Pest Management for mate plants.

Laccase production at reactor scale by filamentous fungi

Laccases have received much attention from researchers during the past decades due to their broad substrate specificity and to the fact that they use molecular oxygen as the final electron acceptor instead of hydrogen peroxide as used by peroxidases. This makes laccases highly interesting for a wide variety of processes, such as textile dye decolouration, pulp bleaching, effluent detoxification, biosensors and bioremediation. The successful application of laccases to the above-mentioned processes requires the production of large quantities of enzyme at low cost. Filamentous fungi are able to produce laccases in high amounts, however, an efficient production system at bioreactor scale is still lacking. This is mainly due to the fact that laccase production by wild-type strains of filamentous fungi is linked to secondary metabolism, which implies that the following drawbacks must be overcome: uncontrolled fungal growth, the formation of polysaccharides around mycelia and the secretion of certain compounds (i.e. proteases) that inactivate laccases. This review summarizes the current status of laccase production by wild-type strains of filamentous fungi at the bioreactor scale.

Potential applications of the oxidoreductive enzymes in the decolorization and detoxification of textile and other synthetic dyes from polluted water: a review

Recently, the enzymatic approach has attracted much interest in the decolorization/degradation of textile and other industrially important dyes from wastewater as an alternative strategy to conventional chemical, physical and biological treatments, which pose serious limitations. Enzymatic treatment is very useful due to the action of enzymes on pollutants even when they are present in very dilute solutions and recalcitrant to the action of various microbes participating in the degradation of dyes. The potential of the enzymes (peroxidases, manganese peroxidases, lignin peroxidases, laccases, microperoxidase-11, polyphenol oxidases, and azoreductases) has been exploited in the decolorization and degradation of dyes. Some of the recalcitrant dyes were not degraded/decolorized in the presence of such enzymes. The addition of certain redox mediators enhanced the range of substrates and efficiency of degradation of the recalcitrant compounds. Several redox mediators have been reported in the literature, but very few of them are frequently used (e.g., 1-hydroxybenzotriazole, veratryl alcohol, violuric acid, 2-methoxy-phenothiazone). Soluble enzymes cannot be exploited at the large scale due to limitations such as stability and reusability. Therefore, the use of immobilized enzymes has significant advantages over soluble enzymes. In the near future, technology based on the enzymatic treatment of dyes present in the industrial effluents/wastewater will play a vital role. Treatment of wastewater on a large scale will also be possible by using reactors containing immobilized enzymes.

Production of superoxide radical in reductive metabolism of a synthetic food-coloring agent, indigocarmine, and related compounds

Indigocarmine, which is widely used as a synthetic colouring agent for foods and cosmetics in many countries, was reduced to its leuco form and decolorized by rat liver microsomes with NADPH under anaerobic conditions. The reductase activity was enhanced in liver microsomes of phenobarbital-treated rats, and inhibited by diphenyliodonium chloride, a NADPH-cytochrome P450 reductase (P450 reductase) inhibitor, but was not inhibited by SKF 525-A or carbon monoxide. Indigocarmine reductase activity was exhibited by purified rat P450 reductase. In contrast, when indigocarmine was incubated with rat liver microsomes and NADPH under aerobic conditions, superoxide radical was produced and its production was inhibited by superoxide dismutase and diphenyliodonium chloride. When indigocarmine was incubated with purified rat P450 reductase in the presence of NADPH, superoxide radical production was enhanced 17.7-fold (similar to the enhancement of indigocarmine-reducing ability) as compared with that of rat liver microsomes. A decrease of one molecule of NADPH was accompanied with formation of about two molecules of superoxide radical. P450 reductase exhibited little reductase activity towards indigo and tetrabromoindigo, which also afforded little superoxide radical under aerobic conditions. These results indicate that indigocarmine is reduced by P450 reductase to its leuco form, and superoxide radical is produced by autoxidation of the leuco form, through a mechanism known as futile redox cycling.

Improving the yield and quality of DNA isolated from white-rot fungi

A new simple method used to eliminate polysaccharides that cause problems during DNA isolation was established for 6 different white-rot fungi using 1% hexadecyltrimethylammonium bromide (CTAB) as wash buffer and followed by centrifugation. Variation in the DNA yield and quality was ascertained using precipitating agents, detergents and cell-wall-hydrolyzing chitinase. Considerable amount of exopolysaccharides from fungal biomass was removed with the use of 1% CTAB wash buffer followed by centrifugation. The DNA varied in terms of yield and quality. For the DNA extraction use of 2% SDS in extraction buffer worked best for Pycnoporus cinnabarinus, Cyathus bulleri, Cyathus striatus and Cyathus stercoreus, while 2% CTAB worked best for Phanerochaete chrysosporium and Pleurotus ostreatus. Elimination of phenol and use of absolute ethanol for precipitating DNA resulted in good yield and quality of DNA. This DNA was amenable to restriction endonuclease digestion.

Decolorization of sulfonphthalein dyes by manganese peroxidase activity of the white-rot fungusPhanerochaete chrysosporium

Manganese peroxidase (MnP) was produced by shallow stationary cultures of Phanerochaete chrysosporium growing on N-limited medium. Decolorization of sulfonphthalein (SP) dyes by MnP was investigated. The MnP activity profile and decolorization of SP dyes was correlated and almost all dyes were decolorized at pH 4.0. The influence of various inhibitors on Bromocresol Purple decolorization suggested an oxidative nature of the MnP-catalyzed decolorization of SP dyes.

Decolorization of orange G byPleurotus ostreatus monokaryotic isolates with different laccase activity

The effect of enhanced laccase (Lac) activity (obtained after copper addition to cultivation media) on decolorization of azo dye Orange G in two basidiospore-derived monokaryotic isolates of Pleurotus ostreatus was determined. The high Lac-producing isolate efficiently decolorized Orange G. The low-producing isolate showed only poor decolorization ability during cultivation in liquid medium and no decolorization on agar plates containing Orange G after a 25-d growth. A substantial enhancement of Lac activity caused by copper addition into cultivation media was detected in both isolates but, at the same time, the biomass production decreased and decolorization rate was reduced.

Decolorization of textile dyeing wastewater byPhanerochaete chrysosporium

The potential use of fungal pellets for decolorization of the textile dyeing wastewater was evaluated. The live pellets of the fungus Phanerochaete chrysosporium were found to remove more than 95% of the color of this wastewater within 1 d. The dye-removal capacity was a function of time and was proportional to the agitation rate; the optimum temperature was 30 degrees C. Both live and dead pellets were further examined in a repeated-batch mode for 5 d. The decolorization performance of live pellets remained high and stable for 5 d and they showed twice to thrice higher decolorization capacity than dead pellets.

Passing of fluorescein derivatives into the hyphae of Phanerochaete chrysosporium

Fluorescein derivatives added into the growth medium were decolorized during submerged cultivation of Phanerochaete chrysosporium. The highest decrease of absorbance A450 was observed in the growth phase regardless of the presence of inducers Tween 80 or poly(ethylene glycol) (PEG). Fluorescein linked to PEG was prepared and, after addition to cultures, shown to stimulate the production of lignin peroxidase. Passing of fluorescing substances into hyphae (observed by confocal microscopy) showed that they were concentrated on some structures inside hyphae.

Decolorization and bioremediation of molasses wastewater by white-rot fungi in a semi-solid-state condition

Molasses wastewater (vinasse; the by-product of distillation of fermented sugar) was decolorized and its chemical oxygen demand (COD) was reduced in static cultivation using the fungi Coriolus versicolor, Funalia trogii, Phanerochaete chrysosporium and Pleurotus pulmonarius ('Pleurotus sajorcaju'). The effect of cotton stalk on decolorizing and COD removing capability of four fungi was determined. In the entire concentration range tested (10-30%), wastewater was effectively decolorized by C. versicolor and F. trogii. Cotton stalk addition stimulated the decolorization activity of all fungi. The utilization of cotton stalk represents several advantages due to its function as an attachment place and as a source of nutrients; its use also reduces process costs.

Decolorization of synthetic dyes by Pleurotus ostreatus isolates differing in ligninolytic properties

The ability to decolorize four synthetic dyes (Phenol Red, Evans Blue, Eosin Yellowish and Poly B411) in five Pleurotus ostreatus strains (a parental strain and four isolates derived from it) was determined. Two of the isolates had markedly higher and other two substantially lower production of ligninolytic enzymes and hydrogen peroxide than the parental strain. Like the parental strain, the higher-producing isolates were able to decolorize all the tested dyes, but not to a higher extent than the parental strain. In contrast, two lower-producing isolates exhibited slow decolorization, which was incomplete even at the end of cultivation. Evans Blue and Eosin Yellowish strongly suppressed the growth of the strains, while Phenol Red and Poly B411 induced none or only a very slight growth reduction.