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Terminators and introns are vital regulators of gene expression in many eukaryotes; however, the functional importance of these elements for controlling gene expression in Agaricomycetes remains unclear. In this study, the effects of Ceriporiopsis subvermispora terminators and introns on the expression of a recombinant hygromycin B phosphotransferase gene (hph) were characterized. Using a transient transformation system, we proved that a highly active terminator (e.g., the gpd terminator) is required for the efficient expression of the hph gene. Mutational analyses of the C. subvermispora gpd terminator revealed that hph expression was dictated by an A-rich region, which included a putative positioning element, and polyadenylation sites. In contrast, our results indicated that introns are not required for the expression of hph directed by the Csβ1-tub and Csgpd promoters in C. subvermispora. This study provides insights into the functions and cis-element requirements of transcriptional terminators in Agaricomycetes, which may be relevant for designing recombinant genes for this important fungal class. [ABSTRACT FROM AUTHOR]

Abstract Background The white-rot fungi Ceriporiopsis subvermispora (Cs), Pleurotus eryngii (Pe), and Lentinula edodes (Le) have been shown to be high-potential species for selective delignification of plant biomass. This delignification improves polysaccharide degradability, which currently limits the efficient lignocellulose conversion into biochemicals, biofuels, and animal feed. Since selectivity and time efficiency of fungal delignification still need optimization, detailed understanding of the underlying mechanisms at molecular level is required. The recently developed methodologies for lignin quantification and characterization now allow for the in-depth mapping of fungal modification and degradation of lignin and, thereby, enable resolving underlying mechanisms. Results Wheat straw treated by two strains of Cs (Cs1 and Cs12), Pe (Pe3 and Pe6) and Le (Le8 and Le10) was characterized using semi-quantitative py-GC–MS during fungal growth (1, 3, and 7 weeks). The remaining lignin after 7 weeks was quantified and characterized using 13C lignin internal standard based py-GC–MS and whole cell wall HSQC NMR. Strains of the same species showed similar patterns of lignin removal and degradation. Cs and Le outperformed Pe in terms of extent and selectivity of delignification (Cs ≥ Le >> Pe). The highest lignin removal [66% (w/w); Cs1] was obtained after 7 weeks, without extensive carbohydrate degradation (factor 3 increased carbohydrate-to-lignin ratio). Furthermore, though after treatment with Cs and Le comparable amounts of lignin remained, the structure of the residual lignin vastly differed. For example, Cα-oxidized substructures accumulated in Cs treated lignin up to 24% of the total aromatic lignin, a factor two higher than in Le-treated lignin. Contrarily, ferulic acid substructures were preferentially targeted by Le (and Pe). Interestingly, Pe-spent lignin was specifically depleted of tricin (40% reduction). The overall subunit composition (H:G:S) was not affected by fungal treatment. Conclusions Cs and Le are both able to effectively and selectively delignify wheat straw, though the underlying mechanisms are fundamentally different. We are the first to identify that Cs degrades the major β-O-4 ether linkage in grass lignin mainly via Cβ–O–aryl cleavage, while Cα–Cβ cleavage of inter-unit linkages predominated for Le. Our research provides a new insight on how fungi degrade lignin, which contributes to further optimizing the biological upgrading of lignocellulose.

Cis-acting elements play a vital role in regulation of transcription initiation. Several cis-acting elements have been identified in filamentous fungi; however, the fundamental requirements for basic promoter function in basidiomycetes are obscure. In this study, core elements in β1-tubulin promoters of basidiomycetes were functionally characterized. Using transient transformation in Ceriporiopsis subvermispora as a promoter assay, we found that a 14-bp region (β1-tubulin core promoter element, BCE), as well as CT-rich stretch, in the β1-tubulin promoter of the species played a critical role in the expression of a recombinant hph as a reporter gene. In addition, in silico analysis revealed other members of basidiomycetes also harboured the BCE motif as well as CT-rich stretch in the β1-tubulin promoter region, suggesting their functional conservation among the species of basidiomycetes. To confirm the function of BCE, we investigated the effects of BCE motif deletion in the Pleurotus ostreatus β1-tubulin promoter on expression levels of a recombinant luminous shrimp luciferase reporter gene, which was targeted into the Pofcy1 locus. Intriguingly, luciferase activity was abolished when the BCE motif was deleted in the β1-tubulin promoter, strongly demonstrating its essential function in transcription from this promoter on the chromosome. This study clearly demonstrates the crucial role of the BCE as well as the CT-rich stretch regions in the β1-tubulin promoter among basidiomycetes and provides new insights into the fundamental mechanism of transcription initiation in this group. [ABSTRACT FROM AUTHOR]

Ceriporiopsis subvermispora (C. subvermispora) is a selective degrader of lignin in the woody biomass. Glutathione S-transferases (GSTs) are multifunctional enzymes that play important roles in cellular detoxification and metabolism. The crystal structures of a GST of C. subvermispora , CsGST83044, in GSH-free and -bound forms were solved at 1.95 and 2.19 Å resolution, respectively. The structure of the GSH-bound form revealed that CsGST83044 can be categorized as an atypical-type of GST. In the GSH-bound form of CsGST83044, Asn22, Asn24, and Tyr46 are located closest to the sulfur atom and form hydrogen bonds with the thiol group. The functional mutagenesis indicated that they are critical for the enzymatic activities of CsGST83044. The critical residues of an atypical-type GST belonging to the GSTFuA class were revealed for the first time. A previous study indicated that CsGST83044 and another GST, CsGST63524, differ in substrate preference; CsGST83044 prefers smaller substrates than CsGST63524 for its esterase activity. The GSH-bound pocket of CsGST83044 turns out to be small, which may explain the preference for smaller substrates. Protein engineering of GSTs of C. subvermispora in the light of the obtained insight may pave a path in the future for utilization of the woody biomass. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Unsterilized corn stover, miscanthus, hardwood, and softwood were fungal pretreated. • Fungal pretreatment increased the enzymatic digestibility of non-sterile feedstocks. • Effects of fungal pretreatment on structure and composition depended on feedstock. • Sequential unsterilized fungal pretreatment was ineffective after second generation. • Fungal pretreatment was more effective for woods than herbaceous feedstocks. Abstract Fungal pretreatment with the white rot fungus Ceriporiopsis subvermispora was performed under non-sterile conditions for four different feedstocks, corn stover, miscanthus, softwood, and hardwood, using a sequential inoculation process that employed fungal-colonized feedstock as inoculum. Fungal pretreatment improved the enzymatic digestibility of unsterilized hardwood, softwood, and miscanthus after the first generation of the sequential process, increasing the glucose yield by 2-, 3- and 4.5- fold, and the xylose yield by 9-, 7- and 10- fold, respectively. However, the fungal pretreatment of unsterilized feedstocks was unsuccessful for corn stover throughout the sequential process and for all feedstocks for the second and third generation. Modifications in feedstock structure and composition were analyzed using microscopy, spectroscopy, and thermogravimetric analysis, and showed that the effects of fungal pretreatment with C. subvermispora were feedstock-dependent. A significant fungal colonization was observed in all the fungal pretreated feedstocks, but an extensive cell wall degradation was only detected in miscanthus and hardwood. Lignin-to-cellulose ratio decreased in all successful fungal pretreated feedstocks, but the lignin units (syringyl, guaiacyl, or p-hydroxyphenyl units) that were preferentially degraded varied with each feedstock. Interestingly, C. subvermispora was able to degrade terpenes from the pine resin during the fungal pretreatment of pine wood (softwood). [ABSTRACT FROM AUTHOR]

• C. subvermispora modification mechanism of corn stover was studied. • Tendency of lignocellulose degradation changed during C. subvermispora modification. • C. subvermispora modification for 15 d increased methane yield of corn stover by 15.2%. • Selective delignification was highly correlated to methane yield of corn stover. Ceriporiopsis subvermispora was used to modify corn stover for improving the biodegradability and biomethane yield. Corn stover was incubated with C. subvermispora for 5–90 days then anaerobically digested. It was found that the corn stover modified for 15 days achieved the highest biomethane yield of 235 mL·g−1 VS, which was an increase of 15.2% over that of the non-modified one. The mechanism analyses indicated that the improvement resulted from the combined roles of degradation selectivity, destruction of lignocellulosic structures, and linkages. The analyses showed that C. subvermispora has a high relative selectivity of lignin degradation. The structure of the lignin and the linkages among lignin and hemicellulose and cellulose were broken obviously by acetyl group removal, and the enzymatic hydrolysis of cellulose was increased by 35.61%. The finding indicated that C. subvermispora modification is one of the effective methods for enhancing biomethane yield of corn stover. [ABSTRACT FROM AUTHOR]

Abstract Ceriporiopsis subvermispora (C. subvermispora), one of the white-rot fungi, is known as a selective lignin degrader of the woody biomass. Glutathione S-transferases (GSTs) are multifunctional enzymes that are capable of catalyzing the reactions involved in detoxification and metabolic pathways. In this study, a GST of C. subvermispora , named CsGST63524, was overexpressed in E. coli , and then purified by affinity, anion exchange, and size exclusion column chromatography. The crystal structures of the CsGST63524 in ligand-free and complex with GSH were refined at 2.45 and 2.50 Å resolutions, respectively. The sulfur atom of glutathione forms a hydrogen bond with Ser21 of CsGST63524, indicating it is a serine-type GST. Mutagenesis of Ser21 unexpectedly indicated that this serine residue is not essential for the enzymatic activity of CsGST63524. Comparative sequence and structural analyses, together with functional mutagenesis, newly identified the enzymatically important non-canonical amino acid residues, Asn23 and Tyr45, other than the serine residue. Highlights • GSH-free and -bound structures of a C. subvermispora GST, CsGST63524, were solved. • Ser21 is located closest to a sulfur of GSH, indicating CsGST63524 is a serine-type. • S21A mutant unexpectedly indicated Ser21 is not crucial for the enzymatic activity. • Functional mutagenesis revealed Asn23 and Tyr45 are crucial for enzymatic activity. • A putative substrate-binding site was deduced from those of homologous proteins. [ABSTRACT FROM AUTHOR]

The present work aimed to study sugarcane bagasse fibers pre-treated with fungi and using NaOH/ anthraquinone (AQ) in chemical pulping processes for applications in composite materials. Bagasse was decayed with 250 mg of Ceriporiopsis subvermispora inoculum in a 20 L bioreactor. After that, samples were submitted to similar conditions of decaying without inoculum charge. Decayed and undecayed fibers were treated with NaOH 12.5 wt%, 0.15 of AQ and a 12:1 (v/w) liquor:bagasse ratio at 160°C. Then, all obtained fibers were characterized according to their chemical composition. Dried biotreated (decayed) and control (undecayed) fibers were mixed through an extruder process with polypropylene. Later, composite granulates were injected directly in mold with cavities for tensile, flexural and shear tests. Composite materials with 10 and 20 wt% fibers were submitted to static mechanical standard tests and DMA (Dynamic Mechanical Analysis) to evaluate the effect of biotreatment. Biotreatment, cook time (pulping), and fiber content contributed to improvements in the mechanical properties of the composites. The interface between fiber and matrix was increased with the biotreatment and pulping of fibers. Furthermore, DMA results also showed that fiber incorporation into PP improved the modulus, mainly for biotreated fibers/PP composites. The Tg (tan δ data) from composites was dislocated at lower temperatures with respect to neat PP due to the influence of fibers on matrix.

Glutathione S-transferases (GSTs) of wood-degrading fungi play essential roles in cellular detoxification processes and endogenous metabolism. Fungal GSTs of GSTFuA class are suggested to be involved in lignin degradation. Ceriporiopsis subvermispora is one of the important model fungi of the selective lignin degraders, we found it interesting to study its GSTs. Here, we characterized the activities of two GSTs of the GSTFuA class of C . subvermispora (CsGST63524 and CsGST83044). A high-yield expression systems involving Escherichia coli was developed for each of these enzymes. Both enzymes were found to exhibit GSH-conjugation activity toward 1-chloro-2,4-dinitrobenzene, and GSH-peroxidase activity toward cumene hydroperoxide. Both enzymes showed high GSH-conjugation activity under basic conditions (pH 8.0 to 9.0), and the optimum temperature for their activity was 40 °C. In addition, three fluorescent compounds were used i . e ., methylumbelliferyl acetovanillone was used to monitor etherase activity, and 5-chloromethylfluorescein diacetate and 4-methylumbelliferyl acetate to monitor esterase activity. CsGST83044 exhibited both etherase and esterase activities, while CsGST63524 displayed only esterase activity, which was much higher than that of CsGST83044. These findings imply the functional diversity of the GSTFuA class GSTs of C . subvermispora , suggesting that each protein plays distinctive roles in both the fungal detoxification system and wood compound metabolism. [ABSTRACT FROM AUTHOR]

Abstract: BACKGROUND: No attention has been paid so far to the preservation of fungal‐treated lignocellulose for longer periods. In the present study, we treated wheat straw (WS) with the white‐rot fungi Ceriporiopsis subvermispora and Lentinula edodes for 8 weeks and assessed changes in pH, chemical composition and in vitro gas production (IVGP) weekly. Fungal‐treated WS was also stored for 64 days ‘as is’, with the addition of lactic acid bacteria (LAB) or with a combination of LAB and molasses in airtight glass jars mimicking ensiling conditions. RESULTS: Both fungi significantly reduced the lignin and hemicellulose content of WS, and increased the cellulose content. The IVGP increased with increasing time of incubation, indicating the increase in digestibility. Both fungi lowered the pH of WS under 4.3, which guarantees an initial and stable low pH during anaerobic storage. Minor changes in fibre composition and IVGP were observed for stored L. edodes treated WS, whereas no change occurred for C. subvermispora. CONCLUSION: It is possible to conserve C. subvermispora and L. edodes treated straw under anaerobic condition without additives up to 64 days. This finding is important for practical application to supply fungi‐treated feed to ruminant animals for a prolonged period. © 2017 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

The functions and properties of fungal sheath, an extracellular polysaccharide produced by many white-rot fungi, have been studied. However, the strong adherence of the sheath to fungal hyphae had been a major impediment in preparing intracellular proteins from the fungi and analyzing their cellular responses. To overcome this issue, we developed a rapid and easy method to remove the polysaccharide sheath using a selective lignin degrader, Ceriporiopsis subvermispora , which produces large sheath amounts in the presence of a lignin-derived aromatic compound. Using this approach, we achieved thorough removal of sheath and cell disruption using beads and a solution with a high protein-solubilizing power, which enabled the efficient extraction of intracellular proteins from C . subvermispora surrounded by sheath. In addition, for proteomic analysis, we investigated whether these extracted proteins were compatible with two-dimensional electrophoresis. By efficiently concentrating on protein solubilization in the first dimension and using a stacking gel in the second dimension, we successfully obtained a high-resolution proteome map of C . subvermispora . We also used the same proteins for fluorescence two-dimensional difference gel electrophoresis to obtain the quantitative protein expression profiles. These steps demonstrated that two-dimensional electrophoresis-based proteomics can be used to clarify the composition of intracellular proteins from sheath-producing white-rot fungi. [ABSTRACT FROM AUTHOR]

Oxygen transfer in submerged cultures of basidiomycetes is a key factor for efficient fungal growth. However, conventional stirred tank and airlift reactors are not utterly suitable for basidiomycetes culturing because they promote high shear stress to the mycelial hyphae and favor rapid agglomeration of mycelial pellets, compromising the diffusion of oxygen to the inner side of mycelium. We describe an original reactor design that overcome some of the limitations of conventional bioreactors used in submerged cultures of basidiomycetes. The strategy was to use a mechanism that permits simultaneous axis rotation and air injection, being the agitation promoted by an L-shaped tube. Adherence of mycelium and shear stress is avoided once only rounded surfaces exist inside the bioreactor. Ceriporiopsis subvermispora was selected as a model basidiomycete. The most productive system employed sucrose/corn steep liquor as the culture medium and pulsed addition of sucrose during the culturing. This approach provided efficient mycelial growth (maximum of 14.1 g·L –1 ), and avoided pH increase and pellet agglomeration throughout the fungal cultivation for 7 days, resulting in a biomass productivity of 1.72 g·L –1 ·day –1 . Microscopic evaluation of chlamydospores accumulation in the grown mycelium confirmed that minimal fungal stress occurred in the cultures performed in the new designed bioreactor, contrasting with cultures carried out in conventional stirred tank bioreactors. [ABSTRACT FROM AUTHOR]

Aim This study evaluated differences between two strains of Ceriporiopsis subvermispora on improving the nutritive value and in vitro degradability of wheat straw. Methods and Results Wheat straw was treated with the fungi for 7 weeks. Weekly samples were analysed for ergosterol content, in vitro gas production ( IVGP), chemical composition and lignin-degrading enzyme activity. Ergosterol data showed CS1 to have a faster initial growth than CS2 and reaching a stationary phase after 3 weeks. The IVGP of CS1-treated wheat straw exceeded the control earlier than CS2 (4 vs 5 weeks). CS1 showed a significantly higher ( P < 0·001) selectivity in lignin degradation compared to CS2. Both strains showed peak activity of laccase and manganese peroxidase (MnP) at week 1. CS1 showed a significantly higher ( P < 0·001) laccase activity, but lower ( P = 0·008) MnP activity compared to CS2. Conclusion Both CS strains improved the nutritive value of wheat straw. Variation between strains was clearly demonstrated by their growth pattern and enzyme activities. Significance and Impact of the Study The differences among the two strains provide an opportunity for future selection and breeding programs in improving the extent and selectivity of lignin degradation in agricultural biomass. [ABSTRACT FROM AUTHOR]

Fungal pretreatment by Ceriporiopsis subvermispora of two forest residues (hazel and acacia branches) and two agricultural lignocellulosic residues (barley straw and sugarcane bagasse) were studied as a pretreatment to improve their subsequent anaerobic digestion for methane production. Biomass samples were grinded to 2 ranges of particle sizes (<4 or 1 mm), autoclaved, inoculated with two strains of C. subvermispora (ATCC 90467 and ATCC 96608) and incubated at 28 °C for 28 days. The effects of fungal pretreatment were assessed by analyzing the samples before and after incubations for dry solids mass, biochemical composition, bio-methane production (BMP) and availability of cellulose to hydrolysis. The production of ligninolytic enzymes MnP and/or laccase was observed with both strains during incubation on most of the samples tested. It almost doubled the hazel branches BMP per unit mass of dry solids but did not improve however the BMP of the agricultural residues and acacia branches. These observations were explained by the fact that although both strains were able to degrade 20–25% of lignin in <1 mm and <4 mm hazel branches samples, none of them was successful however to significantly degrade lignin in the other samples, except for sugarcane bagasse. [ABSTRACT FROM AUTHOR]

Eucalyptus globulus wood chips were decayed by the lignin-degrading fungus Ceriporiopsis subvermispora as a pretreatment step before kraft pulping. Weight and component losses of wood after the biotreatment were the following: weight (5%), glucans (1.5%), xylans (4.3%), lignin (5.7%) and extractives (57.5%). The residual amount of lignin (expressed by the kappa number) in pulps from biotreated wood chips was lower than that of pulps from the undecayed control. Depending on the delignification degree, kraft biopulps presented similar or up to 4% increase in pulp yield and 20% less hexenuronic acids (HexA) than control pulps. The extended delignification with O2 decreases approximately 50% of the kappa number of the pulps and increases brightness, but had no effect in HexA reduction. The bleaching steps with chlorine dioxide (D0ED1 sequence) decreased the kappa number up to 97%, increased pulp brightness up to 84% ISO and decreased HexA amount up to 91%. The use of C. subvermispora in biopulping of E. globulus generated important benefits during the production of kraft pulps that are reflected in a high pulp yield, low residual lignin content, low HexA amount, high brightness and viscosity of the biopulps as compared with pulps produced from untreated wood chips.

Ceriporiopsis subvermispora foi utilizado para a biodegradação de cavacos de Eucalyptus grandis na presença ou ausência de cossubstratos (glicose e milhocina) durante 7, 14 e 28 dias. Os cavacos obtidos em cada um desses períodos foram extraídos com tampão acetato de sódio 50 mM (pH 5,5) adicionado de 0,01% de Tween 60. A atividade de manganês peroxidases (MnPs) nos extratos foi marcante ao longo de todo o período de biodegradação, tanto na ausência (430, 765 e 896 UI kg-1, respectivamente) quanto na presença de cossubstratos (1.013, 2.066 e 2.323 UI kg-1, respectivamente). Os extratos apresentaram elevadas relações entre absorbância a 280 e a 405 nm, indicando forte abundância de compostos aromáticos derivados da lignina em relação à heme-peroxidases. A adsorção em carvão ativado se mostrou uma estratégia adequada para reduzir a absorbância a 280 nm em todos os extratos. Além disso, permitiu maximizar a capacidade de um leito de resina trocadora de ânions (DEAE Sepharose), utilizado para concentrar as MnPs presentes nos referidos extratos. Concluiu-se que o uso de carvão ativado seguido de adsorção em DEAE Sepharose é uma estratégia que pode ser utilizada para concentrar MnPs em extratos obtidos durante a biodegradação de E. grandis por C. subvermispora.

Ceriporiopsis subvermispora foi utilizado para a biodegradação de cavacos de Eucalyptus grandis na presença ou ausência de cossubstratos (glicose e milhocina) durante 7, 14 e 28 dias. Os cavacos obtidos em cada um desses períodos foram extraídos com tampãoacetato de sódio 50 mM (pH 5,5) adicionado de 0,01% de Tween 60. A atividade de manganês peroxidases (MnPs) nos extratos foi marcante ao longo de todo o período de biodegradação, tanto na ausência (430, 765 e 896 UI kg-1, respectivamente) quanto na presença de cossubstratos (1.013, 2.066 e 2.323 UI kg-1, respectivamente). Os extratos apresentaram elevadas relações entre absorbância a 280 e a 405 nm, indicando forte abundância de compostos aromáticos derivados da lignina em relação à heme-peroxidases. A adsorção em carvão ativado se mostrou uma estratégia adequada para reduzir a absorbância a280 nm em todos os extratos. Além disso, permitiu maximizar a capacidade de um leito de resina trocadora de ânions (DEAE Sepharose), utilizado para concentrar as MnPs presentes nos referidos extratos. Concluiu-se que o uso de carvão ativado seguido de adsorção em DEAE Sepharose é uma estratégia que pode ser utilizada para concentrar MnPs em extratos obtidos durante a biodegradação de E. grandis por C. subvermispora.Ceriporiopsis subvermispora was used for the biodegradation of Eucalyptus grandis chips in the presence or absence of cosubstrates(glucose and corn steep liquor) during 7, 14 and 28 days. Afterwards, the biodegraded chips were extracted with 50 mM sodium acetate buffer (pH 5.5) supplemented with 0.01% Tween 60. High activities of manganese peroxidases (MnPs) were observed in all the extracts, both in the absence (430, 765 and 896 UI kg-1, respectively) and in the presence of co-substrates (1,013; 2,066 and 2,323 UI kg-1, respectively). The extracts presented a high ratio between absorbances at 280 and 405 nm, indicating a strong abundance of aromatic compounds derived from lignin over hemeperoxidases. Adsorption into activated charcoal showed to be an adequate strategy to reduce the absorbance at 280 nm in all the extracts. Moreover, it allowed to maximize the capacity of an anion exchange resin bed (DEAE-Sepharose) used to concentrate the MnPs present in the extracts. It was concluded that the use of activated charcoal followed by adsorption into DEAE Sepharose is a strategy that can be used to concentrate MnPs in extracts obtained during the biodegradation of E. grandis by C. subvermispora.

Laccases of white-rot fungi provide a promising future as a tool to be used in the field of biodegradation of synthetic dyes with different chemical structures. The aim of this study was production, characterization, and application of laccases from the white-rot fungus Ceriporiopsis subvermispora ATCC 90467 for decolorization of triphenylmethane dyes that could remain persistent in wastewater. Laccase was purified from a C. subvermispora culture by a four-step method resulting high specific activity of 2,571 U g−1, 88-fold higher than crude laccase. Purified laccase (molecular weight 45 kDa) had the optimum activity at pH 2.0 and the optimum temperature 50 °C using ABTS as chromogenic substrate. Laccases efficiently decolorized triphenylmethane dyes such as Malachite Green (87.8%), Bromocresol Purple (71.6%), and Methyl Violet (68.1%) without redox mediator. However, decolorization percentage of hardly degradable triphenylmethane dyes such as Phenol Red, Bromophenol Blue, and Brilliant Blue R-250 was increased the presence of some low-molecular weight compounds (natural or synthetic redox mediators). Purified laccases were resistant to Mg2+, Ca2+, Ba2+, Mn2+, Fe2+, Cu2+, Zn2+, and Sn2+ (10 mmol L−1). These findings suggest that laccases from C. subvermispora are able to decolorize triphenylmethane dyes without the negative influence of metal ions that can be found in wastewater. [ABSTRACT FROM AUTHOR]

Miscanthus was pretreated with the fungus Ceriporiopsis subvermispora under non-sterile conditions, using sterile miscanthus that had been previously colonized with the fungus as the inoculum. Inoculum ratios equal to or greater than 30% yielded a successful pretreatment, enhancing the enzymatic digestibility of miscanthus by 3- to 4-fold over that of raw miscanthus, which was comparable with the fungal pretreatment under sterile conditions. This enhanced digestibility was linearly correlated with lignin degradation. Although cellulose loss of up to 13% was observed for the successful non-sterile pretreatments, the final glucose yield was 3–4 times higher than that of raw miscanthus and comparable to that of the sterile pretreated miscanthus. A time course study showed that maximum glucose yield can be achieved with a pretreatment time of 21 days. [ABSTRACT FROM AUTHOR]

Corn stover pretreated by Ceriporiopsis subvermispora was used as substrate to enhance biogas production via solid state anaerobic digestion (SS-AD). Effects of temperature, inoculum volume and alkaline concentration on the biogas production profermance were investigated. The results showed that pretreatment of corn stover by C. subvermispora benefited the biogas production. The optimal conditions were temperature 35°C, inoculum 10:1 (w/w) and adding 5.0% of alkali, under which the maximum productions were obtained for daily and cumulative biogas of 14.07 L/kg VS and 211.09 L/kg VS. During the SS-AD process, the total solids (TS) and volatile solid (VS) were significantly degraded. The volatile fatty acids (VFA) concentration increased to 106 mmol/L and alkalinity decreased by about 23%. The results collectively suggested that microbial-alkali pretreatment of corn stove combining mesophilic condition could be a promising way to produce biogas in SS-AD. [ABSTRACT FROM AUTHOR]

This study carried out for the first time a comparison among ligninolytic (white-rot) and cellulosolytic or xylanolytic (Trichoderma) pre-treated wheat straw, for biogas production, potential, without or with pig slurry in co-digestion. Methane (CH4) production from wheat straw pre-treated for 4 and 10 weeks with seven different fungal isolates was preliminarily measured. Then, the effects on biogas yield of the co-digestion with pig slurry were checked on straw pre-treated with 3 selected fungal strains. The maximum production of CH4 from pre-treated straw with Ceriporiopsis subvermispora (SUB) for 4 and 10 weeks was higher than the control (16% and 37%, respectively). The accumulation daily rate was higher than control (42% and 81%, respectively). A positive correlation between CH4 accumulation daily rate and straw enzymatic digestibility was found. In co-digestion with pig slurry, SUB pre-treated straw for 10 weeks showed an accumulation daily rate of 17.4 mL d-1 g-1 VS, significantly higher (17%) than that of the control. The time to reach the maximum CH4 production was shortened on average from 34 to 21 days in co-digestion with pig slurry, in comparison with pre-treated mono-digested wheat straw. The biological pre-treatment with selected white-rot fungi appears a promising technology to increase methane production from wheat straw. [ABSTRACT FROM AUTHOR]

Solid-state anaerobic digestion of Miscanthus sinensis harvested in fall and spring was compared under different total solids contents and feedstock-to-inoculum ratios. The highest specific methane yields reached 170–175 L CH 4 /kg volatile solids for both harvest seasons. Miscanthus harvested in fall generated a 6% higher methane yield in average than miscanthus harvested in spring. Fungal pretreatment with Ceriporiopsis subvermispora decreased the lignin content of miscanthus harvested in spring by 25.7%, but there was no significant delignification observed for miscanthus harvested in fall. Fungal pretreatment of miscanthus harvested in spring increased the specific methane yield by 25%, but fungal pretreatment caused a slight methane yield reduction for miscanthus harvested in fall. Methane yields for miscanthus were comparable with those from other energy crops. [ABSTRACT FROM AUTHOR]

The genome of Ceriporiopsis subvermispora includes 13 manganese peroxidase (MnP) genes representative of the three subfamilies described in ligninolytic fungi, which share an Mn2+-oxidation site and have varying lengths of the C-terminal tail. Short, long and extralong MnPs were heterologously expressed and biochemically characterized, and the first structure of an extralong MnP was solved. Its C-terminal tail surrounds the haem-propionate access channel, contributing to Mn2+ oxidation by the internal propionate, but prevents the oxidation of 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonate) (ABTS), which is only oxidized by short MnPs and by shortened-tail variants from site-directed mutagenesis. The tail, which is anchored by numerous contacts, not only affects the catalytic properties of long/extralong MnPs but is also associated with their high acidic stability. Cd2+ binds at the Mn2+-oxidation site and competitively inhibits oxidation of both Mn2+ and ABTS. Moreover, mutations blocking the haem-propionate channel prevent substrate oxidation. This agrees with molecular simulations that position ABTS at an electron-transfer distance from the haem propionates of an in silico shortened-tail form, while it cannot reach this position in the extralong MnP crystal structure. Only small differences exist between the long and the extralong MnPs, which do not justify their classification as two different subfamilies, but they significantly differ from the short MnPs, with the presence/absence of the C-terminal tail extension being implicated in these differences. [ABSTRACT FROM AUTHOR]

Biological pretreatment of lignocellulosic biomass by fungi can represent a low-cost and eco-friendly alternative to physicochemical methods to facilitate enzymatic hydrolysis. However, fungal metabolism can cause cellulose loss and it is therefore necessary to use the appropriate fungal strain-biomass type combination. In this work, the effects of biological pretreatments carried out by five different fungi on enzymatic hydrolysis of wheat straw were investigated. The best results were obtained with a Ceriporiopsis subvermispora strain, which minimized weight and cellulose losses and gave the highest net sugar yield (calculated with respect to the holocellulose content of the untreated straw), up to 44 % after a 10-week pretreatment, more than doubling the yields obtained with the other isolates. Moreover, prolonging the pretreatment from 4 up to 10 weeks produced a 2-fold increase, up to 60 %, in digestibility (sugar yield, calculated considering the holocellulose content of the pretreated material). The hemicellulose content of the pretreated material resulted inversely correlated with digestibility, and it could thus be utilized as an index of the pretreatment efficacy. Finally, a correlation was also found between digestibility and the difference between the absorbance values at 290 and 320 nm of pretreated wheat straw extracts. [ABSTRACT FROM AUTHOR]

Three types of bamboo pellets as a ruminant feed: P1 (ground bamboo ( GB) cultured with the fungus Ceriporiopsis subvermispora ( CGB) : soybean curd residue ( T) : soy sauce cake ( S) in a 5:4:1 ratio on a dry matter ( DM) basis); P2 ( GB : T : S = 5:4:1 on a DM basis); and P3 ( CGB : T : S = 5.5:0.8:3.7 on a DM basis) were prepared. Four wethers were assigned in a 4 × 4 Latin square design experiment to evaluate the applicability of the bamboo pellets. The experimental treatments were C (control): fed alfalfa hay cubes ( AC) only, and T1, T2 and T3: fed P1, P2, and P3 with AC by 1:1 on a DM basis, respectively. The digestibility of the DM, organic matter and acid detergent fiber of P1 were significantly higher than those of P2 and P3 ( P < 0.05). The total digestible nutrient ( TDN) contents of AC, P1, P2 and P3 were 56.5%, 60.2%, 53.2% and 47.0%, respectively. No significant differences in nitrogen retention or ruminal pH and NH3 were observed among the treatment groups. The results indicate that bamboo pellets cultured with C. subvermispora and mainly mixed with soybean curd residue improved nutritional quality of ground bamboo because of its high digestibility and TDN content. [ABSTRACT FROM AUTHOR]

Abstract: Aqueous extracts from wood biotreated with the white-rot fungus Ceriporiopsis subvermispora were evaluated for their Fe3+- and Cu2+-reducing activities and their anti- or prooxidant properties in Fenton-like reactions to decolorize the recalcitrant dye Azure B. The decolorization of Azure B was strongly inhibited in the presence of 10% (v/v) wood extracts. Only 0.1% (v/v)-diluted extracts provided some enhancement of the Azure B decolorization. The iron-containing reactions decolorized more Azure B and consumed substantially more H2O2 than the reactions containing copper. This study demonstrates that water-soluble wood phenols exert anti- or prooxidant effects that depend on their concentration in the reactions and on the type of cation, Fe3+ or Cu2+, used to convert H2O2 to OH radicals. [Copyright &y& Elsevier]

Abstract: Pinus taeda wood chips were treated with the biopulping fungus Ceriporiopsis subvermispora in calcium- or oxalic acid-amended cultures. The secretion of hydrolytic and oxidative enzymes was inhibited only in the cultures having the highest concentration of calcium (1400 mg kg−1 wood). Calcium decreased the availability of free oxalic acid, inhibited fungal growth, and reduced lignin mineralization and transformations. Oxalic acid amendment in the cultures was found not to affect the lignin mineralization and transformations; however, it did inhibit the depolymerization reactions detectable in the residual lignin that was retained in the biotreated wood. C. subvermispora presented catabolic activity for oxalic acid in the cultures amended with 1660 mg acid kg−1 wood, whereas oxalic acid was synthesized when it was amended at low amounts or initially absent in the cultures. These data suggest one ideal ratio of oxalic acid in C. subvermispora cultures and indicate that its exogenous addition does not necessarily accompany the further degradation of lignin. [Copyright &y& Elsevier]

Copyright of Acta Scientiarum: Technology is the property of Universidade Estadual de Maringa and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The lignin-modifying enzymes (LMEs) play an important role in decomposition of agricultural residues, which contain a certain amount of lignin. In this study, the production of LMEs by three co-cultivated combinations of Phlebia radiata, Dichomitus squalens and Ceriporiopsis subvermispora and the respective monocultures was comparatively investigated. Laccase and manganese peroxidases (MnP) were significantly promoted in the co-culture of P. radiata and D. squalens, and corncob was verified to be beneficial for laccase and MnP production. Moreover, laccase production by co-culture of P. radiata and D. squalens with high ratio of glucose to nitrogen was higher than low ratio under carbon- and nitrogen-meager conditions. New laccase isoenzymes measured by Native-PAGE were stimulated by co-cultured P. radiata with D. squalens or C. subvermispora, respectively, growing in the defined medium containing corncob, but the expression of laccase was greatly restrained by the co-culturing of D. squalens with C. subvermispora. This study showed that the synergistic and depressing effects of co-cultivation of P. radiata, D. squalens and C. subvermispora on LMEs were species specific. [ABSTRACT FROM AUTHOR]

Abstract: Storage of lignocellulosic biomass is critical for a year-round supply of feedstock for a biorefinery. Compared with dry storage, wet storage is a promising alternative technology, providing several advantages including reduced dry matter loss and fire risk and improved feedstock digestibility after storage. This study investigated the concurrent pretreatment and wet-storage of corn stover with the assistance of NaOH or a lignin-degrading fungus, Ceriporiopsis subvermispora, during a 90-d period. Compared with ensilage, adding NaOH or inoculation with C. subvermispora significantly enhanced the enzymatic degradability of corn stover by 2–3-fold after 90-d wet storage. Lignin and xylan removal during NaOH pretreatment and wet-storage were influenced by NaOH loading and moisture. NaOH pretreatment retarded the production of organic acids during storage and the acetate release correlated with lignin and xylan removal. Further study is needed to reduce cellulose degradation during the late stage of fungal treatment. [Copyright &y& Elsevier]

Cinereomyces clade is a newly proposed monophyletic group of polypores containing currently four genera and five species, including two promising biopulping fungi, Ceriporiopsis rivulosa and C. subvermispora. The Cinereomyces clade is well-delimited in nrDNA-based phylogenetic analysis, but its position in Polyporales remains unclear. Its closest relative may be found in the core polyporoid clade. Only a few morphological characters are common for all the species in the clade, e.g. CB- and CRB+ hyphae, white fruiting bodies, presence of oil, and middle-sized spores. Culturally, the species are unified by producing simple-septate generative hyhpae in the margin, which produce simple-clamped hyphae backwards. The genus Gelatoporia is the correct place for Ceriporiopsis subvermispora. Two new genera are described in the group: Obba to incorporate C. rivulosa and a new austral species, Obba valdiviana, known from southern Argentina and recorded here also from Tasmania, and Sebipora to accommodate a new species from tropical Asia, S. aquosa. ITS sequences imply that Eurasian Gelatoporia subvermispora may belong to a different species from the North American one. G. subvermispora is recorded as new to Indonesia. [ABSTRACT FROM AUTHOR]

Abstract: European black pine (Pinus nigra Arn.) chips were treated with the white-rot fungus Ceriporiopsis subvermispora for periods ranging from 20 to 100 days. The effects of pretreatment on the chemical composition of wood and kraft pulping were investigated. The results showed that fungal pretreatment reduced the lignin and extractive content of wood chips. Also, weight losses occurred. Kappa number, viscosity, and reject ratio of biokraft pulps decreased. Biokraft pulps gave better response to beating, which led to significant energy saving during refining. The tear index, burst index, and tensile index of biokraft pulps were found to be lower than those of kraft pulps. However, the tensile index and burst index of 20-day biotreated and unbeaten pulp was higher than those of kraft pulp. Also, the tear index of 20-day biotreated and beaten pulp was higher than that of kraft pulp. The brightness of biokraft pulps decreased irregularly with increasing incubation time. [Copyright &y& Elsevier]

Spruce wood that had been degraded by white-rot fungi ( Trametes versicolor or Ceriporiopsis subvermispora) and suffered mass losses up to 17% was investigated by transmission Fourier transform infrared (FT-IR) imaging microscopy. A significant marker during incipient simultaneous white-rot ( T. versicolor) was the cleavage of glycosidic bonds of polysaccharides that preceded their metabolisation. Simultaneous white-rot processes were also characterised by a relative decrease of the overall lignin content and a relative accumulation of wood polysaccharides. No early marker was found for selective white-rot ( C. subvermispora) that removes mainly lignin by an oxidative process. This feature was detected only in wood samples exhibiting mass losses higher than 12%. Furthermore, it was shown, that simultaneous and selective white-rot processes were unevenly distributed within the wood samples but quite evenly distributed within single tracheids. [ABSTRACT FROM AUTHOR]

Abstract: This work evaluates linoleic acid peroxidation reactions initiated by Fe3+-reducing compounds recovered from Eucalyptus grandis, biotreated with the biopulping fungus Ceriporiopsis subvermispora. The aqueous extracts from biotreated wood had the ability to reduce Fe3+ ions from freshly prepared solutions. The compounds responsible for the Fe3+-reducing activity corresponded to UV-absorbing substances with apparent molar masses from 3kDa to 5kDa. Linoleic acid peroxidation reactions conducted in the presence of Fe3+ ions and the Fe3+-reducing compounds showed that the rate of O2 consumption during peroxidation was proportional to the Fe3+-reducing activity present in each extract obtained from biotreated wood. This peroxidation reaction was coupled with in-vitro treatment of ball-milled E. grandis wood. Ultraviolet data showed that the reaction system released lignin fragments from the milled wood. Size exclusion chromatography data indicated that the solubilized material contained a minor fraction representing high-molar-mass molecules excluded by the column and a main low-molar-mass peak. Overall evaluation of the data suggested that the Fe3+-reducing compounds formed during wood biodegradation by C. subvermispora can mediate lignin degradation through linoleic acid peroxidation. [ABSTRACT FROM AUTHOR]

In this study, the influences of sodium borohydride (NaBH4) on properties of kraft pulp and paper obtained from European black pine (Pinus nigra Arn.) chips treated with Ceriporiopsis subvermispora for periods varying from 20 to 100 days were investigated. Biokraft-NaBH4 cookings were done under the fixed cooking conditions by adding NaBH4 at the amounts of 0.5%, 1%, 1.5%, and 2% (oven dried wood) to the cooking liquor. For comparison, NaBH4 free biokraft cooking was carried out. The results revealed that addition of NaBH4 to cooking liquor during biokraft pulping not only increases the pulp screened yield but also decreases kappa number of pulp. In addition, brightness of biokraft-NaBH4 papers was higher than those of biokraft papers. However, tear index, burst index, and tensile index of biokraft-NaBH4 pulps were found lower than biokraft pulps. [ABSTRACT FROM AUTHOR]

Abstract: Pinus taeda wood chips were treated with the biopulping fungus Ceriporiopsis subvermispora in soybean-oil-amended cultures. The secretion of oxalic acid and the accumulation of thiobarbituric acid reactive substances were significantly increased in soybean-oil-amended cultures. By contrast, the secretion of hydrolytic and oxidative enzymes was not altered in the cultures. Biotreated wood samples were characterized for weight and component losses as well as by in-situ thioacidolysis. Residual lignins were also extracted from biotreated wood using a mild-non-razing extraction procedure. The lignins were characterized by 31P nuclear magnetic resonance (31P-NMR) spectroscopy. Soybean oil amendment in the cultures was found to affect lignin degradation routes; however, it inhibited depolymerization reactions detectable in the residual lignin that was retained in the biotreated wood. As a consequence, chemithermomechanical pulping of the biotreated samples was not improved by soybean oil amendment in the cultures. [ABSTRACT FROM AUTHOR]

Copyright of Acta Scientiarum: Technology is the property of Universidade Estadual de Maringa and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Abstract: The feasibility of concurrent wet storage and microbial pretreatment of corn stover with Ceriporiopsis subvermispora for ethanol production was investigated in this study. The effects of particle size (5–15mm), moisture content (45–85%), pretreatment time (18–35 d), and temperature (4–37°C) on lignin degradation and enzymatic hydrolysis yield were studied. The results showed that C. subvermispora selectively degraded lignin up to 31.59% with a limited cellulose loss of less than 6% during an 18-d pretreatment. When 5mm corn stover was pretreated at 28°C with 75% moisture content, overall glucose yields of 57.67%, 62.21%, and 66.61% were obtained with 18-, 28-, and 35-d microbial pretreated corn stover, respectively. For the above conditions, the highest overall ethanol yield of 57.80% was obtained with 35-d-pretreated corn stover. Enzymatic hydrolysis yield was highly related to the lignin removal during microbial pretreatment. [Copyright &y& Elsevier]

Abstract: Delignification of corn stover by the white rot fungus Ceriporiopsis subvermispora in solid-state cultivation was evaluated for improving subsequent enzymatic hydrolysis. The results showed that C. subvermispora selectively degraded lignin by as much as 39.2% while the cellulose loss was less than 5% during 42d of cultivation. However, hemicellulose loss of up to 27.0% was concomitant with the lignin degradation. Ligninolytic enzymes, MnP and laccase, were detected during degradation of corn stover by C. subvermispora. For major hydrolytic enzymes, xylanase was the only enzyme detected. The enzymatic hydrolysis yield of corn stover delignified by C. subvermispora was remarkably improved, reaching about 57–67% overall glucose yield after 18–42d of pretreatment, while the glucose yield of the untreated was only 22%. A higher overall glucose yield of about 72% was obtained when the enzymatic hydrolysis of the 18d treated corn stover was supplemented with an accessory xylanase/cellulase enzyme complex. [Copyright &y& Elsevier]

Abstract: Ceriporiopsis subvermispora is a white-rot fungus used in biopulping processes and seems to use the fatty acid peroxidation reactions initiated by manganese-peroxidase (MnP) to start lignin degradation. The present work shows that C. subvermispora was able to peroxidize unsaturated fatty acids during wood biotreatment under biopulping conditions. In vitro assays showed that the extent of linoleic acid peroxidation was positively correlated with the level of MnP recovered from the biotreated wood chips. Milled wood was treated in vitro by partially purified MnP and linoleic acid. UV spectroscopy and size exclusion chromatography (SEC) showed that soluble compounds similar to lignin were released from the milled wood. SEC data showed a broad elution profile compatible with low molar mass lignin fractions. MnP-treated milled wood was analyzed by thioacidolysis. The yield of thioacidolysis monomers recovered from guaiacyl and syringyl units decreased by 33% and 20% in MnP-treated milled wood, respectively. This has suggested that lignin depolymerization reactions have occurred during the MnP/linoleic acid treatment. [Copyright &y& Elsevier]

Abstract: The degradation of the components of Japanese beech and Japanese cedar wood was measured over time in cultures of the white-rot fungus Ceriporiopsis subvermispora. Although there was no initial degradation of cedar wood, after 12 weeks the mass loss of both cedar and beech wood was 15–20%. The mass losses of filter paper in beech wood-containing cultures and glucose cultures after 12 weeks were 87% and 70%, respectively. The ratio of lignin loss to mass loss of both beech and cedar wood cultures approached 2.0. Although the cellulose loss in cedar wood was very low throughout the 12-week incubation, C. subvermispora degraded the hemicellulose in Japanese cedar much more effectively than that in Japanese beech. These results confirm that C. subvermispora is a selective lignin degrader. During the 12-week incubation with Japanese beech wood, C. subvermispora continuously produced at least one of three phenol oxidases: laccase was produced initially, followed by Mn-independent peroxidase activity peaking at 6 weeks and Mn-dependent peroxidase activity peaking at 10 weeks. Lignin peroxidase and carboxymethylcellulase activities peaked after 3 weeks of incubation. Avicelase activity was present throughout the incubation period, although the activity was very low. The low-molecular-mass fraction of the extracellular medium, which catalyzes a redox reaction between O2 and electron donors to produce hydroxyl radical, may act synergistically with the enzymes to degrade wood cell walls. [Copyright &y& Elsevier]