Evaluating the combined efficacy of polymers with fungicides for protection of museum textiles against fungal deterioration in Egypt.

Fungal deterioration is one of the highest risk factors for damage of historical textile objects in Egypt. This paper represents both a study case about the fungal microflora deteriorating historical textiles in the Egyptian Museum and the Coptic museum in Cairo, and evaluation of the efficacy of several combinations of polymers with fungicides for the reinforcement of textiles and their prevention against fungal deterioration. Both cotton swab technique and biodeteriorated textile part technique were used for isolation of fungi from historical textile objects. The plate method with the manual key was used for identification of fungi. The results show that the most dominant fungi isolated from the tested textile samples belong to Alternaria, Aspergillus, Chaetomium, Penicillium and Trichoderma species. Microbiological testing was used for evaluating the usefulness of the suggested conservation materials (polymers combined with fungicides) in prevention of the fungal deterioration of ancient Egyptian textiles. Textile samples were treated with 4 selected polymers combined with two selected fungicides. Untreated and treated textile samples were deteriorated by 3 selected active fungal strains isolated from ancient Egyptian textiles. This study reports that most of the tested polymers combined with the tested fungicides prevented the fungal deterioration of textiles. Treatment of ancient textiles by suggested polymers combined with the suggested fungicides not only reinforces these textiles, but also prevents fungal deterioration and increases the durability of these textiles. The tested polymers without fungicides reduce the fungal deterioration of textiles but do not prevent it completely.

[Screening of three straw-cellulose degrading microorganism].

OBJECTIVE: The aim of this study was to screen straw-cellulose degrading microorganisms and to investigate their degradation ability of straw-cellulose. METHODS: The methods used to screen the high effect straw-cellulose degrading microorganism included the traditional isolation methods of straw-cellulose degrading microorganism such as holes observation method on filter paper sheet, disintegration test of filter paper scrip, hydrolysis spot diameter measurement method of CMC-Na, weight lose assay method of straw, measurement method of cellulose decomposition rate, measurement method of extracellular enzyme activity. RESULTS: We isolated 3 fungi with cellulose degrading ability, of which 98MJ was identified as Penicillium oxalicum, W3 as Trichoderma sp., and W4 as Penicillium expansum. Strain W4 possessed high straw-cellulose degrading ability with straw-cellulose degrading rate of 56.3%, cellulose 59.06%, hemicellulose 78.75% and lignin 33.79% in 10 days. CONCLUSION: Strain W4 was a cellulase-producing strain with broad development potential.

Isolation and characterization of different promising fungi for biological waste management of polyurethanes.

As a highly resistant polymer family, polyurethanes (PU) are responsible for increasing environmental issues. Then, PU biodegradation is a challenging way to develop sustainable waste management processes based on biological recycling. Since the metabolic diversity of fungi is a major asset for polymer degradation, nearly thirty strains were isolated from sampling on six different PU wastes-containing environments. A screening of the fungi on four thermoplastic PU (TPU) with different macromolecular architectures led to the selection of three strains able to use two polyester PU as sole carbon source: Alternaria sp., Penicillium section Lanata-Divaricata and Aspergillus section flavi. Weight loss, FT-IR, Scanning Electron Microscopy and Size Exclusion Chromatography analyses revealed that these three fungi degrade slightly and similarly a fatty acid dimer-based TPU while variability of degradation was noticed on a polycaprolactone-based TPU. On this last TPU, robust analysis of the degraded polymers showed that the Penicillium strain was the best degrading microorganism. Membrane enzymes seemed to be involved in this degradation. It is the first time that a strain of Penicillium of the section Lanata-Divaricata displaying PU biodegradation ability is isolated. These newly discovered fungi are promising for the development of polyester PU waste management process.

Isolation of filamentous fungi exhibiting high endoxylanase activity in lignocellulose hydrolysate.

For complete degradation of hemicellulose into its monomers from lignocellulose biomass, the synergistic action of a broad range of hydrolytic enzymes is needed. Therefore, production of enzymes from their natural producer is desirable. To obtain a powerful ß-1,4-endoxylanase producing fungus, 304 environmental samples were collected from various locations in Singapore, leading to 603 isolates. Among them, 71 exhibiting ß-1,4-endoxylanase activity were identified belonging mainly to the genera of Aspergillus, Penicillium, and Trichoderma. Further analysis revealed Aspergillus niger DSM 26641 as a potential and stable ß-1,4-endoxylanase producer, being able to grow in hydrothermal lignocellulose hydrolysate exhibiting its maximal ß-1,4-endoxylanase activity at pH 4 and 60 °C. This strain is thought to be very suitable for lactic acid production in a simultaneous saccharification and fermentation at pH values below 5.

Selection and molecular characterization of cellulolytic-xylanolytic fungi from surface soil-biomass mixtures from Black Belt sites.

Plant biomass is an abundant renewable natural resource that can be transformed into chemical feedstocks. Enzymes used in saccharification of lignocellulosic biomass are a major part of biofuel production costs. A cocktail of cellulolytic and xylanolytic enzymes are required for optimal saccharification of biomass. Accordingly, thirty-two fungal pure cultures were obtained from surface soil-biomass mixtures collected from Black Belt sites in Alabama by culturing on lignocellulosic biomass medium. The fungal strains were screened for the coproduction of cellulolytic and xylanolytic enzymes. Strains that displayed promising levels of cellulolytic and xylanolytic enzymes were characterized by molecular analysis of DNA sequences from the large subunit and internal transcribed spacer (ITS) of their ribosomal RNA gene. Nucleotide sequence analysis revealed that two most promising isolates FS22A and FS5A were most similar to Penicillium janthinellum and Trichoderma virens. Production dynamics of cellulolytic and xylanolytic enzymes from these two strains were explored in submerged fermentation. Volumetric productivity after 120 h incubation was 121.08 units/L/h and 348 units/L/h for the filter paper cellulase and xylanase of strain FS22A, and 90.83 units/L/h and 359 units/L/h, respectively for strain FS5A. Assays with 10 times dilution of enzymes revealed that the activities were much higher than that observed in the crude culture supernatant. Additionally, both FS22A and FS5A also produced amylase in lignocellulose medium. The enzyme profiles of these strains and their activities suggest potential applications in cost effective biomass conversion and biodegradation.

Novel Penicillium cellulases for total hydrolysis of lignocellulosics.

The (hemi)cellulolytic systems of two novel lignocellulolytic Penicillium strains (Penicillium pulvillorum TUB F-2220 and P. cf. simplicissimum TUB F-2378) have been studied. The cultures of the Penicillium strains were characterized by high cellulase and ß-glucosidase as well moderate xylanase activities compared to the Trichoderma reesei reference strains QM 6a and RUTC30 (volumetric or per secreted protein, respectively). Comparison of the novel Penicillium and T. reesei secreted enzyme mixtures in the hydrolysis of (ligno)cellulose substrates showed that the F-2220 enzyme mixture gave higher yields in the hydrolysis of crystalline cellulose (Avicel) and similar yields in hydrolysis of pre-treated spruce and wheat straw than enzyme mixture secreted by the T. reesei reference strain. The sensitivity of the Penicillium cellulase complexes to softwood (spruce) and grass (wheat straw) lignins was lignin and temperature dependent: inhibition of cellulose hydrolysis in the presence of wheat straw lignin was minor at 35°C while at 45°C by spruce lignin a clear inhibition was observed. The two main proteins in the F-2220 (hemi)cellulase complex were partially purified and identified by peptide sequence similarity as glycosyl hydrolases (cellobiohydrolases) of families 7 and 6. Adsorption of the GH7 enzyme PpCBH1 on cellulose and lignins was studied showing that the lignin adsorption of the enzyme is temperature and pH dependent. The ppcbh1 coding sequence was obtained using PCR cloning and the translated amino acid sequence of PpCBH1 showed up to 82% amino acid sequence identity to known Penicillium cellobiohydrolases.

Effect of alkali pretreatment on the structural properties and enzymatic hydrolysis of corn cob.

An effective alkali pretreatment which affects the structural properties of cellulose (corn cob) has been studied. The pretreatment of corn cob was carried out with different combinations of alkali at varying temperatures. The most effective pretreatment of corn cob was achieved with 1 % alkali at 50 °C in 4 h. The crystallinity index (CrI) and specific surface area (SSA) of untreated corn cob was 39 % and 0.52 m(2)/g wherein after alkali pretreatment CrI decreased to 15 % and SSA increased to 3.32 m(2)/g. The fungal organism was identified as Penicillium pinophilum on the basis of ITS sequence. At 5 % substrate concentration using a complete cellulase from Penicillium pinophilum the hydrolysis of untreated corn cob with 5, 10 and 20 FPU/g enzyme loadings were 11 %, 13 % and 16 %, whereas after alkali treatment the hydrolysis increased to 78 %, 90 % and 100 %, respectively. Further hydrolytic potential of commercial cellulases viz. Accellerase™ 1,000, Palkofeel-30 and Palkocel-40 were investigated under similar conditions.

[Isolation and identification of a cellulose degrading fungus Y5 and its capability of degradating wheat straw].

In order to promote the decomposition of crop straw and return it to soil rapidly and solve the problems such as the waste of straw resources and pollution, we screened the bacterial or fungi with high-efficient degradation of straw lignocelluloses and studied its capability of degradating wheat straw. An isolate of filamentous fungus with higher cellulase activity and ability to decompose CMC and straw lignocellulose was screened from black soil samples taken from Heilongjiang province by using the soil dilution, plating and liquid culture methods. Morphological status on various media, and ITS rDNA sequences homology analysis were performed to identify the taxonomy of the isolate. The effects of different time, different N resources, different cellulose resources and different pH values on enzyme activities produced by fungus was analyzed, and The ability of wheat straw degradation of Y5 was determinated by using weight loss method and liquid culture. The fungus was identified as Penicillium ochrochloron and named Y5. Filter paper activity (FPA) and endo-1,4-beta-D-glucanase (EG) were both reached the maximum after the first fourth day inoculated, averaged 53 IU/mL and 55 IU/mL, respectively, which were 22.6% and 18.2% higher than that of strain Trichoderma viride (AS3. 3711), respectively. Enzyme activities were the highest under the condition of wheat straw used as C resources, which were 27.5% and 24.8% higher than that of AS3. 3711. The FPA and EG activities were 35.7% and 14.9% higher than the AS3. 3711 strain with NaNO3 as nitrogen source. The optimal pH value of liquid culture was 6. The cellulose, hemicellulose and lignin contents were degraded by 43.5%, 49.7% and 9.3% after the first 10 days inoculated, respectively, which indicated that Y5 had strong enzyme activities on degradation of cellulose and hemicelluloses of wheat straw. The Penicillium ochrochloron Y5 has strong ability of wheat straw cellulose degradation, and its cellulase activities are higher than some published researches. The Penicillium ochrochloron Y5 strain has the great potential in research and development for inoculant of crop straw decomposition.

Heterologous expression of two ferulic acid esterases from Penicillium funiculosum.

Two recombinant ferulic acid esterases from Penicillium funiculosum produced in Aspergillus awamori were evaluated for their ability to improve the digestibility of pretreated corn stover. The genes, faeA and faeB, were cloned from P. funiculosum and expressed in A. awamori using their native signal sequences. Both enzymes contain a catalytic domain connected to a family 1 carbohydrate-binding module by a threonine-rich linker peptide. Interestingly, the carbohydrate binding-module is N-terminal in FaeA and C-terminal in FaeB. The enzymes were purified to homogeneity using column chromatography, and their thermal stability was characterized by differential scanning microcalorimetry. We evaluated both enzymes for their potential to enhance the cellulolytic activity of purified Trichoderma reesei Cel7A on pretreated corn stover.

Degradation of mikan (Japanese mandarin orange) peel by a novel Penicillium species with cellulolytic and pectinolytic activity.

AIMS: The mikan, or Japanese mandarin orange, is a popular fruit in Japan, but its peel is one of the major agricultural wastes. The aims of this study were to screen, isolate, and characterize a mikan peel-degrading microbe. METHODS AND RESULTS: Several samples including activated sludge, sediment, compost and spoiled mikan peel were collected and cultured in a minimal salt medium containing mikan peel as the sole carbon source. Degradation activity was found in a culture of the spoiled mikan peel, and a fungal strain, designated OP1, with both cellulolytic and pectinolytic activity was isolated. No toxic metabolites, such as mycotoxins, were found in OP1 cultures, as evaluated by gas chromatography/mass spectrometry. A phylogenetic analysis strongly suggested that OP1 is a novel species of the genus Penicillium. CONCLUSIONS: Results suggest that Penicillium sp. OP1 plays an important role in aerobic microbial degradation of cellulose/pectin-rich biomasses in soil ecology, and further imply that this strain may be useful for both simultaneous cellulase/pectinase production and reduction of agricultural waste. SIGNIFICANCE AND IMPACT OF THE STUDY: The present results advance our understanding of microbial degradation of cellulose/pectin-rich biomasses in the natural environment, and offer a new tool for reduction of agricultural waste, which is important for sustaining circulatory societies.

Germination and adhesion of fungal conidia on polycarbonate membranes and on apple fruit exposed to mycoactive acetate esters.

The adhesion and germination of conidia of nine fungal species were assessed on polycarbonate membranes or on the skin of apple fruit in sealed glass bottles injected or not injected with acetate esters. Adhesion was determined after dislodging conidia from surfaces using a sonication probe. Adhesion and germination of conidia of Aspergillus flavus, Aspergillus fumigatus, Aspergillus niger, Penicillium citrinum, Penicillium claviforme, or Trichoderma sp. on membranes after 48 h were not increased in a 1.84 microg mL(-1) headspace of butyl acetate (BA), ethyl acetate, hexyl acetate, 2-methylbutyl acetate, pentyl acetate, or propyl acetate. Adhesion and germination of Botrytis cinerea, Penicillium expansum, and Penicillium roquefortii conidia were stimulated by all esters. Only conidia of B. cinerea and P. expansum exhibited increased adhesion and germination on the skin of apple fruit in bottles exposed to 0.92 microg mL(-1) of BA. Only conidia of B. cinerea and P. expansum produced decay in inoculated puncture wounds on fruit. Freshly made puncture wounds or 24-h-old puncture wounds in fruit were more adhesive than the unpunctured skin of fruit to conidia of B. cinerea or P. expansum. Fresh wounds were more adhesive to both fungi than 24-h-old puncture wounds. The skin and wounds of fruit were as adhesive to B. cinerea conidia as they were to P. expansum conidia. A 4-h exposure to 1.43 microg mL(-1) of BA increased adhesion of B. cinerea and P. expansum conidia in 24-h-old wounds. Results suggest that acetate-ester stimulation most likely is not a rare phenomenon in the fungi. For nutrient-dependent decay pathogens of apple fruit, acetate esters may be an alternative chemical cue used to maintain adhesion of conidia to wound surfaces.

Microbial characterization of organic carrier colonization during a model biofiltration experiment.

AIMS: Dynamic microbial characterization of the colonization of organic carrier during a model biofiltration experiment using methanol as air pollutant. METHODS AND RESULTS: A model biofilter was used in order to characterize the micro-organisms involved in the colonization of a model organic carrier. The model system consisted of closed vial as biofilter, peanut shells as lignocellulosic carrier and methanol as air pollutant. The micro-organisms involved in biofiltration were identified and characterized for their lignocellulolytic and methylotrophic activities. Fungi presented a higher lignocellulolytic activity than bacteria. A steady-state was reached after 15 to 20 days. CONCLUSIONS: The consortium naturally associated to peanut shells is limited to few aerobic bacteria and lignocellulolytic fungi. This consortium was able to degrade methanol without external nutrient supply. SIGNIFICANCE AND IMPACT OF THE STUDY: To our knowledge, this is the first paper that focuses on carrier degradation processes and the micro-organisms involved during the start-up period of a biofiltration process.

Actividades hidrolíticas y caracterización isoenzimática de poblaciones microbianas aisladas del patrimonio documental del Archivo General de Colombia / Hydrolytic activity and isoenzymatic characterization of microbial population Isolated of documental Heritage of General Archive of Colombia (AGN)

Este trabajo presenta un modelo para el aislamiento y evaluación de microorganismos agentes deteriorantes del acervo documental. Se recuperaron e identificaron 28 aislamientos tanto de las unidades de conservación con biodeterioro como de la atmósfera del depósito 15 del Archivo General de la Nación de Colombia (AGN). De este grupo, 16 aislamientos microbianos mostraron capacidad hidrolítica sobre fibras vegetales cuando se cultivaron en medios con paredes celulares al 1porciento como única fuente de carbono. A las poblaciones microbianas recuperadas se les evaluó su capacidad para hidrolizar celulosa, xilano, almidón y proteínas, considerando los halos de degradación y el número de sustratos hidrolizados, se seleccionaron cuatro aislamientos: dos de Penicillium sp., uno de Bacillus sp. y uno de Actinopolyspora sp. A los aislamientos se les cuantificó las actividades depolimerasas y accesorias y se les determinó el perfil isoenzimático para celulasas y xilanasas. Los resultados sugieren: (i) los hongos filamentosos y actinomycetes son más eficientes en la degradación de polímeros complejos, (ii) posiblemente las poblaciones bacterianas actúan como colonizadores secundarios y (iii) el perfil isoenzimático permite descartar microorganismos saprófitos, de especializados en degradar soporte celulolítico