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Enzymes derived from microbial sources have gained increasing popularity in industrial applications over the past decades. Despite the high production cost, alkaline proteases have wide applications in industries such as tanneries, food production, and detergents. In recent years, there has been a shift towards utilizing natural carbon sources for cultivating microorganisms and extracting proteases in order to reduce production costs. This study aimed to investigate the biochemical and kinetic properties of protease enzymes obtained from Aspergillus niger cultivated in a paper waste medium and compare with the enzyme produced in a basal medium. Glucose is a more favorable carbon source compared to cellulose, so paper waste was pretreated with cellulose-degrading bacteria to convert cellulose into smaller carbohydrates. After the growth of A. niger in basal and combinational media, the enzymatic properties were compared between the extracted enzymes by using casein as substrate. The results demonstrated that A. niger could produce protease enzymes in the paper waste medium similar to the basal medium with more than 5-fold cost saving. The specific activity of the enzymes isolated from the basal and paper waste media was calculated to be 184.95 ± 10.56 U ml−1 and 169.88 ± 11.05 U ml−1, respectively. Carbon sources did not affect the optimum pH and temperature of the protease enzyme, which were found to be 8 and 37 °C, respectively. This study provides valuable insights into the production of alkaline protease from A. niger using a combinational medium (paper waste pretreated by cellulose-degrading bacteria), offering a cost-effective approach for industrial applications. [ABSTRACT FROM AUTHOR]

Melanins play a fundamental role in the biology and ecology of several fungal species. Unfortunately, this group of amorphous macromolecules also severely (and most times irreversibly) stains cultural heritage objects. Despite efforts made throughout the years, knowledge of the chemical composition and structure of melanins is still insufficient, which hampers the task of safely cleaning these colourants from cultural heritage materials in a targeted way without causing further deterioration. This work aimed therefore to contribute towards enlightening the characteristics of fungal melanins from three fungi that are common paper colonizers: Aspergillus niger, Chaetomium globosum and Cladosporium cladosporioides. The extracted melanins were characterized by FTIR, Raman, UV-vis, Solid-State NMR and MALDI-TOF MS spectroscopies and the effect of inhibitors of DHN-melanin and DOPA-melanin pathways on colony pigmentation and growth was evaluated. Although all the extracted colourants show a predominantly aromatic structure with carbonyl and phenolic groups, some differences between the melanins can be highlighted. Melanins obtained from Ch. globosum and Cl. cladosporioides exhibited similar structures and composition and both presented DHN-melanin characteristics, while A. niger's melanins revealed a more complex and ordered structure, with a higher prevalence of highly conjugated carbonyls than the others, besides the additional presence of a yellow/green component. These conclusions cannot be overlooked while selecting targeted cleaning methodologies for melanin stains on cultural heritage materials. [ABSTRACT FROM AUTHOR]

The purpose of this study was to develop a biotechnological process to produce citric acid using paper residues from Urban Solid Waste (USW), like raw material. The selected microorganism to transform degraded cellulose from paper to produce citric acid was Aspergillus niger. The aerobic bioreaction was carried out in a heterogeneous bioreactor. The efficiency of the biotransformation in this study was measured under different operating conditions: 2 and 3 pH levels, 30 and 40 °C temperatures, and high and low concentrations of trace elements: Copper (Cu), Manganese (Mn) and Zinc (Zn). In optimized operation conditions from 20 g of waste paper the maximum citric acid amount obtained was 5.73 g l−1. [ABSTRACT FROM AUTHOR]

Purpose: This paper aims to identify the most common fungal species that grow on paper manuscripts and cause bio-deterioration. It also detects the impact of additive materials on fungal degrading and builds a wide database. Thus, it helps conservators understand this phenomenon. Design/methodology/approach: In total, 15 samples were collected from different paper manuscripts suffering from fungi. The achievement of the study objectives depends on using a variety of analyzes, such as a microbiological study, which indicated that three main fungi grew on the paper samples. Then, a digital microscope and an environmental scanning electron microscope were used to detect the effect of fungi on paper fibers. Fourier transform infrared microscopy was used to identify the binding medium and the X-ray diffraction method was used to measure the crystallinity index of cellulose of the paper samples. Findings: Arabic gum was used as a binder medium with the samples. Aspergillus Niger, Aspergillus Fumigatus and Aspergillus Clavatus were the most common fungal species that grew on the Qur'an papers under investigation. They also caused much common damage to the paper samples. The results of the analyzes also showed that the highest crystallinity index of cellulose was in the samples that contained the lowest rate of fungal growth. Originality/value: This paper highlights the relationship between fungal degradation and the multi-component nature of paper manuscripts. It builds a wide database that correlates the composition and the degradation of the Qur'an papers. [ABSTRACT FROM AUTHOR]

In this study, extractives from Pinus rigida heartwood (PRW), Eucalyptus camaldulensis var. obtusa aerial parts (ECL), and Eucalyptus flower buds (ECF) were used as additives in paper sheets produced from the pulp of linen fibers, and their effects on the mechanical and antifungal properties of the paper sheets were studied. The highest tensile and tear indices were 31.5 Nm/g, and 17.3 mNm2/g as pulp treated with PRW (4%), and ECL (1%), respectively. All the pulp additives yielded lower burst index values compared to the control (2.24 KPa.m2/g); the nearest value was 2.23 KPa.m2/g (ECL 4% pulp additive). The brightness percentages (ISO%) ranged from 65.7% to 70.2%, which were lower than the control treatment (70.3%). The paper sheets produced from pulp treated with 2% or 4% PRW, and with 4% ECL suppressed Aspergillus niger growth on the paper disc; pulp treated with 2% or 4% PRW, 4% ECL, and with 2% or 4% ECF completely suppressed A. terreus growth. However, all pulp extract additives did not inhibit the growth of Fusarium culmorum. [ABSTRACT FROM AUTHOR]

The deinking in the paper industry is in great demand, and microbial enzymes are key players. In the present study, the endoglucanase production from newly isolated fungi Aspergillus niger MPS25 is reported. The optimization of endoglucanase production was carried out using one factor at a time approach resulting in endoglucanase activity (2.37 IU/ml) at 45 °C and pH 8 in submerged fermentation (SmF), which shows optimum enzyme activity at 60 °C. Interestingly, the metal ions viz. Co2+ stimulated the endoglucanase activity, whereas Mn2+ reduced the enzyme activity, which shows that this enzyme can be used for effluent treatment released through deinking. The enzymatic hydrolysis of wheat straw produced 26.96 ± 0.108 mg/g of reducing sugars, indicating its potential in saccharification and the biofuel industry. Furthermore, the validation of the deinking efficiency of this enzyme resulted in improved deinking of mixed office waste and old newspapers by 31.5% and 20.4%, respectively. The strength properties, viz. burst factor and tear index, breaking length, and tensile index of the handmade paper sheets, were also improved which were analyzed by the scanning electron micrographs. The FTIR and XRD analysis of pulp provided insights into the changes in functional groups and cellulose crystallinity, respectively. These results indicate that multi-efficient endoglucanase from Aspergillus niger MPS25 is suitable for enzyme-based eco-friendly deinking for waste paper recycling and lignocellulosic biomass saccharification. [Display omitted] • The endoglucanase from newly isolated fungi Aspergillus niger MPS25 is reported. • The endoglucanase showed stability at 60 °C with wide pH range. • The endoglucanase significantly improved the deinking efficiency for mixed office waste (31.5%) and old newspapers (20.4%). • The SEM, FTIR and XRD analysis provided technological insights for process scale up. • This multi-efficient endoglucanase proved to be suitable enzyme in eco-friendly recycling of MOW and ONP. [ABSTRACT FROM AUTHOR]

In paper conservation ethanol is used as an antifungal agent. However, information on the antifungal efficacy of this alcohol is scarce and often inconsistent. In this study, we clarify if ethanol is effective and safe to use in paper conservation in the short as well as in the long term. None of the tested ethanol concentrations (5–100%) promoted conidia germination, but rather delayed or entirely inhibited it, depending on alcohol concentration and contact time. In a simulation of an interventive treatment of samples colonized by fungi, all the tested ethanolic solutions (30, 70, and 100%) revealed antifungal activity. The best results were obtained with 70% ethanol, showing fungicidal properties on four of the five-tested fungal species (Aspergillus niger,Cladosporium cladosporioides,Penicillium chrysogenum, andPenicillium corylophilum). No deleterious effects of 70% ethanol on the tested paper were observed either in the short or in the long term. [ABSTRACT FROM PUBLISHER]

Xylanase is a hemicellulase enzyme that catalyses the hydrolysis of xylan to xylose which is widely used in processing of feed, pulp and paper. It is produced by many microorganisms especially filamentous fungi like Trichoderma and Aspergillus. A potential xylanolytic fungal isolate Aspergillus niger was isolated from forest soils of Tirumala, AP, India, and its crude enzyme was checked for its potential in paper bleaching. Under submerged fermentation, production of xylanase, cellulase, biomass, total protein and sugar released were analysed after 7 days of incubation at room temperature. Maximum enzyme activity was recorded on the fifth day of incubation, biomass after the seventh day, total protein and sugar released on the sixth day of incubation. Enzyme pretreatment of paper reduced 3.5 points in kappa number, 3.1 points increase in brightness and removal of chromophores and hydrophobic compounds. The FTIR and SEM analysis of enzyme-treated sample had shown modification in surface morphology and functional groups. These results clearly demonstrated that the xylanase produced by A. niger was effective as a pulp biobleaching agent which can be used on an industrial scale. [ABSTRACT FROM AUTHOR]

• Density of a paper has a decisive impact on its air permeability. • Exposure of both historical and common papers to A. niger decreases permeability. • Nano-wollastonite is recommended to improve biological resistance of paper. The effect of nano-wollastonite and Aspergillus niger fungus on permeability of historical and common paper was studied here. Specimens were immersed in aqueous wollastonite nano-suspension (NW) at 10, 20, 30, and 40% concentration, and their permeability was finally compared with that obtained from control specimens. Permeability of each specimen was measured before and after the immersion in NW. To fix solid particles on NW-treated specimens, polyvinyl acetate (PVA) was mixed in all treatments. Results showed that wollastonite significantly limited the growth of A. niger. Permeability of historical specimens was significantly lower than that of the common paper, 29 in comparison to 190 cm3.s−1, respectively. This was due to the higher density in the historical paper, providing lower empty voids and spaces for fluid to pass through. Fungi culture resulted in significant decrease in both paper types. In fact, fungal hyphae penetrated into the specimens, eventually blocking the paths through which fluid could transfer. High significant R-square values were found between permeability values before and after the exposure to A. niger. It was concluded that permeability is closely correlated to the density of paper, and it has a significant effect on the potentiality of fungi hyphae to be penetrated into the texture of papers, affecting the weight loss values. Moreover, NW-suspension can be used to decrease permeability as well as susceptibility to fungal attack. [ABSTRACT FROM AUTHOR]

Highlights • Starch paste was the most bioreceptive adhesive. • Starch paste was the most stable adhesive to artificial ageing. • CMC and Archibond ® showed physical-chemical and aesthetic deterioration with ageing. • CMC and Archibond ® presented only scarce bioreceptivity to the tested fungi. • MC and HPC showed the best chemical stability vs bioreceptivity relationship. Abstract In paper conservation practice, adhesives are used for several purposes, such as mending tears and gaps, or paper consolidation. The criteria to choose one or another adhesive should be based on the knowledge of the properties and stability of those adhesives. However, the several different adhesives available on the market still lack enough information to help the process of a rational decision-making. In the present work, five adhesives currently used in the paper conservation field (starch paste, unsupported Archibond TM, carboxymethylcellulose, hydroxypropylcellulose and methylcellulose) were analyzed for their chemical stability and fungal bioreceptivity (the ability of a material to be colonized by fungi). Bioreceptivity of products used in conservation and restoration is a still poorly explored subject, despite its great relevance for the preservation of objects. The chemical and physical properties of the adhesives, before and after moist heat artificial ageing, were analyzed by thermogravimetry, capillary viscometry, measurement of water absorption capacity, colourimetry, and pH measurement. Fungal bioreceptivity of the adhesives was tested on two different substrates (paper and glass) against three fungal species: Aspergillus niger, Aureobasidium pullulans and Penicillium pinophilum. Along 56 days of incubation, the colonization area on the adhesives was measured through digital photo analysis. Starch paste was the most bioreceptive adhesive, but on other hand was also the most stable adhesive to artificial ageing, regarding colour alteration, degree of polymerization and pH. Carboxymethylcellulose and Archibond TM showed chemical deterioration with ageing. Nevertheless, these two adhesives presented only scarce bioreceptivity to the tested fungi. Methylcellulose and hydroxypropylcellulose showed the best relationship between higher chemical stability with artificial ageing and lower fungal bioreceptivity. [ABSTRACT FROM AUTHOR]

Despite substantial literature on the dyeing of textiles, there is a lack of research about colouring Japanese mending papers (tissue papers) used for paper conservation purposes. This study investigates the fungal bioreceptivity of Japanese tissue papers after they have been treated with various dyes and pigments. A variety of toning materials including plant dyes, watercolours, acrylic paints, inks, pastels, gouaches, and colour pencils are commonly used by conservators for paper toning purposes. In this study, two Japanese tissue papers (Yukyu-shiandSekishu Mare) were treated with selected plant dyes, watercolours, and acrylic paints and then inoculated with fungal species. Quantitative real-time polymerase chain reaction (qPCR) was used to quantify the DNA fromAspergillus nigerandPenicillium rubrumas a proxy for fungal species abundance before and after inoculation and artificial moist heat ageing. qPCR primers which were universal for fungi amplified DNA from papers inoculated withA. nigerandP. rubrumand these species were found to grow less on treatedSekishu MareandYukyu-shipapers compared with untreated papers.Sekishu Marepapers treated with artists' acrylic paints were found to be more resistant to fungal growth than similarly treatedYukyu-shipapers. This study suggests that for the best long-term preservation outcomes for paper materials in archives, libraries, galleries, and museums, acrylic paints generally perform better in conservation terms than most plant dyes and watercolours, although most colourants displayed some bioinhibition. [ABSTRACT FROM PUBLISHER]

Unsuitable storage conditions or accidents such as floods can present a serious threat for large quantities of book making them prone to attack by harmful microorganisms. The microbiological degradation of archives and book collections can be efficiently inhibited with irradiation processing. Application of EB irradiation to book and archive collections can also be a very effective alternative to the commonly used ethylene oxide treatment, which is toxic to the human and natural environment. In this study was evaluated the influence of EB irradiation used for microbiological decontamination process on paper-based objects. Three different kinds of paper (Whatman CHR 1, office paper and newsprint paper) were treated with 0.4, 1, 2, 5, 10 and 25 kGy electron beam irradiation. Optical and mechanical properties of different sorts of paper treated with e-beam, before and after the radiation process were studied. These results, which correlated with absorbed radiation doses effective for the elimination of Aspergillus niger (A. niger) allowed to determine that EB irradiation with absorbed radiation dose of 5 kGy ensures safe decontamination of different sorts of paper-based objects. [ABSTRACT FROM AUTHOR]

Abstract: Gluconic acid production was investigated using an enzymatic hydrolysate of waste office automation paper in a culture of Aspergillus niger. In repeated batch cultures using flasks, saccharified solution medium (SM) did not show any inhibitory effects on gluconic acid production compared to glucose medium (GM). The average gluconic acid yields were 92% (SM) and 80% (GM). In repeated batch cultures using SM in a turbine blade reactor (TBR), the gluconic acid yields were 60% (SM) and 67% (GM) with 80–100g/l of gluconic acid. When pure oxygen was supplied the production rate increased to four times higher than when supplying air. Remarkable differences in the morphology of A. niger and dry cell weight between SM and GM were observed. The difference in morphology may have caused a reduction of oxygen transfer, resulting in a decrease in gluconic acid production rate in SM. [Copyright &y& Elsevier]

Abstract: Zinc oxide nanoparticles were prepared and used for surface treatment of oil paintings painted on paper supports. The prepared coating mixture containing 2% of ZnO nanoparticles showed excellent transparency. The effect of coating on protecting the paper support and paintings against microbial attack by Trichoderma reesei and Aspergillus niger, dirt accumulation, and UV aging was studied. Coatings containing ZnO nanoparticles enhanced the durability of linseed oil-based paintings toward UV aging regarding the change in color. Coatings containing ZnO nanoparticles improved resistance to microbial attack when subjected to inoculums containing T. reesei or A. niger fungi. In addition, coatings containing ZnO nanoparticles reduced accumulation of dirt on oil paintings when left in open air for 6 months; cleaning of paintings was quite easy compared to the non-coated paintings or those coated with the varnish without ZnO nanoparticles. [Copyright &y& Elsevier]

• Waste paper was used to obtain nanocrystalline cellulose (CNC). • The obtained CNC was compared with CNC from cotton linter. • The biocidal activity of CNC added with Ag nanoparticles was assessed. • The growth of Aspergillus niger on Whatman paper is inhibited by CNC/Ag coating. • The mechanical properties of Whatman paper improve by the CNC coatings. Waste paper is an environmentally friendly source of cellulosic material. Here we propose a new treatment based on nanocrystalline cellulose (CNC) for paper preservation and consolidation. Suspensions of CNC were prepared by sulfuric acid hydrolysis using waste paper as cellulose source (CNC WP) and compared with CNC from cotton linter (CNC CL). Both CNCs were obtained with good yield, showing high crystallinity index and comparable morphology, as demonstrated by DLS-ELS, XRD, FTIR, Raman and TEM analyses. CNCs were mixed with silver nanoparticles (CNC/Ag) and their biocidal activity was tested against Escherichia coli and Bacillus subtilis , measuring the minimum inhibitory concentration. CNCs were exploited as treatments for biocidal activity and consolidation on Whatman paper. The presence of silver nanoparticles doesn't affect aesthetic appearance of the original paper and prevents the growth of Aspergillus niger fungus. Mechanical tests demonstrated that the coatings by CNC based products improve stretch and toughness of the paper support. [ABSTRACT FROM AUTHOR]

Cellulose nanocrystals are an important class of bio‐based crystalline nanostructures, finding application in several technological fields, including paper and textile coating, biocomposite engineering, biocatalysts immobilization, etc. This study explores enzymatic hydrolysis of Avicel, using endoglucanase from Aspergillus niger, to find an environmentally friendly method to extract cellulose nanocrystals from cellulose sources. Enzymatic hydrolysis has the advantage of reduced energy consumption and higher environmental friendliness compared to acid hydrolysis. In this work, we report for the first time very high nanocrystals yield by combining mechanical pretreatment of the cellulose starting material with a ball miller and endoglucanase hydrolysis, as a result of an extensive optimization of reaction conditions. In particular, a ball milling pretreatment carried out for 50 minutes at 3 Hz, allowed to isolate enzymatic CNCs with 76 % yield and with crystallinity as high as 75 %. The materials were characterized by X‐Ray diffractometry, attenuated total reflectance Fourier transform infrared (ATR‐FTIR) spectroscopy, dynamic light scattering, zeta potential and field emission scanning electron microscopy (FE‐SEM). Their characteristics were compared with the properties of sulfated CNCs, prepared from Avicel by sulfuric acid hydrolysis. Our results are technologically relevant, as they contribute to the accessibility and sustainability of CNCs for a wide range of applications in various industries. [ABSTRACT FROM AUTHOR]

The current study was designed to isolate and identify superior cellulose-degrading fungi from Egyptian soils reached with cellulosic compounds, then production of bioethanol from paper wastes using this isolate. Among 9 fungal isolates, one isolate was selected as the highest cellulases producer. This isolate was identified by morphological and genetic characteristics as Aspergillus niger MK543209. Basal mineral salt medium amended with 1% rice straw was the best medium for cellulose-degrading enzymes production under submerged fermentation (SmF). Additionally, bagasse at 30% and urea at 2% were the best carbon and nitrogen sources, respectively. In respect to the environmental conditions, the optimum temperature, pH and incubation period were 45 °C, 5.5 and 4 days, respectively. The optimized conditions were applied to produce reducing sugars from paper wastes, followed by production of bioethanol as a renewable energy. A 0.9 g/l/h of ethanol were produced as the best value. This study may be considered the initial point for production of renewable energy and protection of environment from wastes. [ABSTRACT FROM AUTHOR]

Abstract: A new process using aminoalkylalkoxysilanes (AAAS) was developed recently for paper and book mass deacidification. This process is entirely novel in that, besides deacidifying, it also improves the mechanical properties of paper. In the present article, the properties of inhibition of fungal growth of the treated papers are investigated. It was found that the AAAS tested acted as surface-active antifungal agents when introduced in the paper, significantly reducing the growth of Aspergillus niger and Paecilomyces variotii, two fungal species commonly found in storage areas of libraries and archives. The AAAS which seemed the most efficient in preventing the fungal development was 3-aminopropylmethyldimethoxysilane (AMDES), functionalised with a primary amine. The effect was significant in the different papers tested which demonstrated the protection against the proliferation of filamentous fungi in vitro for papers treated with AMDES. The higher concentration of AMDES inside the paper proved to be the most effective. The highest efficiency was reached for AAAS uptakes around 6%. At this concentration the sporulation of the two strains was inhibited and the development of A. niger mycelia was highly reduced. [Copyright &y& Elsevier]

The zone of inhibition method to test the release of biocides from paper and board food contact materials was evaluated. The method tests the paper by placing a small specimen directly onto culture plates of Bacillus subtilis and Aspergillus niger. The principle is that any extractable biocide will diffuse from the paper into the surrounding nutrient medium and so inhibit growth of the microorganism in the vicinity. The test was found to have insufficient sensitivity for assuring food safety, where detection limits for migration at or below the mg l−1 (parts per million) level are needed. Also, the test does not mimic the actual or foreseeable conditions of use since most paper/board materials are not intended for direct contact with an aqueous medium for up to 3 days at 30°C (B. subtilis) or 25°C (A. niger), which are the incubation conditions used. The sensitivity of the test was increased approximately 100-fold by preparing a concentrated extract of the paper to be tested and applying this extract to the assay via a blank paper carrier. This was done using methanol as a good solvent for most biocides, as a proof of principle. Other solvents or food simulants could be used to mimic the conditions of use intended for the particular paper/board samples under examination, e.g. contact with dry, fatty, aqueous or acidic foods, hot or cold. Twenty-four plain (unconverted) paper and board samples and 100 food packaging samples were evaluated using the modified procedure. The results revealed that the method has been developed to the stage where background cytotoxic action of normal paper constituents gives a weak response. Unlike the original method, therefore, the modified method with its improved sensitivity and the facility to link with the intended food contact conditions may be considered a suitable bioassay screening test to complement chemical analysis of paper/board for composition and migration. [ABSTRACT FROM AUTHOR]

Microbial xylanases that are thermostable, active at alkaline pH and cellulase-free are generally preferred for biobleaching of paper pulp. We screened obligate and facultative marine fungi for xylanase activity with these desirable traits. Several fungal isolates obtained from marine habitats showed alkaline xylanase activity. The crude enzyme from NIOCC isolate 3 (Aspergillus niger), with high xylanase activity, cellulase-free and unique properties containing 580 U l-1 xylanase, could bring about bleaching of sugarcane bagasse pulp by a 60 min treatment at 55°C, resulting in a decrease of ten kappa numbers and a 30% reduction in consumption of chlorine during bleaching. The culture filtrate showed peaks of xylanase activity at pH 3.5 and pH 8.5. When assayed at pH 3.5, optimum activity was detected at 50°C, with a second peak of activity at 90°C. When assayed at pH 8.5, optimum activity was seen at 80°C. The crude enzyme was thermostable at 55°C for at least 4 h and retained about 60% activity. Gel filtration of the 50-80% ammonium sulphate-precipitated fraction of the crude culture filtrate separated into two peaks of xylanase with specific activities of 393 and 2,457 U (mg protein)-1. The two peaks showing xylanase activity had molecular masses of 13 and 18 kDa. Zymogram analysis of xylanase of crude culture filtrate as well as the 50-80% ammonium sulphate-precipitated fraction showed two distinct xylanase activity bands on native PAGE. The crude culture filtrate also showed moderate activities of ß-xylosidase and a-l-arabinofuranosidase, which could act synergistically with xylanase in attacking xylan. This is the first report showing the potential application of crude culture filtrate of a marine fungal isolate possessing thermostable, cellulase-free alkaline xylanase activity in biobleaching of paper pulp. [ABSTRACT FROM AUTHOR]

Abstract: Microbial volatile organic compounds (MVOCs) emitted from the mould species Penicillium expansum, P. chrysogenum, Aspergillus versicolor, A. fumigatus, A. niger and Cladosporium cladosporoides were analyzed by means of solid phase microextraction (SPME) and GCMS. The mould species were cultivated on the synthetic agar dichloran chloramphenicol (DG 18) and on wet wall paper. The production of MVOCs was monitored over several weeks to detect changes in the emission rates between the initial stage and later periods of growth. The cultivation on the synthetic agar resulted in MVOC patterns with a wide variety of signals. In contrast, the growth on wet wall paper led to changed MVOC patterns with less signals. The emission rates were drastically reduced. Components emitted by all six fungi species on wall paper were 2-pentanol and 2-pentanone. 1-Octen-3-ol was emitted by five fungi species. 2-Pentanol was only detected in considerable amounts during the first days of growth whereas 1-octen-3-ol had a more constant emission rate over the whole period of growth. On the basis of our studies some MVOCs could be proposed as specific for single fungi on wall paper, e.g. 1,3-dimethoxybenzene for A. versicolor and 2,4-pentandione for A. fumigatus. [Copyright &y& Elsevier]

Abstract: Intense light pulse (ILP) is one of the emerging non-thermal techniques investigated as an alternative to traditional thermal treatment because it has been proven to be effective for microbial inactivation on food surfaces and food packages. The aim of this study was to evaluate the possibility of using pulsed light treatment for the effective killing of moulds on paper–polyethylene packaging material. Coupons of 20×20mm paper–polyethylene were artificially contaminated with Cladosporium herbarum, Aspergillus niger, Aspergillus repens and Aspergillus cinnamomeus than subjected to different light energetic densities (from 0.244 to 0.977J/cm2) for different durations (from 10×10−3 to 30×10−3 s). The results showed that there is a significant reduction of population along with an increase of light fluence and ILP treatment duration. The highest level of inactivation achieved in this study was about a 2.7-log reduction, which is more than enough for a normal contaminated packaging material. It is estimated that pulse light treatment could lead to an effective reduction of moulds, being also possible to obtain a sterile surface of the packaging material. Blastospores as those produced by C. herbarum are easier destroyed (z =0.795J/cm2) than fialospores as those produced by aspergilli (z =0.81–0.927J/cm2). Spore colour seems to play some role in spore resistance to light pulses: green fialospores, as those produced by A. repens, has higher z values (0.927J/cm2) than the black or brown ones as those produced by A. niger (z =0.81J/cm2), and A. cinnamomeus (z =0.875J/cm2) respectively. [Copyright &y& Elsevier]

The study was to screen, isolate and identify Aspergillus niger strains that could efficiently degrade cellulose from microorganisms in fermented feed. Aspergillus niger was isolated by PDA medium. The isolated strains were identified by morphological characteristics and ITS sequence analysis, and the phylogenetic tree was constructed to determine the taxonomic status of strains. The colony morphology and growth characteristics of the strain were detected, and the zymogram of the strain was qualitatively studied. Different carbon sources were selected to induce the activity of endoglucanase, filter paper enzyme and xylanase. The results showed that one Aspergillus strain was isolated and cultured by PDA medium, which was identified as Aspergillus niger, and the number was 0729. When the inoculum size was 5% and the fermentation temperature was 30 ℃, the highest endoglucanase activity and filter paper enzyme activity were induced by xylose on the 2rd day, and the highest xylanase activity was induced by filter paper on the 1st day. The study indicates that fermented feed is rich in microbial resources that can degrade fiber, and Aspergillus niger produces cellulase, amylase and lipase, which is of great value to develop feeding microorganisms for ruminants. [ABSTRACT FROM AUTHOR]

In this paper, for the first time, photopolymers were synthesized from glycerol acrylates with different numbers of functional groups, 2-hydroxy-3-phenoxypropyl acrylate, glycerol dimethacrylate or glycerol trimethacrylate, without and with the addition of vanillin styrene. The photocuring kinetics were monitored by real-time photorheometry. The mechanical, rheological, thermal, antimicrobial and shape-memory properties of the photopolymers were investigated. All polymers synthesized demonstrated antibacterial activity against Escherichia coli and Staphylococcus aureus, as well as antifungal activity against Aspergillus flavus and Aspergillus niger. 2-Hydroxy-3-phenoxypropyl acrylate-based polymers showed thermoresponsive shape-memory behavior. They were able to maintain their temporary shape below the glass transition temperature and return to their permanent shape above the glass transition temperature. Synthesized photopolymers have potential to be used as sustainable polymers in a wide range of applications such as biomedicine, photonics, electronics, robotics, etc. [ABSTRACT FROM AUTHOR]

Currently, heavy metal pollution is a challenge that needs to be solved urgently, and there is a broad prospect for food waste(FW) utilization. In this paper, activated hydrochar (AHC) made from FW according to actual proportion was produced by hydrothermal carbonization (HTC) and activated with K2CO3. The effects of the AHC on Cu(II) adsorption were investigated using static adsorption experiments. The results indicated that the sample fabricated at 160°C (FW-160) for 6 h had the best adsorption performance with the maximum adsorption amount of Cu(II) (36.77 mg/g). The oxygenated functional group on the surface of FW-160 was observed. The pseudo-second-order kinetic model fitted the experimental results better, which proved that chemisorption was the main adsorption mechanism, and the surface complexations, including oxygenated functional groups, were the predominant factors in hydrochar(HC) sorption for Cu(II). The adsorption amount of the sample simulating rotten FW with Aspergillus niger (FW-160A) was 24.82 mg/g. Through the HTC process, the rotten FW can be made into heavy metal absorbents which can be stored for long term, and finally realize the reduction of volume and cost of storage. [ABSTRACT FROM AUTHOR]

To prepare and characterize silver nanoparticles from Guava leaves (Psidium guajava), extracts (chloroform and ethanol). The fabricated silver nanoparticles were tested on resistant fungal strains, Aspergillus niger and Candida glabrata. Psidium guajava leaf extracts were obtained by cold maceration method, by using Chloroform and Ethanol. To one mL of extract 2mM silver nitrate solution was added. The mixture was kept overnight in a dark chamber at room temperature. The solution was centrifuged at 10,000 rpm for 15 minutes and filtered by wattman filter paper after centrifugation. Psidium guajava leaf extract based silver nanoparticles were prepared and evaluated for anti-fungal activity by microtitre well plate method on resistant strains Aspergillus niger and Candida glabrata. The silver nanoparticles showed significant activity at 120 μL, Nystatin was used as standard. [ABSTRACT FROM AUTHOR]

• Isolation of thirty-two fungal endophytes from stem and bark of Albizia lebbeck (L.) Benth. • Screening of fungal endophytes for extracellular enzymes amylase, protease, lipase, laccase, cellulase and gelatinase. • Exploitation of crude enzymes of endophyte Aspergillus niger in bioremediation of municipal waste water, blood stain removal, biodegradation of oil, dye decolorization of methylene blue and methyl orange, saccharification of paper and baggase and extraction of silver from x-ray film. • First report on extracellular enzyme screening of Albizia lebbeck (L.) Benth endophytes. Endophytic fungi reside inside plants in a mutualistic relationship with the host and produce numerous bioactive compounds, including extracellular enzymes. A rich diversity of endophytic fungi associated with the medicinal plant Albizia lebbeck (L.) Benth was bio-prospected in the present study. Thirty-three isolates obtained from the plant were assessed for secretion of six different extracellular hydrolytic enzymes. The results showed that 38%, 9%, 69%, 16%, 38%, and 13% of the endophytic isolates could produce amylase, protease, lipase, laccase, cellulase, and gelatinase enzymes, respectively. Overall, 78% of the isolates showed positive results for one or the other enzyme. Aspergillus niger (Isolate 8) isolated from the bark proved to be most efficient in producing all the enzymes and was further exploited for various applications. The crude fungal amylase of the isolate helped in 39.08% reduction in biochemical oxidation demand (BOD) of municipal wastewater. Effective blood stain removal from the white cotton cloth was achieved when crude protease was used in combination with detergent. 13.29% biodegradation of vegetable oil was observed using fungal lipase. Dye decolorization of methylene blue (71.65%) and methyl orange (56.53%) was observed by fungal laccase. Saccharification of bagasse (83.94%) and paper (64.93%) was achieved by using fungal cellulase. Complete extraction of silver from waste X-ray films was achieved by crude gelatinase. The results obtained in the present study can further be strengthened using purified enzymes. [ABSTRACT FROM AUTHOR]

Bioconversion of lignocellulosic wastes to valuable end-products via multi-enzymatic hydrolysis is a potential low costing process for large-scale application in many industrial sectors. Thus, in this study, among thirty local fungal isolates, Aspergillus niger which gave the highest cellulase production, was identified under the accession number MZ062603 in GeneBank. Three types of pre-treatments (0.0–0.7%) acid, (0.0–2%) alkali, and (70–90 °C) hot water were applied to increase wheat straw (WS) digestibility by A. niger, and 1% NaOH treated WS was superior to the other pre-treatments (acid and hot water). During solid-state fermentation, the total cellulolytic activity of [filter-paper cellulase (FPase), carboxy-methyl cellulase (CMCase), and β- glucosidase (βGase)] increased about 2.8-fold. While reducing sugar was increased by 3.1 times. The optimum values of total cellulases activities and reducing sugar (8907.2 and 92.4 mg/gds) were obtained after 3 days of incubation at 30 °C and pH 5.2 at 75% v/w moisture using 3 days old inoculum (106 spores/mL/gds). The WS substrate which was subjected to alkali pre-treatment subsequent to fungal bioconversion was varied in its chemical composition and detailed structure compared to the raw and alkali pre-treatment ones as indicated by its chemical analysis, Scanning electron microscopy (SEM) observation, Fourier Transform Infra-red Spectroscopy (FTIR), and X-Ray Diffraction (XRD). All these analyses revealed that the lignocellulosic matrix was completely destroyed after the fungal treatment. [ABSTRACT FROM AUTHOR]

In this paper, the inhibitory effect of various nanomaterials on the growth of Aspergillus niger was studied. Among them, copper nanorods had the most obvious inhibitory effect on the growth of Aspergillus niger. The phase of copper nanorods was modified by chitosan, and its inhibitory effect on the expansion of Aspergillus niger was measured. 1. Preparation of copper nanorods and chitosan@copper nanorods: Copper nanorods with a diameter of about 300–350 nm and a length of about 100–800 nm were prepared by the liquid-phase reduction method. The chitosan solution was prepared by using the characteristics of chitosan dissolved in dilute acid to prepare chitosan@copper nanorods and modify the phase of copper nanorods. 2. Determination of the inhibitory effect of various copper nanomaterials on the growth of Aspergillus niger, including Cuprous Oxide nanoparticles, copper nanorods, nano copper oxide, and copper hydroxide, which have certain inhibitory effects on the growth of Aspergillus niger. Among them, copper nanorods have a better effect. On this basis, chitosan@copper nanorods are obtained by modifying the phase of copper nanorods with chitosan. The measured antibacterial effect is that the EC50 value is 344 mg/L. [ABSTRACT FROM AUTHOR]

In this paper, the natural antibacterial agent thymol was used as a mildew inhibitor for bamboo, which was immobilized in bamboo by laccase. The mildew resistance of the treated bamboo against Aspergillus niger, Trichoderma virens and Penicillium citrinum was tested, respectively. The laccase-catalyzed fixation effect was evaluated by volatility of thymol, the mildew resistance after leaching treatment and the changes of water contact angle. Scanning electron microscopy (SEM) was used to study the micro-morphology of the treated bamboo, and further Fourier transform infrared spectroscopy (FT-IR) and X-ray photoelectron spectroscopy (XPS) were employed to explore the chemical bond changes during the laccase-catalyzed process. The results show that, compared with the bamboo treated by thymol alone, the bamboo treated by laccase catalysis exhibited a good inhibitory effect on A. niger, T. virens and P. citrinum before and after the leaching treatment, the mildew-proof efficiency was above 80%, and the mildew-proof performance of the bamboo treated both with thymol and laccase after the leaching treatment was better than that treated with thymol alone. The volatility of thymol was significantly reduced from 17.03% to 6.75%. The water contact angle increase significantly from 35° to 97°, which was contributing to the mildew resistance of treated bamboo. The enzymatic immobilization did not significantly change the micro-morphology of bamboo, but a large number of flaky substances appeared on the surface of bamboo cell wall, which was considered as aggregates of thymol molecules grafted onto the surface of bamboo. The FT-IR and XPS results shown new formed chemical bonds between thymol and bamboo lignin were the key factor for immobilization of thymol. This study realized the green fixation of natural antibacterial agent through the catalysis of laccase, reducing its volatilization and leaching, and the mildew resistance of treated bamboo was prolonged. The results of this study provide a new idea for green mildew prevention of bamboo, which can achieve safe and long-lasting protection of bamboo. [ABSTRACT FROM AUTHOR]

Background: Aspergillus niger is one of the most common fungal contaminants of food products, leading to several economic losses on fruit, vegetables and other food products during storage. Over the years, several new techniques have been developed to control fungal growth, including photodynamic inactivation, in which excitation of a photosensitizer in the right wavelength leads to ROS production and microbial death. Results: On this paper, curcumin was used as a natural photosentitizer against A. niger spores. Nanoemulsions were used in order to encapsulated curcumin and increase its water solubility. Results showed that spores inhibition could reach up to 80% after 3 min of irradiation while values for un‐encapsulated curcumin were around 30%. Conclusion: Results presented show that nanoemulsions could be use to enhance the photoinactivation properties of curcumin, against fungal spores from A. niger. This type of process can be use for food decontamination and preservation. [ABSTRACT FROM AUTHOR]

In this paper, 20 compounds containing bis-(1,2,3 and 1,2,4)-triazole structure were synthesized and their antifungal activities against Candida fungi and Aspergillus niger were analyzed in vitro. Some of the prepared compounds exhibited the most promising activity compared with voriconazole and amphotericin B. Molecular docking studies were performed to for additional substantiation of antifungal activity of these derivatives. So, these compounds are expected to provide new ideas for the development of antifungal drugs. [ABSTRACT FROM AUTHOR]

Cellulases are commercially important enzymes with application in various industries such as biofuel, detergent, food processing, brewery, pulp and paper. To make its production cost-effective, a preferred method is to use solid-state fermentation and with use of inexpensive substrates. Solid-state fermentation is an alternative culturing method and yields higher enzymes compared to submerged fermentation. In the current study, Aspergillus niger was isolated and further developed as inoculum for solid-state fermentation. Agroindustrial discards like banana pseudostem, jackfruit waste were used as the substrates. The substrates were pretreated by acid and were characterized by FTIR analysis to confirm the presence of cellulosic content. Different concentrations of the substrates were attempted for fermentation and the yield of the enzyme was compared. The solid-state fermentation was stable for enzyme production as well as microbial growth. The cellulase activity per gram of the substrate (U/g) was obtained maximum for jackfruit waste-based media (17±1.1 U/g). Both the lignocellulosic substrates were potential substrates for the production of cellulase enzyme. With further optimization and scale-up, this could be a cheap and sustainable process. This study has validated agro-industrial waste's bioconversion into value-added products that have a remarkable environmental and economic advantage. [ABSTRACT FROM AUTHOR]

A great amount of carrots is discarded daily in the word because they do not meet the quality standards imposed by consumer market. The aim of this work was to evaluate the feasibility of using carrot discards as substrate of solid-state fermentation to produce p-fructofuranosidase by Aspergillus niger and its subsequent use to catalyze the synthesis of fructooligosaccharides (prebiotics) using carrot juice. Results indicated that carrot bagasse has adequate nutrients for the growth of A. niger, but supplementation with a source of nitrogen is required to obtain a high production of β-fructofuranosidase (90.82 U/mL). Maximum specific activity (251 U/Ing) was obtained after 3 days of fermentation at 30 °C, using an inoculum of 106 conidia/mL. β-fructofuranosidase was successfully used to synthesize fructooligosaccharides using carrot juice as substrate, raising the possibility for future development of a natural functional beverage. Tweetable abstract: A great amount of carrots is discarded daily. This paper evaluates the use of carrot bagasse to produce β-fructofuranosidase and its subsequent application in carrot juice to produce a natural beverage with prebiotics. [ABSTRACT FROM AUTHOR]

The aim of paper was to determine the activation, deactivation energies and optimum temperatures for recombinant endo-inulinases of various origins, including also recombinant endo-inulinases from Aspergillus niger, Escherichia coli, Saccharomyces cerevisiae and Yarrowia lipolytica. The activity recombinant endo-inulinases of various origins vs. temperature curves were analyzed. A mathematical model describing the effect of temperature on recombinant endo-inulinase activity was used. Based on the analysis, values of the activation energies E were in the range from 22.08 ± 13.94 kJ mol - 1 to 62.62 ± 17.24 kJ mol - 1 and in the range from 29.80 ± 8.83 kJ mol - 1 to 92.69 ± 15.31 kJ mol - 1 for recombinant endo-inulinase A. niger and various origins, respectively. The deactivation energies E D were from the range from 146.80 ± 20.31 kJ mol - 1 to 301.95 ± 95.81 kJ mol - 1 and in the range from 159.96 ± 14.80 kJ mol - 1 to 289.43 ± 21.18 kJ mol - 1 for recombinant endo-inulinase A. niger and various origins, respectively. The optimum temperatures T opt were obtained in the range from 328.67 ± 1.32 K to 335.94 ± 1.22 K and in the range from 319.41 ± 0.85 K to 338.53 ± 0.45 K for recombinant endo-inulinase A. niger and various origins, respectively. [ABSTRACT FROM AUTHOR]

The optimization of extraction, chemical characterization, and the evaluation of antioxidant activity and α-amylase inhibition capacities of the cell wall polysaccharides extracted from Aspergillus niger ATCC 1004 were studied in this paper. The response surface methodology through a factorial design of three levels indicated the optimal conditions for extraction: pH 13 and 180 min. Characterization results showed that the polysaccharide is glucogalactan, consisting of β-D-galactose-linked units (1 → 6) and β-D-linked glucose (1 → 3). The antioxidant activity was evaluated through three in vitro assays. It could effectively scavenge DPPH, ABTS and hydroxyl radicals with inhibition rates of 82.12%, 75.87% and 79.24, respectively, at 6.4 mg/mL, which were higher than those of the other polysaccharides. For inhibitory activity against α-amylase, a blocking effect of 53.7% was observed at a concentration of 2 mg/mL. Therefore, the cell wall polysaccharides of Aspergillus niger, (1 → 3)(1 → 6)-β-D-glucogalactan, seem to be a promising source for use as an antioxidant, in addition to holding an in vitro hypoglycemic potential. [ABSTRACT FROM AUTHOR]

【Objective】The present paper aimed to study the effect of solid-state fermentation of Aspergillus, yeast and lactic acid bacteria on the content and antioxidant activity of polyphenols and flavonoids in freeze-dried figs (Ficus carica L.), and to provide a basis and data reference for the development of functional food or ingredients using figs.【Method】In the study, Aspergillus oryzae, A.niger, Saccharomyces cerevisiae, Rhodotorula glutinis NY5 and Lactococcus garvieae were employed to solid-state fermentation of freeze-dried figs for 7 days.The total contents of phenol and flavonoid, and the in vitro scavenging ability of 1,1-diphenyl-2-trinitrophenylhydrazine radical (DPPH) and reducing ability were determined in the ultrasonic extracts from 0, 1, 3, 5 and 7 days of fermentation by different strains, respectively.The components of polyphenols and flavonoids in the extracts were identified using liquid chromatography-mass spectrometry (LC-MS), and analyzed by principal component analysis (PCA).【Result】The total contents of polyphenol and flavonoid, the antioxidant in extracts fermenting by A.oryzae, A.niger, S.cerevisiae, R.glutinis NY5 and L.garvieae were all increased.Among all tested strains, L.garvieae and A.niger were more capable of increasing polyphenol content than the others.The DPPH radical scavenging and reducing ability of the extracts fermented by L.garvieae were increased by 37.63% and 12.50 times, respectively, compared with that before fermentation.PCA showed that the main compounds produced by the fermented extracts of A.oryzae, A.niger, S.cerevisiae, R.glutinis NY5 and L.garvieae were somewhat different, with the main compounds of A.oryzae and A.niger being flavonoids, S.cerevisiae and S.cerevisiae NY5 being phenols, and L.garvieae having both phenols and flavonoids.【Conclusion】The above results show that it is an effective method to select microbial solid fermentation to improve the content and antioxidant activity of polyphenols and flavonoids in freeze-dried figs.Microbial solid fermentation can effectively improve the contents and antioxidant activities of polyphenols and flavonoids in figs. [ABSTRACT FROM AUTHOR]

This study investigates the potential of bioethanol production from agro wastes. Agro waste from rice husk was subjected to a pretreatment process using acid hydrolysis. 20g of rice husk was soaked in 2%, 6% and 10% H2SO4 acid concentration for 2 hours, followed by filtration using 1 Whatman filter paper. The pH of the filtrate sample was adjusted to pH of 4.5 using 10% NaOH, and co-culture of Saccharomyces cerevisiae and A. Niger was introduced into the filtrate and stored for 5 days. Distillation was carried out at 78 °C. The ethanol yield, sugar content and ethanol content of all the samples obtained was analysed. The results obtained shows that 10% H2SO4 pretreated sample resulted into maximum ethanol yield (32.13 g/ml) and sugar content (13.4%). The colour change to green colour, indicates that ethanol is present in the samples. [ABSTRACT FROM AUTHOR]

Black mold of onion caused by Aspergillus niger is a serious and prevalent postharvest disease of onion. This problem drastically reduces the quality and marketability of onion bulbs. Conventional fungicides employed to control A. niger contamination posed negative impact on human health and environment and highlighted the need to discover ecofriendly management practices. In the present study we attempted to explore the use of eugenol for the management of black mold of onion. Eugenol may exhibit differences in antifungal activity in liquid state and in volatile phase. Hence, we developed and validated a new method, conical flask-paper cone method to study the antifungal activity of vapour phase disinfectants. This method was found to be precise, reproducible, sensitive and accurate with inter-assay R.S.D < 10%, intra-assay R.S.D <5% and R2>0.99. Conical flask-paper cone method was further utilized to determine the minimum inhibitory concentration of eugenol against A. niger. We observed that 0.03355 µl / cm3 eugenol caused invitro and invivo inhibition of A. niger. Onion bulbs that were stored by eugenol fumigation, prior inoculated by A. niger, did not develop black mold symptoms and maintained high sensory acceptability. Microscopic observations revealed that eugenol fumigation resulted in inhibition of spore germination, coagulation of cytoplasm, formation of large vesicles and shrinkage of A. niger mycelium. In conclusion, our study showed for the first time that eugenol fumigation significantly controlled black mold incidence during storage and maintained post harvest quality and sensory acceptance. This study also introduced a new method for evaluating antifungal activity of volatile compounds. [ABSTRACT FROM AUTHOR]

The removal of microalgae represents a problematic part of the water decontamination process, in which most techniques are expensive and non-ecological. In the paper, we focus on the synergistic relationship between microscopic filamentous fungi and algal culture. In the process of decontamination of a model sample containing ammonium ions, efficient biocoagulation, resp. co-pelletization of dried algae Chlorella sp. and Aspergillus niger sensu stricto are shown. The microscopic filamentous fungus species A. niger was added to a culture of an algal suspension of Chlorella sp., where the adhesion of the algal cells to the fungi subsequently occurred due to the electrostatic effect of the interaction, while the flocculation activity was approximately 70 to 80%. The algal cells adhered to the surface of the A. niger pellets, making them easily removable from the solution. The ability of filamentous fungi to capture organisms represents a great potential for the biological isolation of microalgae (biocoagulation) from production solutions because microalgae are considered to be a promising renewable source of oil and fermentables for bioenergy. This form of algae removal, or its harvesting, also represents a great low-cost method for collecting algae not only as a way of removing unnecessary material but also for the purpose of producing biofuels. Algae are a robust bioabsorbent for absorbing lipids from the environment, which after treatment can be used as a component of biodiesel. Chemical analyses also presented potential ecological innovation in the area of biofuel production. Energy-efficient and eco-friendly harvesting techniques are crucial to improving the economic viability of algal biofuel production. [ABSTRACT FROM AUTHOR]

Maize is a principal food crop used extensively by both humans and animals in Africa and across the globe. Unfortunately, maize is highly susceptible to fungal contamination, especially with toxicogenic species. The contamination is exacerbated subsequently by mycotoxins of these fungi, which is indeed a major concern to governments and the international community, as it renders the food unsafe for human and animal consumption. Whole maize was sampled from 10 different sites in the Ho municipality, Ghana, and evaluated for moisture contents, fungal count, and species diversity. The fungal analysis was conducted at three points per location. Fungal species were cultured and identified on the two media used; Sabouraud Dextrose Agar (SDA) and Dichlor Rose Bengal Chloramphenicol (DRBC). A total of sixteen (16) fungal species belonging to eleven (11) genera were identified in this study. They included Aspergillus niger, A. flavus, A. fumigatus, A. tamarii, A. ochraceous, and A. parasiticus, Cladosporium herbarium, Curvularia lunata, Penicillium citrinum, Fusarium moniliforme, Eurotium sp., Mucor racemosus, Rhizopus stolonifer, Paecilomyces variotii, Neurospora sitophilia and Rhodotorula sp. The genus Fusarium was found to be the most overriding fungus. The overall decreasing order of ranking of occurrence was Fusarium>Penicillium>Aspergillus. Fungal counts of the maize samples ranged between 2.77±1.01-4.1±0.81 Log10 CFU/g and 3.00±1.13-4.08±1.22 Log10 CFU/g for SDA and DRBC respectively and showed no significant differences (p>0.05). The moisture content of the maize grains ranged between 12.06 ±1.17-16.71 ± 2.65 %. Generally, there was a weak association between moisture content and fungal counts, which showed a poor fit to the linear equations (R2= 0.1989, R2= 0.0047 for SDA and DRBC respectively). Our results underscore that consumers and farmers should be up-to-date on the danger of fungal contamination in maize. The outcomes of this paper would be worthwhile in advising policy makers to particularly stress on in adopting international legislations on food quality parameters and to use tools that will change the frame of mind of the population on risks involving fungal intoxication. [ABSTRACT FROM AUTHOR]

[Display omitted] • Bioleaching combined with roasting can improve V recovery from stone coal. • V leaching rate achieved 94.52% by Aspergillus niger under optimum conditions. • Mechanisms of action of roasting and bioleaching of stone coal were elucidated. • Recovering V from stone coal by Aspergillus niger is a promising green method. Vanadium is a rare metal with excellent properties. The recovery of vanadium from low-grade stone coal and vanadium-containing solid wastes using microbial leaching, has become an increasingly popular technology. In this paper, Vanadium was obtained from stone coal using Aspergillus niger as the leaching strain, and the process of vanadium bioleaching was strengthened. Compared with plasma treatment and ultrasonic pretreatment of stone coal, the leaching effect of stone coal after roasting at 900 °C was the best, and the leaching rate of vanadium was as high as 94.52 %. The vanadium bioleaching mechanism was explored by SEM-EDS, XRD, XPS and FTIR analysis. The findings indicated that Aspergillus niger has the ability to adhere to the surface of stone coal, resulting in subsequent corrosion and degradation. The roasting treatment of stone coal and bioleaching of Aspergillus niger jointly lead to the decrease of crystallinity, the increase of interplanar spacing and the decrease of stability of stone coal. Meanwhile, the valence state and binding form of vanadium changed, and V (III) was oxidized to V (IV) and V (V). The mineral structure may be distorted as a result of the distinctive peak's vibratory stretching and the influence of functional categories that include oxygen, which in turn causes the change of the coordination form of the internal metal ions, which affects the symmetry of the mineral and facilitates the dissolution of vanadium from the stone coal. Research indicates that roasting and Aspergillus niger bioleaching have a great deal of promise to increase vanadium recovery from stone coal. [ABSTRACT FROM AUTHOR]

It is well known that Trichoderma reesei 's cellulase is deficient in β-glucosidase and cellobiohydrolase II, hampering the synergism of cellulase components and attenuating the cellulose-degrading capability. T. reesei was engineered to enhance its cellobiohydrolase II and cellulase production. However, it was still deficient in β-glucosidase. Therefore, the mixed culture of the recombinant T. reesei and Aspergillus niger was introduced to further improve cellulase production and the performance in enzymatic hydrolysis. It was found to produce the most robust cellulase, whose filter paper activity was 12.17 ± 1.18 FPIU/mL, cellobiohydrolase activity 53.10 ± 2.95 U/mL, endoglucanase activity 716.11 ± 41.16 U/mL, and β-glucosidase activity 1.93 ± 0.28 IU/mL. It had the highest enzymatic hydrolysis yield 89.35%, the lowest cellulase input 25.18 FPIU for 1 g glucose. It just needed 1.96 g SECS (dry material) for producing 1 g glucose. This work is profound and meaningful for lignocellulose-based biorefineries. [ABSTRACT FROM AUTHOR]

The high cost of cellulase is one of the main obstacles hindering the large-scale biorefining of lignocellulosic biomass. Therefore, developing efficient method for preparation of cellulase is promising. In the present study, the production of cellulase by Trichoderma reesei, Trichoderma harzianum, and Aspergillus niger was optimized, and the synergistic effect of these cellulase on enzymatic hydrolysis of pretreated ramie stalks was also evaluated. The maximum CMCase (Carboxymethyl Cellulase) and filter paper activity (FPA) produced by T. reesei reached to 3.12 IU/mL and 0.13 IU/mL, respectively. The maximum activities of CMCase (3.68 IU/mL), FPA (0.04 IU/mL) and β-glucosidase (8.44 IU/mL) were obtained from A. niger. The results also showed that under the premise of the same FPA activity, the contribution of β-glucosidase activity to yield of reducing sugar was greater than that of CMCase. Besides, cellulase produced by T. reesei and A. niger had the best synergistic effect on enzymatic hydrolysis of pretreated ramie stalks. The highest reducing sugars yield (417 mg/g dry substrate) was achieved when enzyme cocktail was prepared at the ratio of 1:1, which was 1.36–3.35 folds higher than that of different single enzymes. The present research has provided a novel method for efficient preparation of enzymes consortium for enzymatic hydrolysis of ramie stalks. [ABSTRACT FROM AUTHOR]

The advantages of recombinant enzymes over native include the control in a production environment, product purity and also high yield. The paper presents the determination the optimum temperatures and the activation energies for various origin recombinant exo-inulinases, among others from Aspergillus niger, A. awamori, Kluyveromyces marxianus and K. cicerisporus. The parameters were estimated based on the literature of the activity curves versus temperature for hydrolysis of inulin. It was assumed that both the hydrolysis reaction process and the deactivation process of recombinant exo-inulinase were first-order reactions by the enzyme concentration. A mathematical model describing the effect of temperature on recombinant exo-inulinase activity was used. Based on the comparison analysis, values of the activation energies E a were in the range from 32.01 ± 7.80 to 43.83 ± 4.87 kJ mol - 1 , the deactivation energies E d were in the range from 83.93 ± 4.82 to 352.44 ± 14.26 kJ mol - 1 and the optimum temperature T opt were obtained in the range from 318.91 ± 1.19 to 328.76 ± 0.25 K. [ABSTRACT FROM AUTHOR]

The current agricultural practice is to develop novel Nano agrochemicals in the form of Nano pesticides. Many researchers in the world have foretold an upheaval in present agricultural practice. This paper aims at the application of nanotechnology for plant protection in the form of Nano pesticides. Our study endowed with a novel polymeric Nano formulation of a dithiocarbamate nonsystemic agricultural fungicide called Mannose (MCB) by using polycaprolactone as a capping agent. The encapsulated dithiocarbamate complex was characterized by using analytical techniques like UV-Visible spectroscopy, Dynamic light scattering, Scanning electron microscope, and Transmission electron microscope. The particle size distribution emerged at 17-44nm. The bioassay was conducted against Aspergillus flavus, Aspergillus niger, Sclerotium rolfsii, and Rhizoctonia solani. The bioassay illustrated better results as compared to the commercial pesticide. [ABSTRACT FROM AUTHOR]

Background: As common pathogens in the human respiratory tract, fungal-spore-related health risks have been challenging to evaluate properly. This paper presents numerical simulations of particle deposition of Aspergillus niger spores in human nasal cavities. Methods: 30 healthy adults (including 60 nasal chambers) who lived in northwest China were recruited to conduct a nasal cavity numerical simulation using computational fluid dynamics–discrete phase model (CFD-DPM). The deposition rate in each anatomic area and its influencing variables, such as body position and respiratory flow rate, were analyzed. Results: (1) Under a resting condition, only about 5.57% ± 1.51% Aspergillus niger spores were deposited in the nasal cavity, while most of them escaped from the nasopharynx, and 0.31% ± 0.20% spores entered the maxillary sinus; (2) under an exercising condition, spores deposited in the nasal cavity were about 2.09 times as many as that in the resting state; (3) in a lying position, the A. niger spores deposited evenly on the lateral wall of the nasal cavity and the sinus when compared with a standing position. However, the deposition rate in each anatomic area did not change significantly. [ABSTRACT FROM AUTHOR]

In this paper, the preparation method of bio-hybrid hydrogels incorporated into a system of salicylic acid-pH/thermosensitive nanocarriers to speed up the wound-healing process was developed. This combination creates a dual drug delivery system, which releases the model hydrophobic active substance—salicylic acid—in a gradual and controlled manner for an extended time. Our research team has determined the various properties of bio-hybrid hydrogels based on their physicochemical (swelling degree, and degradation), structural (FT-IR), morphological (SEM), and mechanical (elongation tests) traits. Moreover, empty pH/thermosensitive nanocarriers and their salicylic acid-containing systems were characterized using the following methods: DLS, TG/DTG, and DSC. Additionally, salicylic acid release profiles directly from thermosensitive nanocarriers were compared to the bio-hybrid matrix. These studies were conducted in PBS (pH = 7.4) for 7 days using the USP4 method. To evaluate the antibacterial properties of the obtained materials, the inhibition of growth of Staphylococcus aureus, Escherichia coli, Candida albicans, and Aspergillus niger—as the main microorganisms responsible for human infections—were tested. The obtained results indicated that the pH/thermosensitive nanocarrier–salicylic acid system and bio-hybrid hydrogels are characterized by antibacterial activity against both S. aureus and E. coli. [ABSTRACT FROM AUTHOR]