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Extremophiles are a group of organisms growing in a wide range of extreme environmental conditions. The extremophilic microorganisms are diverse and are classified into psychrophiles (− 2°C to 20°C), thermophiles (55–121°C), piezophiles (> 500 atm), halophiles (2–5 M NaCl or KCl), metallophiles (high concentrations of metals, e.g., copper, zinc, lead, cadmium, and arsenic), alkaliphiles (pH > 8), and acidophiles (pH

In the present work, we isolated and identified Aspergillus sydowii NYKA 510 as the most potent laccase producer. Its medium constituents were optimized to produce the highest possible amount of laccase, which was after 7 days at 31°C and pH 5.2. Banana peel and peptone excelled in inducing laccase production at concentrations of 15.1 and 2.60 g/l, respectively. Addition of copper sulfate elevated enzyme yield to 145%. The fungus was employed in a microbial fuel cell (MFC). The best performance was obtained at 2000 Ω achieving 0.76 V, 380 mAm-2, 160 mWm-2, and 0.4 W. A project to design a self-sufficient lighting unit was implemented by employing a system of 2 sets of 4 MFCs each, connected in series, for electricity generation. A scanning electron microscopy image of A. sydowii NYKA 510 was utilized in algorithmic form generation equations for the design. The mixed patterning and patterned customized mass approach were developed by the authors and chosen for application in the design.

Propolis was responsible for in vitro growth suppression of some tested phytopathogenic fungi. Four tested species were partially inhibited by using propanolic or ethanolic extract associated with promising growth reduction of Fusarium oxysporum in a per cent of growth recorded 38.2% or 58.9% during propanolic or ethanolic application, respectively, while Helminthosporium sp. and Cladosporium sp. showed unexpected activation of growth during propanolic or ethanolic extract applications. The antimicrobial products identified during GC-MS analysis of the propolis propanolic extract were Pyrazole, Quinic acid, D-lactic acid, Pentanoic acid, Erythritol and sulfonamide derivatives. The SDS gel electrophoresis of soluble proteins of Fusarium oxysporum treated with propanolic or ethanolic propolis extracts showed a specific protein band at 26.002 kDa with the untreated pathogen, and several characterized bands at 21.160, 26.012, 28.666, 38.44, 102 kDa related to propolis propanolic extract (2) and finally a two markedly visible bands at 18.871, 33.083 kDa with propolis ethanolic extract (3). The decrease in enzyme activity of cellulase and pectinase of Fusarium oxysporum was recorded under treatment with either propanolic or ethanolic extracts. There was suppression in the degree of infectivity such as the number of rotted seeds, wilting, brown discoloration of Phaseolus seedlings presoaked in either of the two propolis extracts compared to infected plants with more reduction individually in case of propanolic extract over that of ethanolic one.

This work aims at isolating a fungal source for L-asparaginase production to be applied in reducing acrylamide levels in coffee beans at non-cytotoxic levels. An L-asparaginase-producing fungus was isolated from an agricultural soil sample and identified as Penicillium crustosum NMKA 511. A maximum L-asparaginase activity of 19.10 U/mL was obtained by the above-mentioned fungus when grown under optimum conditions (i.e. 16.96 g/L sucrose as carbon source, 1.92 g/L peptone as nitrogen source, pH 7.7 and 33.5 °C). Further, the produced L-asparaginase was purified and sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) showed that P. crustosum L-asparaginase was a heterodimer enzyme with molecular weights of approximately 41.3 and 44.4 kDa. Also, the purified P. crustosum L-asparaginase was specific towards L-asparagine and showed negligible and no effects towards L-glutamine and D-asparagine, respectively. Additionally, the purified L-asparaginase reduced the acrylamide levels by 80.7% and 75.8% in light and dark roasted coffee beans, respectively. The amount of L-asparaginase used to reduce acrylamide was considered safe when cell viability reached 94.6%.

AN AGRICULTURAL soil was used to isolate Alternaria alternata. It was molecularly identified and was given an accession number MN645469 at the National Center for Biotechnology Information (NCBI) and a strain identifier to be Alternaria alternata strain NMK1. Four fractions were collected from the acetic acid extract of its filtrate. Fraction no. 2 showed highest antioxidant activity (71 and 64%, at 200 and 150μg/mL) followed by the crude extract (60 % at 200μg/mL). Safety of using the extracted fractions was tested against the normal human amnion (WISH) cell line. Lowest cytotoxicity values were recorded for fraction no. 2 (19%) followed by the crude extract (28%) at 50μg/mL. Aspergillus flavus, Aspergillus niger and Penicillium griseofulvum exhibited highest relative density percentages (28.4, 30.8 and 24.3%) on their respective isolation seeds; wheat, broad bean and kidney bean. Interestingly, fraction no. 2 caused 100% inhibition of these isolated fungal species at 100μg/mL. The minimum fungicidal concentration (MFC) was estimated to be 50μg/mL against A. flavus and 40μg/mL for A. niger and P. griseofulvum. Generally, subjecting each of the tested isolates to fraction no. 2 led to damage in their DNA as shown by the comet assay. Gas chromatography- mass spectroscopy (GC-MS) profiling of fraction no. 2 showed 12 major compounds with diverse possible biological activities being antiinflammatory, insecticide, anticancer, antineoplastic antifungal, and antimicrobial.

In the present work, we isolated and identified

TWENTY FIVE Aspergillus isolates were screened from Giza Governorate and Saint Catherine Protectorate soils in Egypt. The antimicrobial activity of the crude extracts was tested against two Gram positive bacteria (Bacillus subtilis NRRL-B-4219, Staphylococcus aureus ATCC29213), four Gram negative bacteria (Alcaligenes faecalis B-170, Escherichia coli ATCC25922, Klebsiella pneumoniae ATCC10131, Pseudomonas aeruginosa ATCC27953), and one yeast (Candida albicans ATCC10231). The antioxidant activity using free radical scavenging model was assayed for the crude extracts. The antitumor activity for all of crude extracts was determined against HCT116 (Colon carcinoma cell line), HEPG2 (Liver carcinoma cell line), and MCF-7 (Breast carcinoma cell line). Aspergillus nomius was the most potent fungal species accordingly, it was chosen for bioactivity assay. Identification of this species was further confirmed at the molecular level based on nuclear ribosomal DNA 18s identities. An accession number, LC199488, was given at the DDBJ GenBank. The column chromatography of its crude extract yielded five distinguished fractions. The biological (antimicrobial, antioxidant and antitumor) activities of these fractions were assayed. Fraction B proved to be of most potential. HPLC analysis of this fraction showed that there was a sharp and clear peak at about 18.1 min. This denoted the presence of an active compound. The compound at this peak was purified and its structure was elucidated via 1HNMR and 13CNMR spectroscopy. It was concluded that it would be 1,2,3,9 tetrahydropyrrolo [2,1-b] quinazolin-3-ol.

THIS STUDY aimed at investigating the effect of gamma irradiation…… on the phenotypic characters of Aspergillus niger and its impacton the activities of some enzymes such as lipase, protease, cellulase,pectinase and amylase. Two phenotypically different mutants wereobtained after gamma irradiation at doses of 1 and 3 kGy. SEMmicroscopy showed clear morphological changes in conidiophores,conidial heads and spores among all strains. The activities of lipase,protease and cellulase in both mutants become less than that of theparent strain, while, pectinase showed no significant difference amongthe tested strains. Amylase activity was enhanced by gammairradiationin the mutants. The obtained mutants were molecularlycharacterized using RAPD-PCR. The results demonstrated theoccurrence of polymorphic pattern between parent and mutant strainsdue to change in the genetic makeup.

THE MAIN concept of this study was to assess the potentiality of hydrolytic enzymes as virulence factors for Aspergillus species during aspergillosis infection process. Forty Aspergillus species were isolated from medical (15 isolates) as well as environmental isolates (25 isolates) from soils, outdoor and indoor environments. Extracellular proteases, phospholipases and esterase activities were measured. The pathogenicity of some Aspergillus species was in vivo assessed. It was represented in mean survival times, mortality percentages, fungal counts in different organs, and histopathological examination of lung tissue. The expression levels of protease, phospholipase and esterase genes were studied by real time PCR. Four physiologically significant isolates were selected out of forty and were identified up to molecular level. Aspergillus ochraceus fm90 recorded the highest pathogenicity as represented by mortality percentages and mean survival times of mice, while A. flavus fm90 was the least pathogenic one. Expression of genes of protease, phospholipase and esterase was found to be greater in A. ochraceus fm90 than in A. flavus fm90. It can be concluded that pathogenicity is probably related to physiological (enzymatic) activities of the isolates. Also, variation in expression levels of protease and phospholipase genes in A. ochraceus fm90 and A. flavus fm90 could denote their possible involvement in the pathogenicity process.

The cell-free culture filtrate (CFF) of the fungi Fusarium chlamydosporum NG30 and Penicillium chrysogenum NG85 was tested to synthesize silver nanoparticles (AgNPs). The synthesized AgNPs were further characterized by means of transmission electron microscopy (TEM), dynamic light scattering (DLS) and Fourier transform infra-red (FTIR) spectroscopy. TEM revealed their spherical shape, homogeneity and a size range between 6 and 26 nm for F. chlamydosporum AgNPs (FAgNPs) and from 9 to 17.5 nm for P. chrysogenum AgNPs (PAgNPs). DLS showed that the diameter of FAgNPs was narrower than that of PAgNPs. FTIR spectroscopy indicated that the functional groups present in the CFF might be responsible for the reduction of silver ions to form stabilized protein-capped AgNPs. In addition, the AgNPs showed notable antifungal activity and potency in thwarting mycotoxin production. Thus, using Aspergillus flavus as a test microorganism the minimum inhibitory concentration (MIC) was 48, 45 and 50 μg/mL for FAgNPs, PAgNPs and the antifungal compound itraconazole, respectively. Also, when testing Aspergillus ochraceus FAgNPs, PAgNPs and itraconazole led to MIC values of 51, 47 and 49 μg/mL, respectively. The statistical MIC values to inhibit completely the total aflatoxin production by A. flavus were 5.9 and 5.6 μg/mL for FAgNPs and PAgNPs, respectively, and to inhibit the ochratoxin A production by A. ochraceus 6.3 and 6.1 μg/mL for FAgNPs and PAgNPs, respectively. The cytotoxicity assay of the AgNPs on human normal melanocytes (HFB 4) revealed a cell survival of 80% and 75% at a concentration of 6 μg/mL for FAgNPs and PAgNPs, respectively.

The fungus, Emericella nidulans was isolated from soil. The ITS region of 5.8S rRNA of the isolated fungus was amplified and sequenced. E. nidulans EGCU312 was given an accession number: KC511056 in the NCBI GenBank. Twenty one (21) fractions were obtained from the ethyl acetate extract of fungal filtrate. Fraction no. 12 showed the highest antioxidant activity with 81.54% at 200 µg/ml. High anticancer activities (against EACC cell line) ranging between 64.3 and 87.7% at 200 µg/ml, were exhibited by fractions no. 1, 2, 4, 9, 12 and 20. The mode of action of anticancer activity was studied by measuring activities of lactate dehydrogenase (LDH) and caspase-3. Fraction no. 12 gave the highest effect (2249.2 U/l) in LDH released as compared to control cells (1127.7 U/l) and caused a 1.56-fold increase in caspase-3 activity. Interestingly, fraction no. 12 caused 100% inhibition of Staphylococcus aureus and Escherichia coli at 50 µg/ml, and Aspergillus fumigatus at 100 µg/ml. The minimum bactericidal concentrations (MBC) of this fraction were 4 and 10 µg/ml for S. aureus and E. coli, respectively, while the minimum inhibitory concentration (MIC) was 45 µg/ml against A. fumigatus. GC-MS profile of fraction no. 12 showed 21 compounds, six of which, that is, 2-methylbenzylamine, N-heptyl-N-octyl; naphthalene, 2,3,6-trimethyl-; octadecanoic acid, ethyl ester; 1,2-benzenedicarboxylic acid, butyl octyl ester; tributylacetylcitrate; 1,2- and benzenedicarboxylic acid, diisooctyl ester, were of known biological activities. Key words: Emericella nidulans EGCU 312, antioxidant, anticancer, antimicrobial.

In the past few decades, nanoparticles have emerged as a field in biomedical research. Four isolated Aspergillus species were tested for extracellular synthesis of silver nanoparticles using their cell free filtrate (CFF). Silver nanoparticles of the most potent producer, Aspergillus terreus, were further characterized. Transmission electron microscope (TEM) and atomic force microscope (AFM) revealed their spherical shape, homog eneity and size range between 20 and 140 nm. X-ray diffraction (XRD) showed the crystalline nature of the biogenic silver nanoparticles. Fourier transform infra-red (FTIR) spectroscopic analysis indicated that the coordination behaviors between amino groups of the secreted fungal proteins and other functional groups present in the CFF may be liable for the reduction of silver ions to form stabilized protein-capped silver nanoparticles. They were stable in aqueous solution for four months of storage at room temperature under dark conditions. The biogenic silver nanoparticles showed remarkable antifungal activity against the human pathogenic fungus A. fumigatus. The spore cell wall, plasma membrane and the inner constituents were damaged as shown by TEM. Furthermore, comet assay proved high breakage of DNA. Key words: Silver nanoparticles, biosynthesis, fungi, antifungal, comet assay.

Sodium dodecyl sulfate–polyacrlyamide gel electrophoresis (SDS–PAGE) was used to assess the purity and molecular weight of the previously purified alkaline keratinase enzyme of Scopulariopsis brevicaulis. The enzyme was homogenous, as seen by a single band of protein, and had an apparent molecular weight of 28.5kDa. Amino acid profile of the purified keratinase revealed that it was composed of 14 different amino acids with high proportions of glutamic acid (20.86%), alanine (14.52%), glycine (14.21%), leucine (8.59%) and serine (7.81%). The enzyme contained moderate amounts of valine (6.01%), threonine (5.58%) and phenyl alanine (5.22%). The purified enzyme of S. brevicaulis exerted a potent keratinolytic activity and was capable to hydrolyze different keratinaceous materials with highest activity on chicken feathers followed by human nails and human hair.

Poly ( N -vinyl imidazole) (PNVI) has been grafted onto carboxymethyl chitosan in aqueous solution using potassium persulphate (KPS) as initiator. The effect of the monomer and initiator concentration, the reaction temperature and time on the grafting yield have been investigated. The maximum grafting yield was achieved at [KPS] = 8 × 10 −2 mol/L, [M] = 1 mol/L at reaction temperature = 60 °C within reaction time = 2.5 h. The grafted products were characterized by FTIR, elemental analysis, SEM photographs, solubility tests, thermal analysis and antibacterial activity. Grafted products have improved the antimicrobial activity of carboxymethyl chitosan.

In our search for new fungal isolates capable of degrading polycyclic aromatic hydrocarbons (PAHs) in soil, twenty one fungal isolates were recovered from Orman Garden, Wadi Degla Protectorate and benzene station soils. All tested fungi exhibited lignin peroxidase and manganese peroxidase activities in solid as well as in liquid cultures. However, laccase was detected in low amounts by some of the tested fungal isolates. Accordingly, laccase was eliminated from further work. Aspergillus terreus was superior in ligninolytic enzyme production. Hence, it was chosen for the following studies. The statistical optimum temperatures for lignin peroxidase and manganese peroxidase production by A. terreus were 33.6 and 33.1°C, respectively. Meanwhile lignin peroxidase and manganese peroxidase yields were maximal at pH 4.1 and 5.8, respectively. Highest ligninolytic enzyme secretions were established on D-glucose and sodium nitrate. An experiment to study biodegradation of PAHs in soil was conducted. A. terreus was able to degrade 98.5% of naphthalene and 91% of anthracene in soil models. Key words: Biodegradation, fungi, polycyclic aromatic hydrocarbons (PAHs) Ligninolytic enzymes, soil model