Aspergillus Niger Strain Research Articles

Microbial Application to Improve Olive Mill Wastewater Phenolic Extracts.

Olive mill wastewater (OMW) contains valuable and interesting bioactive compounds, among which is hydroxytyrosol, which is characterized by a remarkable antioxidant activity. Due to the health claims related to olive polyphenols, the aim of this study was to obtain an extract from OMW with an increased level of hydroxytyrosol by means of microbial enzymatic activity. For this purpose, four commercial adsorbent resins were selected and tested. The beta-glucosidase and esterase activity of strains of Wickerhamomyces anomalus, Lactiplantibacillus plantarum, and Saccharomyces cerevisiae were also investigated and compared to those of a commercial enzyme and an Aspergillus niger strain. The W. anomalus strain showed the best enzymatic performances. The SP207 resin showed the best efficiency in selective recovery of hydroxytyrosol, tyrosol, oleuropein, and total phenols. The bioconversion test of the OMW extract was assessed by using both culture broths and pellets of the tested strains. The results demonstrated that the pellets of W. anomalus and L. plantarum were the most effective in hydroxytyrosol increasing in phenolic extract. The interesting results suggest the possibility to study new formulations of OMW phenolic extracts with multifunctional microorganisms.

Photocatalytic degradation of real textile and tannery effluent using biosynthesized magnesium oxide nanoparticles (MgO-NPs), heavy metal adsorption, phytotoxicity, and antimicrobial activity

Industrial wastewater treatment is one of the greatest challenges of humanity that require an increased awareness to address water scarcity worldwide. Herein, an eco-friendly and cost-effective approach was established to cope with real textile and tannery effluents via the biosynthesis of highly adsorbent magnesium oxide nanoparticles (MgO-NPs). Physicochemical characterization of as-formed MgO-NPs confirms the successful fabrication of MgO nano-rods (30–85 nm) and nano-rectangular (18.6–27.6 nm) by harnessing metabolites secreted by Aspergillus niger strain F1. Moreover, the energy dispersive spectroscopy (EDX) confirms that Mg and O are the main components in the sample with weight percentages of 41.1% and 33.6%, respectively. X-ray photoelectron spectroscopy (XPS) confirms the successful formation of MgO at different bending energies. The catalytic degradation and decolorization analyses were conducted under sunlight and dark conditions. These analyses demonstrated that the highest decolorization of real textile and tannery effluents (92.8% ± 0.06% and 97.5% ± 0.7%, respectively) was accomplished after 180 min by treatment with 1.0 mg mL−1 of MgO-NPs in the presence of sunlight. At optimum experimental conditions, the quality of treated effluents was monitored by the reduction of total suspended solid (TSS), total dissolved solid (TDS), and chemical oxygen demand (COD) levels at the percentages of 86.9% ± 0.8%, 77.0% ± 0.8%, and 89.3% ± 0.9%, respectively, for textile effluent and the percentages of 94.3% ± 1.6%, 80.7% ± 1.6%, and 97.4% ± 0.9% respectively, for tannery effluent. The reusability of MgO-NPs showed its activity for textile effluents treatment for four cycles. Biosynthesized MgO-NPs showed a high adsorption capacity for predominant tannery heavy metals, namely, Cr, Co, Pb, Cd, and Ni having removal percentages of 94.2% ± 1.2%, 63.4% ± 1.7%, 72.7% ± 1.3%, 74.1% ± 1.8%, and 70.8% ± 1.5%, respectively. The toxicity of treated effluents was assessed by the germination of corn and broad bean seeds, which exhibited a decreased toxicity as compared with untreated effluents. Interestingly, the biosynthesized MgO-NPs exhibit antimicrobial activity against different pathogenic microbes and their activities were dose-dependent.

Efficacy Assessment of Biosynthesized Copper Oxide Nanoparticles (CuO-NPs) on Stored Grain Insects and Their Impacts on Morphological and Physiological Traits of Wheat (Triticum aestivum L.) Plant.

Simple SummaryIn the current study, copper oxide nanoparticles (CuO-NPs) were successfully formed through the reduction of CuSO4·5H2O by the activity of Aspergillus niger strain (G3-1) metabolites. The as-formed CuO-NPs were characterized by UV–visible (UV–vis) spectroscopy, X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy–energy dispersive spectroscopy (SEM-EDX), Fourier-transform infra-red (FT-IR) spectroscopy, and X-ray photoelectron spectroscopy (XPS). Data showed the efficacy of fungal metabolites to fabricate crystallographic, spherical CuO-NPs with sizes of 14.0 to 47.4 nm at varied bending energies. The biosynthesized CuO-NPs exhibited activity against two wheat grain insects, Sitophilus granarius and Rhyzopertha dominica, in a size- and dose-dependent manner. Moreover, the lower CuO-NP concentrations had beneficial effects on the morphological and physiological aspects of wheat plants, without displaying any toxicity or repression of growth.Herein, CuO-NPs were fabricated by harnessing metabolites of Aspergillus niger strain (G3-1) and characterized using UV–vis spectroscopy, XRD, TEM, SEM-EDX, FT-IR, and XPS. Spherical, crystallographic CuO-NPs were synthesized in sizes ranging from 14.0 to 47.4 nm, as indicated by TEM and XRD. EDX and XPS confirmed the presence of Cu and O with weight percentages of 62.96% and 22.93%, respectively, at varied bending energies. FT-IR spectra identified functional groups of metabolites that could act as reducing, capping, and stabilizing agents to the CuO-NPs. The insecticidal activity of CuO-NPs against wheat grain insects Sitophilus granarius and Rhyzopertha dominica was dose- and time-dependent. The mortality percentages due to NP treatment were 55–94.4% (S. granarius) and 70–90% (R. dominica). A botanical experiment was done in a randomized block design. Low CuO-NP concentration (50 ppm) caused significant increases in growth characteristics (shoot and root length, fresh and dry weight of shoot and root, and leaves number), photosynthetic pigments (total chlorophylls and carotenoids), and antioxidant enzymes of wheat plants. There was no significant change in carbohydrate or protein content. The use of CuO-NPs is a promising tool to control grain insects and enhance wheat growth performance.

Phytochemical screening and biological activities of Aloe vera (L.) Burm. F.

In the present work phytonutrients including tannins, phlobatannins, flavonoids, saponins, cardiac glycosides and terpenoids were investigated in Aloe vera plant. Leaves of Aloe vera were chosen for this investigation. The plants were collected from the botanical garden of Islamia College, Peshawar. The phytochemicals were determined quantitatively using different solvents. The leaves were also investigated to find its antibacterial and antifungal activities. All the photochemicals excepting Phlobotannins were found in all the extracts. Results revealed very profound activities of the plant extracts against the tested gram positive strains including Staphylococcus aureus, Bacillus subtilis, Bacillus atrophoeus and gram negative bacterial strains i.e. Escherichia coli, Klebsiella pneumoniae, Salmonella typhi. The extracts also showed considerable activity against the tested fungal strains Aspergillus flavus, Aspergillus niger and Candida albicans. Keywords: Alkaloids; Aloe vera; Cardiac Glycosides; Escherichia coli; Phlobatannins; Staphylococcus aureus; Steroids http://dx.doi.org/10.19045/bspab.2021.100039

CreA-mediated repression of gene expression occurs at low monosaccharide levels during fungal plant biomass conversion in a time and substrate dependent manner

Carbon catabolite repression enables fungi to utilize the most favourable carbon source in the environment, and is mediated by a key regulator, CreA, in most fungi. CreA-mediated regulation has mainly been studied at high monosaccharide concentrations, an uncommon situation in most natural biotopes. In nature, many fungi rely on plant biomass as their major carbon source by producing enzymes to degrade plant cell wall polysaccharides into metabolizable sugars. To determine the role of CreA when fungi grow in more natural conditions and in particular with respect to degradation and conversion of plant cell walls, we compared transcriptomes of a creA deletion and reference strain of the ascomycete Aspergillus niger during growth on sugar beet pulp and wheat bran. Transcriptomics, extracellular sugar concentrations and growth profiling of A. niger on a variety of carbon sources, revealed that also under conditions with low concentrations of free monosaccharides, CreA has a major effect on gene expression in a strong time and substrate composition dependent manner. In addition, we compared the CreA regulon from five fungi during their growth on crude plant biomass or cellulose. It showed that CreA commonly regulated genes related to carbon metabolism, sugar transport and plant cell wall degrading enzymes across different species. We therefore conclude that CreA has a crucial role for fungi also in adapting to low sugar concentrations as occurring in their natural biotopes, which is supported by the presence of CreA orthologs in nearly all fungi.

Evaluation of plant beneficial microbes for bio-hardening of in-vitro raised pomegranate saplings

Five beneficial microbial agents either alone or in combinations were used to inoculate one year old in-vitro raised pomegranate plants of cv. Bhagawa for further utilization of these microbes as bio-hardening agents. A pot culture experiment was initiated comprising 15 treatments each having three replications. The growth, physiological and biochemical parameters of the inoculated and control plants were recorded at 90 days after inoculation. Microbes and microbial formulations were evaluated for their further utilization as bio-priming agents in in-vitro raised pomegranate plants. Plants inoculated with Aspergillus niger strain AN27 (Asp) + Penicillium pinophilum registered significant increase in plant height (225.00 cm) and plant spread E-W (198.33 cm) as compared to control. Asp + Pseudomonas fluorescens inoculated plants performed significantly better with respect to total chlorophyll (1.84 mg/g FW), SPAD value (41.23) and total phenol content (0.81 mg/g FW) as compared to non-inoculated plants. Plants inoculated with AMF (Glomus intraradices) + T. viridae and T. harzianum was at par with Asp + P. fluorescens in total chlorophyll content (1.71 mg/g FW) and SPAD value of leaves (36.10). Plants inoculated with AMF in combination with P. pinophilum (T10), P. fluorescens (T11) and T. viridae and T. harzianum (T12) registered higher photosynthesis as compared to control and many other treatments. Microbial treatments were found effective in improving most of the morphological, physiological and biochemical attributes of inoculated pomegranate plants.

Efficient biorefinery of whole cassava for citrate production using Aspergillus niger mutated by atmospheric and room temperature plasma and enhanced co-saccharification strategy.

The non-grain crop cassava has attracted intense attention in the biorefinery process. However, efficient biorefinery of whole cassava is faced with some challenges due to the existence of strain inhibition and refractory cellulose during the citrate production process. Here, a novel breeding method - atmospheric and room temperature plasma (ARTP) - was applied for strain improvement of citrate-producing strain Aspergillus niger from whole cassava. The citrate yield of the mutant obtained using ARTP mutagenesis increased by 36.5% in comparison with the original strain. Moreover, citric acid fermentation was further improved on the basis of an enhanced co-saccharification strategy by supplementing glucoamylase and cellulase. The fermentation efficiency increased by 35.8% with a 17.0g L-1 reduction in residual sugar on a pilot scale. All these results confirmed that a combination of the novel breeding method and enhanced co-saccharification strategy could be used to efficiently refine whole cassava. The results also provide inspiration for the production of value-added products and waste disposal in agro-based industries. © 2021 Society of Chemical Industry.

Synthesis, Identification and Study of the Anti-microbial Activity of Novel Chalcone and Epoxy Chalcone Compounds

Abstract In this study, new chalcone and epoxy chalcone synthesized by condensation of 4-acetylbiphenyl with the appropriate aldehydes. The epoxy chalcone prepared via the reaction chalcone with alkaline hydrogen peroxide in methanol. We characterized their mass spectra and 1H, 13C-NMR, and 2D-HSQC spectra to confirm their structure and absolute configuration. The target compounds were then screened for their potential antibacterial and antifungal activities. Most of the tested chalcone compounds had better activity against the fungal strains Fusarium and Aspergillus niger.

Evaluation of Physico-mechanical and Antifungal Properties Of Gluten-based Film Incorporated with Vanillin, Salicylic Acid, and Montmorillonite (Cloisite 15A)

A novel wheat gluten (WG) film was developed by adding vanillin, salicylic acid, and montmorillonite cloisite 15A (MMT). Some physico-mechanical properties, including thickness, tensile strength (TS), elongation at break (E), yellowness index (YI), whiteness index (WI), and water solubility (SWF) of the film were investigated using response surface methodology. Results revealed that maximum tensile strength occurred at the highest level of MMT and salicylic acid, and that the effect of MMT on elongation at break was considerable. The YI and WI of the composite films increased respectively, while the WI value and increment of MMT reduced. Moreover, the water solubility was raised with an increasing amount of MMT, vanillin, and salicylic content in the films. The optimum level of the variables obtained by the software was 0.92% vanillin, 0.94% salicylic acid, and 1.92% MMT (% w/w). The intensity and shifting of some absorption peaks in the FTIR spectra pattern confirmed the interaction of functional groups of additive and gluten chain. SEM images revealed an even distribution of the particles with no evidence of particle agglomeration in WG/vanillin/salicylic acid/MMT. Inhibition zone around the nanocomposite films against Aspergillus niger and Alternaria alternate strains indicated antifungal activity of WG nanocomposite films, which was more considerably observed for Aspergillus niger.

Green Synthesis of Zinc Oxide Nanoparticles by Justicia adhatoda Leaves and Their Antimicrobial Activity

AbstractZinc oxide is recognized as one of the best antimicrobial agents. Zinc oxide nanoparticles were fabricated through a green approach using zinc sulfate, zinc nitrate, and zinc acetate dihydrate as precursors and an extract of Justicia adhatoda leaves as a reducing agent. The synthesized zinc oxide nanoparticles were checked for their antimicrobial activity against the bacterial strains Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, and the fungal strains Aspergillus niger, Aspergillus flavus, and Aspergillus fumigates. All three zinc oxide nanoparticles were found to inhibit the growth of microbes by the release of zinc ions and production of reactive oxygen species followed by destruction of microbes. Antimicrobial results of zinc oxide nanoparticles from the three different precursors were compared.

Sclerotia formed by citric acid producing strains of Aspergillus niger: Induction and morphological analysis

Some strains of Aspergillus niger have been previously reported to produce sclerotia under certain conditions. Sclerotia are aggregations of hyphae which can act either as survival or as sexual structures in species related to A. niger. In this study, we were able to induce the formation of sclerotia in the progenitor of the industrial citric acid producing strains of A. niger, ATCC 1015, and in pyrG mutants derived from it. Sclerotia can be stably formed by ATCC 1015 on malt extract agar medium supplemented with raisins, showing a spatial differentiation of the fungus dependent on the addition and on the position of the fruits into the medium. On other media, including malt extract agar, pyrG auxotrophs also form abundant sclerotia, while the complementation of this gene reverses this phenotype. Additionally, a macro- and microscopical analysis of the sclerotia is reported. Our results show that the sclerotia formed by A. niger are similar to those formed by other fungi, not only in their morphology but also in their ability to germinate and regenerate the organism.

Differential proteomics reveals main determinants for the improved pectinase activity in UV-mutagenized Aspergillus niger strain.

To reveal the potential mechanism and key determinants that contributed to the improved pectinase activity in Aspergillus niger mutant EIMU2, which was previously obtained by UV-mutagenesis from the wild-type A. niger EIM-6. Proteomic analysis for Aspergillus niger EIMU2 by two-dimensional electrophoresis demonstrated that mutant EIMU2 harbored a multiple enzyme system for the degradation of pectin, mainly constituting by main-chain-cleaving enzymes polygalacturonase, pectate lyase, pectinesterase, and some accessory enzymes rhamnogalacturonan lyase and arabinofuranosidase. Further quantitatively differential proteomic analysis revealed that the quantities of four proteins, pectinesterase, rhamnogalacturonan lyase A, DNA-directed RNA polymerase A, and a hypothetical protein in strain EIMU2 were much higher than those in EIM-6. PCR amplification, sequencing and alignment analysis of genes for the two main members of pectin-degrading enzymes, pectate lyase and polygalacturonase showed that their sequences were completely consistent in A. niger EIM-6 and mutant EIMU2. The result demonstrated that the improved pectinase activity by UV-mutagenesis in A. niger EIMU2 was probably contributed to the up-regulated expression of rhamnogalacturonan lyase, or pectinesterase, which resulted in the optimization of synergy amongst different components of pectin-degrading enzymes.

Mobilisation of hazardous elements from arsenic-rich mine drainage ochres by three Aspergillus species

Natural ferric ochres that precipitate in streambeds at abandoned mining sites are natural scavengers of various metals and metalloids. Thus, their chemical and structural modification via microbial activity should be considered in evaluation of the risks emerging from probable spread of contamination at mining sites. Our results highlight the role of various aspergilli strains in this process via production of acidic metabolites that affect mobility and bioavailability of coprecipitated contaminants. The Mössbauer analysis revealed subtle structural changes of iron in ochres, while the elemental analysis of non-dissolved residues of ochres that were exposed to filamentous fungi suggest coinciding bioextraction of arsenic and antimony with extensive iron mobilisation. However, the zinc bioextraction by filamentous fungi is less likely dependent on iron leaching from ferric ochres. The strain specific bioextraction efficiency and subsequent bioaccumulation of mobilised metals resulted in distinct tolerance responses among the studied soil fungal strains. However, regardless the burden of bioextracted metal(loid)s on its activity, the Aspergillus niger strain has shown remarkable capability to decrease pH of its environment and, thus, bioextract significant and environmentally relevant amounts of potentially toxic elements from the natural ochres.

Antimicrobial and Antioxidant Activities of Methanolic Extract and Fractions of <i>Epilobium roseum</i> (Schreb.) against Bacterial Strains

Present study aims to evaluate antimicrobial and antioxidant activities of the crude methanolic extract and different fractions of the Epilobium roseum (Schreb). The extract and fractions were used against pathogenic bacteria (Bacillus subtilis, Bacillus atrophaeus, Klebsiella pneumonia and Pseudomonas aeruginosa) and fungal strains (Aspergillus niger and Aspergillus flavus). The methanolic extract and their sub fraction n-hexane showed a prominent inhibition zone against all bacterial strains but inactive against fungal strains. The various extracts of Epilobium roseum (Schreb) from various parts were tested for their antioxidant activity by 1,1-Diphenyl-2-picryl-hydrazyl (DPPH) assay. The IC50 of the stem and root of methanolic extract and their sub fraction n-hexane showed best activity ranged between 22.73 ± 6.92, 21.49 ± 6.26 and 14.94 ± 3.54, 13.92 ± 1.04 μg/ml compared to another fraction. The results support that Epilobium roseum can be used as antimicrobial and antioxidant agents. The results support the present study that Epilobium roseum (Schreb) has a potential source of natural antibacterial, antifungal and antioxidant potentials.

Mikania mikrantha leaf extract mediated biogenic synthesis of magnetic iron oxide nanoparticles: Characterization and its antimicrobial activity study

With an aim to introduce a new highly potent antimicrobial nanoparticles using an environment-friendly route, he present work reports the green synthesis of iron oxide nanoparticles (Fe3O4NPs) utilizing Mikania mikrantha leaf extract and its application as efficient antimicrobial agent. The green Fe3O4NPs have been described by X-beam diffraction (XRD), Ultraviolet–Visible (UV–Vis) spectroscopy, Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM) and Fourier Transform-Infra Red (FT-IR) investigation. The TEM image shows the rhomboidal Fe3O4NPs with average mean sizes 20.27 nm. The FT-IR investigation proved Fe3O4NPs have been balanced out through the associations of steroids, terpenoids, flavonoids, phenyl propanoids, phenolic acids and proteins present in the leaf extract. The synthesized Fe3O4NPs shows a very high antibacterial and antifungal property against 5 bacterial strains such as Bacillus cereus, Acinetobacter johnsonii, Pseudomonas aeruginosa, Achromobacter spanius and Chromobacterium pseudoviolaceum strain, and 4 fungal strains (Aspergillus niger, Penicillium citirinum, Fusarium oxysporium, and Candida albicans). The green synthesized iron oxide nanoparticles can interfere metabolic activities of microorganisms which determine its antimicrobial properties and could bring a promising application in the fields of medicine.

Purification and some properties of fungal Xylanase

Partial purification of xylanase produced by Aspergillus niger strain AUMC 14230 is carried out with 80% saturation of ammonium sulfate under pH5.0 as first step. The second step in partial purification is Acetone 2.5/1 (v/v). The last step is gill filtrations which give the highest specific from both enzymes. Many factors affecting on purified enzymes. The best activity of xylanase was produced till 72 hrs and decreased by (8.8% & 10.9%), respectively after 72 hrs. Xylan (1mg) concentration was the best substrate to produce relative activity 100% for xylanase enzyme. We found that the glucose has an inhibitory effect on both enzymes activity. Optimum temperature for xylanase is 50oC, increased temperature decreased productivity of both enzymes. The addition of Ca2+, Ba2+, Mg2+ and EDTA strongly enhanced both xylanase activity, While, Co2+ and Ag+ decreased the productivity. On the other hand, the Fe2+, Cu2+ and Mn2+ showed moderate inhibition.

Safety evaluation of the food enzyme triacylglycerol lipase from the genetically modified Aspergillus niger strain NZYM‐DB

The food enzyme triacylglycerol lipase (triacylglycerol acylhydrolase EC 3.1.1.3) is produced with a genetically modified Aspergillus niger strain NZYM‐DB by Novozymes A/S. The genetic modifications do not give rise to safety concerns. The food enzyme is free from viable cells of the production organism and recombinant DNA. The food enzyme is intended to be used in an immobilised form in the production of modified fats and oils by interesterification. Based on the estimated use levels recommended for interesterification of fats and oils and individual data from the EFSA Comprehensive European Food Database, dietary exposure to the food enzyme–total organic solids (TOS) was estimated to be up to 0.75 mg TOS/kg body weight (bw) per day in European populations. Genotoxicity tests did not raise a safety concern. The systemic toxicity was assessed by means of a repeated dose 90‐day oral toxicity study in rats. The Panel identified a no observed adverse effect level at the highest dose of 1,132 mg TOS/kg bw per day, which when compared with the estimated dietary exposure, results in a margin of exposure of at least 1,500. Similarity of the amino acid sequence to those of known allergens was searched and no match was found. The Panel considered that, under the intended conditions of use, the risk of allergic sensitisation and elicitation reactions by dietary exposure cannot be excluded, but the likelihood of such reactions to occur is likely to be low. Based on the data provided, the immobilisation of the food enzyme and the removal of total organic solids during fats and oils processing, the Panel concluded that the food enzyme does not give rise to safety concerns under the intended conditions of use.

Hepatoprotective Potential of Endophytic Aspergillus Niger Strain A6 Fractions Isolated from Phyllanthus Amarus Schum and Thonn

Aim To isolate characterize and screen for the in vitro antioxidant and hepatoprotective effects of P1EA and P1nB extracts from the endophytic fungi Aspergillus niger strain A6 PALF-1 isolated from leaves of Phyllanthus amarus in paracetamol induced hepatotoxicity.Materials and methods PALF-1 was isolated from Phyllanthus amarus leaves by standard procedures. Chloroform P1C ethyl acetate P1EA and n-butanol P1nB extracts were drawn up. P1C P1EA and P1nB were screened for in vitro antioxidant activity against 2 2-diphenyl-1-picrylhydrazyl DPPH hydroxyl radical followed by reducing power assay. P1EA 50 and 100 mgkg b. w. and P1nB 50 and 100 mgkg b. w. were screened for hepatoprotective activity against paracetamol model in rats. High performance thin layer chromatography HPTLC profile of P1EA and P1nB was also studied. Characterization of PALF-1 was done by polymerase chain reaction PCR sequential analysis.Results P1EA and P1nB found to scavenge DPPH hydroxyl radicals and also showed reductive ability. In animal studies administration of paracetamol 2 gmkg b. w. significantly increased the levels of liver biochemical marker enzymes in comparison to normal group. A marked decrease in the levels of superoxide dismutase SOD and catalase CAT was also observed. Administration of P1EA and P1nB 50 amp100 mg kg significantly reduced the actions of paracetamol by lowering the levels of serum biochemical parameters at various significance levels plt0.001 plt0.01 increasing the levels of SOD and CAT plt0.001 and decreased lipid peroxidation LPO. rDNA PCR sequencing analysis phylogenetic and molecular studies of PALF-1 confirmed the endophytic fungus as Aspergillus niger strain A6. HPTLC finger printing of P1EA and PnB showed the presence of polyvalent compounds.Conclusion P1EA and P1nB fractions of Aspergillus niger strain A6 showed significant antioxidant and hepatoprotective activity in paracetamol induced hepatotoxicity. This may be attributed to the antioxidant principles present in P1EA and P1nB which need to be explored.

Fungal Xylanase production using agricultural and industrial wastes

Lignocellulosic biomass is the most plentiful of all the naturally occurring organic compounds. Conversion of cellulosic polymers into useful products by fermentation involves two stages: firstly conversion of cellulose to glucose by cellulase, and secondly microbial conversion of the resulting glucose to products. The experiments were conducted to obtain xylanase enzyme from the Aspergillus niger strain AUMC 14230 by using corn cob (1%) as main component in fermentation media. The experiments were carried out in the laboratory of Soil, Water and Environmental Institute, Giza Egypt. To achieve this target. The best carbon source in this study is corn cob 1% concentration. The ideal nitrogen source is corn steep liquor (CSL) 3% concentration. The highest production of the enzyme was obtained when we were used modified medium (corn cob 1%, wheat bran1% and CSL 3%). The ideal environmental conditions to give highest production from both enzymes was found as: inoculum size 0.50% (v/ml), initial pH 4.5, aeration 1:5 (Vm:Vf), incubation temperature 50oC, agitation rate 175 rpm and time course 72 hr.

Synthesis, crystal structures and antimicrobial activity of palladium metal complexes of sulfonyl hydrazone ligands

Palladium complexes of sulfonyl hydrazone based ligands have been prepared by refluxing with the corresponding ligands and Pd(II) salt in 2:1 ratio. The compounds have been characterized by FT-IR and UV-Vis spectroscopic methods. The crystal structure of the prepared palladium complexes has been determined by single-crystal X-ray crystallographic technique. Crystal data for C40H50N4O6PdS2 (PMHT-Pd(II) complex): triclinic, space group P-1 (no. 2), a = 7.1561(6) Å, b = 12.1300(11) Å, c = 12.6117(17) Å, α = 63.498(11)°, β = 86.694(9)°, γ = 81.451(7)° and Z = 1. The final R1 was 0.0699 (I > 2σ(I)) and wR2 was 0.1834 (all data). Crystal data for C36H42N4O6PdS2 (PTHC-Pd(II) complex): monoclinic, space group P21/n (no. 14), a = 8.6726(2) Å, b = 20.8824(4) Å, c = 10.3351(2) Å, β = 104.429(2)° and Z = 2. The final R1 was 0.0344 (I > 2σ(I)) and wR2 was 0.0840 (all data). Crystal data for C36H42N4O6PdS2 (PTHT-Pd(II) complex): monoclinic, space group P21/n (no. 14), a = 9.7658(2) Å, b = 10.0488(3) Å, c = 18.7714(4) Å, β = 99.602(2)° and Z = 2. The final R1 was 0.0334 (I > 2σ(I)) and wR2 was 0.0832 (all data). Crystal data for C40H50N4O6PdS2 (PMHC-Pd(II) complex): triclinic, space group P-1 (no. 2), a = 10.2070(9) Å, b = 12.1841(13) Å, c = 16.8879(19) Å, α = 109.005(6)°, β = 90.061(5)°, γ = 99.032(5)° and Z = 2. The final R1 was 0.0822 (I > 2σ(I)) and wR2 was 0.2293 (all data). The single-crystal structure data showed a good agreement with the experimental results. The synthesized complexes were screened for their in vitro antibacterial activity against one Gram-negative (Escherichia coli) and two Gram-positive (Bacillus subtilis and Staphylococcus aureus) bacterial strains and for in vitro antifungal activity against Aspergillus niger, Aspergillus flavus and Aspergillus fumigatus. The PTHC-Pd(II) complex possesses the nearby significant antifungal activity analogous to the standard drug fluconazole against selected fungal strains Aspergillus niger, Aspergillus Flavus and Aspergillus fumigatus as well as the same complex showed the antibacterial activity for Staphylococcus aureus as comparable to standard ofloxacin drug.