Evaluation of antidiabetic, antioxidant, and cytotoxic potential of maize (zea mays l.) husk leaf extracts.

In current study, Maize (Zea mays L.) husk leave extracts were appraised for biological activities such as cytotoxicity, antidiabetic, antioxidant and antimicrobial. Maceration was performed to collect various fractions of husk leave extracts using a pool of solvents i.e., n-hexane, chloroform, ethyl acetate, butanol and methanol. Antioxidant potential was measured by 1,1-diphenyl-2-picrylhydrazyl (DPPH) scavenging, reducing power and linoleic acid oxidation assay, using butylated hydroxy toluene (BHT) as a positive control. Total phenolic and flavonoid contents were found to be 18.47-425.11 mg/100 g GAE and 5.83-16.72 mg/100 g CE, respectively. The DPPH scavenging assay was exhibited in the range of 76.36 to 88.53%. The percentage inhibition in linoleic acid oxidation was found from 10.16 to 79.51%. Significant antimicrobial activity was demonstrated by husk leaf extracts against bacterial strains and fungal strains using disc diffusion and minimum inhibitory concentration (MIC) method. Amylase alpha assay was employed to analyze the antidiabetic activity which ranged between 9.52-24.81%. Cytotoxicity was evaluated by % age lysis (0.35-9.54%), while thrombolytic activity ranged between 7.67 to 31.27%. The results presented in this study revealed that maize (Zea mays L.) husk leaf extracts can be a valuable source of biologically active compounds and may be consumed as a source of potent herbal medicine in pharmaceuticals.

Phytochemical screening and biological activities of Bromus pectinatus Thunb.

The present research study investigates the phytochemical and pharmacological importance of Bromus pectinatus. Qualitative phytochemical analysis of this plant was carried out to use standard method for the presence of various bioactive constituents. Results showed the ethanolic extract contain natural product such as steroids, alkaloids, tannins, coumarin, saponins, flavonoids and phenols. These compounds play a key role to reducing various disease and microbial inhibition. The ethanolic extract also showed the antimicrobial and antifugal activity against different pathogenic bacterial strains e.g Escherichia coli, Micrococus leutus, Protus vulgarus, and Kelebsela pneumona and three fungal strains Aspergillus fumigatus, Aspergillus flavous, Aspergillus niger. The antioxidant assay was performed as % inhibition of DPPH (1, 1-diphenyl-2-picryl-hydrazyl) free radicals. The plant extract has more antioxidant activity as compared to ascorbic acid. The maximum concentration (800µg/ml) is the most effective of all. The plant extract showed the high cytotoxicity activity against Brine shrimp. Moreover, the plant extract exhibited allelopathic effect on different growth parameters of wheat plant mostly at higher concentration. These results indicate that the BPEE have a potential broad-spectrum antimicrobial, cytotoxic, antioxidant and phytotoxic activity due to the presence of bioactive compounds.

Integrated proteomics and metabolomics analysis of tea leaves fermented by Aspergillus niger, Aspergillus tamarii and Aspergillus fumigatus.

Post-fermented Pu-erh tea (PFPT) is a microbially-fermented tea with distinct sensory qualities and multiple health benefits. Aspergillus are the dominant fungi in the fermentation and the main contributors to the characteristics of PFPT, so their underlying functions warrant detailed study. Here, tea leaves were fermented by Aspergillus niger, Aspergillus tamarii and Aspergillus fumigatus, and resulting samples (designated as Asn, Ast and Asf, respectively) were analyzed by proteomic and metabolomic methods. Changes to the composition of flavonoids, glycerophospholipids, organo-oxygen compounds and fatty acids resulting from Aspergillus fermentation were observed. Carbohydrate-active enzymes, e.g., endoglucanases and cellulases, for degradation of cellulose, starch, lignin, pectin, xylan and xyloglucan were identified. Glycoside hydrolase, glycosyltransferases, tannase, laccases, vanillyl-alcohol oxidases and benzoquinone reductase were identified and hypothesized to catalyze hydrolysis, oxidation, polymerization and degradation of phenolic compounds. Together, functions of Aspergillius were demonstrated as production of enzymes to change concentrations and compositions of metabolites in tea leaves.

Physical Properties, Chemical Analysis, and Evaluation of Antimicrobial Response of New Polylactide/Alginate/Copper Composite Materials.

In recent years, due to an expansion of antibiotic-resistant microorganisms, there has been growing interest in biodegradable and antibacterial polymers that can be used in selected biomedical applications. The present work describes the synthesis of antimicrobial polylactide-copper alginate (PLA-ALG-Cu2+) composite fibers and their characterization. The composites were prepared by immersing PLA fibers in aqueous solution of sodium alginate, followed by ionic cross-linking of alginate chains within the polylactide fibers with Cu(II) ions to yield PLA-ALG-Cu2+ composite fibers. The composites, so prepared, were characterized by scanning electron microscopy (SEM), UV/VIS transmittance and attenuated total reflection Fourier-transform infrared spectroscopy ATR-FTIR, and by determination of their specific surface area (SSA), total/average pore volumes (through application of the 5-point Brunauer-Emmett-Teller method (BET)), and ability to block UV radiation (determination of the ultraviolet protection factor (UPF) of samples). The composites were also subjected to in vitro antimicrobial activity evaluation tests against colonies of Gram-negative (E. coli) and Gram-positive (S. aureus) bacteria and antifungal susceptibility tests against Aspergillus niger and Chaetomium globosum fungal mold species. All the results obtained in this work showed that the obtained composites were promising materials to be used as an antimicrobial wound dressing.

Arbuscular mycorrhizal symbiosis and achene mucilage have independent functions in seedling growth of a desert shrub.

Arbuscular mycorrhizal (AM) symbiosis can play a role in improving seedling establishment in deserts, and it has been suggested that achene mucilage facilitates seedling establishment in sandy deserts and that mucilage biodegradation products may improve seedling growth. We aimed to determine if AM symbiosis interacts with achene mucilage in regulating seedling growth in sand dunes. Up to 20 A M fungal taxa colonized Artemisia sphaerocephala roots in the field, and mycorrhizal frequency and colonization intensity exhibited seasonal dynamics. In the greenhouse, total biomass of AM fungal-colonized plants decreased, whereas the root/shoot ratio increased. AM symbiosis resulted in increased concentrations of nutrients and chlorophyll and decreased concentrations of salicylic acid (SA) and abscisic acid (ABA). Achene mucilage had a weaker effect on biomass and on nutrient, chlorophyll, and phytohormone concentration than did AM symbiosis. We suggest that AM symbiosis and achene mucilage act independently in enhancing seedling establishment in sandy deserts.

Enhanced Production of Two Bioactive Isoflavone Aglycones in Astragalus membranaceus Hairy Root Cultures by Combining Deglycosylation and Elicitation of Immobilized Edible Aspergillus niger.

A cocultivation system of Astragalus membranaceus hairy root cultures (AMHRCs) and immobilized food-grade fungi was established for the enhanced production of calycosin (CA) and formononetin (FO). The highest accumulations of CA (730.88 ± 63.72 µg/g DW) and FO (1119.42 ± 95.85 µg/g DW) were achieved in 34 day-old AMHRCs cocultured with immobilized A. niger (IAN) for 54 h, which were 7.72- and 18.78-fold higher than CA and FO in nontreated control, respectively. IAN deglycosylation could promote the formation of CA and FO by conversion of their glycoside precursors. IAN elicitation could intensify the generation of endogenous signal molecules involved in plant defense response, which contributed to the significantly up-regulated expression of genes in CA and FO biosynthetic pathway. Overall, the coupled culture of IAN and AMHRCs offered a promising and effective in vitro approach to enhance the production of two health-promoting isoflavone aglycones for possible nutraceutical and pharmaceutical uses.

Identification and genomic analysis of antifungal property of a tomato root endophyte Pseudomonas sp. p21.

Pseudomonas sp., which occupy a variety of ecological niches, have been widely studied for their versatile metabolic capacity to promote plant growth, suppress microbial pathogens, and induce systemic resistance in plants. In this study, a Pseudomonas sp. strain p21, which was isolated from tomato root endophytes, was identified as having antagonism against Aspergillus niger. Further analysis showed that this strain had the ability to biosynthesise siderophores and was less effective in inhibiting the growth of A. niger with the supplementation of Fe3+ in the agar medium. Genomic sequencing and the secondary metabolite cluster analysis demonstrated that Pseudomonas sp. p21 harboured 2 pyoverdine biosynthetic gene clusters, which encode compounds with predicted core structures and two variable tetra-peptide or eleven-peptide chains. The results indicated that siderophore-mediated competition for iron might be an important mechanism in Pseudomonas suppression of the fungal pathogen A. niger and in microbe-pathogen-plant interactions.

Amphotericin B-copper(II) complex shows improved therapeutic index in vitro.

The AmB-Cu(II) complex has recently been reported as an antifungal agent with reduced aggregation of AmB in aqueous solutions, increased anti C. albicans activity and lower toxicity against human cells in vitro. In the present work, investigations of the activity of the AmB-Cu (II) complex against fungal pathogens with varying susceptibility, including C. albicans and C. parapsilosis strains and intrinsically resistant A. niger, and cytotoxicity in normal human dermal fibroblasts (NHDF) in vitro were performed. For better understanding of the mechanism of reduced cytotoxicity and increased fungicidal activity, the influence of the AmB-Cu (II) complex on membrane integrity and accumulation of cellular reactive oxygen species (ROS) and mitochondrial superoxide was compared with that of conventional AmB. In the sensitive C. albicans and C. parapsilosis strains, the AmB-Cu(II) complex showed higher fungicidal activity (the MIC value was 0.35-0.7µg/ml for the AmB-Cu (II) complex, and 0.45-0.9µg/ml for Fungizone) due to increased induction of oxidative damage with rapid inhibition of the ability to reduce tetrazolium dye (MTT). In the NHDF cell line, the CC50 value was 30.13±1.53µg/ml for the AmB-Cu(II) complex and 17.46±1.24µg/ml for (Fungizone), therefore, the therapeutic index (CC50/MIC90) determined in vitro was 86.09-43.04 for the AmB-Cu(II) complex and 38.80-19.40 for Fungizone. The lower cytotoxicity of the AmB-Cu(II) complex in human cells resulted from lower accumulation of cellular and mitochondrial reactive oxygen species. This phenomenon was probably caused by the induction of successful antioxidant defense of the cells. The mechanism of the reduced cytotoxicity of the AmB-Cu(II) complex needs further investigation, but the preliminary results are very promising.

Photodynamic inactivation of mold fungi spores by newly developed charged corroles.

The photodynamic effect, originally used in photodynamic therapy (PDT) for the treatment of different diseases, e.g. of cancer, has recently been introduced for the inactivation of bacteria. Mold fungi, which provoke health problems like allergies and diseases of the respiratory tract, are even more resistant and their biology is also very different. This study presents the development of four new photosensitizers, which, in combination with low doses of white light, inhibit the germination of mold fungi spores. Two of them even cause lethal damage to the conidia (spores) which are responsible for the spreading of mold fungi. The photoactivity of the newly synthesized corroles was obtained by their application on three different mold fungi: Aspergillus niger, Cladosporium cladosporoides, and Penicillium purpurgenum. To distinguish between inactivation of germination and permanent damage, the fungi were first incubated under illumination for examination of photosensitizer-induced growth inhibition and then left in darkness to test the survival of the conidia. None of the compounds displayed dark toxicity, but all of them attenuated or prevented germination when exposed to light, and the positively charged complexes induced a complete damage of the conidia.

Biosolubilization of rock phosphate by three stress-tolerant fungal strains.

Three stress-tolerant phosphate-solubilizing fungal strains identified as Aspergillus niger, Aspergillus japonicus, and Penicillium simplicissimum were isolated from wheat rhizospheric soil. The strains demonstrated different capabilities of phosphate solubilization in National Botanical Research Institute's phosphate medium containing rock phosphate (RP) as sole phosphorus (P) source, and the solubilization of RP by P. simplicissimum was the most effective among these strains, followed by A. niger and A. japonicus. All the strains exhibited high levels of stress tolerance like 10∼45°C temperature, 4∼11 pH, 0∼3.5% NaCl, and 0∼35% PEG 10000. The strains also differed in their abilities to survive and release soluble P from RP under different stresses. A. niger showed significantly higher tolerance to temperature and pH over the other two strains. Higher amount of spores and content of soluble P in the medium were observed in the presence of 3.5% NaCl with P. simplicissimum, followed by A. niger and A. japonicus. P. simplicissimum could not solubilize RP in the presence of 35% PEG 10000, which exhibited the lowest tolerance to desiccation stress among the three strains.

Response surface optimization of medium components for citric acid production by Aspergillus niger NRRL 567 grown in peat moss.

Aspergillus niger NRRL 567 was grown in an inert support material for citric acid production. Optimization of the medium components, including ethanol, methanol, phytate, olive oil and surfactant was carried out using "one-factor-at-a-time" and central composite design (CCD) methods. Optimization using "one-factor-at-a-time" was performed and the supplement of ethanol and methanol between 15 and 30 g/kg dry peat moss (DPM) enhanced citric acid production while higher levels than 30 g/kg DPM had an inhibitory effect on citric acid production at 48 and 72 h of incubation. Based on the results of "one-factor-at-a-time" optimization, phytate, olive oil and methanol were the selected additives to test the effect on citric acid production using CCD. The three variables were identified to have significant effects on citric acid production and the maximum citric acid production of 354.8 g/kg DPM was resulted from the combination of 19 g phytate/kg DPM, 49 g olive oil/kg DPM and 37 g methanol/kg DPM at 120 h. Maximum citric acid production in optimized condition by CCD represented about a 2.7-fold increase compared to that obtained from control before optimization.

Influence of pectin and glucose on growth and polygalacturonase production by Aspergillus niger in solid-state cultivation.

The solid-state production of endo- and exo-polygalacturonases (PG) by Aspergillus niger was studied in a media containing wheat bran, salts, and different citric pectin and/or glucose concentrations. Kinetic analysis of the process indicated that the formation of PG and the growth of A. niger are associated processes. By increasing citric pectin from 0 to 16% (w/w), the maximum A. niger concentration (X (m)) was raised from 94 to 121 mg/g dry medium suggesting that pectin can be used by A. niger as a growth substrate besides its role as an inducer. With 16% (w/w) pectin, 281 U exo-PG/gdm and 152 U endo-PG/gdm were obtained. Otherwise, pectin concentrations from 20 to 30% (w/w) hindered both production and growth. A. niger concentrations of 108-113 mg/gdm were achieved in runs with glucose from 5 to 12% (w/w), whereas at 16 and 20% (w/w) glucose, lower X (m) values (ca. 100 mg/gdm) were measured. The addition of glucose to the wheat bran medium, up to 10% (w/w) led to maximum endo-PG titers slightly lower than those found in the absence of glucose. Nevertheless, exo-PG formation in these media was strongly increased and activities over 370 U/gdm were achieved. The results suggest that in experiments with pectin concentrations until 16% (w/w), exo-PG production was repressed by pectin-degradation products although these same substances had favored biomass growth. When glucose concentrations over 10% (w/w) were added to the media, the maximum activities of both enzymes decreased drastically, suggesting that glucose at high concentrations also exerts a repressive effect on PG production.

Antifungal activities of actinomycete strains associated with high-altitude sagebrush rhizosphere.

The antifungal-producing potential of actinomycete populations from the rhizosphere of low-altitude sagebrush, Artemisia tridentata, has been examined. In a continued investigation of new sources of antifungal-producing microorganisms, this study examined the antifungal-producing potential of actinomycetes from the rhizosphere of high-altitude A. tridentata. With high-altitude sagebrush, rhizosphere soil actinomycete numbers were one to four orders of magnitude higher than those found in nonrhizosphere bulk soils and different from those found with the low-altitude plants. A total of 122 actinomycete isolates was screened against nine fungal species and six bacterial species for the production of antimicrobial compounds. Four rhizosphere isolates, Streptomyces amakusaensis, S. coeruleorubidus, S. hawaiiensis and S. scabies, showed broad-spectrum antifungal activity against three or more fungal species in plate assays. In liquid antagonism assays, mycelium production by Aspergillus niger was reduced by up to 50% by two of the actinomycete isolates. These results demonstrate the potential of rhizosphere microbiology in the search for new antimicrobials.

Bio-active composts from rice straw enriched with rock phosphate and their effect on the phosphorous nutrition and microbial community in rhizosphere of cowpea.

Composts were produced from rice straw enriched with rock phosphate and inoculated with Aspergillus niger, Trichoderma viride and/or farmyard manure (FYM). The resulting composts were evaluated as organic phosphate fertilizers for cowpea plants in pot experiments. The results showed that the maximum amount of soluble phosphorous (1000 ppm) was produced in composts inoculated with A. niger+T. viride with or without FYM. Any of the produced composts was much better than superphosphate fertilizer in providing the growing cowpea plants with phosphorous. Fertilization of the cowpea plants with the compost inoculated with FYM+A. niger+T. viride resulted in maximum amount of phosphorous uptake (295 ppm). The highest phosphate dissolving fungi numbers in rhizosphere soils of cowpea plants were obtained after fertilization with composts which received A. niger and T. viride treatments, while the highest phosphate dissolving bacterial numbers were found after fertilization with composts which received FYM treatments.

[Studies on influence of fungal elicitor on hairy root of Panax ginseng biosynthesis ginseng saponin and biomass].

OBJECTIVE: To study influence of fungal elicitors on the biomass and ginseng saponin biosynthesis of hairy roots of Panax ginseng (HRPG). METHOD: Fungal elicitors were extracted from Colletorichum lagnarinm, Phoma filtrate, Fusarium oxysponum, Asperillus niger and culture with HRPG. The total ginseng sponin and four kinds of monomeric sponins were analysed by UV-spectrophotometry and RP-HPLC. RESULT: Fungal elicitors coula not only can influence on HRPG biomass and total ginseng sponin, but also improve or decrease some monomeric sponin. The total ginseng sponin could be increased to 3.649% but Rg1 and Re could not be detected when A. niger elicitors wss 20 mg x L(-1) in the culture fluid. CONCLUSION: Fungal elicitor has specificity influence on secondary metabolite of HRPG. HRPG can biosynthesize specially active component by using specific fungal elicitor is used.

Disruption of the Aspergillus niger argB gene: a tool for transformation.

We disrupted the Aspergillus niger gene argB, encoding ornithine transcarbamylase. Full characterisation of the argB deletion was performed by Southern blot analysis, growth tests and by means of mitotic recombination, complementation and transformation. The argB locus was found to be physically removed, thus creating an auxotrophic mutation. The latter can be supplemented by addition of arginine into the culture medium. The argB gene and its disruption do not correlate to the argI13 (formerly argB13) allele described. The delta argB is on chromosome I whereas argI13 is on V. In addition, the argI13 mutation can only be complemented by the A. nidulans argB gene, whereas the new argB deletion can be complemented by both the A. niger and A. nidulans argB genes. The delta argB strain has been used to generate several strains in a breeding programme and to study the expression of important genes, such as areA and kexB.