Isolated Aspergillus Niger Research Articles

Investigation of inter- and intraspecies variation through genome sequencing of Aspergillus section Nigri

Aspergillus section Nigri comprises filamentous fungi relevant to biomedicine, bioenergy, health, and biotechnology. To learn more about what genetically sets these species apart, as well as about potential applications in biotechnology and biomedicine, we sequenced 23 genomes de novo, forming a full genome compendium for the section (26 species), as well as 6 Aspergillus niger isolates. This allowed us to quantify both inter- and intraspecies genomic variation. We further predicted 17,903 carbohydrate-active enzymes and 2,717 secondary metabolite gene clusters, which we condensed into 455 distinct families corresponding to compound classes, 49% of which are only found in single species. We performed metabolomics and genetic engineering to correlate genotypes to phenotypes, as demonstrated for the metabolite aurasperone, and by heterologous transfer of citrate production to Aspergillus nidulans. Experimental and computational analyses showed that both secondary metabolism and regulation are key factors that are significant in the delineation of Aspergillus species.

Application of silver nanoparticles on Cephalosporium maydis in vitro and in vivo

IT IS NOTICEABLE that Cephalosporium maydis causes late wilt disease that is considered sole of the ultimate destructive diseases in Zea maize. The crop output is declined due to the infection riskiness raises. Silver nanoparticles (AgNPs) were prepared using a simple bio-reduction method, which is ecologically welcomed and cost-effective. In our investigation, the effect the antifungal activity of AgNPs was evaluated alone or combined with one of each two different fungicides on C. maydis in vitro and in vivo. An isolate of Aspergillus niger previously isolated and identified in our laboratory was used to induce AgNPs. The NPs production,s undergone to optimization study for increasing AgNPs product besides its stability. AgNPs production after optimization showed very stable product compared with those before optimization conditions. A significant increase in the absorbance was noticed from 0.8OD into 1.25OD and the NPs size decreased from 19nm into 9nm. In addition, TEM showed more obvious and clear AgNPs, in addition, a higher degree of stability and protein functional surface reactive groups at (-29.3mv) with single peak was revealed for six months. Under laboratory conditions, the higher rate of growth inhibition of C. maydis was obvious in case of using AgNPs either alone or combined with fungicides. Parallel results were found under greenhouse conditions where AgNPs caused a severe reduction in disease severity of C. maydis infected plants accounting (57.7%) alone or combined with Maxim XL (75.5%) or Vitavax (90%). This research opens up new possibilities in the field of using AgNPs in plant disease treatment.

Hydrolytic activity of amylase produced in solid - state fermentation by a local isolate of Aspergillus niger

Hydrolytic activity of amylase produced in solid - state fermentation by a local isolate of Aspergillus niger

Occurrence of Toxigenic Fungi and Mycotoxins on Root Herbs from Chinese Markets

Herbs derived from roots, leaves, flowers, or fruits of plants are unavoidably contaminated with fungi and mycotoxins during growth, harvest, and storage, thereby posing a health threat to humans. Especially, root herbs (RHs) are more easily contaminated with fungi and mycotoxins because the roots are in direct contact with the soil. Here, we investigated the occurrence of fungi, aflatoxins (AFs), and ochratoxin A (OTA) in eight RHs that are used as medicines, beverages, dietary supplements, and functional foods in China and other countries. Morphological observation and MultiGeneBlast (β-tubulin and calmodulin) were used to identify the potentially toxigenic fungi. Of the 48 samples tested, all were contaminated by fungi, and 1,844 isolates belonging to 25 genera were detected. The genera Aspergillus and Penicillium, which contain potentially toxigenic fungal species, represented a frequency of 10 and 25%, respectively. Thirty-three isolates of Aspergillus flavus, Aspergillus parasiticus, Aspergillus niger, and Penicillium polonicum were arbitrarily selected for analysis of their toxigenic potential. Five of 13 isolates of A. flavus and 1 isolate of A. parasiticus produced AFs, whereas OTA production was not detected for any of the isolates of A. niger and P. polonicum. The occurrence of AFs and OTA in the 48 samples of eight RHs was tested by ultraperformance liquid chromatography-tandem mass spectrometry; 37.50% of samples from six RHs were contaminated with AFs and 16.67% of samples from four RHs were contaminated with OTA. Seven (14.58%) and four (8.33%) samples of ginseng, polygala, and liquorice exceeded the permissible limits of aflatoxin B1 and AFs, respectively. Because ginseng, polygala, and liquorice are widely used as herbs, dietary supplements, and functional foods, the high frequency of AF contamination of these herbs indicated by our current study warrant attention to raise public awareness.

English

Pineapple (Ananas comosus L.) is one of the most important crops grown in Africa. The fruit is consumed fresh by many people and hence, source of essential mineral elements, nutrients and vitamins. This study was conducted to investigate the fungi associated with black rot disease of pineapple fruits and the effect of the disease on nutritional value of the fruits. The fungi isolated from black rot pineapple fruits got from Uselu, Ikpoba Hill, Oba, Oluku and New-Benin Markets in Benin City, were grown on Potato Dextrose Agar (PDA) at room temperature (28±2°C) and observed morphologically and microscopically for cultural and spore characteristics. Assimilative property of yeasts was determined with carbon substrates and peptone. Freshly harvested pineapple fruits (six wounded and six unwounded) were inoculated with the fungus responsible for black rot and incubated for six days (pathogenicity test). Healthy fruits as well as infected ones were analysed for carbohydrate, fibre, moisture, protein, and minerals. Two isolates of Ceratocystis paradoxa (black rot fungus), four isolates of yeasts, Aspergillus niger and Penicillium species were identified. Black rot was prominent in wounded pineapple fruits after six days of inoculation. The four isolates of yeast assimilated the carbon substrates and peptone. Furthermore, the infected fruits showed relative decrease in nutrient composition as compared to healthy fruits. With this basic knowledge of growth of C. paradoxa, the cause of black rot of pineapple fruit, better handling and storage can be planned in order to reduce crop losses. Key words: Black rot, Ananas comosus fruit, Ceratocystis paradoxa, nutritional value.

Cost effective production of complete cellulase system by newly isolated Aspergillus niger RCKH-3 for efficient enzymatic saccharification: Medium engineering by overall evaluation criteria approach (OEC)

A newly isolated fungus Aspergillus niger RCKH-3 was employed for cost effective production of a complete cellulase system under solid state fermentation (SSF). Overall evaluation criteria approach (OEC) was used as a novel approach for medium engineering to maximize the cellulase production. Among several factors studied, NH4Cl, inoculum age and temperature contributed maximally towards cellulase production. The highest interactions were observed between inoculum age and beef extract, followed by substrate to moisture ratio and PEG 8000. The statistical model provided optimal enzyme production conditions as: 5 g wheat bran; mineral salt solution (pH 5) and containing (g/L); NH4Cl (0.5), beef extract (2.0) and PEG 8000 (3.0) substrate to moisture ratio of 1:3.5 and 30% (v/w) 18 h old inoculum. Under optimum conditions, cellulase production experienced 2.5, 3.0 and 1.5 fold enhancements in FPase, CMCase and β-glucosidase activities, respectively. The estimated production costs ($ per 1000 units) for FPase, CMCase, β-glucosidase were 0.47, 0.21 and 0.04, respectively. Saccharification of office waste paper using crude cellulase resulted in reducing sugar yield of 534 mg/g dry substrate. Cellulase of newly isolated fungi A. niger RCKH-3 shows potential in biofuel applications based on its comparatively higher saccharification abilities and lower production costs.

Role of Metal Ions, Surfactants and Solvents on Enzymatic Activity of Partial Purified Glucoamylase from Aspergillus niger ER05

The glucoamylase requirement of different industries should vary in their physiochemical and functional properties, so the investigation of new sources for the novel enzymes is the only solution. The current study describe the production of glucoamylase from Aspergillus niger ER05 in a submerged fermentation. The enzyme then partially purified and then effect of thirteen different metal ions (Cs+, K+, Na+, Ba2+, Ca2+ Co2+, Cu2+ , Hg2+, Mg2+, Mn2+, Ni2+, Zn2+ , Fe3+), surfactant as well as organic solvent on catalytic performance of glucoamylase was studied. A newly isolated Aspergillus niger ER05 is hyper producing strain of glucoamylase. Specific activity for the crude enzyme was found to be 6.87 KU/mg. The crude enzyme was partially purified via fractional ammonium sulphate precipitation. Ammonium sulphate saturation from 40-80% was found suitable to precipitate the enzyme. After dialyzing precipitates, the specific activities were found to be 66.33KU/mg with percent yield of 26.5. The inhibitory influence of all metal studies was interestingly found on glucoamylase activity. The strong inhibition was demonstrated in presence of Hg2+, Ni2+, Zn2+, Cu2+, Fe3+. Only Na+ ions were able to maintain the 101% relative activity at 1mM concentration. The SDS completely inhibits the enzyme activity and in presence of tween-80 and triton X-100 glucoamylase exhibited less than 45% relative activity. Furthermore, formaldehyde, isopropanol, ethanol, methanol, and DMSO stabilized the enzyme activity while chloroform inhibits enzyme activity by 48%.

Bioethanol Production from Fungal Treated Rice Husks Fermented with Bakers Saccharomyces cerevisiae and Yeast Isolates from Palm Wine

This research was necessitated by the quest to create a useful product from wastes (bio-ethanol from rice husk). This if successful will serve two purposes; first, help reduce wastes in the environment and to create wealth from waste. Separated isolates of Trichophyton soudanense, Trichophyton rubrum, Trichophyton mentagrophyte, Aspergillus oryzae, Aspergillus niger and Aspergillus fumigatus were obtained from husks of processed rice undergoing decomposition for more than 8 months. Husks of freshly processed rice were pretreated by autoclave boiling for 20 minutes at a temperature of 121°C after mixing in Mandle’s media. The experimental test samples consisted of co-culture combinations and monocultures individually inoculated into various measured heat treated husks; additional control groups were also made. Non-reducing sugar, reducing sugar and total sugar were assayed at the seventh day following hydrolysis. The resulting filtrates of the various husks (treated and control experimental units) were subjected to 7 days fermentation with yeasts from palm wine as well as bakers’ yeasts. Values of the result indicated highest trends in the following treatments: T. mentagrophyte treated husks with soluble reducing sugar value of 2.66 ± 0.14 g/L, A. fumigatus treated husk with soluble non reducing sugar value of 18.08 ± 2.61%, co-culture of T. soudanense and T. rubrum treated husks gave total sugar value of 20.53 ± 2.73%. Fermented A. oryzae treated husk filtrate inoculated with palmwine yeasts had optimal bio-ethanol yield (120.82 ± 0.39 g/L) followed by A. oryzae and T. soudanense treated husks fermented with bakers yeasts with 60.60 ± 0.10 g/L bioethanol. Recognizable yields of bioethanol from palm wine yeast fermented husk as well as sugar from other treated husks were obtained.

Diversity of Azoles Resistant Aspergillus Species Isolated from Experience and Naïve Soils in Nairobi County and Naivasha Sub-County Kenya

New triazole antifungals voriconazole, itraconazole and posaconazole are recommended for prophylaxis and treatment of both invasive and chronic fungal infections such as aspergillosis and aspergilloma. Emergence of azole-resistant among A. fumigatus isolates have been reported in other countries including Tanzania ascribed to either previous antifungal treatment, prophylaxis or triazoles use in agriculture. The use of azole based fungicides in the robust horticulture in Kenya is a significant risk factor for antifungal resistance. The study proposes to analyze environmental isolates of Aspergillus fumigatus, Aspergillus flavus and Aspergillus niger for the presence of resistance against the triazoles antifungals. Fungicide naïve soils were obtained from uncultivated virgin fields while fungicide experience soils were collected from flower, agricultural and horticultural fields and greenhouses within Naivasha sub-county and Nairobi County. The fungal isolates were subjected to antifungal susceptibility to triazoles using broth micro dilution method. A total of 492 samples were analyzed in Nairobi, 52 isolates were identified and they resistance were as follow: A. fumigatus (32%), A. niger (26.09%), A. flavus (33.33%) and A .terreus (0%) and in Naivasha 44 isolates were isolated out of which 25 were A. fumigatus and its resistance was at 36%. Data were analyses using student T test and showed they no different between resistant and susceptible isolates from the two location. Data generated will serve to inform on the current status of triazoles resistance pattern and to raise concern emerging antifungal resistance in clinical practice.

Lipase Production from a Newly Isolated Aspergillus niger by Solid State Fermentation Using Canola Cake as Substrate

Lipase Production from a Newly Isolated Aspergillus niger by Solid State Fermentation Using Canola Cake as Substrate

ISOLASI DAN KARAKTERISASI JAMUR LIGNINOLITIK SERTA PERBANDINGAN KEMAMPUANNYA DALAM BIODELIGNIFIKASI

Fungi can survive in various environments on different media including wood. Lignin in timber is hard to degrade efficiently because of its polymer form, and only a few of it can be hydrolyzed because of its composite and complex structure. Ligninolytic fungi produce an extracellular enzyme to withstand to toxic or mutagenic chemicals exposure and known to degrade different types of pollutant compounds. Lignin decomposers were also known to play a significant role in the pulping process of paper mills, used in waste treatment such as textile and hydrocarbon wastes. This study was conducted to obtain fungal isolates that have de-lignification capability and to compare the ability of fungal isolates to degrade lignin. The research isolated samples from rotten wood and soil using selective lignin medium with tannic acid as sole C source. This study characterized the isolates by its morphology and identified using the Morphology and Taxonomy of Fungi book by Bessey (1950) as a reference. This study compared the ligninolytic capability by measuring the transparent zone formed on selective lignin media. This research found 14 isolates of fungi and all of them had a ligninolytic capability. Aspergillus niger isolate has the highest ligninolytic capability by producing 6.45 cm clear zone diameter on the 7th day. Aureobasidium sp has the smallest clear zone diameter of 1.9 cm within the same period.

Antioxidant Bioactive Compounds and Spoilage Microorganisms of Wax Apple (Syzygium samarangense) during Room Temperature Storage

ABSTRACTPostharvest deterioration of wax apple leads to unacceptable appearances, physical and quality losses that raise serious concerns commercially. Bioactive compounds of wax apple and spoilage microorganisms were studied at room temperature storage (23 ± 1 °C). Antioxidant activity and total phenolic content increased up to a maximum of 1.56 mg AAE/100 g and 88.37 mg GAE/100 g, while prolonged storage resulted in 70.0% and 33.6% loss, respectively. Further, 80% loss in vitamin C content was observed from an initial value of 21.63 mg AAE/100 g during storage. Bacterial isolates of Enterobacter sakazakii, Klebsiella pneumoniae, Klebsiella planticola, Pantoea agglomerans, Chromobacterium violaceum, and Streptomyces roseochromogenus with microbial load of 1.19 * 108 CFU/g fresh weight, and fungal isolates of Penicillium purpurogenum, Mucor hiemalis, Aspergillus niger, Aspergillus fumigatus, and Candida tropicalis with a total load of 5.64 * 107 CFU/g fresh weight were identified as spoilage organisms. Bacterial isolates of Klebsiella pneumoniae was the most prevalent at 47.78%, occurring 21 times, while Penicillium purpurogenum was the most prevalent fungi, occurring 5 times at 38.46%. Results have significant implications on measures to preserve quality of wax apples during storage by adoption of advanced postharvest handling and processing approaches.

Ochratoxin A in Food: An Overview

Ochratoxin A (L-phenylalanine-N-[(5-chloro-3, 4-dihydro-8-hydroxy-3-methyl-1-oxo-1H-2 benzopyrane-7-yl)carbonyl]-(R)-isocoumarin) (OTA) one of the most studied mycotoxins is produced by Penicillium verrucosum and by Aspergillusochraceus but a few isolates of Aspergillus niger. It is one of the most important mycotoxin contaminants in agricultural products and continues to attract global attention concerning the hazard and impact on both human and animals due to its toxicity and occurrence. It has been detected in food commodities such as cereals, wine, coffee, figs, dried fruits and beer and in feeds for animals. The International Agency for Research on Cancer classifies it as a possible carcinogen to human (group 2B). Its symptom includes low appetite, weight loss, faintness, depression, high thirst and increased urination. OTA is one of the major causes of death in human beings and animals. These toxic fungi, contaminate food products in different phases of production and processing, especially in suitable environmental conditions viz., temperature and moisture conditions.

Aspergillus niger PA2 Tyrosinase Covalently Immobilized on a Novel Eco-Friendly Bio-Composite of Chitosan-Gelatin and Its Evaluation for L-DOPA Production

Tyrosinase (EC 1.14.18.1) a copper-containing monooxygenase, isolated from a fungal isolate Aspergillus niger PA2 was subjected for immobilization onto a composite consisting of chitosan and gelatin biopolymers. The homogeneity of the chitosan-gelatin biocomposite film was characterized by X-ray diffraction analyses. To evaluate immobilization efficiency, chitosan-gelatin-Tyr bio-composite films were analyzed by field emission scanning electron microscopy, atomic force microscopy and UV-spectroscopy. The rough morphology of the film led to a high loading of enzyme and it could retain its bioactivity for a longer period. The enzyme adsorbed onto the film exhibited 72% of its activity after 10 days and exhibited good repeatability for up to nine times, after intermittent storage. Moreover, the immobilized enzyme exhibited broader pH and temperature profile as compared to free counterpart. Immobilized enzyme was further evaluated for the synthesis of L-DOPA (2,4-dihydroxy phenylalanine) which is a precursor of dopamine and a potent drug for the treatment of Parkinson's disease and for myocardium neurogenic injury.

Continuous generation of fructose from Taraxacum officinale tap root extract and inulin by immobilized inulinase in a packed-bed reactor

Abstract Production of exo-inulinase from newly isolated Aspergillus niger was statistically optimized using dandelion tap root extract (% fresh w/v) resulting in a ~2.5 fold (2337 nkat/ml) enhancement. Exo-inulinase (1166 nkat/mg) immobilized in Ca-alginate beads was used for continuous generation of fructose from crude inulin extracted from Taraxacum officinale (dandelion) and chicory juice. Immobilized enzyme was optimally active at 50 °C and pH 5.0 and the kinetic parameters evaluated were 3.74 mM ( K m ) and 1.62 µm/min ( V max ). Continuous generation of fructose syrup from low-cost dandelion root extract and chicory inulin using a packed bed bioreactor prepared with exo-inulinase immobilized in alginate beads was demonstrated. Successive degradation of dandelion oligosaccharides and fructans to pure fructose was observed over 30 days period. The bioreactor had a half-life of 15 days and more than 90% (w/w) yield of fructose was observed. The study demonstrated use of a fructan-rich common weed for continuous production of fructose.

Optimization of Glucoamylase Production by Local Isolate of Aspergillus niger Using Agro-Industrial Substrates under Solid State Fermentation

Optimization of Glucoamylase Production by Local Isolate of Aspergillus niger Using Agro-Industrial Substrates under Solid State Fermentation

Optimization of physical and morphological regime for improved cellulase free xylanase production by fed batch fermentation using Aspergillus niger (KP874102.1) and its application in bio-bleaching

ABSTRACTThe physiological and morphological changes were extensively studied during fed batch fermentation using newly isolated Aspergillus niger (KP874102.1). Significantly higher xylanase production was possible through optimization of environmental stresses by fed batch process. The fed batch fermentation was carried out for improved xylanase production (2524 U) where initial xylan was kept 1.5 g/L in the production medium. However, 3 g/L of xylan with 50 mM K2HPO4 having pH-7 was consecutively fed at 72 and 120 h of fermentation. K2HPO4 showed significant role both the morphology of the microorganism and produces enzymes in fed batch fermentation. During feeding phase, the pH was found in the range of 6.5 to 7 which was used as marker for the fed batch process. The crude enzyme was used for the bio-bleaching of banana pulp.

Characterization and treatment of colored textile wastewaters from the typical Tunisian hat Chechia dyeing using newly isolated Aspergillus niger

This study aimed to characterize and investigate, for the first time, the treatment of real colored wastewaters from the artisanal dyeing of the typical Tunisian hat Chechia, using a newly isolated fungal strain. This textile effluent was a mixture called Mix of colored wastewaters from the three main types of C hechia . The major pollutant of the Mix was the toxic Azo dye Amaranth Acid or Acid Red 27. The fungal strain that made the cleanup was discovered in a C hechia dyeing wastewater’s container and identified by ITS rDNA gene sequencing. This isolated Aspergillus niger showed interesting performances on the demonstration of Chechia wastewater’s biodegradation in batch cultures. In order to understand the effect of agitation, Mix dilution and inoculum size on decolourisation and pollution removal, a full factorial experimental design 2 3 was set up. At the optimal conditions which were 20% inoculum size, 25% Chechia Mix dilution and an agitation of 100 rpm, Aspergillus niger was able to remove color as high as 70.18±2.84% at an initial dye concentration of 1346.6±0.01 mg/L, and to reduce COD to 74.17±14.52% at an initial COD of 4157±422 mg/L. FT-IR spectra analysis confirmed the decolourisation by biodegradation and transformation of the dyes. The treatment by the isolated Aspergillus niger could be successfully applied as a sustainable method to solve one of handicraft dyeing plants environmental management issues.

Determination of azole antifungal drug resistance mechanisms involving Cyp51A gene in clinical isolates of Aspergillus fumigatus and Aspergillus niger

Aims: The main aim of this research is to investigate azole resistance mechanisms in A. fumigatus and A. niger which involve Cyp51A gene that encodes 14-α sterol demethylase enzyme. Methodology and Results: Itraconazole susceptibility was determined through E-test method. A conventional PCR method was used to amplify and sequence Cyp51A gene in fungal DNA, to detect the presence of gene mutations. Real-time PCR method was applied to determine overexpression of Cyp51A gene in A. fumigatus and A. niger isolates. Susceptibility test found that 3/13 (23.1%) A. fumigatus and 7/23 (30.4%) A. niger isolates were resistant to Itraconazole, with minimum inhibitory concentrations (MICs) of 2.5 μg/ml to 3.0 μg/ml. Sequencing of A. fumigatus DNA showed presence of L98H mutation in 7/13 (53.8%) and M220 mutation in 3/13 (23%) isolates. Whereas, sequencing of A. niger DNA detected the presence of G427S mutation in 3/23 (13%) isolates. Tandem Repeat mutation was not detected in all A. fumigatus and A. niger isolates. Only M220 mutation showed significant correlation (r (13)=0.041038, p<0.05) with Itraconazole antifungal resistance in A. fumigatus isolates while L98H mutation was not involved. G427S mutation also showed correlation (r (15)=0.038434, p<0.05) with Itraconazole antifungal resistance in A. niger isolates. A higher level of Cyp51A gene expression was detected in 4/8 (50%) A. fumigatus isolates and 7/12 (58.3%) A. niger isolates. Resistant isolates more often showed higher level of Cyp51A gene expression compared to susceptible isolates; however the difference in level of expression between resistant isolates and susceptible isolates is not significant. This may be due to similar MIC values in resistant and susceptible isolates. Conclusion, significance and impact of study: In conclusion the level of azole resistance in A. fumigatus and A. niger isolates in Malaysia is low and mutations in Cyp51A gene may contribute towards Itraconazole antifungal resistance, however other factors may also be involved.

Screening of Citric Acid Producing Fungi from the Leaf Litter Soil of Sathuragiri Hills

Soil samples were collected from ten different locations of Sathuragiri Hills (Western Ghats, Tamilnadu). Percentage frequency of occurrence of fungal isolates was calculated. Cultural characteristics of fungal isolates on Sabouraud's dextrose agar were observed. Fungal isolates were identified based on morphology, cultural characteristics and 18S rRNA sequencing. Citric acid production ability of fungal isolates was screened. Among the isolates Aspergillus niger found to produce the highest quantity of citric acid (2.5 ± 0.01 g/L) and it is selected for further work.