Niger Van Tieghem Research Articles

Molecular and biochemical characterization of Trichoderma isolates inhibiting a phytopathogenic fungi Aspergillus niger Van Tieghem

Random Amplified Polymorphic DNA (RAPD) was used to examine the genetic variability among twelve isolates of Trichoderma representing three species and their ability to antagonize Aspergillus niger Van Tieghem causing collar rot in peanut using dual culture assay for correlation among RAPD products and their hardness to A. niger. One hundred and three of the 108 bands, using random decamer fungal primers, were polymorphic with an average frequency of 11.4 bands. The calculated Polymorphism Information Content (PIC) values for RAPD markers ranged from 0.172 to 0.401 and RAPD primer index (RPI) ranged from 0.99 to 6.01. RPI showed that RFu C-5 gave best results of polymorphism among the primer used in the experiment. RAPD analysis showed 10 marker loci for diagnosis of Trichoderma viride 60 and/or Trichoderma harzianum 2J, first two highest inhibitory acting antagonists. A UPGMA dendrogram constructed on the basis of Jaccard’s similarity coefficient using NTSYS 2.2 program which illustrated two distinct clusters of 12 isolates of Trichoderma and A. niger pathogen, and shared only 19% similarity. However, the in vitro highest A. niger growth inhibitory Trichoderma isolates – T. viride 60 (86.2%) and T. harzianum 2J (80.4%) were in same out group and shared 63% similarity. Relationship was found between the polymorphism showed by the Trichoderma isolates and their hardness to A. niger, in terms of in vitro production of cell wall degrading enzymes- chitinase, β-1,3 glucanase and protease, during antagonism.

Early discrimination of fungal species responsible of ochratoxin A contamination of wine and other grape products using an electronic nose

An electronic nose (e-nose) system using an array of metal oxide sensors (Fox 3000, Alpha MOS) was used to detect and discriminate two ochratoxigenic fungal species, Aspergillus carbonarius (Bain.) Thom and A. niger Van Tieghem, that are responsible for the contamination of wine and other wine grape products, using their volatile production patterns. Two well-known ochratoxigenic strains were used in this study: A. carbonarius A941 and A. niger A75. These strains were grown on three culture media, Czapek Dox modified (CDm) agar, yeast extract sucrose (YES) agar and white grape juice (WGJ) agar, and the volatile organic compounds produced in the headspace by these species were evaluated over periods of 48-120h. The e-nose system was able to differentiate between the two species within 48h of growth on YES and WGJ agar using principal component analysis (PCA), which accounted for 99.9% and 97.2% of the data respectively, in principal components 1 and 2, based on the qualitative volatile profiles. This differentiation was confirmed by cluster analysis of data. However, it was not possible to separate these species on CDm agar. Our results show that the two closely related ochratoxigenic species responsible for the contamination of wine and other wine grape products can be discriminated by the use of qualitative volatile fingerprints. This approach could have potential for rapid identification of A. carbonarius and A. niger on wine grape samples, thereby significantly reducing the time of detection of these ochratoxin A producing species.

Immobilization of polygalacturonase fromAspergillus nigeronto activated polyethylene and its application in apple juice clarification

The present work is focused on efficient immobilization of polygalacturonase on polyethylene matrix, followed by its application in apple juice clarification. Immobilization of polygalacturonase on activated polyethylene and its use in apple juice clarification was not reported so far. Aspergillus niger Van Tieghem (MTCC 3323) produced polygalacturonase when grown in modified Riviere's medium containing pectin as single carbon source by fed-batch culture. The enzyme was precipitated with ethanol and purified by gel filtration chromatography (Sephacryl S-100) and immobilized onto glutaraldehyde-activated polyethylene. The method is very simple and time saving for enzyme immobilization. Various characteristics of immobilized enzyme such as optimum reaction temperature and pH, temperature and pH stability, binding kinetics, efficiency of binding, reusability and metal ion effect on immobilized enzymes were evaluated in comparison to the free enzyme. Both the free and immobilized enzyme showed maximum activity at a temperature of 45 degrees C and pH 4.8. Maximum binding efficiency was 38%. The immobilized enzyme was reusable for 3 cycles with 50% loss of activity after the third cycle. Twenty-four U of immobilized enzyme at 45 degrees C and 1 h incubation time increased the transmittance of the apple juice by about 55% at 650 nm. The immobilized enzyme can be of industrial advantage in terms of sturdiness, availability, inertness, low price, reusability and temperature stability.

Study on the increase mechanism of the caffeine content during the fermentation of tea with microorganisms

The tea caffeine content had previously been shown to increase reasonably after being treated with mixed microorganisms for a period of time. In this study, single microorganisms were used in the fermentation of black and green teas in order to find which microorganism has the best effect on increasing the caffeine content. The results demonstrated that molds fermentation increased the caffeine content, but yeasts fermentation decreased the caffeine content. Among the three molds in this study, Aspergillus niger van Tieghem has the most remarkable effect, and the caffeine content in dry green tea increased from an initial 3.47% to 9.63%. The increase rate was 177.5% on the 16th day. Furthermore, the changes of caffeine and theophylline were of a similar trend. Possibly theophylline instead of theobromine is the precursor of caffeine in the living microorganisms. The new biosynthetic route is different from that in tea plants.

Microbiota fúngica dos condicionadores de ar nas unidades de terapia intensiva de Teresina, PI

With the aim of identifying the fungus microbiota in air conditioners in intensive care units (ICUs) within public and private hospitals in Teresina, Piauí, solid material was collected from ten different ICUs. Thirty-three species of Moniliaceae and Dematiaceae were isolated, which was the first report of these in Piauí. High frequencies of Aspergillus niger Van Tieghem (60%), Aspergillus fumigatus Fres (50%), Trichoderma koningii Oudem (50%) and Aspergillus flavus Link: Fr. (40%) were recorded. The air conditioner cleanliness validity had expired in all the ICUs, and the quantity of colony-forming units exceeded the levels permitted by Law 176/00 from the Ministry of Health. It is important to provide individual protection equipment for professionals, adopt hospital infection control measures, raise the awareness of the presence of fungus infection, improve air circulation around the environment, periodically clean the air conditioners, and make health professionals alert to the importance of these fungi in the hospital environment.

Effects of Cymbopogon citratus L. essential oil on the growth, lipid content and morphogenesis of Aspergillus niger ML2‐strain

The mycelial growth of Aspergillus niger van Tieghem was completely inhibited using 1.5 (microl/ml or 2.0 (microl/ml of Cymbopogon citratus essential oil applied by fumigation or contact method in Czapek liquid medium, respectively. This oil was found also to be fungicidal at the same concentrations. The sublethal doses 1.0 and 1.5 (microl/ml inhibited about 70% of fungal growth after five days of incubation and delayed conidiation as compared with the control. Microscopic observations using Light Microscope (LM), Scanning Electron Microscope (SEM) and Transmission Electron Microscope (TEM) were carried out to determine the ultra structural modifications of A. niger hyphae after treatment with C. citratus essential oil. The hyphal diameter and hyphal wall appeared markedly thinner. This oil also caused plasma membrane disruption and mitochondrial structure disorganization. Moreover, Ca+2, K+ and Mg+2 leakages increased from the fumigated mycelium and its total lipid content decreased, while the saturated fatty acids decreased and unsaturated fatty acids increased. These findings increase the possibility of exploiting C. citratus essential oil as an effective inhibitor of biodegrading and storage contaminating fungi and in fruit juice preservation.

Moulds identification and detection of aflatoxin B1 on commercial codiments fermented of shrimp

Indonesian tropical climate have an opportunity for fungi growth as Aspergillus flavus Link which can produce aflatoxin within foodstuffs, include condiment of fermented shrimp. Aflatoxin B1 is the dangerous agent having roles as carcinogenic, mutagenic and teratogenic. The aims of this research were known kinds of moulds and detection of aflatoxin B1 on commercial condiments fermented of shrimp. Two brands of commercial condiments fermented of shrimp were taken from traditional markets and supermarkets in Surakarta. Isolation was done by made suspension of sample in aquadets. Suspension on appropriate dilutions was grown on CDA (Czapek’s Dox Agar) media withsurface spread. The grown colonies were separated and grown on PDA (Potato Dextrose Agar) slant media. Furthermore, isolates were cultured on CDA and MEA (Malt Extract Agar) media. The grown colonies were microscopes and microscopes examined and identified. Existence of aflatoxin B1 was known by Commercial RIDA Screen ELISA Kit that could detect qualitatively and quantitatively with detection sensitive < 1.7 ppb. Moulds that could be isolated from condiments fermented of shrimp were: Aspergillus flavus Link, Aspergillus niger vanTieghem, Aspergillus wentii Wehmer, Aspergillus PU1 or Aspergillus PU2 and Penicillium citrinum Thom. There was aflatoxin B1 contaminated to 2 brands of commercial condiments fermented of shrimp that were examined. Traditional markets’ commercial condiments fermented of shrimp contained higher aflatoxin B1 than supermarkets’. The brands of commercial condiment of fermented shrimp which hadbetter inner package quality contained lower aflatoxin B1 than the worst inner package quality of commercial condiments of fermented of shrimp.© 2006 Jurusan Biologi FMIPA UNS SurakartaKeywords: commercial condiments fermented of shrimp, moulds, aflatoxin B1

The Ability of Plant Compost Leachates to Control Black Mold (Aspergillus niger) and to Induce the Accumulation of Antifungal Compounds in Onion Following Seed Treatment

Onion seeds treated with leachates of composts prepared from alfalfa and sunflower stalks, at the dosages of 10% and 20% respectively, were inoculated with Aspergillus niger van Tieghem, causal agent of onion black mold disease. The ability of the leachates to induce the production of antifungal compounds and to control black mold were tested at seedling and set stages. Leachates from both composts were able to reduce disease incidence in sets, but not disease severity in onion seedlings. Extracts from treated seedlings and sets were fractionated by thin layer chromatography for their content of antifungal compounds. There were no significant differences between the fractions of alfalfa and sunflower compost leachates in the inhibition of the mycelium growth of A. niger, with the exception of one fraction. The presence of fluorescent pseudomonads and Pantoae agglomerans [synonym: Erwinia herbicola (Lohnis)] bacteria was determined in both leachates. The population of P. agglomerans was higher in the sunflower compost leachate compared to the alfalfa leachate. The tested strains of both bacteria were able to inhibit mycelium growth of the fungal pathogen in agar tests. This study suggests the possible role of beneficial bacteria in the induction of antifungal compounds in onion against A. niger during seedling and set stages.

A NEW SEMI-SELECTIVE MEDIUM FOR THE OCHRATOXIGENIC FUNGUS ASPERGILLUS CARBONARIUS

SUMMARY Aspergillus carbonarius (Bainier) Thom. and Aspergillus niger Van Tieghem are common fungal contaminants of several commodities, including grapes. A. carbonarius is the most important, if not the exclusive, responsible for wine contamination by ochratoxin A (OTA) in Mediterranean areas. Identification of A. carbonarius is made difficult by its high similarity with A. niger, the Aspergillus species most common on grapes, as well as with other species of the section Nigri of this genus. Hence, it requires deep knowledge of fungal taxonomy. A semi-selective medium based on Malt Extract Agar amended with appropriate antibiotics (chloramphenicol and chlortetracycline) and fungicides (dichloran and boscalid) was developed in order to speed up the quantitative detection of A. carbonarius in grapes and musts and improve risk assessment of OTA contamination in wine.

Growth response to squalene, a tick allomonal component, by fungi commonly associated with the american dog tick, Dermacentor variabilis (Say)

Squalene, a bloodmeal component secreted by ticks for defense (allomone), was tested for antifungal activity against naturally occurring antagonistic molds isolated from the American dog tick, Dermacentor variabilis (Say). Temperature-growth profiles separated Aspergillus niger van Tieghem, Penicillium glabrum (Wehmer) Westling and the entomopathogen Metarhizium anisopliae (Metsch.) from slower developing Cladosporium cladosporioides (Fresenius) de Vries and Scopulariopsis brevicaulis (Sacc.) Bainier and demonstrated peak growth at 24°C-34°C. In contrast to fast growing fungi, C. cladosporioides and S. brevicaulis showed heightened growth on blood agar but suppressed growth on media supplemented with squalene. Squalene had no effect on the growth of other fungi, indicating its release has minimal significance as a surface antimycotic. Scopulariopsis brevicaulis is endosymbiotic in D. variabilis, and depleting tick secretory (squalene) reserves by leg pinching promoted susceptibility to increasing levels of S. brevicaulis by creating a fungal bloom that killed the tick. We conclude that mycostatic ability of squalene to regulate growth of S. brevicaulis within the tick is more important than its ability to deter fungi from penetrating internally.

Modulation of water activity on fungicide effect on Aspergillus niger growth in Sabouraud dextrose agar medium*

To examine whether water activity (aw) in combination with low concentration of fungicides can be used to effectively control Aspergillus niger van Tieghem growth in cultural medium, the Sabouraud dextrose agar (SDA). The data would be used as baseline information for reducing A. niger contamination in insect artificial diets. Aspergillus niger was isolated from an insect artificial diet. Four concentration levels (i.e. 0, 1, 10 and 20 micromol) of two fungicides (i.e. amphotericin B and itraconazole) were tested against A. niger under four aw levels (i.e. 0.994, 0.961, 0.921 and 0.859) adjusted by including 0, 12.5, 25 and 38% of glycerol in the medium mixture. Aspergillus niger growth was significantly reduced at low fungicide concentration (1 micromol), and at reduced aw. The spore germination was prevented with either higher fungicide concentration (>10 micromol), or low aw in the medium (aw < 0.921). The two ecological determinants (fungicides and aw) showed a significant impact on A. niger survival in the medium (P < 0.0001). Itraconazole is more effective than amphotericin B in controlling A. niger contamination in the agar medium. Adjustment of aw (with 12.5% of glycerol) in combination with 1 mumol of itraconazole can effectively prevent A. niger growth in the SDA cultural medium. Aspergillus niger contaminations have frequently affected the quality of insects produced from mass rearing facilities. Low aw in combination with low fungicide concentration has the potential to become one of the most cost-effective management strategies to prevent A. niger contamination in insect artificial diets. The effect of fungicides and low aw in artificial diets on insect biology needs to be further examined.

Scopulariopsis brevicaulis (Deuteromycota) affords protection from secondary fungus infection in the American dog tick, Dermacentor variabilis (Acari: Ixodidae): inference from competitive fungal interactions in vitro

Scopulariopsis brevicaulis (Sacc.) Bainier is an internal fungal associate of the American dog tick, Dermacentor variabilis (Say) - vector of Rocky Mountain spotted fever. When cultured in vitro, S. brevicaulis reduces or prevents the initiation of conidia and diminishes growth of other common, but potentially antagonistic molds (Aspergillis niger van Tieghem, Cladosporium cladosporioides (Fresen.) de Vries, Penicillium glabrum (Wehmer) Westling) isolated from tick external surfaces. Based on evidence through secondary resource capture, S. brevicaulis appears to serve as a deterrent to other fungi that may have the potential to infect and exploit the tick internally. By developing a “combative” (C) strategy, S. brevicaulis illustrates a novel form of mycoprophylaxis, and may explain this fungus' sole occurrence inside the tick. Thus, harboring this fungus may be of considerable benefit to D. variabilis, especially when conditions promote growth of potentially harmful fungi in the tick's environment.

New bis-quaternary ammonium and bis-imidazolium chloride wood preservatives

Abstract Bis-quaternary ammonium and bis-imidazolium chlorides, the compounds containing in their structure two symmetrical quaternary nitrogen atoms, were prepared and tested on wood destroying and sapstaining fungi. The effect of the position of quaternary nitrogen atoms upon fungicidal and surface properties was analysed. The antifungal activity of new bis-quaternary ammonium and bis-imidazolium chlorides against Coniophora puteana (Schum.:Fr.)Kr., Trametes versicolor (L.:Fr.)Pilát and Aspergillus niger van Tieghem was much more pronounced than that of quaternary ammonium chlorides. The results confirm the correlation between surface activity and fungicidal activity. The adsorption of bisimidazolium chloride onto pine wood was influenced by pH of applied solutions and the initial solution concentration. With increasing pH of ammonium solution, the adsorption was much greater than in neutral or acidic solutions. Cation structure of the quaternary ammonium chloride exerted a strong influence on quantity of wood-adsorbed chemicals and resistance to water leaching.

Degradation of the Herbicides Thiobencarb, Butachlor and Molinate by a Newly Isolated Aspergillus niger

Thiobencarb (S-4-chlorobenzyl diethylthiocarbamate) is a thiocarbamate herbicide used for weed control in rice production. After screening, a strain able to degrade thiobencarb, identified as Aspergillus niger van Tieghem, was successfully isolated. Optimal conditions for thiobencarb degradation in culture were at pH 5.5 and 30°C. The strain also showed the ability to degrade the herbicides molinate and butachlor. © Pesticide Science Society of Japan

BIODEGRADED COCOPEAT AS A HORTICULTURAL SUBSTRATE

Cocopeat or coir dust is a by-product separated during processing of coconut (Cocos nucifera L.) coir. As a by-product of coir manufacturing, cocopeat is often unutilized or burnt in the open. Of late, due to environmental concerns and also diminishing supplies of peat soils for horticultural substrates, cocopeat is being considered as a renewable peat substitute for use in horticulture. However, in its raw form, cocopeat has been reported to contain phytotoxic elements which inhibit plant growth. As such, cocopeat is often recommended for use only with a mixture of other organic or inert materials. The present study was conducted to determine the effect of biodegradation (composting) on improving the qualities of cocopeat as a horticultural substrate. Cocopeat was supplemented with 0.75% N and inoculated with selected mould and wood rotting micro-fungi viz. Aspergillus niger van Tieghem, Penicillium citrinum Thom, Trichoderma sp., Humicola sp. and Chaetomium globosum Kunze. The medium was maintained at about 80% moisture content (wet weight basis) and incubated at 27°C for 3 months. The results showed that the 3-month biodegraded cocopeat has lower C/N ratio, higher CEC and humic acid than the raw cocopeat. The lowering of C/N ratio was due to addition of N and the reduction of carbon, mainly the hemicellulose, cellulose and to a lesser extent the lignin components. In the greenhouse trial, tomato plants grew well in the 3-month 'composted' cocopeat. Though their plant heights and stem diameters were not significantly different from those grown in the untreated cocopeat, the plants on 'composted' cocopeat produced higher dry root weights (22%), fruit numbers (43%) and total yield (64%).

Wilt disease of Arachis hypogaea L. in Ekpoma, Edo State, Nigeria

Summary. A 2-year survey (1993, 1994) of peanut farms in Ekpoma, Edo State, Nigeria, showed that 21.5 ± 1.1% of the crop was affected by wilt disease. The microflora associated with the roots of wilted peanut plants were Penicillium oxalicum Currie and Thom (15.2%), P. citrinum Thom (12.3%), Fusarium oxysporum Schlect. I (35.6%), F. oxysporum II (55.3%), F. oxysporum III (26.8%), F. solani (Mart.) Sacc. I (6.3%), F. solani II (10.5%), Aspergillus niger Van Tieghem (5.5%), Trichoderma koningii Rifai (15.0%) and Botryodiplodia theobromae Pat. (5.0%). Others included Ralstonia (Pseudomonas) solanacearum (Smith) Smith (5.0%), Rhizobium sp. (20.0%) and Bacillus sp. (15.3%). Pathogenicity tests using 106 fungi spores/mL and 106 cells of bacteria isolates/mL showed that Fusarium oxysporum was responsible for the wilting of peanut seedlings in this locality.

Isolation, purification and properties of tannase from Aspergillus niger van Tieghem

Tannase (tannin acyl hydrolase E.C. 3.1.1.20) has been isolated from Aspergillus niger van Tieghem and purified 29-fold. The enzyme had a temperature optimum of 60 °C, pH optimum of 6.0 with a second peak at pH 4.5, Km of 0.20 mM and Vmax of 5.0 μmol min−1 mg−1protein.

Comparison of Glycosylation Patterns of Phytase from Aspergillus Niger (A. Ficuum) NRRL 3135 and Recombinant Phytase

The glycosylation patterns of phytase (E C 3.1.3.8) from Aspergillus niger NRRL 3135 with recombinant phytase from A. niger van Tieghem were compared. The following characteristics were studied: size of the whole molecule, type of linkage (N-linked or O-linked oligosaccharide), profile (number of different types of oligosaccharides present), monosaccharide composition, their order, and configuration. The molecular weights of both glycoproteins, after deglycosylation, was approximately 55 kDa as determined by SDS-PAGE. Both glycoproteins were about 35.29% glycosylated (calculations were made on the basis of 85 kDa molecular weight before deglycosylation). Only N-linked oligosaccharides were present. When N-linked oligosaccharides were released and labeled, the same profile was obtained for both glycoproteins. Mannose residues were detected after digestion by combinations of various exoglycosidases. N-acetylneuraminic acid, galactose, and N-acetylglucosamine residues were not detected. Released mannose residues were (α1-2,3,6) linked. The trisaccharide core structure was non-fucosylated for all the oligosaccharides released from both glycoproteins. The only major difference found between the two glycoproteins was the migration pattern of oligosaccharide bands on gel after digestion with α-mannosidases. The structure of N-linked oligosaccharides ranged from (Man)5(GlcNAc)2 to (Man)10 (GlcNAc)2.

Preliminary studies on tannin degradation by Aspergillus niger van Tieghem MTCC 2425.

A tannin-degrading strain of Aspergillus niger van Tieghem was grown at pH 5.0 and 30 degrees C in a defined medium where tannins were the sole source of carbon and energy. The fungus had variable growth in tannic acid- and quebracho tannin-medium and could tolerate these tannins even up to 150 g-1 without showing any growth inhibition.

Isolation of a tannin-protein complex-degrading fungus from faeces of hill cattle.

Faecal samples of 52 hill cattle fed largely on oak leaves were screened for tannin-protein complex-degrading micro-organisms under different culture conditions using tannin-treated brain heart infusion agar medium. None of the animals were found to harbour tannin-protein complex-degrading enterobacteria. However, a fungus identified as Aspergillus niger van Tieghem having tannin-protein complex-degrading activity, was consistently isolated from the faeces of such animals. Optimum growth and sporulation was noticed under aerobic conditions at 30 degrees C on Czapek Yeast Agar medium.