Aspergillus Tamari Research Articles

Nutritional compositions, fungi and aflatoxins detection in stored 'gbodo' (fermented Dioscorea rotundata) and 'elubo ogede' (fermented Musa parasidiaca) from South western Nigeria

Inadequate storage facilities in Nigeria have led to yearly wastage of harvested agricultural food products thereby causing great economic loss to our farmers. The dried yam and plantain chips in storage usually loose their integrities and nutrients due to contamination from biodeteriorating and aflatoxigenic fungi. Aflatoxin detection, food values and mineral element compositions of locally made ‘gbodo’ (prepared from fermented yam, Dioscorea rotundata) and ‘elubo ogede’ (prepared from fermented plantain, Musa parasidiaca) stored for one and six months respectively were carried out using standard methods. Six different samples of each stored chips were collected and used for these investigations. Each set was carried out in triplicates using completely randomize design. A total number of 15 fungal species were isolated from stored ‘gbodo’ (GB) and ‘elubo ogede’ (EO) flour samples. These organisms include Aspergillus flavus, Aspergillus fumigatus, Aspergillus niger, Aspergillus japonicum, Aspergillus parasiticus, Aspergillus ochraceus, Aspergillus tamari, Aspergillus tereus, Fusarium sp, Mucur racemosus, Paccilomyces varioti, Penicillum sp., Penicillum notatum, Rhizopus stolonifer, Rhizopus sp. The presence of mycotoxins (aflatoxin B1, B2, G1 and G)were detected in all the samples. Aflatoxin B1 has the highest concentration: 32.33 μg/kg in 6 months old ‘gbodo’ (6MOG) and 25.17 μg/kg in (1MOG). Its concentration was however lower in 1 and 6 month old ‘elubo ogede’ (1MOEO and 6MOEO) in which 23.83 μg/kg and 15.0 μg/kg were detected respectively. The results showed that, with the exception of 1MOEO, with AFB1 15.0 μg/kg, the levels of aflatoxin contamination in all the stored chips exceeded the maximum AFB1 residue limit permitted in most countries. Starch content of the samples was found to be higher in 1 MOG and’ EO with 73.06 and 75.89% respectively but, the sugar content was generally low. Moisture contents of stored GB and EO also varied from 10.51 to 14.36%. The flours were found to contain moderate amount of protein (7.73 to 9.19%). The ascorbic acid contents of 1MOG and 6MOG were 4.44 and 5.25 mg/100g while that of 1MOEO and 6MOEO were 4.85 and 6.46 mg/100g respectively. It was observed that both GB and EO contained adequate amount of mineral elements such as K, Mg, P, Ca and Na. These fermented flour also has trace amount of Mn, Fe, Cu and Zn. The results showed that ‘gbodo ‘and ‘elubo ogede’ stored for over 6 months (without any preservatives) may be medically unsafe for consumption because of the contamination from aflatoxigenic and biodeteriorating fungi. All these observations were discussed in relation to the food safety of the fresh and stored traditional food investigated. Key words: Traditional food, mycotoxins, white yam, plantain, food safety, storage chips.

Produção de amilases por Aspergillus tamarii em fermentação em estado sólido a altas concentrações iniciais de glucose

The effect of glucose and other soluble sugars (xylose, fructose, maltose, cellobiose and lactose) in the production of amylases by Aspergillus tamari was studied in solid state fermentation (SSF). Wheat bran solid state cultures were resistant to catabolite repression even at high concentration of glucose (10%). Results show the potential of solid state systems to overcome the adverse effects of high sugar concentrations in the media. The ability to prevent catabolite repression appear to be related with the content moisture of solid state systems: less content moisture of cultures means less catabolite repression caused by glucose

Extracts from the Shoots of Arctotis arctotoides Inhibit the Growth of Bacteria and Fungi

Acetone, methanol and water extracts obtained from the shoots of Arctotis arctotoides through shaking and homogenization, were investigated for their antimicrobial activities. Growth inhibition using agar dilution assays was determined against ten selected bacterial and six fungal species. Although not fungicidal, extracts from the herb showed significant growth inhibition against all the fungi tested. The homogenized water extract was particularly inhibitory to the growth of the fungi with inhibitory activity ranging from 50.7 to 95.2% on Aspergillus tamari and Penicillum digitatum, respectively. Acetone and methanol extracts were very active against the Gram positive bacteria. The Gram negative bacteria were, however, more resistant to the extracts than the Gram positive ones. None of the extracts inhibited Klebsiella pneumoniae and Pseudomonous aeruginosa, both Gram negative bacteria.

A Brief Survey of Fungi as Allergen in Respiratory Allergic Patients by Intradermal Skin Sensitivity Test in Terai Area

The present survey was conducted to observe allergic effect of various fungi in patients of respiratory allergy of terai area.Terai area has humid, subtropical climate, warm in winter and hot in summer total of 96 patients were studied after full clinical examination. Age group of patients was 12 to 48 yrs and male female ratio was 3:2.About 12% patients had acute problem of breathlessness and rhinitis while rest were having chronic respiratory allergy. Intradermal test was performed to observe skin sensitivity.Rhizopus nigricans was found most offending fungal allergen (50%), Next to it was Aspergillus fumigates (30 %). Among other fungal allergens eg.Alternaria tenuis (28 %), Aspergillus flavus.(26 %),Curvularia sp.(24 %),Neurospora Sp.( 22 % ), Phoma sp. (18 % ),Fusarium solani (13 % ) ,Helminthosporium sp.(12 %) and Penicillium sp. (11 %) were found as common fungal allergens. Acrothecium sp, Aspergillus niger, Aspergillus tamari, Candida albicans, Cladosporium sp., Mucor sp., Nigrospora sp. and Trichoderma sp.etc were having allergenic effect in less than 10 % patients. About 12 % patients had not shown positive skin sensitivity test against any fungal allergen.

Proximate Composition, Phytonutrient Analysis and Antimicrobial Activity of Ethanolic Extracts of the Young and Mature Leaves of Greenwayodendron suaveolens

The antimicrobial activity, proximate composition and phytonutrient contents of the ethanolic extracts of the young and mature leaves of Greenwayodendron suaveolens were analyzed using standard microbiological methods. The moisture contents of the young and mature leaves were 9.9% and 11.882% respectively. The ash contents of the young and mature leaves were 6.142% and 6.418% respectively. The crude fiber content of the young and mature leaves was 5.550% and 5.080% respectively. The crude fat content of the young and mature leaves was 14.750% and 18.870% respectively. The crude protein content of the young and mature leaves was 1.338% and 1.025% respectively. The carbohydrate content of the young and mature leaves was 72.220% and 68.607% respectively. The phytonutrient analysis carried out indicated that percentage alkaloid was 24.43 and 11.45 in the young and mature leaf extracts respectively. Phenolic contents were 64.00 µg/mL and 51.00 µg/mL in the young and mature leaf extracts respectively. Flavonoid content was 39.50 µg/mL and 13.75 µg/mL in the young and mature leaf extracts at respectively. Saponin content at 1,147 µg/mL and 1,205 µg/mL in the young and mature leaf extracts respectively. While tannin content was 65.00 mg/mL and 47.25 mg/mL in the young and mature leaf extracts at respectively. The ethanolic leaf extracts of Greenwayodendron suaveolens inhibited the growth of all the test organisms at the concentration of 25 mg/mL. However, the minimum inhibitory concentration (MIC) of the young and mature leaf extracts against Bacillus subtilis and Trichodermaharzianum was 6.25 mg/mL while the minimum inhibitory concentration (MIC) of the young leaf extract against Acinobactercalcoaceticus and Candida albican was also 6.25 mg/mL. The minimum inhibitory concentration (MIC) of the young and mature leaf extracts against Aspergillus tamari and Aspergillus niger was 12.5 mg/mL. The antimicrobial results indicated that the ethanolic leaf extracts of Greenwayodendron suaveolens are active against bacteria and fungi and therefore can be utilized to remedy infections caused by the test organisms.