Mycoflora of fungal contamination in wheat storage (silos) in golestan province, north of Iran

Background: Cereal products are susceptible to mould damage during pre- and post-harvesting stages of the production. The regional specificity of Golestan province in the northern region of of Iran, with its high temperature and high relative humidity, acts as a leading factor for the growth of aflatoxin-producing fungi. It is well known that contamination of starch-based ingredients with mycotoxigenic fungi is a risk factor among the consumers due to its aflatoxins. Objectives: This survey was carried out to determine the extent of fungal contamination of wheat in three silos of Golestan province in Iran. Materials and Methods: 34 samples from three active silos were collected in order to clean the polyethylene bags. Wheat analyzed for fungal contamination and aflatoxins extracted by immunoaffinity column chromatography, and measured by HPLC method. Results: The most common moulds isolated were Alternaria spp. 26.7%, Aspergillus niger 21.4%, Fusarium spp. 17.8%, Aspergillus flavus 10.7%, Cladosporium spp. 10.7%, Penicillium spp. 8.9%, and Rhizopus spp. 3.5%. The screening of aflatoxin, B1, B2, G1 and G2 was carried out. 10(29.4%) samples of wheat had traces of aflatoxin, but in a level lower than the standard levels [Institute of Standards and Industrial Research of Iran (ISIR< 15 ng/g)]. Conclusions: Despite the lower detected aflatoxin levels (lower than the ISIR level), the fungal contamination rate could not be neglected. Since the isolated mycotoxigenic fungi such as Aspergillus spp. and Fusarium spp. are important in food industry, it would be possible that the increased retention time of samples might have raised the detected contamination rate. © 2013, Ahvaz Jundishapur University of Medical Sciences

Properties of the amniotic membrane for potential use in tissue engineering

An important component of tissue engineering (TE) is the supporting matrix upon which cells and tissues grow, also known as the scaffold. Scaffolds must easily integrate with host tissue and provide an excellent environment for cell growth and differentiation. Most scaffold materials are naturally derived from mammalian tissues. The amniotic membrane (AM) is considered an important potential source for scaffolding material. The AM represents the innermost layer of the placenta and is composed of a single epithelial layer, a thick basement membrane and an avascular stroma. The special structure and biological viability of the AM allows it to be an ideal candidate for creating scaffolds used in TE. Epithelial cells derived from the AM have the advantages of stem cells, yet are a more suitable source of cells for TE than stem cells. The extracellular matrix components of the basement membrane of the AM create an almost native scaffold for cell seeding in TE. In addition, the AM has other biological properties important for TE, including anti-inflammatory, anti-microbial, anti-fibrosis, anti-scarring, as well as reasonable mechanical property and low immunogenicity. In this review, the various properties of the AM are discussed in light of their potential use for TE

Quantitative determination of aflatoxin by high performance liquid chromatography in wheat silos in Golestan province, north of Iran

Background: Aflatoxins are the most common mycotoxins that contaminate crops. They are produced by fungi such as Aspergillus flavus and Aspergillus parasiticus. Wheat (Tricitumaestivum) is one of the most important staple foods used in Iran, and the environmental conditions in the north of Iran are favorable to fungal growth. This study was designed in order to determine the aflatoxin concentration in wheat samples from silos in Golestan Province north of Iran. Methods: Samples were collected from three silos of Golestan province. First, aflatoxins were isolated using immu-noaffinity chromatography. Then the aflatoxin concentrations were determined by High performance liquid chroma-tography (HPLC) method and fluorescence detector. Results: Ten out of 34 samples (29.4 of samples) were contaminated by aflatoxins.No concentration was found above permitted aflatoxin levels in Iran (15 ng/g). In one sample (2.9), aflatoxin B1 was seen over the permissible limits in Iran. The highest level found in samples for total aflatoxin, aflatoxin B1, aflatoxin B2, aflatoxin G1 and aflatox-in G2 were 7.08 ng/g, 6.91 ng/g, 0.29 ng/g, 1.37 ng/g and 0.23 ng/g, respectively. No correlation was found between humidity levels in wheat samples contained aflatoxin and wheat samples without aflatoxin. Conclusion: Despite the total aflatoxins determined in samples were below the permissible limits in Iran, the 29 aflatoxin contamination rate can negatively affect health factors and it should not be neglected. So, it is predictable that if the storage duration of samples increases, the aflatoxin contamination levels will increase. © 2015, Iranian Journal of Public Health. All rights reserved

Synthetic dye decolorization by three sources of fungal laccase

Decolorization of six synthetic dyes using three sources of fungal laccase with the origin of Aspergillus oryzae, Trametes versicolor, and Paraconiothyrium variabile was investigated. Among them, the enzyme from P. variabile was the most efficient which decolorized bromophenol blue (100%), commassie brilliant blue (91%), panseu-S (56%), Rimazol brilliant blue R (RBBR; 47%), Congo red (18.5%), and methylene blue (21.3%) after 3 h incubation in presence of hydroxybenzotriazole (HBT; 5 mM) as the laccase mediator. It was also observed that decolorization efficiency of all dyes was enhanced by increasing of HBT concentration from 0.1 mM to 5 mM. Laccase from A. oryzae was able to remove 53% of methylene blue and 26% of RBBR after 30 min incubation in absence of HBT, but the enzyme could not efficiently decolorize other dyes even in presence of 5 mM of HBT. In the case of laccase from T. versicolor, only RBBR was decolorized (93%) in absence of HBT after 3 h incubation. © 2012 Forootanfar et al.; licensee BioMed Central Ltd

Implementing Time-of-Use Demand Response Program in microgrid considering energy storage unit participation and different capacities of installed wind power

Penetration of wind units in Microgrid (MG) imposes remarkable challenges on MG operation. Demand Response Programs (DRPs) and Energy Storage Units are used by MG operators to address these challenges. This paper analyzes the effect of running the Time-of-Use Demand Response Program (TOU-DRP) on an isolated MG by considering different capacities of installed wind power with/without energy storage unit. The energy storage unit is deployed to cover the stochastic nature of wind generation unit. TOU-DRP is modeled based on price elasticity and customer benefit function in an isolated MG. Different levels of customers’ participation in TOU-DRP has also been studied and its effects on operation cost, unserved energy, and wind power spillage are investigated comprehensively. To verify the proposed model’s efficiency, the study is implemented on an 11-bus MG over a 24-h period for twelve detailed case studies. The case study results confirmed the effectiveness of the proposed model in running DRP and providing MG operator a general overview for optimal operation

Isolation of keratinophilic fungi and aerobic actinomycetes from park soils in Gorgan, North of Iran

Background: Keratinophilic fungi are a group of fungi that colonize in various keratinous substrates and degrade them to the components with low molecular weight. This study was conducted to determine the prevalence of keratinophilic fungi and aerobic Actinomycetes in soil of city parks in Gorgan. Objectives: In this study, we surveyed the city park soils of Gorgan (a northern province of Iran) to determine the identities and diversity of soil aerobic Actinomycetes, keratinophilic and non-keratinophilic fungi. Materials and Methods: A total of 244 soil samples were collected from 22 diferent parks of Gorgan, North of Iran. The samples were collected from the superfcial layer with depth not exceeding than 0-10 cm in sterile polyethylene bags. We used hair bait technique for isolation keratinophilic fungi. The colonies identifed by macroscopic and microscopic characterization after slide culturing. Actinomycetes were isolated by antibiotic dilution methods and detected by using physiological tests such as Lysozyme, Casein, Xanthine, Hypoxanthine, Gelatin, Urea Broth, and modifed acid-fast stain. Results: Totally, 75 isolates of aerobic Actinomycetes were detected that Actinomadura madurae and Nocardia asteroides were the most prevalent strains, with 14.66 and 28% prevalence respectively. Microsporum gypseum was more frequent than other keratinophilic fungi (22.96%) and Aspergillus spp. was the most species of saprophyte fungi (15.92%). Conclusions: This study showed that the collected soil from studied areas was rich of keratinophilic fungi and Actinomycetes, therefore hygiene protocol should be taken to prevent the spread of pathogenic and saprophytes fungi in the environment of susceptible person. © 2013, Ahvaz Jundishapur University of Medical Sciences

Halotolerant Ability and α-Amylase Activity of Some Saltwater Fungal Isolates

Four halotolerant fungal isolates originating from the saltwater Lake Urmia in Iran were selected during a screening program for salt resistance and α-amylase activity. The isolates were identified based on sequencing the ITS region and a part of the β-tubulin gene, as Penicillium chrysogenum (isolate U1; CBS 132820), Fusarium incarnatum (isolate U2; CBS 132821), and Penicillium polonicum (isolate U3; CBS 132822, and isolate U4; CBS 132823). The growth of these isolates was determined by measuring the colony diameter and mycelia dry weight in Sabouraud dextrose agar and yeast nitrogen base medium supplemented with NaCl, KCl, and LiCl. Isolate U4 showed a growth up in 15% NaCl and U1 was the only isolate that could grow in 20% KCl. None of the strains grew in a media containing LiCl. The salt supplemented medium did not increase the size of colony diameter in all isolates (p > 0.05). The ability of the selected isolates for amylase production was quantitatively tested and showed that P. polonicum isolate U4 was the most potent producer of amylase with a yield of 260.9 U/L after 60 h, whereas P. polonicum isolate U3 was the lowest one with a production level of 97.9 U/L after 48 h. P. polonicum isolate U4 could be a suitable candidate for production of amylase on an industrial scale after optimization. © 2013 by School of Pharmacy

Experimental study on the energy absorption capability of circular corrugated tubes under lateral loading and axial loading

A new type of energy absorber called an expansion joint (i.e. a corrugated tube) is examined in this research. Several experiments are performed on three types of thin-walled specimen, namely circular tubes, preformed corrugated tubes and complete corrugated tubes, to investigate the energy absorption of steel specimens under different conditions for quasi-static lateral loading and axial loading. For this purpose, some steel specimens were compressed between two rigid platens in the axial direction, and the other specimens were laterally compressed. The preformed corrugated tubes and the complete corrugated tubes were produced by the hydroforming method. In each geometrical group of specimens, several tubes, which have different wall thicknesses, different inner diameters and different lengths and which are either empty or filled with polyurethane foam, were tested. Experiments show that, for a lateral load, the specific absorbed energies of the complete corrugated tubes are higher than those of the corresponding preformed corrugated tubes and circular tubes with the same characteristics. Tests show that, under lateral loading, a complete corrugated tube with a thicker wall and a smaller diameter is the optimum energy absorber system. Therefore, when a circular tube transforms into the corrugated tube, a better energy absorber system with a higher capability is achieved under lateral loading. Also, experiments show that, under axial loading, simple circular tubes with no forming process have higher specific absorbed energies than corrugated tubes do. Corrugated specimens have more controllable plastic deformation and a more regular deformation mode than simple tubes have. Tests under axial loading illustrate that, when the preformed corrugated tubes are filled with polyurethane foam, the specific absorbed energy increases by up to 74%. A comparison of the results on empty and filled specimens shows that, in some cases, the specific absorbed energies of corrugated tubes under lateral loading are higher than the specific absorbed energies of circular tubes under axial loading. This means that, by shaping the circular tubes into preformed corrugated tubes and complete corrugated tubes via the hydroforming process, a new thin-walled structure with a high specific absorbed energy during the lateral compression process is introduced