javad fakhari

Dried Black Curd (DBC), also known as Gharahghorut (Persian), is a dairy product produced from curd of yogurt or doogh. The aim of this study was to evaluate microbial contamination of industrially and traditionally produced DBC in Iran.

Four DBC brands holding certification of the Institute of Standards and Industrial Research of Iran (ISIRI), Iran Ministry of Health and Medical Education (IMHME) and ISO were purchased from a market in Tehran, Iran. Microbial monitoring for presence of coliform, Escherichia coli, coagulase-positive Staphylococcus aureus, mold and yeast was performed using different basic, enriched, selective and differential media including peptone water agar, MacCankey agar, blood agar and brain heart infusion agar, etc. according to the ISIRI standards (No.13299).

None of the tested samples had microbial contamination. However, in one traditional DBC sample, the population of mold and yeast was higher than the acceptable level defined by the ISIRI standard.

We found no contamination with coagulase-positive S. aureus, E. coli and coliforms in four brands of traditionally and industrially produced DBC in Iran. This indicates that the hygienic practices designated by the IMHME are well-implemented in the industrial sector. However, the mold and yeast contamination in traditionally produced DBC should be prevented by applying hygienic practices during the process of manufacturing and distribution.

Sohan is one of the confectionery products produced in Qom, Iran. Microbial contamination of confectionary items is crucial in terms of hygienic and economic issues. This sort of spoilage shortens the storage time and causes an outbreak of food poisoning. Due to the high utilization of these products, it is vital to implement microbiological management to improve shelf life and maintain quality. The present study aimed to evaluate the levels of microbiological contamination in Sohan.

In this study, the Sohan products of Qom were classified according to the Code of Health, standard logo, as well as ISO 9001:2008 and 22000:2005 certifications. Then, 1 to 2 boxes (out of 7 boxes) were purchased from an official representative shop in Qom. The diagnostic and enumeration tests for Enterobacteriaceae, Escherichia coli (E. coli), coagulase-positive staphylococcus, as well as molds and yeasts, were performed in accordance with the national standards of 2461-1, 2946, 6806-3, and 10899-2, respectively.

Results of this study showed that 71.4% of the samples contained Enterobacteriaceae, and 14.2% of the samples contained coagulase-positive staphylococci higher than the determined standard levels. In addition, no case of contamination with molds, yeasts, and E. coli was observed among the samples.

Findings of the present investigation indicated the necessity for the precise implementation of Good Hygiene Practices in the factories manufacturing this product.

The microbial communities of traditional milk-based food are of great importance in its manufacturing process, especially when using raw milk with natural cultures. Liqvan (Lighvan or Levan) is a traditional Iranian buried cheese, which is made from raw ewe´s milk without a starter addition. The aim of this study was to explore the fungal active population during this cheese manufacturing process by comparing DNA and RNA based culture independent method Denaturing Gradient Gel Electrophoresis (DGGE).
Four samples of each milk, curd and ripened cheese were collected from Liqvan village located in East Azerbaijan province of Iran. Total DNA and RNA of each sample were extracted and PCR amplicons of D1 region of 26S rRNA gene was targeted for DGGE analysis. This method applied at both DNA and RNA levels in order to examine which taxonomic groups of fungi are active at each step of ripening.
DGGE profiles of yeast amplicons showed different results between extracted DNA and RNA during ripening process. However, the main group that is present in all stages of ripening process belongs to the genus Candida although Kluyveromyces, Pichia, Galactomyces, Saccharomyces and Cryptococcus are most abundant fungi.
As no starter culture added to Liqvan cheese it seems fungal diversity are mainly rely on the indigenous microbiota of milk. Furthermore, the percentage of the dominant fungal genera from the total sequences differed among DNA and cDNA libraries.

Hepatitis B virus (HBV) is an enveloped DNA virus belongs to Hepadnaviridea family. HBV infection is a serious global health problem, with 2 billion people infected worldwide, and 350 million suffering from chronic HBV infection. The aim of this study was to determine the serological pattern and molecular characterization of HBV diversity in asymptomatic blood donors in Iran alongside with the mutation status of HBV in relation to blood safety.
One hundred and sixty six samples from asymptomatic blood donors who were positive for hepatitis B surface antigen during 2012 to 2014 were selected. The serological and molecular markers were analyzed by screening HBsAb, HBcAb, HBeAg and HBeAb and HBV-DNA. For detection of HBV genotypes and possible mutations, HBV polymerase and pre core/core regions were sequenced.
In term of serologic markers of HBV, 100% of asymptomatic blood donors were HBsAg positive and 97.6%, 92.2%, 5.4% and 2.4% of them were HBcAb, HBeAb, HBeAg and HBsAb positive respectively in asymptomatic blood donors. The maximum of samples viral load was 4.41 × 107 IU/ml for HBeAg positive blood donors. While the minimum and maximum of viral load in HBeAb positive samples was 1.21 × 102 IU/ml and 1 × 106 IU/ml respectively and the mean of viral load in HBeAb positive samples was 5.882 × 103 IU/ml. About 9.7% of HBeAb positive samples had a pre core mutation that is related to stopping the synthesis of HBeAg and only genotype D was prevalent in asymptomatic blood donors.
This study showed that from 166 samples most of them were in a chronic phase of HBV infection and just 5.4% of asymptomatic blood donors were in the acute phase or acute chronic phase of HBV infection. The major risk factor for HBV infection was a familial history of HBV.

Much of the environment is affected by petroleum contamination. It imposes serious health problems for humans as well as serious environmental impact. Bioremediation is an important consideration for removing environmental pollutants because, compared with other technologies, it incurrs lower costs and is environmentally compatible.
Crude oil degrading bacteria were isolated using serial dilutions of a bacterial consortium. The Taguchi experimental design L16 (45) was used to optimize the biodegradation process of crude oil by the isolated strain. This investigation applied the parameters of temperature, salinity, pH, NH4Cl and FeSO4.7H2O. Modeling the kinetics of crude oil biodegradation included five batch cultivation experiments (2.5 ml/L to 40 ml/L) using crude oil as a single limiting substrate.
Halomonas sp. MS1 was identified using identification tests. Maximum biodegradation efficiency was predicted to occur at pH=9, temperature=30 ˚C, salinity=2%, NH4Cl concentration=0.4 g/L and FeSO4.7H2O=0.04 g/L. After optimization, biodagradation was significantly (P Overall, bacteria in surface sediment samples from Kish Island have been determined as having good potential for application in oil biodegradation. Optimum amounts of the studied factors were determined successfully by applying the Taguchi experimental design and the models of Teissier and Haldane are suggested as kinetic models to describe the batch crude oil degradation behavior of MS1.

Paper and paperboard packaging play an important role in safety and quality of food products. Common bacteria of paper and paperboard food packaging could grow due to specific conditions included humidity, tem- perature and major nutrition to contaminate the food. The purpose of this research was to investigate numbers and the types of bacteria in the food packaging paperboard. The surface and the depth of the each paperboard sample were examined by the dimension of one cm2 and one gram. The paperboard samples were randomly collected from popular confectionaries and fast food restaurants in Tehran, Iran. The results indicated the range of 0.2×103 to >1.0×105 cfu/1g bacterial contamination in paperboard food packaging. Also, most detected bacteria were from spore forming and family Bacillaceae. The bioburden paperboard used for food packaging showed high contamination rate more than standard accep- tance level.

Since metal extraction from sulfide ores by physicochemical methods is expensive and also detrimental to the environment، microorganisms، mainly bacteria are being increasingly used for desulfurization of sulfide minerals. Microbial leaching or bioleaching is an inexpensive and environmentally friendly technology for metal recovery. In the present study، to isolate iron and sulfur-oxidizing bacteria which are active in bioleaching process، spring water samples were collected and enriched by iron and sulfur-containing media. In order to identify the isolated bacteria، several morphological، physiological، biochemical and 16S rDNA phylogenetical methods were implemented. After several sub-cultures، a gram-positive spore-forming rod (NS strain) was isolated and then characterized. Sequence analysis of 16S rDNA revealed that the isolated strain was closely related to Bacillus firmus strain IAM 12464 (99%)، that was capable to oxidize several sulphur and iron component such as: thiosulfate 5%، elemental sulphur 3%، sodium sulphate 3%، pyrite 3%، pyrrhotite 3%، ferrous sulphate 4. 5% and Iron powder 2%. Also، this isolate could dissolve copper of SARCHESHME ore to copper sulphate and change the colour of medium to blue-green. The optimal growth of the isolate was observed at 25°C and pH 4. Discussion and Due to the optimum pH and temperature، and the iron and sulphur oxidizing activity of this isolate، this bacterium together with a consortium of lithotrophic bacteria could be used in bioleaching processes.