JOURNAL OF MICROBIAL WORLD
Year:2016 | Volume:9 | Issue:2 (27)|Papers Count:11

Background & Objectives: Recently, a new protein, named Core+1, has been reported to be expressed through a+1 ribosomal frame shift in the Core protein coding region of Hepatitis C virus. The purpose of this study was to design a recombinant Baculovirus vector containing HCV -2a (JFH1) Core+1 sequence, and also, to verify the production of this recombinant Core+1 protein in Baculovirus expression system.Materials & Methods: Core+1 gene of HCV -2a (JFH1) was synthesized into pUC57 plasmid. The synthesized target gene was sub-cloned into the plasmid pFastBac-HTA. The recombinant vector was used to transform the competent E. coli DH10Bac containing the donor clone. The recombinant Baculovirus bacmid was produced following transposition. Recombinant bacmid was verified by PCR and then was transfected into Sf9 insect cells to package a new recombinant Baculovirus. SDS-PAGE and Western blotting was used to confirm the expression of Core+1 protein in insect cells.Results: Sequence analysis and white-blue colony selection confirmed a successful cloning of the Core+1 sequence of HCV (JFH1) into the pFastBac-HTA vector and transformation of E. coli DH10Bac. Production of recombinant Baculovirus. The HCV -2a (JFH1) Core+1 protein was successfully expressed and confirmed in SDS-PAGE and Western blot.Conclusions: Baculovirus expression system provides a high yield post-translational modification tool for HCV Core+1 protein expression, which is similar to Core+1 protein produced during natural infection with HCV.

Background & Objectives: Pseudomonas aeruginosa is a common opportunist pathogen in hospitals and the etiologic agent of the majority of infections in human beings. This study aimed to genotyping of P. aeruginosa isolated from hospital infections.Materials & Methods: This cross-sectional study was performed on 18 isolates of P. aeruginosa isolated from hospitalized patients in Shahrekord hospitals. We applied three different methods, RAPD-PCR, Rep-PCR and ERIC-PCR for genotyping of the isolates.Results: Based on RAPD-PCR method, overall 86 different bands of DNA with a range of 300 to 1000 bps were obtained from the under study isolates and among them, 74 bands were polymorphic. Analysis of P. aeruginosa isolates based on ERIC-PCR produced 98 bands with a range of 150-8000 bps. Overall 16 genomic profile with 30 to 86% and for a few strains, 100% similarities were produced based on Rep-PCR.Conclusion: Overall, all isolates showed polymorphic band patterns and no monochromic band was observed for the isolates. The presence of polymorphic band patterns in these techniques shows high rates of polymorphism in the genome of P. aeruginosa. Furthermore, the techniques used in this study are reliable approaches for genotyping of P. aeruginosa.

Background & Objectives: Sexual stage of Alternaria alternata has not been discovered yet. However, high levels of phenotypic and genetic diversity have been reported in different populations of A. alternata. In other Ascomycetes similar to this species, sexual reproduction is controlled by a single locus, named MAT1, with two alleles MAT1-1 and MAT 1-2. The aims of this research were identification of frequency and distribution of both alleles of MAT1 in A. alternata population of citrus collected from South of Iran.Materials & Methods: In this cross-sectional study, DNA was extracted from young mycelia of 45 isolates of A. alternata that previously were collected and isolated directly from different species and cultivars of the citrus plants showing leaf spot disease symptoms in different orchards of Southern region of Iran using CTAB method. Mating types were determined using specific primer sets for MAT1-1 and MAT1-2 idiomorphs and PCR assay.Results: A 642 bp amplicon and a 882 bp amplicon were amplified pecificlly for Mat1-1Mat1-2 isolates, respectively. No equal frequency of both mating type idiomorphs were observed in studied samples. Totally 16 and 29 isolates showed the presence of MAT1-1 and MAT1-2 idiomorphs, respectively. Unequal frequency of both idiomorphs was observed in the citrus species and cultivars collected from different regions.Conclusion: It seems that unknown factors are involved in sexual induction of A. alternata in some regions and citrus hosts in South of Iran.

Background & Objectives: Macaroni is produced since 1313 in Iran, but with not desirable quality due to low accessibility of durum wheat and semolina production technology. In this study, we analysed the effect of Bacillus licheniformis alkaline protease on qualitative, rheological and sensory properties of macaroni enriched with soy.Materials & Methods: 1 kg of dough and dried macaroni was sampled based on the standard methods and used for evaluation of qualitative, rheological and sensory properties of macaroni enriched with hydrolyzed soy protein. Bacillus licheniformis was used because of its ability to produce an efficient alkaline protease for hydrolysis of soy proteins. Alkaline protease was produced in a submerged culture of Bacillus licheniformis at pH 9 and 300oC for 3 days.Results: Addition of 20% hydrolyzed soy protein caused decrease in some factors including 15.78% in cooking time, 18.13% in resistance to defeat for a spaghetti filament, 29.02% in dough development time and 6.27% in loosening the dough as well as an increase of 37.37% in cooking loss, 57.24% in adhesion, 5.55% in water absorption percentage and 16.44% in dough stability time. Total acceptance of macaroni samples with 20% hydrolyzed soy protein were 33% less than control. The maximum useable hydrolyzed soy protein in macaroni dough without any negative impacts on its properties was determined as 5%.Conclusion: Hydrolyzed soy protein is not a suitable case for macaroni enrichment.

Background & Objectives: Highly demands of consumption of industrial food products has led to removal of probiotic bacteria from daily diet. The aim of this study was evaluating the probiotic properties of dominant Lactobacillus isolated from whole wheat sourdough.Materials & Methods: In this experimental study, after isolation of dominant Lactobacillus from whole wheat sourdough, the isolates were identified by polymerase chain reaction (PCR). Probiotic properties of these isolates, including survival in simulated conditions of gastrointestinal tract, antimicrobial effects against prototype bacteria (Staphylococcus aureus, Listeria monocytogenes and Escherichia coli), the ability of co-aggregation with E. coli as an infection agent of intestine and resistance of these isolates against some of routine antibiotics were also investigated in this study.Results: Sequencing of the PCR products led to identification of Lactobacillus acidophilus, Lactobacillus plantarum, Lactobacillus sakei and Lactobacillus brevis as dominant Lactobacillus in whole wheat sourdough. Among the mentioned isolates, Lactobacillus plantarum showed the maximum survival in simulated conditions of gastrointestinal tract. Inhibition zone diameter of three pathogenic bacteria in the presence of Lactobacillus plantarum and Lactobacillus brevis were significantly more than the others. Comparison between co-aggregation ability of isolated Lactobacillus with E. coli showed that Lactobacillus brevis and Lactobacillus plantarum were more effective. Furthermore, these strains along with L. acidophilus were resistant to Streptomycin, Kanamycin, Vancomycin and Nalidixic acid.Conclusion: Lactobacillus brevis and Lactobacillus plantarum isolated from whole wheat sourdough are highly useful to be uses as probiotic bacteria in food and medicinal applications.

Background & Objectives: Bioremediation is a technology to remove oil pollution. Microbial bioremediation id the best technology to remove contaminants in which pollutants are converted to non-toxic chemicals in expenses of lowest amount of energy, chemicals and time. This study aimed to isolate and identify the petroleum hydrocarbons degrading bacteria from oil reservoirs located at Asmari Ahwaz.Materials & Methods: This field study was performed in the oil reservoirs located at Asmar, Ahvaz. The primary isolation was performed using a salt containing base medium through a multistep process, and the salt tolerance of isolates were tested by this medium. The elimination of the hydrocarbons by isolated bacteria were studied using gas chromatography. The identity of bacteria was determined based on biochemical tests and sequencing of 16S rRNA gene.Results: In this study, a halotolerant Gram-positive bacteria, belonged to Streptomyces, was isolated from the field. This isolate showed an acceptable growth into 7.5% salt concentration and was able to use oil as the sole source of carbon. Also, this strain was able to reduce the level of hydrocarbons to 71.58 % through incubation in the saline medium for 10 days.Conclusion: According to the results, the isolated strain is capable to tolerate high concentrations of salts and is desirable to remove the hydrocarbons, which is beneficiary due to the difference in salt concentration in contaminated areas. As a result, this isolate can be useful for removal of pollutants from the environment and reduction of their side effects on life.

Background & Objectives: Biodegradation is one of the most useful methods for elimination of oil spills and is recently considered as a promising approaches due to numbers of advantages, including low costs, high efficiency and being environment friendly. Gharehsoo river is one of those regions which have been contaminated by oil spills during recent years due to its vicinity to Kermanshah Oil Refining Company. This study was aimed to isolate and identify the toluene-degrading bacteria from oil spills in Gharehsoo river located at Kermanshah city.Materials & Methods: In this experimental study, the samples were collected from water, soil and active sludge of the contaminated areas. Two isolates were achieved by enrichment of the samples into a selective medium containing toluene. Then, the isolates were identified using morphology, Gram staining, biochemical methods and 16S rRNA sequencing. Also, the ability of isolates to eliminate toluene was testes based on Gas chromatography.Results: Both isolates were identified as Pseudomonas putida strains. Gas chromatography tests showed that the isolates 1 and 2 were able to degrade toluene into the selective medium (0.5% v/v) 89% and 87%, at 72 C, respectively. The isolates were also able to resist and grow under harsh conditions of temperature, pH and osmolality. It was proved that the isolates were able to continue their activity and growth in the presence of other crude oil pollutants (benzene, xylene, ethyl-benzene).Conclusion: Our results showed that these isolates were very efficient for elimination of oil pollutants due to their high growth rate in the presence of relatively high toluene concentration and to the ability to degrade a wide range of oil toxic compounds.

Clostridium perfringensis an anaerobic, Gram-positive, toxin-forming bacterium and the etiologic cause of enterotoxaemia in animals. Soil is considered as the main source of spore of this bacteria. This study was aimed to genotyping the C. perfringens isolated from intestines of sheep with enterotoxemia and as well as from the soil samples collected from cold area of Kerman province using Multiplex- PCR. This cross-sectional study was carried out on 50 soil samples and 50 intestinal samples collected from three cities located at Kerman to isolate the C. perfringens isolates. The C. perfringens isolates were identified based on enrichment of the samples and growing up the bacteria in specific media and following performance of confirmation tests using biochemical tests. A PCR reaction were performed to confirm the presence of these strains. Overall 42 Clostridial strains were isolated in this study, among them 27 isolates were collected from intestinal samples. Also, 10 soil samples were contaminated with Clostridia, among them 5 samples belonged to C. perfringens. This study showed that C. perfringens is the most prevalent species in the sick sheep and soil in comparison to other species. Furthermore, Type D of this species was more prevalent than others.