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Microbial analysis of ground water, as the sole supplying water source in many areas, must be evaluated. Because the treatment of water cannot remove all pathogenic bacteria leaked from domestic wastewater, bacterial analysis of Bojnourd groundwater sources was performed. For this reason, membrane filter (MF) technique and Most Probable Number (MPN) method were used to evaluate the microbial quality of the water. Escherichia coli (E. coli) and Enteroccocus faecalis (E. faecalis) were traced as excremental indices. E. coli was detected from three out of six stations and E. faecalis was only isolated from one station. Although molecular techniques are very rapid and exact methods for detection of microbial community and can identify ‘Viable But Not Cultivable’ (VBNC) bacteria, they are unable to make a distinction between living and non-living microorganisms. By means of a standard technique, it is possible to study living and metabolically active microorganisms. Due to the detection of E.coli and E.feacalis in some stations the sanitization of groundwater must be revised to lessen the microbial population in this groundwater.

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Lipase is one of the most important hydrolytic enzymes widely used in various commercial activities such as food, dairy, pharmaceutical and detergent inducteries. In this experiment, Taguchi method was attempted as a powerful method to optimize the factors affecting enzyme production and to investigate the interactions among these factors and their optimum combination in Salinivibrio sp. SA2. The optimum conditions for pH, temperature, shaker's rpm, olive oil concentration and salt type turned out to be 8, 35 °C, 100 rpm, 2% and sodium chloride 1 M, respectively. Significant factors influencing on the lipase production proved to be pH, agitation and Salt type. The maximum lipase activity in optimum condition and at the 5% significance level (p< 0.05) was 120.4 U/mg.

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In this paper, the urinary infection, that is a common symptom of the decline of the immune system, is discussed based on the well-known algorithms in machine learning, such as Bayesian networks in both Markov and tree structures. A large scale sampling has been executed to evaluate the performance of Bayesian network algorithm. A number of 4052 samples wereobtained from the database of the Takestan Department of Health, a center affiliated to Qazvin University of Medical Sciences. According to the goals of the study and using the expert opinion of the laboratory and urologist, 15 variables were selected. The database included both urine analysis and culture tests. The results indicated 99.7% accuracy of the diagnosis for the training data, (75% of total data), and 99.8% accuracy of the diagnosis for testing data (25% of total data). Based on the Bayesian network model, the important covariates influencing the Urinary infection have been proved to be the increase of bacteria and the decrease of white blood cells in different age groups. The results of this study can be used in the context of machine learning and intelligent systems for rapid diagnosis of the disease and the treatment of people suspected of suffering from it.
 

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Saline soils are widely spread in Iran. These intact soils are a great source for the isolation of new bacteria with highly functional metabolites in biotechnology. Actinomycete strains were isolated on starch casein agar and ISP2 with different concentrations of sodium chloride (0, 5 and 10%) from treated soil samples. Pure colonies were cultured on a casein glycerol medium. After complete growth, the plates were covered with a thin layer of Muller Hinton Agar (1%) containing methicillin-resistant Staphylococcus aureus (MRSA). Active metabolites of selected strains were extracted and their antibacterial activities analyzed by agar well diffusion method. 38% of isolates produced antibiotics against the pathogen. The metabolites produced by act-2 and act-5 isolates, which had a more effective inhibition zone against MRSA, were extracted and anti MRSA activity of act-5 extract was shown. The antimicrobial activity of act-5 against other bacteria was also investigated and the bacterium was identified. In this study halophilic actinomycetes producing bioactive compounds were isolated from the saline soils of Qom and the anti-MRSA potential of their metabolites was investigated for the first time. The results of this study show the potential of saline soil actinomycetes for the production of useful metabolites.


 

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Phosphorus, the most essential nutrient for plants, becomes quickly unavailable for the plants in the soil. Phosphate solubilizing bacteria (PSB( can play an important role in providing Phosphorus for plants. In this study, the PSBs were screened from plant rhizosphere by Pikovskaya method. Then, the growth rate and phosphate solubilizing ability of 9 superior strains were measured at different temperatures and levels of salinity and pH. The best strain was identified by 16S rDNA gene sequence analysis. Finally, the genetic diversity of phosphate solubilizing strains were examined by RAPD markers. Results showed that 25 strains were capable of solubilizing insoluble phosphates among the 57 isolates studied. Of the nine superior strains, Cke1 had the highest solubilizing index with the average growth rate under all conditions and was introduced as the best PSB strain identified in the present study. 16S rDNA gene sequence analysis showed that this strain belonged to the Enterobacter genus. The results of genetic variation showed that all stains were divided into six groups and three strains that had the lowest similarity with other strains were placed in three separate groups. Given that Cke1 strain has the ability of solubilizing the insoluble phosphate in different stresses, it can be a good candidate for providing phosphorus at temperatures of 30 and 35 °C, 1.2% and 1.8% salinity levels and pH levels of 6 and 8 for the crops.

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The aim of this study was to evaluate the antibacterial activity of the water extracts of three species of Salvia (S. perspolitana, S. palaestina, S. bracteata) on Staphylococcus aureus, Escherichia coli and Pseudomonas aeroginosa. The antibacterial activity of water extracts of the studied species on the bacterial strains was examined using well diffusion method and minimum inhibitory concentration (MIC). Results showed that only S. bracteata formed growth inhibitory zone (9 mm) on Staphylococcus aureus. The extracts of all three plants formed growth inhibitory zone on E.coli and P. aeroginosa. The extract of S. bracteata was more effective than that of the other species. Results for MIC also showed that the extracts of S. perspolitana had the lowest effect on St. aureus and its MIC was observed in a concentration of 1024 µg/ml. The extracts of this species had the inhibitory effect in a concentration of 256 µg/ml. The uppermost inhibitory effect was provided by the extract of S. bracteata, since the minimum inhibitory concentration of this species for S. aureus was equal to 64 µg/ml; and for the other two bacteria, it was equal to 128 µg/ml. The extracts of S. palaestina had the lowest effect on S. aureus and its MIC was observed in a concentration of 1024 µg/ml. The extracts of this species had an MIC equal to 512 µg/ml for the other two bacteria. It was concluded that S. bracreata could be considered a suitable species with anti-bacterial activities in future researches.
 
 
 

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Some rhizobacteria have positive effects on plants growth. Syrian bean-caper (Zygophyllum fabago) is a weed plant with medicinal value. This study was conducted to isolate and identify bacteria from Syrian bean-caper rhizosphere. Characteristics associated with plant growth stimulation, such as phosphate and zinc dissolution, production of Indole acetic acid and antifungal activity, were investigated. The isolates were separately inoculated to the plant and after plant root establishment was ensured, their effectiveness in increasing plant growth in greenhouse conditions was measured. Biochemical and molecular identification results showed that five isolates belonged to the genera Bacillus, Pseudomonas, Pantoea, and Brevibacterium. All five isolates showed some degree of plant growth promotion capabilities. Among the isolates, only the genus Bacillus increased the dry weights of plants significantly. The amount of phosphate solubilization for this isolate was 440 μg ml^-1 and its acid production in the culture medium was higher than that in other isolates. The isolate had zinc solubilisation capability and produced 3.89 mg ml^-1 indole acetic acid. However, this isolate did not show antifungal activity against two fungal pathogens of Aspergillus niger and Botrytis cinerea.  
 
 
 

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Plants have been used as medicines in the treatment of diseases from the past to present. In this research, the anti-microbial effects of aqueous and methanolic extracts of Erythrostemon gilliesii were studied. For this purpose, fresh flowers were ground and then macerated in methanol 100% and water overnight. After the evaporation of solvents, anti-microbial activities of the concentrated extracts were evaluated by the well-diffusion method on Klebsiella pneumoniae, Pseudomonas aeroginosa, Methicilin resistance, Staphylococcus aureus, Bacillus subtilis and Candida albicans. The results showed that the extracts were effective on different bacteria and yeasts. In order to determine the minimum inhibitory concentration (MIC) and minimum biocidal concentration (MBC), anti-microbial tests were performed in micro-plates. Subsequently, the results indicated that the extracts were stable at different temperatures. The aqueous and methanolic extracts of the flowers of E. gilliesii had exhibited anti-microbial effects against important infectious microbes and could be introduced as an excellent source for anti-microbial agents.
 
 

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The occurrence of extended-spectrum beta-lactamases-producing bacteria is an important public health issue. The aim of this study was to investigate phenotypic and genotypic characteristics regarding the presence of extended spectrum β-lactamase ctx-m, per and ver producing Escherichia coli isolated from raw dairy samples. For this purpose, E. coli were isolated from 247 raw dairy samples (milk and cheese) in Yasooj in 2015-2017, and the isolates were screened for antibiotic resistance, extended spectrum β-lactamase and the presence of ctx-m, per and ver. In total, 200 isolates were selected. The highest frequency of resistance in isolates was against tetracycline (96.5%) and ampicillin (95.5%) antibiotics and the lowest against imipenem (12.5%), In addition, multidrug resistance against four or more antibiotics was observed in some isolates. Extended spectrum β-lactamase resistance was detected in 86 isolates (43%) and ctx-m, per and ver genes were detected in 82, 0 and 7 E. coli isolates, respectively. These findings demonstrated that raw dairy products may be reservoirs for the dissemination of β-lactam antibiotics and that resistance genes could be transmitted to humans through the food chain.

 

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Phenazine 1-corboxylic acid (PCA) is an antibiotic, which inhibits the growth of a vast number of micro-organisms. PCA has has been applied in fields such as pharmaceutical, agricultural, marine and chemical industries. In this study, the antibiotic properties of PCA (produced by pseudomonas aeruginosa MUT.3, which is kept at the Microbial Collection of Malek Ashtar University of Technology) was studied. The impacts of temperature and light conditions on the activity of PCA was investigated within a 230-day period. To investigate the rate of PCA destruction in the experiment, high performance liquid chromatography (HPLC) was utilized. Moreover, the antibacterial activity of PCA under various conditions was studied by minimum inhibitory (MIC) and minimum biocidal concentration (MBC) methods against E. coli DH5α. The results showed that PCA could be active up to 210 days in darkness (at 25^oC). Meanwhile, the antibacterial activity of PCA was reduced to 100 and 50 days by increasing the temperature to 35 and 45^oC, respectively. In addition, PCA could be active up to 120 and 10 days in visible and ultraviolet light condition, respectively. The MIC and MBC data were consistent with the HPLC results. Detailed data on the activity and stability of phenazine 1-corboxylic acid under various environmental conditions, as presented in this study, could be helpful in industries and healthcare services.
 
 

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Exopolymers (EPS) are high-molecular-weight polymers secreted by some micro-organisms and have several applications in food, pharmaceutical, packaging and agricultural industries, as well as medicine. Actinobacteria are valuable bacteria in biotechnology and many commercial drugs such as antibiotics, antioxidants and immune-suppressant agents are derived from Actinobacteria. Recently, their other capabilities such as exopolymer production have been taken into consideration. Due to the high potential of actinobacteria in producing various compounds and increased prevalence of infections by antibiotic-resistant pathogens, the aim of the present study was to evaluate the potential of isolated Actinobacteria from various locations of Iran to produce EPS with antimicrobial activity. Appropriate dilutions of the samples were, therefore, cultured in ISP2 medium after treatment. The isolates were primarily identified by morphological tests. Then, their ability to produce EPS was investigated in BHI medium with 5% sucrose. The exopolymers of the most efficient strain were analyzed by UV-visible spectroscopy and FT-IR. Finally, the most efficient isolate was molecularly identified. Of the 120 isolates, 38 were able to produce EPS, and six had significant capability of producing EPS (10-14 g/L) and showed antibiotic activity against Staphylococcus aureus, Bacillus subtilis and Aspergillus niger. The EPS of the strain So49 had high absorbance in 190-230 nm, but did not have absorbance in 260-280 nm. Therefore, it does not have any protein impurity. The EPS has hydroxyl and carboxyl functional groups, according to FT-IR analysis. 16S rRNA gene analysis showed that the most efficient isolate had 99.68% similarity to Promicromonospora xylanilytica. 


 

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Algae are the most important group of organisms which considerably affect the water quality. Although algae constitute one of the fundamental parts of the aquatic food chains, only few researches deal with the freshwater algae of Iran. Filamentous algae are important components of the river vegetation. The Balikhlou River is utilized as a source to obtain drinking water for the city of Ardabil, therefore, the algae flora of this river was studied and a total number of 18 taxa of filamentous algae were determined, of which nine species were belonged to the Cyanophyceae class of Cyanobacteriae, while five speciesof which were belonged to the Chlorophyta. In addition, four species were recorded for the first time from Iran, i.e., Audouinella eugenea, Arthrospira gigantea, Homoeothrix janthina and Tychonema bourrellyi.

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Phytase can improve the nutritional value of plant-based foods by enhancing protein digestibility and mineral availability through phytate digestion in the stomach and the food processing industry. Microbial sources are more promising for the production of phytases on a commercial scale. The objectives of this exploration were to screening and isolation of phytase-producing bacteria from hot spring with commercial interest. Molecular identification of the best isolate was achieved by the 16S rDNA gene. Optimization of phytase production was prepared in the presence of different phosphate, nitrogen, and carbon sources. Enzyme activity and stability were also explored in the presence of different pHs, temperatures, and ion compounds. Comparing the 16S rDNA gene sequence of the isolate LOR10 with those in GenBank using Clustal omega shows 98% sequence homology with Bacillus amyloliquefaciens. Medium optimization studies showed that galactose, yeast extract, and tricalcium phosphate were the best sources of carbon, nitrogen, and phosphate for phytase production, respectively. The optimum temperature activity was also observed to be 70 ^oC. Phytase stability was at its optimum in a pH range of 5.0–8.0. Phytase activity increased in the presence of CaCl₂, ZnCl₂, and MnSO₄ about 1.4, 2.3 and 1.6 folds, respectively. It could be mentioned that phytase activity decreased by about 30 % in the presence of EDTA and SDS. On the basis of the results, it could be concluded that LOR10 phytase has a great potential for commercial interest as an additive to animal plant-based foods.
 

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Salinity stress is an important challenge for wheat production in the world. Plant growth promoting rhizosphere bacteria, isolated from halophytic plants, can increase the tolerance of crop plants to salinity by direct and indirect mechanisms. In this study, plant growth-promoting traits of bacterial strains (Bacillus safensis, Bacillus pumilus and Zhihengliuella halotolerans), isolated from the rhizosphere of several halophyte plants, were deterimined and their effects on some vegetative traits and ionic content of wheat plant irrigated with saline water ( 0.2, as control,  4, 8 and 16 dS/m) were measured. Result showed that all three bacteria were able to produce auxin, hydrogen cyanide, siderophore, 1-aminocyclopropane-1-carboxylic acid deaminase and soluble phosphate. The increase in salinity levels caused increase in the concentration of sodium and decrease in the concentration of potassium, calcium and phosphorus in wheat leaves, as well as decrease in stem length, shoot and root dry weight, root to shoot dry weight ratio and total biomass. In wheat plants irrigated with saline water and inoculated with the bacterial strains, sodium concentration decreased up to 17.7% and concentrations of potassium, calcium, phosphorus and potassium to sodium ratio increased up to 33, 25.7, 200.4 and 41%, respectively. The most efficient bacterium was found to be Z. halotolerans. All bacterial isolates also increased stem length, shoot and root dry weight, root to shoot dry weight ratio and total biomass by 17, 58.6, 137, 88 and 66 %, respectively. The results of this study showed that the plant growth-promoting bacteria of rangeland halophytic plants potentionally improve the growth indices of wheat plants in saline conditions. These results also showed that the rhizosphere of halophytic plants in rangelands can be a good source for the isolation of salinity-resistant bacteria to improve the resistance of wheat plants to salinity.
 

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The biosynthesis of nanoparticles (NPs) has been proposed due to its fast, clean, safe, and cost-effective production and being efficient alternative to conventional physicochemical methods. This study aimed to isolate and identify aquatic yeast strains for their potential to form Zinc oxide nanoparticles (ZnONPs). A yeast strain, NS02, with high tolerance against zinc ion (5.25 mM) was isolated using the enrichment technique and was selected as efficient candidate for the biosynthesis of ZnONPs under cell-free extract (CFE) strategy. The preliminary evaluation on the formation of ZnONPs was performed by visual observation and UV-visible absorption spectra of the biosynthesized ZnONPs. The morphology, size and elemental distribution of the nanoparticles were determined by Field emission scanning electron microscopy (FESEM) equipped with energy-dispersive X-ray (EDX). X-ray diffractometer (XRD) was used to identify the crystalline phase of the ZnONPs. Antibacterial activity of ZnONPs against pathogenic bacteria isolated from the clinical specimens was investigated using agar well diffusion method. The isolate NS02 was characterized based on their morphological properties and amplification the ITS-5.8S-ITS2 rDNA regions. The present study pioneered the capabilities of the native aquatic strain Rhodotorula pacifica for the extracellular synthesis of ZnONPs with CFE strategy. The biosynthesized ZnONPs had a growth inhibitory effect all tested clinical isolates due to their nanometric size and well-defined dispersity. This investigation is attempted to indicate the novel microbial sources of aquatic yeasts as biological plant in the synthesis of ZnONPs with antimicrobial activity under cell-free extract strategy.
 

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Rhizospheric bacteria are among the beneficial soil microorganisms that improve plant growth. These bacteria increase plant growth through various mechanisms such as the production of various phytohormones and the ability to solubilize phosphate. The aim of this study was to investigate the effects of rhizosphere bacteria on the growth of Carthamus tinctorius to improve its physiological and biochemical indicators. Carthamus tinctorius seeds were inoculated with five isolates of rhizosphere bacteria and were then planted the seeds in pots. Subsequently, the physiological and biochemical parameters of the plants, including the rates of auxin production, phosphate dissolving, photosynthetic pigments and the contents of proline and malondialdehyde were measured. For this purpose, a factorial experiment were conducted using a completely randomized design with three replications. The ANOVA was performed and a comparison of the means was carried out using Duncan’s multiple range test. The results indicated that the largest stem fresh weight, root fresh and dry weights observed in the treatments of using Pseudomonas fluorescens (auxin concentration of 23.55 μg/mL) and Bacillus muralis (auxin concentration of 22.27 μg/mL). In addition, all bacterial species increased the safflower seed germination rate compared to the control group. The largest malondialdehyde content was recorded in the treatment with Bacillus albus, and MDA content decreased in the treatments that produced larger amounts of auxin. In general, the finding of this research suggested that bacterial inoculation was capable to significantly affect the growth of safflower and improve its qualitative and quantitative growth parameters.