Search

Background: One of the most widely used medicinal plants in Iranian traditional medicine, Rosa × damascena Herrm. (mohammadi flower) that the people of Kashan use as a sedative and to treat nervous diseases and constipation. In this research, the yield, chemical composition and antimicrobial activity of the essential oil of this plant were evaluated for the first time from Azaran region, Kashan. Methods: The essential oil was extracted by means of hydrodistillation (Clevenger), and its chemical compounds were identified and determined by GC/MS. The antimicrobial activity of the essential oil was determined by the diffusion method in agar, the minimum growth inhibitory concentration (MIC) and the minimum concentration capable of killing bacterial/fungal microorganisms (MBC/MFC). Results: The results showed that the yield of essential oil was 0.1586 ± 0.0331% (w/w). Based on the results of the chemical composition analysis of R. x damascena essential oil, 19 different compounds (98.96%) were identified. The dominant and main components of the essential oil were oleic acid (48.08%), palmitic acid (15.44%), stearic acid (10.17%), citronellol (7.37%) and nonadecane (3.70%). Based on the results of diffusion in agar, the highest zone of inhibition against Candida albicans (ATCC 10231) was ~ 9.5 mm. The strongest inhibitory activity of R. x damascena essential oil against Gram-negative Proteus mirabilis (ATCC 43071) was with the diameter of the inhibition zone (~ 9 mm), which was equal to the strength of rifampin (~ 9 mm). Conclusion: Therefore, this essential oil is a promising natural option rich in fatty acids, which can be a potential for the production of natural antimicrobials against infectious diseases, especially urinary tract infections. [ABSTRACT FROM AUTHOR]

Background: Citrus canker caused by the bacterium Xanthomonas citri (Hasse 1915) is known as a dangerous disease that has serious economic impacts on citrus production in many tropical and subtropical countries. In Iran, Citrus canker disease has caused significant damage to various citrus fruits, particularly limes. Nowadays, employing antagonistic bacteria as an effective and environmentally friendly method for plant disease management has gained special importance. Results: Citrus leaf samples were collected from different regions of Iran, and after isolating epiphytic bacteria, ex planta and in planta investigations concerning antagonistic activities of the isolates against Xanthomonas citri pathotypes A and A* were performed. A total of 94 epiphytic bacterial isolates were isolated from citrus aerial parts. Based on biochemical, physiological, morphological, and genotypic tests, it was determined that these bacteria belong to the Bacillus and Staphylococcus genera. The highest inhibition activity against the pathogenic bacterium was related to isolates D4 and D5. Using the molecular method and the resulting dendrogram, it was found that these isolates were most similar to Bacillus amyloliquefaciens. The present findings demonstrated that pathogenicity test on key lime leaves infected with X. citri pathotypes A and A*, along with the application of the biocontrol strain B. amyloliquefaciens, resulted in a significant reduction in the number of canker lesions. Conclusion: The results strongly suggested that the identified antagonistic bacterial isolates hold promising potential as biocontrol agents for managing citrus bacterial canker disease. [ABSTRACT FROM AUTHOR]

The increasing worldwide demand for antimicrobial agents has significantly contributed to the alarming rise of antimicrobial resistance, posing a grave threat to human life. Consequently, there is a pressing need to explore uncharted environments, seeking out novel antimicrobial compounds that display exceptionally efficient capabilities. Hot springs harbor microorganisms possessing remarkable properties, rendering them an invaluable resource for uncovering groundbreaking antimicrobial compounds. In this study, thermophilic bacteria were isolated from Mahallat Hot Spring, Iran. Out of the 30 isolates examined, 3 strains exhibited the most significant antibacterial activities against Escherichia coli and Staphylococcus aureus. Furthermore, the supernatants of the isolated strains exhibited remarkable antibacterial activity, displaying notable resistance to temperatures as high as 75 °C for 30 min. It was determined that the two strains showed high similarity to the Bacillus genus, while strain Kh3 was classified as Saccharomonospora azurea. All three strains exhibited tolerance to NaCl. Bacillus strains demonstrated optimal growth at pH 5 and 40 °C, whereas S. azurea exhibited optimal growth at pH 9 and 45 °C. Accordingly, hot springs present promising natural reservoirs for the isolation of resilient strains possessing antibacterial properties, which can be utilized in disease treatment or within the food industry. [ABSTRACT FROM AUTHOR]

Background: Congenital entropion is the most frequent ocular disorder in newborn lambs of certain sheep breeds, which, if not treated, can result in complete blindness and death due to starvation. Objectives: The aims of this study were to compare the spontaneous healing of entropion in two breeds and assess the outcome of cases with and without therapeutic intervention. Methods: A total of 158 entropion cases (119 Ile de France and 39 Romane) were investigated, and swab samples were collected from the cornea and conjunctiva of 73 of the affected lambs for bacteriological investigation. In addition, an ocular intervention was carried out in 123 affected animals. Results: The Romane breed developed entropion at an average age of 7 days compared to the Ile de France, which developed it at an average age of 1 day. Likewise, significant differences were found between bilateral and unilateral involvement in both breeds. Meanwhile, 22.1% of cases recovered spontaneously, and the highest rate of spontaneous recovery without intervention was observed in the Romane breed (66%). Bacteria isolated from ocular samples included Staphylococcus spp. (42.5%), Bacillus spp. (21.9%), Trueperella pyogenes (13.7%), Corynebacterium spp. (12.3%) and Escherichia coli (9.6%). Conclusions: The results of the study showed that the onset time of entropion, bilateral involvement, the severity of the process and the need for re‐treatment were higher in the Ile de France breed than in the Romane breed. Likewise, the Romane breed showed a higher degree of spontaneous recovery of entropion. [ABSTRACT FROM AUTHOR]

A collection of Bacillus and Trichoderma isolates from Iran was investigated for the biological control of pear white root rot caused by Rosellinia necatrix. Among the isolates, B. amyloliquefaciens AP4, B. siamensis AP8 and T. harzianum T20a were selected based on their growth inhibition of R. necatrix in dual cultures, as well as by volatiles, diffusible extracts and culture filtrates. Four pear rootstocks (Pyrodwarf, OHF40, OHF60 and Williams) were assessed for white rot in the greenhouse following soil amendment with the three isolates. For OHF40 rootstock, none of the three isolates significantly reduced disease severity, whereas all three isolates significantly reduced disease severity for OHF69 rootstock. For Pyrodwarf rootstock, only T. harzianum T20a and B. amyloliquefaciens AP4 significantly reduced root rot, but all three isolates significantly reduced leaf fall. For Williams rootstock, all three isolates significantly reduced root rot, but only T. harzianum T20a significantly reduced leaf fall. Thus, the effectiveness of both the Bacillus and Trichoderma isolates was highly dependent upon the pear genotype. The lowest levels of white rot symptoms were observed in the Williams‐T. harzianum T20a interaction resulting in root rot severity of 46.6% and leaf fall of 4.7% at 70 dpi. While the effect of plant genotype on biocontrol activity has been reported frequently for Trichoderma, this is one of the first to report such an effect with a Bacillus biocontrol agent. Both Bacillus and Trichoderma can be effective biocontrol agents of pear white rot, but the plant genotype can have a major impact on their effectiveness. [ABSTRACT FROM AUTHOR]

Background: Grapevine trunk diseases (GTDs) are an economically serious threat, affecting grapevine long-term sustainability and productivity. The use of antagonistic endophytic bacteria can be a promissing approach for GTDs' management. Results: 253 bacterial endophytes were isolated from the stems and roots of grapevines from 68 geographic locations in eight provinces of Iran. Based on biochemical properties, 22 strains were selected and identified using the 16S rRNA gene. The representative strains belonged to 13 genera of Agrobacterium, Arthrobacter, Bacillus, Chryseobacterium, Klebsiella, Kocuria, Pantoea, Pseudomonas, Rahnella, Rothia, Serratia, Staphylococcus and Variovorax. Using the dual culture method, antagonistic activity of 27 strains from 50 selected ones was shown against Fomitiporia mediterranea, a pathogen of GTDs; in which its hyphal growth was inhibited from 10 to 55%. Among the tested bacteria, Serratia plymuthica GI154, Bacillus sp. GI298 and Pseudomonas fluorescens GI310 showed the highest fungal growth inhibition zones, respectively. Co-treatment of GI154, GI298, and GI310 with F. mediterranea, in planta, could reduce the length of its internal canker by 54.41, 60.16 and 49.42% in compare with contol, respectively. Conclusions: To the best of our knowledge, this is the first report of isolation of Arthrobacter agilis, Chryseobacterium daecheongense, Rahnella aquatilis, Serratia plymuthica, Staphylococcus epidermidis, Staphylococcus warneri and Variovorax paradoxus from grapevine in Iran. Moreover, this is the first report of Rothia amarae as a bacterial endophyte of the grapevine for the world. Grapevine bacterial endophytes exhibit auspicious biocontrol activities that can be utilized in sustainable and organic agriculture. [ABSTRACT FROM AUTHOR]

Objectives: Air pollutants in dentistry offices may cause problems for the health of staff and patients. Accordingly, the present study was performed to the assessment of bacterial bioaerosols and particulate matter (PM) characteristics in the indoor air of dentistry clinics. Methods: The sampling points were restoration, endodontics, and prosthesis wards. The PM specimens were taken using Grimm Dust Monitor and the microbial specimens were taken using QuickTake 30. Results: The maximum and minimum PM10 concentration across the different measure wards occurred as 70.31 and 30.32 μg/m3 in the Ketabchi Clinic restoration and its endodontics ward, respectively. The total number of bioaerosols was 2079. Gram‑positive Staphylococcus spp.(872), Gram‑positive Micrococcus spp.(706), and Gram‑negative Bacillus spp.(501) were present in the indoor air. The results showed a significant relationship for PM1 and PM2.5 in each sampling site. Conclusion: The low PM and bacterial bioaerosols contamination can be due to the coincidence with coronavirus pandemic, as during this period, health and hygienic protocols have been strictly observed. [ABSTRACT FROM AUTHOR]

This study investigates the potential of epiphytic bacteria isolated from citrus fruits to control green mold post-harvest disease caused by Penicillium digitatum in Thompson Navel sweet oranges in the north of Iran. Twenty-three epiphytic bacteria were isolated and screened in vitro against P. digitatum, and 13 isolates with antagonistic activity were selected for further studies. Isolates B15 (Bacillus sp.), P17 (Pseudomonas sp.), and S13 (Streptomyces sp.) exhibited the most effective inhibitory effects on P. digitatum in vitro and in vivo. Among these, B15 showed the highest percentage of mycelium growth reduction and was further identified as B. cereus by 16S rRNA sequence analysis. Metabolic analysis of Bacillus sp. isolate B15 extract revealed the presence of the inhibiting antifungal substance Iturin A. The result showed that the application of epiphytic B. cereus decreased the percentage of green mold post-harvest diseases in orange fruit. This indicates their potential as an environmentally friendly alternative to chemical post-harvest control of orange diseases caused by P. digitatum. [ABSTRACT FROM AUTHOR]

In order to appraise the bacterial endophyte communities that help resist disease in potato tuber, the separation, the population density, biodiversity and the antagonistic activity of endophytic bacteria, from the tuber peel of potato cultivars (Fontan90, Agria, Sante'a and Jeli89), were examined in the Fars province in Iran. In this study, the bacterial endophyte Colony Forming Units (CFU) were counted based on the most suitable dilution in petri dishes and expressed per g of wet weight of tuber tissue. The presence of bacteria was found mostly in the outer layer. A wide variety of endophyte species biodiversity was in Agria cultivar. To estimate the antagonistic effect of potato associated endophytic bacteria, 115 bacterial isolates were evaluated by dual culture method against main soil-borne potato pathogens Fusarium oxysporum, Rhizoctonia solani, Verticillium dahliae, Streptomyces scabies and Ralstonia solanacearum. Endophyte strains were identified based on physiological, morphological and chemical characteristics and the 16S rRNA gene sequence analysis. The highest degree of the inhibitory activity in all layers of potato cultivars was related to Bacillus subtilis, Bacillus mojavensis and Klebsiella variicola. Antagonistic activity of endophytic bacteria against the pathogens was significantly higher (p<0.01) in the examined strains from the outermost layer of tuber peel and decreased progressively toward the center of the tuber. In this research, Klebsiella variicola was reported as endophyte bacteria in the four commercial potato cultivars mentioned above, for the first time. [ABSTRACT FROM AUTHOR]

Surfactin is one of the most important lipopeptide biosurfactants obtained by biocatalysts of Bacillus subtilis. The aim of this study was to isolate surfactin‐producing bacilli from native soils of the country (Iran), investigate their properties, convert surfactin to surfactin micelles, determine the properties of surfactin micelles and investigate the effect of starch‐coated Fe0 and Fe3+ nanoparticles on the production of surfactin from B. subtilis. To do so, 20 bacilli were isolated from the native soil sample by heat shock method and genome sequenced by SrRNA16 method. The samples with strong β‐hemolysis activity were screened as surfactant‐producing strains. Two species of 61 and 63 (B. subtilis subspecies. Inaquosorum) were selected and examined by quantitative and qualitative screening tests such as hemolysis activity, surfactin production, droplet aggregation, emulsifying activity, and surface tension reduction in MSM medium containing Fe0 and Fe3+ nanoparticles. Surfactin was converted to surfactin micelles by sonication and confirmed by SEM. The antimicrobial and emulsifying activity and surface tension reduction of surfactin micelles were investigated. According to the results, the surface tension reduction of surfactin micelles was greater than that of surfactin. The strain 61 (99.7%) culture in 5 L bioreactors containing Fe3+ nanoparticles produced more surfactin than culture of the same strain without nanoparticles. This study presents an efficient method to increase the biosynthesis of microbial metabolites. [ABSTRACT FROM AUTHOR]

Methyl Tert-Butyl Ether(MTBE) is among oxygenised additives to gasoline, which has high solubility and leads to pollution of water resources. So far, the microbial species affecting the of high MTBEconcentrationsremoval have been less investigated. This study aimed to remove high concentrations of MTBEusing isolated bacteriafrom contaminatedsoil with petroleum compounds in southern regions of Iran and determine their kinetics. After isolating the bacteria and determining their growth in different concentrations, the effects of the following parameters on the removal percentage were examined: incubation time = 1–7 days, pH = 5.0–7.0, and 9.0, initial MTBE concentration = 1000–5000 mg/L, and C: N:P. Then, the four strains with high efficiency were selected, and their kinetic were analysed by zero-order, first-order, and second-order models. The results showed that the highest growth in MTBE concentration (50,000 mg/L) was observed for Acinetobacter sp, Bacillus sp, Ochrobactrum sp, and Sphingomonas sp. after four days. Then, Ochrobactrum sp.was used as a pure strain as well as a microbial consortium for the next steps, including the effects of nutrient ratio and initial MTBE concentration. In this study, the optimal conditions for incubation time and the initial MTBE concentration were 72 hours and 5000 mg/L, respectively. The kinetic modeling indicated that the second-order model (R2 = 0.95, Root Mean Squared Error = 0.012) and the Micheal-Menten model (R2 = 0.99) were the best modelfor MTBE biodegradation. Overall, the results indicated that pure Ochrobactrum sp. and a microbial consortium consisting of resistant bacteria at high MTBEconcentrations could remove MTBE> 90%. [ABSTRACT FROM AUTHOR]

Background: and Aim Acinetobacter baumannii causes various nosocomial infections and has a high antibiotic resistance. Probiotics can produce metabolites with antimicrobial properties. This study aims to evaluate the antimicrobial ability of probiotics against nosocomial pathogens by inhibiting the ompA gene expression effective in biofilm formation in Acinetobacter baumannii. Methods & Materials: The antimicrobial properties of probiotics against nosocomial pathogens were evaluated phenotypically. The polymerase chain reaction (PCR) technique was used to identify the ompA gene in Acinetobacter baumannii. After treatment with Bacillus licheniformis supernatant, the ompA gene expression was compared before and after treatment with real-time PCR technique. Ethical Considerations This study was approved by the ethics committee of Islamic Azad University, Qom branch (Code: IR.IAU.QOM.REC.1398.004). Results: Among the study probiotics, Bacillus licheniformis supernatant had the best antimicrobial properties against nosocomial isolates of Acinetobacter baumannii A52, Acinetobacter baumannii ATCC19606, Kelebsiella pneumonia ATCC70063, and Pseudomonas aeruginosa PAO1. Bacillus licheniformis supernatant also significantly reduced the biofilm formation and ompA gene expression in Acinetobacter baumannii. Conclusion: Bacillus licheniformis can produce substances with antimicrobial and antibiofilm properties. It can be used for controlling the causative agents of nosocomial infections. [ABSTRACT FROM AUTHOR]

Background: Root-knot nematodes (RKNs) cause severe losses in kiwifruit-growing regions. The endophytic bacteria could be biological agents for nematodes management. The aim of this study was the isolation and identification of endophytic bacteria from kiwifruit orchards and the evaluation of their antagonistic ability against RKN in greenhouse conditions. Results: In this study, the population of nematode and the bacterial strains were isolated from kiwifruit roots and leaves in the Mazandaran and Guilan provinces of Iran. Molecular experiments were conducted to identify and confirm the bacterial isolates and RKN species. Also, the effects of bacterial isolates on nematode reproduction factors (number of galls, egg masses, and second-stage juveniles, J2) and growth parameters of kiwifruit plants were determined. The RKN was confirmed as Meloidogyne incognita by molecular identification. Also, the endophytic bacteria were identified based on supplementary experiments and molecular analyses. A total of 31 bacterial endophytes were identified to be including 12 genera of Bacillus, Pseudomonas, Staphylococcus, Exiguobacterium, Sphingomonas, Agrobacterium, Variovorax, Pantoea, Microbacterium, Streptomyces, Chryseobacterium, and Chitinophaga. Generally, Bacillus and Pseudomonas were the dominant genera that included 29.03 and 22.58% of total isolated bacteria, respectively. In vitro screening assays, P. ananatis 121.en and P. chlororaphis 54.en displayed considerable antagonistic ability on J2 mortality of M. incognita and were selected for greenhouse surveys. The isolates displayed a significant reduction in the number of galls and egg masses on roots and juvenile's population in pot soil. Moreover, 121.en and 54.en strains significantly increased growth parameters including root fresh weight and shoot fresh weight than the control kiwifruit seedlings. Conclusions: The bacterial endophytes are safe and have a low risk of managing the RKNs and can be effective microbial bio-fertilizers for improving kiwifruit plant growth under RKNs infections. [ABSTRACT FROM AUTHOR]

Bacillus bacteria are a group of plant growth stimulants that increase plant growth and resistance to plant pathogens by producing various metabolites. With their large surface area and small size, nanoparticles can be used in controlled-release formulations and increase the efficiency of the desired product. Encapsulation of biological agents in combination with nanoparticles can be an essential step in increasing the performance of these agents in adverse environmental conditions. In this study, which is the result of a collaboration between scientists from Italy and Iran, Bacillus velezensis was encapsulated in alginate combined with whey protein and zedo, mastic, and tragacanth gums in the presence of silica and titania nanoparticles to obtain two-layer and multilayer assemblies acting as novel, smart micro-encapsulation systems. The results of laboratory studies showed that the B. velezensis could produce protease, lipase, siderophore, auxin, and a dissolution of mineral phosphate. Scanning electron microscopy images (SEM) showed that the studied microcapsules were almost spherical. Moisture affinity, swelling, and efficiency of each microcapsule were examined. The results showed that the highest encapsulation efficiency (94.3%) was related to the multilayer formulation of alginate-whey protein-zedo. XRD and FTIR spectroscopy showed that the alginate, whey protein, and zedo were mixed properly and no incompatible composition occurred in the reaction. This study aimed to provide a suitable formulation of biofertilizers based on biodegradable compounds as an alternative to chemical fertilizers, which is low cost and very effective without harming humans and the environment. [ABSTRACT FROM AUTHOR]

Auxin produced by plant growth-promoting bacteria (PGPR) in the wheat rhizosphere, can improve plant yield under water deficit stress condition. To investigate this issue, a completely randomized factorial design with three replications was conducted under greenhouse condition at the University of Maragheh, Eastern-Azarbayjan, Iran during 2019. Treatments were two types of growth-promoting bacteria (Bacillus simplex 40, Bacillus simplex 52); two moisture levels (50% and 80% of water holding capacity in perlite) and two levels of tryptophan (0 mg L-1 and 100 mg L-1). Under the condition of 50% of water holding capacity, the application of tryptophan without bacterial inoculation decreased wheat dry matter yield by 5%. Inoculation of Bacillus simplex 40 in the absence of tryptophan led to 25% increase in wheat dry matter yield while application of tryptophan reduced the trait by 17%. Under the stress condition, catalase enzyme activity increased by 33% and guaiacol peroxidase activity increased by 2.3% in inoculation treatments compared to control treatments. In conclusion, bacterial inoculation was able to increase wheat dry matter yield by improving the wheat antioxidant system under drought-induced oxidative stress. Furthermore, the decrease in wheat dry matter in the presence of tryptophan treatment may be attributed to probable hormonal disorders in wheat caused by high concentration of applied tryptophan. [ABSTRACT FROM AUTHOR]

Introduction: Medicinal plants are valuable sources of different antioxidant and antimicrobial compounds. In this study, the effects of different extraction methods with aqueous and methanolic solvents were investigated on the antioxidant and antimicrobial activities of Teucrium hyrcanicum L. Material & Methods: In this basic experimental study, aqueous and methanolic extraction was carried out using three methods, including a magnetic stirrer, a Bain-Marie bath, and Shaker. The antioxidant effects were then determined using DPPH and RP methods along with the determination of total phenol and total flavonoid. The antibacterial effect of aqueous and methanolic extracts against Staphylococcus aureus, Bacillus cereus, and Escherichia coli was determined through the disk diffusion method. (Ethic code: IR.ausmt.rec.1398.11.34) Findings: The evaluation of antioxidant properties showed that methanolic extract had a stronger effect than aqueous extract. Moreover, it was demonstrated that the magnetic stirrer method was superior to the other two extraction methods. The same results were obtained for total phenol and total flavonoid as well. Evaluation of antibacterial properties revealed that methanolic extract had antibacterial activity, while aqueous extract did not show antibacterial activity. Discussion & Conclusion: The results of this study showed that Teucrium hyrcanicum L. was more effectively extracted through the magnetic stirrer method than other extraction methods. Both aqueous and methanolic extracts had antioxidant properties, while only methanol extracts showed antibacterial properties. Therefore, this plant can have good therapeutic application in the treatment of diseases due to its antioxidant properties. [ABSTRACT FROM AUTHOR]

This study reports biochemical features of a novel esterase of Bacillus sp. HP 96 isolated from Bazangan Lake in Iran. The optimum pH and temperature for 53.4 kDa-purified esterase were 8 and 40 °C, respectively. The HPLC technique was used to examine the main compound produced by the enzyme on nitrophenyl derivatives. Vmax and Km of esterase towards 4-nitrophenyl butyrate (p-NPB) were 75.12 µmol.min−1 mg−1 and 4.66 mM, respectively. Organic solvents (15, 30% v/v) did not have a significant effect on the stability of the purified enzyme. The Bacillus sp. HP 96 esterase showed a high compatibility towards various ionic liquids and detergents. In conclusion, the characterized esterase has potential to be used in detergent formularizations and biotechnological processes under harsh conditions. [ABSTRACT FROM AUTHOR]

Background and Aim: Penicillinase plays diverse roles, such as inducing drug resistance by hydrolyzing the amide bond of beta-lactam factors, the metabolism of cephalosporin-attached prodrugs, as well as the metabolism of some antibiotics, and renal clearance. The present study aimed to evaluate the optimum conditions for extracting and purifying penicillinase enzyme. The enzyme source was Bacillus licheniformis 6346 obtained from the Iranian Research Organization for Science and Technology. Materials and Methods: B. licheniformis was cultured in a medium containing mineral salts, nitrogen compounds and carbon sources. Following the harvesting and preparation of bacterial suspension, the destruction of the bacterial cell wall and crude cell extraction was completed using a combination of lysozyme and weak ultrasonication. Afterward, enzyme amount was determined utilizing chromatography and electrophoresis. Furthermore, the optimum growth temperature and incubation time were assessed based on the absorbance of samples at 240 nm, enzyme activity, aerification intensity optimization, enzyme production time, and optimum pH. Results: Approximately 8 g of cells were retrieved in one liter of culture. The optimum pH was determined as 6.5. The heat stability evaluation of the enzyme at different times revealed that the enzyme was stable for more than 1 h at 20°C-45°C, while it is inactivated in 10 min at 60°C. Moreover, the best incubation time for this bacterium was obtained as 9 h at 30°C. In terms of aerification intensity, the highest enzyme production rate of 2394 U/mL was achieved in a 250 mL Erlenmeyer flask with a 50 mL culture medium at 200 RPM. More aerification led to the inhibitory effect of oxygen and reduced enzyme activity. Conclusion: Our findings showed that the bacterium B. licheniformis 6346 can be used for producing penicillinase enzyme in optimum conditions (30°C, 200 RPM, and pH: 6.5). [ABSTRACT FROM AUTHOR]

Objective. Vaccinium genus plants have medicinal value, of which Vaccinium arctostaphylos (Caucasian whortleberry or Qare-Qat in the local language) is the only available species in Iran. Public tendency to use herbal remedies and natural products such as synthesized nanoparticles is increasing due to the proof of the destructive side effects of chemical drugs. Nanosilver products have been effective against more than 650 microbe types. This study was aimed at assessing the possibility of green synthesis of silver nanoparticles using Vaccinium arctostaphylos aqueous extract and at evaluating its antibacterial properties, as well. Materials and Methods. In order to synthesize silver nanoparticles, different volumes of Vaccinium arctostaphylos aqueous extract (3, 5, 10, 15, and 30 ml) were assessed with different silver nitrate solution concentrations (0.5, 1, 3, 5, and 10 mM) and different reaction time durations (1, 3, 5, 10, and 20 minutes) at room temperature using a rotary shaker with a speed of 150 rpm. Ultraviolet-visible (UV-Vis) spectroscopy, X-ray diffraction analysis (XRD), Fourier transform infrared (FTIR) spectroscopy, and scanning electron microscopy (SEM) were carried out. The antibacterial activity of the aqueous extract and the synthesized nanoparticles was evaluated, as well. Results. Silver nanoparticle formation process was confirmed with XRD analysis, transmission electron microscopy (TEM), and FTIR spectroscopy. The UV-Vis spectroscopy of silver colloidal nanoparticles showed a surface plasmon resonance peak at 443 nm under optimal conditions (3 ml aqueous extract volume, 1 mM silver nitrate solution concentration, and 3 min reaction time under sunlight exposure). The reduction of silver ions to silver nanoparticles in solution was confirmed, as well. Based on X-ray diffraction analysis, the size of silver nanoparticles was in the range of 7-16 nm. TEM images showed an even distribution of silver nanoparticles, with a spherical shape. FTIR spectroscopy demonstrated the presence of different functional groups of oxygenated compounds such as carboxyl, hydroxyl, and nitrogenous groups. The antibacterial properties of the synthesized nanoparticles were confirmed. Conclusion. The synthesized nanoparticles showed more antibacterial properties against gram-positive bacteria (Bacillus subtilis and Staphylococcus aureus) than gram-negative ones (Escherichia coli and Salmonella enteritidis). [ABSTRACT FROM AUTHOR]

Background: Cancer is one of the most common causes of death in humans. Therefore, there is a need for new cytotoxic compounds from natural sources such as native bacteria. The current study aimed at investigating the cytotoxic effects of compounds obtained from gram-positive terricolous bacteria on the apoptosis of cells in prostate cancer (PC-3). Materials & Methods: A total of 70 soil samples were obtained from various locations in Chaharmahal & Bakhtiari province (Iran, Spring 2019) and were cultured on Nutrient agar and Trypticase soy agar. After identification of gram-positive species, the best species in regards to microbial activity was identified using 16S rRNA gene sequencing. Then, in order to investigate the cytotoxic activity, PC-3 cell line was treated in different concentrations of the supernatant from the selected species for different durations while viability and apoptosis were determined using MTS and Annexin tests. Results: A total of 467 gram-positive bacteria were isolated from 70 soil samples, among which 9 species had antimicrobial capabilities. Among these selected species, Bacillus licheniformis which had the best antimicrobial compounds, was selected for further investigation of its viability and apoptosis effects on PC-3 cell line. The MTS with incubation time of 24, 48 and 72 hours of the treated cells indicated that the viability is dependent on the dosage an increase in the concentration can result in significant decrease in the viability compared to the control group (P<0.05). The amount of apoptosis induction in PC-3 cells also significantly increased with increase in supernatant concentration dependent on dosage and time (P<0.05). The largest effect was observed at supernatant concentration of 20 mg/mL at 72 hours after cell treatment. Conclusion: Using compounds obtained from gram positive terricolous bacteria can help in treatment of prostate cancer cells. [ABSTRACT FROM AUTHOR]

Background: Recently, using antibacterial peptides has been considered as a strategy to manage the worldwide antibiotic-resistance crisis. Screening of Dasht-Desert Bacterial Culture Collection (DDBCC) for bacteriocin or bacteriocin-like producer was aimed in this study to introduce native antibacterial agent(s). Methods: In this study, 170 isolates were examined by the cross-streak method against G+ and G- indicators. Isolates with antimicrobial activity were compared using turbidity and well diffusion tests. The candidate isolate, DDBCC70, was molecularly and biochemically characterized. Then, the production of an antibacterial agent was physicochemically optimized. The supernatant was saturated ammonium sulfate. SDSPAGE and Thin-Layer Chromatography (TLC) analyses, cytotoxicity, and hemagglutination tests were performed. Results: First, 23 isolates were detected with antimicrobial activity against at least three of the indicator strains. DDBCC70 was distinguished with the broad-spectrum of antibacterial effects of the Cell-Free Supernatants (CFSs). The black pigments on BHI and a 98% similarity in 16S rDNA and similarity in biochemical tests confirmed the strain of DDBCC70 as Bacillus atrophaeus (B. atrophaeus). The highest amount of the antibacterial agent, Bac70, was obtained from the modified brain heart infusion medium. It was revealed that 70% ammonium sulfate-saturated Bac70 was 3.8 and 1.6 times more effective on Pseudomonas aeuroginosa (P. aeuroginosa) and Klebsiella pneumoniae (K. pneumoniae). Bac70, a >25 kDa protein and a safe compound for blood cells, neither agglutinated human erythrocyte nor lysed sheep blood. The purified bacteriocin-like molecule destroyed biofilms from P. aeruginosa and Staphylococcus aureus (S. aureus). Moreover, the fraction of Bac70 from the TLC plate showed higher inhibitory effects against K. pneumoniae. Conclusion: Based on the above-mentioned features, Bac70 is a potential alternative therapeutic agent in pharmaceutical, food preservative and biotech-related industries. [ABSTRACT FROM AUTHOR]

Introduction: Folic acid or vitamin B9 is one of the most essential vitamins and plays a key role in the transport of carbon and many biochemical pathways and its deficiency can lead to neurological diseases, anemia, and developmental problems in children. The present study aimed to take a step towards producing this vitamin from native strains by isolating and sequencing the folic acid production gene from soil isolated bacillus and cloning it in Escherichia coli. Materials and methods: In this study, 40 samples were collected from 10-15 cm depth from different areas around Sirjan city, Kerman province, Iran. Bacillus bacteria were isolated by molecular and biochemical methods. By the PCR method, bacteria with the FOLA gene were identified and the amplified gene was cloned into E. coli and sequenced. Gene expression was then evaluated by the Real-Time PCR method and its phylogenetic relationships were determined. Results: As a result of screening 40 soil samples sent to the laboratory, a total of 12 suspected colonies were isolated from Gram-positive bacilli which were identified based on morphological, microscopic, and biochemical characteristics and all species were identified as having FOLA gene. FOLA cloning was performed successfully in one species and its gene expression was confirmed. Discussion and conclusion: In the present study, the FOLA gene from Bacillus Halotolerance isolated from the soils of the surrounding areas of Sirjan was successfully cloned into the PTG19-T expression vector and its successful expression showed that it could be expanded by this method for industrial production of Folate. [ABSTRACT FROM AUTHOR]

Background and Aim The assessment of indoor air quality and detection of its microbial pollutants in classrooms is very important because of the presence of children sensitive to these pollutants. The aim of this study was to determine the concentration and characterization of dominant species of biological aerosols and their relationship with environmental factors in two selected primary schools in Arak, Iran. Methods & Materials This cross-sectional study was conducted at two primary schools in Arak, Iran in Fall 2018. Indoor air sampling was performed using single-stage Andersen microbial sampler (at flow rate of 28.3 liters/min) containing bacterial and fungal culture media. The effects of suspended Particulate Matter (PM) and environmental parameters (temperature and humidity) on the density of bioaerosols were evaluated. Ethical Considerations This study with an ethics code of IR.ARAKMU.REC.1397.76 was approved by the Research Ethics Committee at Arak University of Medical Sciences. Results The overall mean density of indoor bacteria and fungi was 448 cfu/m3 and 394 cfu/m3, while the mean density of outdoor bacteria and fungi was 210 cfu/m3 and 127 cfu/m3, respectively. There was a positive correlation between indoor density of airborne bacteria and suspected PM concentrations (PM 10 and PM 2.5), and between PM2.5 concentration and indoor fungal density (P<0.05). Penicillium (40%), Cladosporium (19%) and Aspergillus (16%) were dominant species of fungi, while Staphylococcus (42%), Micrococcus (28%), Bacillus (21%) were the dominant species of bacteria. Conclusion The age and type of building and the density of students in a classroom are the main factors in increasing the concentration of bioaerosols. [ABSTRACT FROM AUTHOR]

Aims:Staphylococcus aureus is considered a major cause of food poisoning in the world. We aimed to investigate the prevalence of S. aureus isolated from hamburgers in Kashan city. Materials and Methods: In this study, 71 hamburger samples were collected from supermarkets in Kashan from March to July 2017. The samples were examined after dilution in the Baird–Parker Agar Base medium of inoculation for the bacterial growth of S. aureus. Gram staining, catalase tests, mannitol fermentation, coagulase, DNase, and sensitivity to novobiocin were used to detect the bacteria. Results: The collected hamburgers were about eight types of products. Of the total samples, 15 (21.13%) were Gram-positive bacteria contaminated, including seven cocci and eight bacilli. Seven samples (9.86%) of hamburgers were contaminated with S. aureus. The average counts of S. aureus in positive samples were 1.94 × 103 colony-forming unit (CFU)/g. Conclusion: The outbreak of S. aureus isolates in meat products, particularly hamburger, is of serious threat to public health. To prevent the outbreak of this pathogen in hamburgers, permanent control and monitoring should be performed in food industries. [ABSTRACT FROM AUTHOR]

Background: Bacteria are one of the important sources of producing enzymes. The aim of this study was to the isolate the halophilic bacteria producing amylase, lipase and pectinase from saline soil of the center of Iran. Methods: In this study, soil samples were collected from Dagh Biarjmand and Haj Aligholi in Semnan province. At first, isolated halophilic bacteria were cultured and screened for producing of hydrolytic enzymes including amylase, lipase and pectinase using enzyme-specific media. The enzymatic activities of isolates were recognized by induction of growth inhibition zone and/or precipitation around colonies after addition of related indicators. Afterward, enzyme positive isolates were identifies using the 16S rRNA sequencing. Results: Out of 7 bacterial isolates, 4 bacteria with amylase activity, 6 bacteria with lipase activity and 3 bacteria with pectinase activity were recognized and identified. Results showed that 2 isolates with the ability of producing all three types of enzymes belong to Bacillus genus using molecular identification methods. Furthermore, the halophilic bacteria producing amylase and pectinase were belonging to Bacillus and Halobacillus genera. Besides, bacteria producing lipase belonged to Bacillus and Virgibacillus genera. Conclusion: The Bacillus bacteria isolated from the soil can produce all three amylase, pectinase and lipase enzymes. [ABSTRACT FROM AUTHOR]

Thermo-tolerant phytase has lots of applications in different industries, such as environmental protection, aquaculture, and agriculture. In the present study, Bacillus sp. Dm018 has been isolated from Demand hot spring in Jiroft, which placed in the southwest of Iran. Statistical optimization approach by response surface methodology (RSM) leads to 2.3-fold growth in phytase construction by Bacillus sp. Dm018. The optimal temperature for phytase function was established to be about 60 °C. Furthermore the enzyme reserved more than 70% of its activity over an extensive pH series of 4.0–8. 0. Results showed that Dm018 phytase activity was inhibited by CaCl2 (5 mM) about 60%. Phytase activity was inhibited by SDS (5 mM) about 30% and slightly improved by EDTA about 6.0%. Phytase stability data exhibited that the enzyme reserved more than 50% of it,s original activity after pre-incubated in the existence of diverse ions, except CaCl2. These results indicate that Dm018 phytase has good latent for commercial attention as an animal feed preservative. [ABSTRACT FROM AUTHOR]

The use of medicinal plants has been considered due to increasing bacterial resistance to antibiotics. Semenovia suffruticosa is a plant with high potential in medicine. The aim of this study was to evaluate the antibacterial activities and gas chromatography–mass spectrometry (GC-MS) analyses of the essential oil of S. suffruticosa from four regions in Kerman: Hezar Mountain, Laleh Zar, Bidkhan, and Rabor. The essential oil of this plant was extracted by Clevenger. The antibacterial activities were evaluated against three Gram-negative bacteria (P. aeruginosa, K. pneumonia, Acinetobacter) and three Gram-positive bactria (B. subtilis, S. aureus, S. pneumoniae). By disk diffusion method, minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) values were determined. The composition of essential oil was identified by GC-MS analysis. In our study, most yield of essential oil of S. suffruticosa was 1.2% from the Laleh Zar region and the main components were Z-β-ocimene (25.4%) in Laleh Zar, linalool (17.7%) in Hezar, Z-β-ocimene (18.5%) in Bidkhan, and β-pinene (10.5%) in the Rabor region. Maximum inhibition zone by the essential oil from region Bidkhan was observed against K. pneumoniae (30 mm). The MIC value for S. suffruticosa collected from Laleh Zar was 1.25 mg/ml against S. aureus and S. pneumonia. The results of this study confirm that the significant antibacterial effects of S. suffruticosa and make it a valuable compound in essential oils for pharmaceutical use and a good replacement for chemical antibiotics. Environmental conditions can result in a difference in yields and components; this can be considered significant potential for this plant. [ABSTRACT FROM AUTHOR]

Fusarium wilt of tomato is one of the most prevalent and economically important diseases of tomato worldwide especially in tropical regions. The aims of the present study were to isolate and characterize Bacillus bacteria from tomato rhizospheric soil of various regions in Iran and determine the isolates that exhibit high levels of antagonistic efficiency against tomato Fusarium wilt pathogen, Fusarium oxysporum f. sp. lycopersici (Fol) and growth promotion activity. In this study, 303 Bacillus isolates were obtained from tomato rhizospheric soil. Dual culture and volatile metabolite tests were used to screen for antagonism of Bacillus isolates against Fol. Among them, 20 isolates were found to inhibit pathogen growth by 67.77% and 33.33% in dual culture and volatile metabolite tests, respectively. Based on the results of physiological tests and 16S rRNA and gyrA gene sequence analysis of 20 effective isolates, 11, seven and two isolates were identified as B. subtilis, B. velezensis and B. cereus, respectively. The results of greenhouse assessment showed that KR1-2, KR2-7 and A2-9 isolates which were characterized as Bacillus subtilis, reduced the disease index to 16.67% and promoted the plant growth by 80%. These isolates may serve as potential promising biocontrol agents against Fusarium wilt of tomato. [ABSTRACT FROM AUTHOR]

Introduction: Most cases of blood transfusion-associated bacterial sepsis are caused by platelet concentrates (PCs). Screening of PCs is carried out in the Iranian quality control plans as it is essential for detection of bacterial contamination. With regard to quality control, this study investigated the frequency of bacterial contamination of PCs through Gram staining and microbial culture methods. Materials and Methods: In this descriptive cross-sectional study, 880 cords out of 440 platelet product bags (two cords per platelet bag) were selected on the first and third days and included in the study. Direct smears were prepared from the samples for Gram staining, then they were cultured in blood agar and chocolate agar under aerobic and microaerophilic conditions for detection of both Gram positive and negative cocci and Gram positive bacteria. Cultures were also made in MacConkey medium under aerobic conditions to identify Gram negative bacilli. In cases of bacterial growth and colony formation, differential tests were performed to detect the bacteria. Results: One case of Staphylococcus saprophyticus was isolated of 440 platelet bags collected from donors in Jahrom Blood Transfusion Organization, from which two platelet cord (880 samples) had been isolated on the first and third days. Accordingly, a contamination frequency of 0.23% was detected for platelet products in Jahrom city. Conclusion: Performing staining and bacterial culture from all of the platelet cords before they are used is a good way to ensure safety and prevent bacterial contamination from platelet products and quality control. [ABSTRACT FROM AUTHOR]

Carbapenem-resistant Gram-negative bacilli (GNB) are a concern in the Middle East and worldwide. Simple screening methods have been sought to detect carbapenemase producers to determine appropriate therapeutic measures and implement infection control interventions. In this study, we evaluated the efficiency of agar disc diffusion, commercial combined disc test (Rosco), and carbapenem MIC determination in comparison to molecular detection of carbapenemase genes among 82 carbapenem non-susceptible Enterobacteriaceae (CNSE) and 37 Acinetobacter/Pseudomonas isolates. The blaOXA-48, blaNDM, blaNDM/OXA-48, and blaIMP were detected in 68 out of 82 CNSE isolates. All of the Acinetobacter baumannii isolates were positive for the blaOXA-51 (n = 23), of those some were positive for blaOXA-48 (n = 13) and blaNDM (n = 3). Sensitivities and specificities of combined disc test for detection of blaNDM and blaOXA-48 carrying Enterobacteriaceae isolates were 92.5% and 100%, and 58.5% and 100%, respectively, while those for Acinetobacter/Pseudomonas isolates were 100%, 81.8% and 96.2%, 89%, respectively. While carbapenem MIC values had excellent concordance with phenotypic combined disc test for detection of blaOXA-48 producers (area under curve > 90%), only ertapenem MIC's could precisely detect blaOXA-48 PCR-positive Enterobacteriaceae isolates (AUC 70%, sensitivity 70%, specificity 50%). The phenotypic commercial test showed excellent sensitivity for detection of blaNDM producers, but had poor sensitivity for blaOXA-48-producing Enterobacteriaceae. Ertapenem MIC values had low sensitivity and specificity for detection of the blaOXA-48-carrying Enterobacteriaceae. This is the first report of A. baumannii isolates co-harbored the blaOXA-48/blaNDM carbapenemases from Iran. [ABSTRACT FROM AUTHOR]

Background: A number of aromatic medicinal plants used for treating infection disease have been mentioned in different phytotherapy manuals due to their availability, fewer side effects, and reduced toxicity'. Dracocephahmi L is one of the most important genuses of Lamiaceae.The aim of our studywas to evaluate the chemical compositions of Dracocephahim Lindbergh Reclrf and Dracocephahim snbcapitatimi (O.kuntze) Lipsky and there is antimicrobial activites. Methods: Two species of Dracocephahmi (Dracocephahim Lindbergh Rech.f and Dracocephahim snbcapitatimi fO.kuntze) Lipsky ) were collected at North Khorasan province.Extracting the essential oil of the aeiial parts of the plant was done through the method of hydrodistillation using Clevenger, and the identification of the essential oils components were carried out through GC-MS. The antibacterial activity was performed against three human pathogenic bacteria including: Escherichia Coli, Staphylococcus aureus, Bacillus atrophaeuse, using disk diffusion method. Results: Forty-two components were identified in the essential oil of the species Deracocephahmi Lindbergh Rech.f., representing 90.69% of the total oil. Hie highest percentage of the components belongs to β-ocimene with 17.58%. Thirty components were identified in the plant Deracocephahmi snbcapitatimi (O.kuntze) Lipsky'. representing 87.24% of the total oil, in which the highest percentage belongs to β-ocimene with 24.45%. Hie antibacterial effects showed that the bacteria of Bacillus atrophaeus and Staphylococcus aureus with the diameter inhibition zones of 29 and 33 nun were the most sensitive, hi addition, the essential oil of D.subcapitatuin (O.kuntze) with a diameter of 33 mm inhibition zone had the highest antibacterial activity against Staphylococcus aureus bacteria. Conclusion: Based on the results of this study.tlie chemical variations of the volatile oils of two Dracocephahmi species might be correlated with geographical regions and enviromental conditions play a significant role in biosynthesis of the components of the oil. Also.Hie results of the antibacterial examination of the essential oil s of the studied species can lead to the discovery of new antibacterial agents. [ABSTRACT FROM AUTHOR]

The main goal of the current study was to isolate and characterize endospore-forming soil bacteria that produce parasporal crystalline proteins against larvae of Lepidoptera insects during stationary phase of growth. Two different methods were applied for the isolation of spore-forming strains. Polymerase Chain Reaction (PCR) was used for the characterization of cry gene content of the isolated strains and 16S rRNA sequencing was carried out to identify bacterial strains. Efficiency of the isolates as insecticide was evaluated in a bioassay experiment using insect's larvae. Regarding presence of parasporal inclusion crystals and SDS-PAGE patterns, 10 bacterial strains were isolated from about 200 soil samples. Analysis of crystal-spore mixtures with SDS-PAGE showed a broad range of proteins with molecular weight between 11-230 kDa. Data from PCR analysis indicated that only two isolates (RIPI6 and RIPI18) may contain cry3 gene. Isolate RIPI21 and reference strain (Bacillus thuringiensis subsp. kurstaki) were positive for cry1 gene. 16S rRNA gene sequences of all isolates showed at least 96% sequence match with B. thuringiensis strains deposited in the GenBank. The results of bioassay experiments showed the efficacy of strains RIPI7, 10 and 22 on killing of larvae of both Anagasta kuehniella Zeller and Plutella xylostella Curt. It is concluded that there are some bacterial candidates for biological control of major agricultural pests in north of Iran. [ABSTRACT FROM AUTHOR]

Background: Today, discovery and production of new antimicrobial drugs has been emphasized due to the growing of antimicrobial resistance. The purpose of this study was to screen out antimicrobial producing bacteria among halophilic or halotolerant Gram-positive endospore-forming bacteria isolated from different areas of Iran. Materials and Methods: 62 strains were isolated from salin lakes of Iran, endospore-forming ability was evaluated and further identification of strains was done using 16S rRNA gene sequencing. Screening test was performed using two-layer agar diffusion method in which the indicator strains, Bacillus cereus (ATCC 14579) and Escherichia coli, (PTCC 1330) were inoculated in the seed layer. Finally, the production of antimicrobial active agent during a period of 7 days was studied followed by evaluating the effect of base-layer agar concentration on the dissemination of antibacterial metabolite. Results: Isolates WT6, R4A19 produced an agent(s) which inhibited the growth of both B.cereuse and E.Coli. The inhibition zone against only E.Coli was observed when R4A20 strain had been cultured in the base layer, while four non-bacillus strains (R4S2, LbS2, RF1 and WT19) could inhibit the growth of B.cereuse. The antibacterial compound production of WT6 against Bacillus cereuse and E.Coli reached to its optimumm leved after 3 and 4 days respectively, while R4A20 produced the active substance, optimally, after 5 days. No significant difference effect on diameter of zone inhibition was observed among various base-layer agar concentrations. Conclusion: Halophile or halotolerant endospore-forming bacteria isolated from different areas of Iran possess a potential to be considered as interesting microorganisms for further antimicrobial research studies. [ABSTRACT FROM AUTHOR]

Background and Aims: The use of microorganisms in the synthesis of metal nanoparticles is known as an eco-friendly method. Moreover, because of the ability of microorganisms to synthesize nanoparticles of various sizes, shapes and morphologies, this method has gained extreme attentions in recent years. The aim of this study was, therefore, to investigate the antimicrobial effects of silver nanoparticles synthesized by bacteria isolated from agricultural soils of Kerman, Iran. Materials and Methods: This study was carried out in 2014. Silver nanoparticles were characterized by SEM, EDS and XRD analyzes. The antimicrobial effects of silver nanoparticles were also assessed against some pathogenic bacteria. Results: Of the 40 silver nanoparticle producing bacteria, the strains that were able to produce silver nanoparticles with high antimicrobial activity yielded under different environmental conditions, were selected. The results of scanning electron microscopy (SEM) confirmed the presence of silver nanoparticles with a spherical shape. EDS analysis showed that silver content of the particles was about 60 wt %. Sequence alignment and phylogenetic tree results showed that M9 and B7 strains are closely related to Bacillus cereus and Pseudomonas argentinensis, respectively, with 99% homology. Conclusions: The results showed that the M9 and B7 strains can synthesize silver nanoparticles with high antimicrobial effects under different environmental conditions. [ABSTRACT FROM AUTHOR]

Although several microorganisms are known to produce proteases, Bacillus strains are often preferred as major sources for commercial alkaline proteases due to their exceptional ability to secrete large amounts of highly active enzymes. The present study aimed at isolation and molecular identification of alkaline protease producing Bacillus spp. from soil samples of Damghan County in Iran. This research was conducted in the laboratory complexes in the school of pharmacy of Islamic Azad University Damghan Branch. Soil samples were collected from 3 different regions. Streaking plate was done and 9 colonies were selected on the basis of appearance. To identify isolates, biochemical tests were performed. 16SrRNA gene duplicated with PCR and sent to Sinagene Company for sequencing. All isolates were oxidase-negative and catalase-positive. The ONPG tests were negative. 16SrRNA analysis showed that the isolated bacteria belonged to genus Bacillus. The results confirmed that four bacterial isolates had alkaline protease production capacity. It appears that after complementary examinations, the isolated Bacillus strains can be used for production of alkaline protease. [ABSTRACT FROM AUTHOR]

Background: As lactobacilli possess an antagonistic growth property, therefore they may be used as bioprotective agents for infection control. The aim of this study was to investigate the antagonistic effect of lactobacilli isolated from local dairy. Materials and Methods: In this study 26 species of Lactobacilli were isolated from milk, homemade yoghurt and cheese. Each isolated bacteria was tested for its tolerance to acidic environments at pH (2.0, 3.0, and 4.0) and bile salt concentrations (0.3, 0.5 and 1% w/v). Also, isolates were further tested for their antimicrobial activity against common pathogenic bacteria such as Enterococcus feacalis, Listeria monocytogenes, Staphylococcus aureus PTCC 1112, Escherichia coli PTCC 1330 and Bacillus cereus PTCC 1015 by using the agar well method. Then the strains that are not only resistant to acidic conditions and bile salts but also have antimicrobial activity, were identified by 16S rRNA gene sequencing. Results: In this study, most of isolated Lactobacilli were found to inhibit growth of pathogens (96.15%). 61.5% and 84.62% of isolated lactobacilli tolerated to pH 2 and 0.3% bile salt. Only two strains, 53C and 22CL, were more resistant to pH 2 and high concentration of bile salt. The Phylogenetic analysis based on 16S rRNA sequencing revealed that two strains (53C and 22CL) belong to species of Lactobacillus casei. Conclusions: According the results the two isolated resistant strains can be employed as probiotic starter in probiotic dairy products preparation. [ABSTRACT FROM AUTHOR]

The use of Plant Growth Promoting Rhizobacteria (= PGPR) to increase crop tolerance to biotic and abiotic stresses such as drought is considered a novel method to increase plant yield. For this purpose, several rhizobacteria isolates from the wheat rhizosphere were screened in Northwest Iran. After sieving the bacteria in the media with PEG6000 5 g/100 ml (PEG= Polyethylene Glycol), a total of 22 bacterial isolates were selected for further experiment. The study was performed as a factorial experiment with three replications. The effect of selected bacterial isolates in three different concentrations of PEG (−0.5, −0.9, −1.2-1.2 MPa) on wheat seeds was evaluated under standard laboratory conditions for two weeks, and major growth factors were measured. After analyzing the data, to confidently conclude the selection of better bacteria, PCA (=Principal Component Analysis) was used for the importance of traits. The first and second components were 49.15% and 15.4% of the changes, respectively which justified all traits. In the first main component, germination percentage (PG), germination rate (GV) and seed vigor index (SV) traits had high coefficients which indicated the greater importance of these traits in justifying the general changes in traits. Finally, three bacterial strains were selected as the desired bacteria on the base of these traits for greenhouse work. The results indicated that all the three bacteria strains increased the mean value of the studied traits compared to that of the control. Among the three selected strains, the 16srDNA region of the bacterium with the best performance was sequenced. The sequencing results showed that this bacterium belonged to Bacillus wiedmannii with 98.8% Likelihood. • The first scientific report for capability of Bacillus wiedmannii as PGPR bacteria of Wheat in Iran. • The first report of Drought Tolerance Induction by Bacillus weidmanii • Over 50% increase in drought tolerance in wheat by a bacterium. [ABSTRACT FROM AUTHOR]

The global atmosphere is a huge and renewable water resource which contains about 14,000 km³ of water vapor. The aim of this study was to investigate the water produced by the air conditioners installed in Bandar-e-Abbas (BA) and its chemical and microbiological quality of this water. Moreover, it was also important to specify the best use of the water. In a nine-month period, 66 samples were taken in four clusters of BA, based on distance to shore and population and vehicle traffic. Quantity was measured by volumetric method; turbidity, alkalinity (ALK), total hardness, dissolved solids (TDS), and electrical conductivity (EC) were tested in laboratory; and counting of bacteria and fungi was done. SPSS 19.0 for Windows was used for data analysis. Mean of produced water was 21.3–47.6 L/d;, and mean for pH, turbidity, EC, TDS, ALK, and total hardness was 6.75–6.89, 2.33–2.55 NTU, 37.8–45.6 μS/cm, 28.8–33.3 mg/L, 34.3–38.2 mg/L as CaCO3, and 18.2–21.6 mg/L as CaCO3, respectively. Legionella pneumophila is present in 22% of samples and Staphylococcus aureus, Micrococcus sp., Corynebacterium diphtheria, Bacillus sp., and Pseudomonas were 21, 13, 18, 13, and 13%, respectively. Observed fungi in the tested samples were 23, 18, 16, 15, 14, and 14% for Penicillium, Aspergillus, Cladosporium, Alternaria, Mucor, and Trichoderma, respectively. The water quality is suitable to many municipal uses and due to the significant volume, the planning of utilizing this significant amount of free water would be economically justified. [ABSTRACT FROM AUTHOR]

Escherichia coli is a Gram-negative, nonspore-forming bacillus, usually motile, and a member of the family Enterobacteriaceae. Virulence factors such as CDT and CNF are associated with the capacity of E. coli strains to cause intestinal and extraintestinal infections, and sheep and mutton are important sources for transmission of this infection to human. The purposes of this study were to determine the presence of E. coli at the first step and to examine samples for detection of virulence genes using specific primers in Iranian sheep carcasses. One hundred fifty muttons were collected randomly from slaughterhouse industries in southwest Iran, and bacterial DNA was extracted. For gene amplification, PCR reaction was performed using 16srRNA primer for the presence of E. coli DNA, and then specific primers were used for the detection of cdt and cnf genes in positive samples. The amplification products were analyzed in 1% agarose gel electrophoresis. E. coli DNA was found to be positive in 32/150 (21.33%) mutton specimens, and cdt, cnf, and both genes were identified in 10/32 (31.25%), 16/32 (50%), and 6/32 (18.75%) of positive samples, respectively. The results showed a significantly frequent presence of cdt and cnf genes in E. coli strains isolated from mutton. These findings indicated that sheep is an important carrier of these infectious agents to humans, and examinations of these animals are significant for food safety and public health in Iran. [ABSTRACT FROM AUTHOR]

Background and Aim: The aim of this study was to evaluate bacterial contamination of keyboards of computers located in various wards of Vali-e Asr Teaching Hospital, Birjand, Iran. Materials and Methods: In this study, all computer keyboards in various wards of Vali-e Asr Hospital were sampled (n=24). Then, the samples were sent to Microbiology Research Laboratory at Birjand University of Medical Sciences and were cultured on Blood ager, Manitol Salt ager and Eosin Methylene Blue media. The isolated bacteria were identified based on their colonial morphology and biochemical characteristics. Results: A total of 26 samples from 24 different computer keyboards of 16 different wards were obtained. Two keyboards of Infectious Diseases and Neurology wards were routinely disinfected at the end of every shift. All samples (100%) showed contamination to different bacteria. The keyboard of the computer located in Internal Medicine ward (women's division) was the most contaminated one. In total, 13 different bacterial spp. were isolated from keyboards of different computers. The species belonging to Enterobacteriaceae family(61.5%) were the most common contaminating bacteria followed by Bacillus spp (30.7%). Conclusion: Based on the results, all the sampled keyboards were contaminated by at least one bacterial spp. Therefore, it is necessary to pay more attention to the fact that computer keyboards in hospitals should regularly be disinfected. [ABSTRACT FROM AUTHOR]

Abstract: A Bacillus mojavensis strain (PTCC 1696) which was isolated from an Iranian oil field was used to produce a lipopeptidic biosurfactant. The surface activity measurement with De Nouy ring detachment method showed that this biosurfactant is able to reduce the surface tension of the media and interfacial tension between aqueous phase and n-hexadecane to 26.7 and 0.1mN/m respectively. The core flooding tests were carried out to evaluate oil recovery from carbonate reservoirs by this lipopeptidic biosurfactant. These tests were conducted at reservoir conditions using low permeability dolomite cores, live crude oil and reservoir formation brine. The experiments showed that the biosurfactant-assisted waterflooding method can be considered as a technique for oil recovery from carbonate formations. The results obtained in this study showed the potential of the biosurfactant produced by Bacillus strains for enhanced oil recovery even from low-permeability carbonate reservoirs. [Copyright &y& Elsevier]

Abstract: The microflora of Ramsar geothermal hot springs located in Mazandaran province, Iran was screened for native thermophilic bacteria that are capable of biosynthesis of silver nanoparticles. One isolate identified as “Ureibacillus thermosphaericus” showed high potential for silver nanoparticle biosynthesis with extracellular mechanism and selected for the biosynthesis optimization. Biosynthesis reactions were conducted using the culture supernatant at different temperatures (60–80°C) and silver ion concentrations (0.001–0.1M). The results obtained showed that pure spherical nanoparticles in the range of 10–100nm were produced, and the maximum nanoparticle production was achieved using 0.01M Ag-NO3 at 80°C. In conclusion, the findings of this study confirmed the great biocatalyzing potential of the extremophilic U. thermosphaericus supernatant for intensified biosynthesis of silver nanoparticle at elevated temperatures and high silver ion concentrations. [Copyright &y& Elsevier]

A xylanase producer Bacillus mojavensis strain, called AG137, isolated from cotton farm (Kashan-Iran). The optimal xylanase activity reached at 55°C & pH 9.0. Enzyme yield was studied using a medium with different agricultural wastes as inducers. Xylanase production of about 249.308 IU/mL was achieved at pH 8 and 37°C, within 48 h submerged fermentation in enzyme production medium supplemented with 2% (w/v) oat bran as an optimum carbon source. A mixture of 1% (w/v) yeast extract and 1%(w/v) tryptone as optimum nitrogen sources, agitation speed 200 rpm, and inoculumsize 2%(v/v) were the optimums for maximum production. Accordingly, xylanase yield from 194.68 IU/mL under non-optimized fermentation condition enhanced to 302.466 IU/mL in optimized condition. Screened xylanase is thermostable, presenting 70% stability at 60?C during 30 min. Further enzyme incubation in higher temperature caused a decrease in the residual enzyme activity, yet it retained 68%-50% of its activity after 1 hour from 45?C to 55°C. Besides, it is stable in pH 9 and 10, maintaining over 70% of its activity for 2 h. The enzyme also could preserve 71% and 63% of its initial activity after 3 hours of pre-incubation in the same alkaline condition. Produced xylanase therefore was introduced as an alkaline-active and stable one, displaying suitable thermostability feature, confirmed by HPLC analysis. Hence, all xylanase properties highlight its promising uses in industrial scale. [ABSTRACT FROM AUTHOR]

Abstract: The potential of an indigenous bacterial strain isolated from an Iranian oil field for the production of biosurfactant was investigated in this study. After isolation, the bacterium was characterized to be Paenibacillus alvei by biochemical tests and 16S ribotyping. The biosurfactant, which was produced by this bacterium, was able to lower the surface tension of media to 35mN/m. Accordingly, thin layer chromatography (TLC) and FT-IR has been carried out to determine compositional analysis of the produced biosurfactant. After all the tests related to characterization of the biosurfactant produced by the isolated bacterium, it was characterized as lipopeptide derivative. The combination of central composite rotatable design (CCRD) and response surface methodology (RSM) was exploited to optimize biosurfactant production. Therefore, variations of four impressive parameters, pH, temperature, glucose and salinity concentrations were selected for optimization of growth conditions. The empirical model developed through RSM in terms of effective operational factors mentioned above was found to be adequate to describe the biosurfactant production. A maximum reduction in surface tension was obtained under the optimal conditions of 13.03g/l glucose concentration, 34.76°C, 51.39g/l total salt concentration and medium pH 6.89. [ABSTRACT FROM AUTHOR]

Abstract: This paper describes the purification and characterization of a novel acidophile α-amylase from newly isolated Bacillus sp. Ferdowsicous. The enzyme displayed a molecular weight of 53kDa and it was stable over a range of pH from 3.5 to 7 with an optimum around 4.5. The optimum temperature for activity was found to be around 70°C and the enzyme remained active to more than 75% up to 75°C for 45min. The enzyme activity was decreased by Zn2+and EDTA but inhibited by Hg2+, whereas the activity was increased by approximately 15% by Ba2+ and Fe2+. Na+, Mg2+, K+, Ca2+, PMSF, Triton X-100 and β-mercaptoethanol had any considerable effect on its activity. The enzyme activity on the amylose as substrate was 1.98 times greater than amylopectin. Partial N-terminal sequencing demonstrated no significant similarity with other known α-amylases, indicating that the presented enzyme was new. Considering its promising properties, this enzyme can find potential applications in the food industry as well as in laundry detergents. [Copyright &y& Elsevier]

Abstract: Bacillus sp. STG-83 that was isolated from Neidasht spring – north of Iran – is a gram positive faculative anaerobic rod which is capable of reducing selenate anion to elemental selenium. This bacterium is also able to catalyze the reduction of tellurite. The chromatographic behavior demonstrated that the reduction of tellurite and selenate in Bacillus sp. STG-83 was carried out by two distinct enzymes. Both enzymes were purified by the same purification procedure. The purification process involved (NH4)2SO4 precipitation, followed by phenyl-Sepharose and Sephacryl S-200 chromatography. Using gel filtration, the relative molecular mass of the native selenate reductase and tellurite reductase was determined to be 182kDa and 197kDa, respectively. Values of 2.7μmolmin−1 mg−1 and 3.24mM were obtained for the V max and K m of selenate reductase, respectively. The K m for selenite reduction was determined to be 10.9mM and the V max was 1.6μmolmin−1 mg−1 of protein. For tellurite the K m was 2.63mM and the V max was 5.2μmolmin−1 mg−1 of protein. Optimal pH range for selenate reductase was 5.5–6, and the maximum activity was achieved at 38°C. Tellurite reductase exhibited its highest activity at 35°C and the optimum pH of the purified enzyme was 8. Cations such as Ca2+, Mg2+ and Na+ abolished the selenate reductase activity and had no effect on the tellurite reductase activity. Tellurite reductase was inactivated by EDTA. Elemental analysis revealed the presence of Zn and Mo in tellurite reductase and Cu in selenate reductase. [Copyright &y& Elsevier]

Abstract: The purpose of this study was to investigate the antimicrobial resistance pattern among common Gram-negative bacilli isolated from patients with nosocomial infection. A total of 200 samples of common Gram-negative bacilli (Klebsiella, Pseudomonas, Acinetobacter, and Escherichia coli) were collected from 2 university hospitals in Iran during a 1.5-year period from June 2004 to December 2005. All samples were examined for the antimicrobial activity of imipenem, cefepime, ciprofloxacin, ceftriaxone, and ceftazidime using E-test methods. The most frequent pathogens were Klebsiella spp. (38.5%) followed by Pseudomonas aeruginosa (28.5%), Acinetobacter spp. (20.5%), and E. coli (12.5%). The most active antibiotic was imipenem (84%). The susceptibility of the studied microorganisms was 25% for cefepime, 24% for ciprofloxacin, 20.5% for ceftazidime, and 11.8% for ceftriaxone. The susceptibility rates of Klebsiella to imipenem, cefepime, ciprofloxacin, ceftazidime, and ceftriaxone were 90.9%, 20.8%, 18.2%, 10.4%, and 5.2%, respectively. Likewise, these rates were 88%, 19%, 17%, 21%, and 21% for E. coli. Among Acinetobacter spp., the susceptibility rates were 77% for imipenem and 21% for ciprofloxacin. Among Pseudomonas, the rates were 75% for imipenem and 39% for ciprofloxacin. The antibiotics resistance among Gram-negative bacilli was widespread, so an antibiotic policy is urgently needed to delay the resistance development. [Copyright &y& Elsevier]