University of Isfahan Journal of Microbial Biology 3060-7647 9 36 2020 12 21 Isolation of Endophytic Bacteria from Grasses Root and Assessing Phosphate Solubilization, Potassium Releasing and Auxin Production Abilities of Isolated Bacteria Isolation of Endophytic Bacteria from Grasses Root and Assessing Phosphate Solubilization, Potassium Releasing and Auxin Production Abilities of Isolated Bacteria 1 13 24492 10.22108/bjm.2019.117674.1207 FA Shokufeh Moradi Department of Soil Science, Faculty of Agriculture, University of Tabriz, Iran Mohammadreza Sarikhani Associate Professor of Soil Biology and Biotechnology, Faculty of Agriculture, University of Tabriz, Iran Nasser Alliasgharzad Department of Soil Science, Faculty of Agriculture, University of Tabriz, Iran Journal Article 2019 07 16 Introduction: Some of plant growth-promoting rhizobacteria are endophytic bacteria that exist in the endo-rhizosphere and are able to promote plant growth via different mechanisms. Materials and methods: 24 endophytic bacteria were isolated from the roots of grasses such as rice, wheat and barley using semi-solid nitrogen-free bromothymol blue (NFB) medium. PGP features including phosphate solubilization, indole acetic acid (IAA) production, potassium releasing and siderophore production were measured according to the standard methods. Results: The dissolution of phosphate 1.67 times was higher in the presence of tri-calcium phosphate (TCP) than rock phosphate (RP), and K release from biotite was more than muscovite (4.7 times); furthermore more IAA was produced in the presence of tryptophan, and this increment was by 30%. The highest and lowest amount of IAA were recorded in Az-3 (2.28 mg/l) and Az-48 (0.75 mg/l), respectively; while the maximum dissolution of phosphate obtained with Az-52 (340.13 mg/l) and the least dissolution of phosphate occurred in Az-13 (98.13 mg/l). The highest K release was accomplished by Az-65 (6.66 mg/l) and the lowest was in Az-3 (4.78 mg/l). Finally, identification of robust isolates by 16S rDNA sequencing showed that Az-8, Az-19, and Az-50 are belonging to the Pseudomonas, Az-3 to Acinetobacter, Az-18 to Rhizobium, Az-48 to Enterobacter, and Az-63 to Advenella. Discussion and conclusion: Our results revealed that different genera of bacteria with varied PGP traits are existing as endophytic bacteria in the plant roots. In total, these bacteria were able to solubilize more phosphate from TCP than RP; and higher K from biotite than muscovite. It seems that the production of organic acids is the main mechanism of P and K solubilization. Moreover, higher production of IAA was measured in the presence of tryptophan. Further research, especially in pot or farm, is necessary to assess the effects of these bacteria. Introduction: Some of plant growth-promoting rhizobacteria are endophytic bacteria that exist in the endo-rhizosphere and are able to promote plant growth via different mechanisms. Materials and methods: 24 endophytic bacteria were isolated from the roots of grasses such as rice, wheat and barley using semi-solid nitrogen-free bromothymol blue (NFB) medium. PGP features including phosphate solubilization, indole acetic acid (IAA) production, potassium releasing and siderophore production were measured according to the standard methods. Results: The dissolution of phosphate 1.67 times was higher in the presence of tri-calcium phosphate (TCP) than rock phosphate (RP), and K release from biotite was more than muscovite (4.7 times); furthermore more IAA was produced in the presence of tryptophan, and this increment was by 30%. The highest and lowest amount of IAA were recorded in Az-3 (2.28 mg/l) and Az-48 (0.75 mg/l), respectively; while the maximum dissolution of phosphate obtained with Az-52 (340.13 mg/l) and the least dissolution of phosphate occurred in Az-13 (98.13 mg/l). The highest K release was accomplished by Az-65 (6.66 mg/l) and the lowest was in Az-3 (4.78 mg/l). Finally, identification of robust isolates by 16S rDNA sequencing showed that Az-8, Az-19, and Az-50 are belonging to the Pseudomonas, Az-3 to Acinetobacter, Az-18 to Rhizobium, Az-48 to Enterobacter, and Az-63 to Advenella. Discussion and conclusion: Our results revealed that different genera of bacteria with varied PGP traits are existing as endophytic bacteria in the plant roots. In total, these bacteria were able to solubilize more phosphate from TCP than RP; and higher K from biotite than muscovite. It seems that the production of organic acids is the main mechanism of P and K solubilization. Moreover, higher production of IAA was measured in the presence of tryptophan. Further research, especially in pot or farm, is necessary to assess the effects of these bacteria.

https://bjm.ui.ac.ir/article_24492_09ea4321406f66caba3e55d7d2f80b2d.pdf

University of Isfahan Journal of Microbial Biology 3060-7647 9 36 2020 12 21 Identification and Characterizations of Shiga Toxin-producing E.coli Isolated from Meat-contact Surfaces Identification and Characterizations of Shiga Toxin-producing E.coli Isolated from Meat-contact Surfaces 15 23 25099 10.22108/bjm.2020.119809.1232 FA Mojtaba Bonyadian Associated professor of Food Microbiology, department of food quality control, Faculty of Vet.Med, institute of zoonoses research, Shahrekord University, Shahrekord-Iran Vahid Shirzadi Department of Health and Food Quality Control, Faculty of Vet.Med, Institute of Zoonoses research, Shahrekord University, Shahrekord-Iran Hamdallah Moshtaghi Department of Health and Food Quality Control, Faculty of Vet.Med, Institute of Zoonoses Research, Shahrekord University, Shahrekord-Iran. Journal Article 2019 11 11 Introduction: Shiga Toxin-producing Escherichia coli (STEC) is an important organism known as an emerging zoonotic microorganism causing diseases such as hemorrhagic colitis and Hemolytic Uremic Syndrome (HUS) as well as thrombotic thrombocytopenia in humans. This study aimed to determine the contamination of meat-contact surfaces to STEC and the characterization of the virulence genes of the isolates. Materials and Methods: Totally, 111 swab samples were obtained from meat-contact surfaces in slaughterhouses and meat supply centers for 6 months. After the primary enrichment and cultivation on EMB and SMAC environments, sorbitol negative colonies were transferred to differential media and confirmed by specific tests as Escherichia coli. Suspected colonies were evaluated by PCR method to determine the existence of serotype O157: H7and virulence genes such as Stx1, Stx2, eae, and Hly. Results: E. coli O157 was detected in 14 samples (12.61%), and only 2 isolates (1.8%) were identified as E.coli O157: H7. In PCR, 4 isolates contained Stx1, Stx2, and Hly genes, 2 isolates contained Stx1, eae and Hly genes, 3 isolates contained Stx1 and Hly genes, 1 isolate contained Stx2 and eae genes, 3 isolates contained the Hly gene and 1 isolate did not have any of the virulence genes. Discussion and Conclusion: Concerning the possibility of the transmission of pathogens such as E.coli O157: H7from contaminated surfaces to carcasses and healthy meat, the lack of attention to the health and care of slaughterhouses and meat supply centers can be concerns for the public health. Introduction: Shiga Toxin-producing Escherichia coli (STEC) is an important organism known as an emerging zoonotic microorganism causing diseases such as hemorrhagic colitis and Hemolytic Uremic Syndrome (HUS) as well as thrombotic thrombocytopenia in humans. This study aimed to determine the contamination of meat-contact surfaces to STEC and the characterization of the virulence genes of the isolates. Materials and Methods: Totally, 111 swab samples were obtained from meat-contact surfaces in slaughterhouses and meat supply centers for 6 months. After the primary enrichment and cultivation on EMB and SMAC environments, sorbitol negative colonies were transferred to differential media and confirmed by specific tests as Escherichia coli. Suspected colonies were evaluated by PCR method to determine the existence of serotype O157: H7and virulence genes such as Stx1, Stx2, eae, and Hly. Results: E. coli O157 was detected in 14 samples (12.61%), and only 2 isolates (1.8%) were identified as E.coli O157: H7. In PCR, 4 isolates contained Stx1, Stx2, and Hly genes, 2 isolates contained Stx1, eae and Hly genes, 3 isolates contained Stx1 and Hly genes, 1 isolate contained Stx2 and eae genes, 3 isolates contained the Hly gene and 1 isolate did not have any of the virulence genes. Discussion and Conclusion: Concerning the possibility of the transmission of pathogens such as E.coli O157: H7from contaminated surfaces to carcasses and healthy meat, the lack of attention to the health and care of slaughterhouses and meat supply centers can be concerns for the public health.

https://bjm.ui.ac.ir/article_25099_8f0f16e4bbe9962923dd95551c453de5.pdf

University of Isfahan Journal of Microbial Biology 3060-7647 9 36 2020 12 21 Effects of Ethanolic and Aqueous Extracts of Propolis on the Microbial Load of Raw Milk Effects of Ethanolic and Aqueous Extracts of Propolis on the Microbial Load of Raw Milk 25 34 25137 10.22108/bjm.2020.120086.1237 FA Hadi Koohsari Department of Microbiology, Azadshahr Branch, Islamic Azad University, Azadshahr, Iran Seyyede Zahra I Seyyed Alang Department of Chemistry, Azadshahr Branch, Islamic Azad University , Azadshahr, Iran Elham Payandan Department of Food Science and Technology, Azadshahr Branch, Islamic Azad University, Azadshahr, Iran Hhanie Naseri Department of Food Science and Technology, Azadshahr Branch , Islamic Azad University, Azadshahr, Iran Journal Article 2019 11 23 Introduction: Propolis is one of the most important bee byproducts that, due to its high antimicrobial properties, has the potential to be used as a food additive. This study investigated the effects of aqueous and ethanolic extracts of propolis on the microbial load of raw milk. Materials and methods: Raw milk samples containing0.1, 0.5, 1, and 2% ethanolic extracts and 0.5, 1, 3, and 5% aqueous extracts were prepared. The treatments were incubated at 4 °C and 25 °C and were cultivated by pour-plate technique in PCA medium during storage times of 0, 2, 24, 48, and 72 hours. By a total count of microorganisms, the effects of different concentrations of propolis extracts on the microbial load of raw milk were investigated. The chemical compounds of the extracts were identified by gas chromatography–mass spectroscopy (GC-MS) analysis. Results: At 25 °C, all concentrations of aqueous and ethanolic extracts affected the microbial load of raw milk, but at low concentrations, such effects were observed after 24 hours. Aqueous and ethanolic extracts of propolis at 25 °C compared to 4 °C in lower concentrations showed more antimicrobial activity. It was also found that propolisextracts need time to exhibit high antimicrobial activity. Forty-onecompounds were identified with the dominance of phenolic and flavonoid compounds. Discussion and conclusion: The antimicrobial properties of the tested propolis extracts can be attributed to the high amounts of phenolic and flavonoid compounds and the use of this bee product as an additive is recommended. Introduction: Propolis is one of the most important bee byproducts that, due to its high antimicrobial properties, has the potential to be used as a food additive. This study investigated the effects of aqueous and ethanolic extracts of propolis on the microbial load of raw milk. Materials and methods: Raw milk samples containing0.1, 0.5, 1, and 2% ethanolic extracts and 0.5, 1, 3, and 5% aqueous extracts were prepared. The treatments were incubated at 4 °C and 25 °C and were cultivated by pour-plate technique in PCA medium during storage times of 0, 2, 24, 48, and 72 hours. By a total count of microorganisms, the effects of different concentrations of propolis extracts on the microbial load of raw milk were investigated. The chemical compounds of the extracts were identified by gas chromatography–mass spectroscopy (GC-MS) analysis. Results: At 25 °C, all concentrations of aqueous and ethanolic extracts affected the microbial load of raw milk, but at low concentrations, such effects were observed after 24 hours. Aqueous and ethanolic extracts of propolis at 25 °C compared to 4 °C in lower concentrations showed more antimicrobial activity. It was also found that propolisextracts need time to exhibit high antimicrobial activity. Forty-onecompounds were identified with the dominance of phenolic and flavonoid compounds. Discussion and conclusion: The antimicrobial properties of the tested propolis extracts can be attributed to the high amounts of phenolic and flavonoid compounds and the use of this bee product as an additive is recommended.

https://bjm.ui.ac.ir/article_25137_4f57c3ed76e00155d928a60370110b28.pdf

University of Isfahan Journal of Microbial Biology 3060-7647 9 36 2020 12 21 Optimization of Cyanocobalamin Production by Propionibacterium Freudenreichii in Different Concentrations of Folic Acid and Methionine Optimization of Cyanocobalamin Production by Propionibacterium Freudenreichii in Different Concentrations of Folic Acid and Methionine 35 45 24945 10.22108/bjm.2020.121079.1265 FA Sahar Parchizadeh Department of Biochemistry, Payame Noor University, Isfahan, Iran Mohammad Fazilati Department of Biochemistry, Payame Noor University, Isfahan, Iran Hossein Salavati Department of Chemistry, Payame Noor University, Isfahan, Iran Behrooz Salehi Eskandari Department of Biology, Payame Noor University, Isfahan, Iran Habibollah Nazem Department of Biochemistry, Payame Noor University, Isfahan, Iran Journal Article 2020 01 18 Introduction: Vitamin B12 is a key factor in many growth-related processes in the human body and its large-scale industrial production is carried out using microorganisms, especially Propionibacterium freudenreichii. The aim of this study was to evaluate the effect of folic acid, methionine, and oxygen on the optimal production of vitamin B12 and Dry Cell Weight (DCW) of this bacterium. Materials and methods: Bacteria were maintained in four different conditions including anaerobic conditions and different concentrations of folic acid, aerobic conditions and different concentrations of folic acid, anaerobic conditions and different concentrations of folic acid and methionine 0.05% (w/v), aerobic conditions and different concentrations of folic acid and methionine 0.05% (w/v). Results: The maximum production of vitamin B12 and DCW was obtained in 750 mg / L of folic acid in the presence of methionine and aerobic conditions. By increasing the concentration of folic acid up to 1000 mg / L, the amount of vitamin B12 production and dry weight of the bacterium decreased. Discussion and conclusion: Due to the effect of folic acid on the fermentative processes of Propionibacterium freudenreichii, the present study could be an effective optimization to increase the final production of vitamin B12. Based on the above findings, aerobic conditions along with the presence of methionine can be effective in improving vitamin B12 production and this optimization may help as an effective strategy to improve vitamin B12 production at the industrial level. Introduction: Vitamin B12 is a key factor in many growth-related processes in the human body and its large-scale industrial production is carried out using microorganisms, especially Propionibacterium freudenreichii. The aim of this study was to evaluate the effect of folic acid, methionine, and oxygen on the optimal production of vitamin B12 and Dry Cell Weight (DCW) of this bacterium. Materials and methods: Bacteria were maintained in four different conditions including anaerobic conditions and different concentrations of folic acid, aerobic conditions and different concentrations of folic acid, anaerobic conditions and different concentrations of folic acid and methionine 0.05% (w/v), aerobic conditions and different concentrations of folic acid and methionine 0.05% (w/v). Results: The maximum production of vitamin B12 and DCW was obtained in 750 mg / L of folic acid in the presence of methionine and aerobic conditions. By increasing the concentration of folic acid up to 1000 mg / L, the amount of vitamin B12 production and dry weight of the bacterium decreased. Discussion and conclusion: Due to the effect of folic acid on the fermentative processes of Propionibacterium freudenreichii, the present study could be an effective optimization to increase the final production of vitamin B12. Based on the above findings, aerobic conditions along with the presence of methionine can be effective in improving vitamin B12 production and this optimization may help as an effective strategy to improve vitamin B12 production at the industrial level.

https://bjm.ui.ac.ir/article_24945_77db506604fa36ef4e0424fd67a3f2e0.pdf

University of Isfahan Journal of Microbial Biology 3060-7647 9 36 2020 12 21 Characterization of Psychrophilic and Psychrotolerant Cultivable Bacteria in Alpine Soil in Iran Characterization of Psychrophilic and Psychrotolerant Cultivable Bacteria in Alpine Soil in Iran 47 57 25135 10.22108/bjm.2020.121439.1273 FA Elham Lashani Department of Biology, Faculty of Science, Ferdowsi University of Mashhad, Mashhad, Iran, Bahar Shahnavaz Department of Biology, Faculty of Science, Ferdowsi University of Mashhad, Mashhad, Iran Ali Makhdoumi Department of Biology, Faculty of Science, Ferdowsi University of Mashhad, Mashhad, Iran Journal Article 2020 02 03 Introduction: Bacteria in cold ecosystems play a vital role in biochemical cycles, the biodegradation of pollutants, and biotechnology. For this reason, the identification and evaluation of their extracellular enzymes have received a lot of attention in recent years. Materials and methods: In this study, 43 psychrophilic or psychrotolerant bacteria were characterized from alpine soils on different culture media. The ability to produce extracellular enzymes by these bacteria was studied. Results: These bacteria belonged to the four major phyla including Actinobacteria, Firmicutes, Proteobacteria, and Bacteroidetes.A total of nine genera were identified among which Pseudomonas, Arthrobacter, and Bacillus were the most abundant. Discussion and conclusion: All of the obtained strains have the ability to produce at least one extracellular enzyme; proteolytic and amylolytic activities were the highest among these strains. Cellulase and pectinase activities were observed in 44 and 22 percentage of these strains. This study was the first report on psychrophilic and psychrotolerant bacteria in the Zagros Mountains (Oshtorankuh) and their extracellular enzyme production. The present study indicated that a wide range of bacteria in cold native ecosystems of Iran can be a suitable source for cold active enzymes. Introduction: Bacteria in cold ecosystems play a vital role in biochemical cycles, the biodegradation of pollutants, and biotechnology. For this reason, the identification and evaluation of their extracellular enzymes have received a lot of attention in recent years. Materials and methods: In this study, 43 psychrophilic or psychrotolerant bacteria were characterized from alpine soils on different culture media. The ability to produce extracellular enzymes by these bacteria was studied. Results: These bacteria belonged to the four major phyla including Actinobacteria, Firmicutes, Proteobacteria, and Bacteroidetes.A total of nine genera were identified among which Pseudomonas, Arthrobacter, and Bacillus were the most abundant. Discussion and conclusion: All of the obtained strains have the ability to produce at least one extracellular enzyme; proteolytic and amylolytic activities were the highest among these strains. Cellulase and pectinase activities were observed in 44 and 22 percentage of these strains. This study was the first report on psychrophilic and psychrotolerant bacteria in the Zagros Mountains (Oshtorankuh) and their extracellular enzyme production. The present study indicated that a wide range of bacteria in cold native ecosystems of Iran can be a suitable source for cold active enzymes.

https://bjm.ui.ac.ir/article_25135_b8fe8b7448092e9796b1ae849853c447.pdf

University of Isfahan Journal of Microbial Biology 3060-7647 9 36 2020 12 21 The High Anti-cytotoxic Effects of Novel Lactobacillus Plantarum HBM-IAUF-1 and Lactococcus Lactis HBM-IAUF-8 against SK-BR-3 Breast Cancer Cell Line The High Anti-cytotoxic Effects of Novel Lactobacillus Plantarum HBM-IAUF-1 and Lactococcus Lactis HBM-IAUF-8 against SK-BR-3 Breast Cancer Cell Line 59 68 25471 10.22108/bjm.2020.121092.1266 FA Ziba Harandi Department of Microbiology, Faculty of Biological Sciences, Islamic Azad University, Falavarjan Branch, Falavarjan, Isfahan, Iran, Keivan Beheshti Maal Department of Microbiology, Faculty of Biological Sciences, Islamic Azad University, Falavarjan Branch, Falavarjan, Isfahan, Iran, Ramesh Monajemi Department of Biology, Faculty of Biological Sciences, Islamic Azad University, Falavarjan Branch, Falavarjan, Isfahan, Iran, Journal Article 2020 01 14 https://bjm.ui.ac.ir/article_25471_ac7a13c7dffc182afd23b2bb192a90e8.pdf