Journal of Microbial Biology
Year:2019 | Volume:8 | Issue:31 |Papers Count:6

Introduction: Helicobacter pylori is a gram-negative and microaerophilic bacterium. About half of the human population in the world is infected with this bacterium. Helicobacter pylori is known to be one of the main causes of stomach ulcers and gastric cancer. The increased antibiotic resistance, the high cost of combined treatments and adverse side effects have led to an increase in the tendency to alternative methods such as the use of antioxidants, anti-inflammatory agents, probiotics and herbal medicines. Material and method: In this study the published articles on the effects of 29 plant families, including 69 Iranian plant species against H. pylori in vitro and in vivo conditions were reviewed and categorized. Results: According to the obtained results, plants such as Mentha Piperita, Zataria multiflora, Salvia mirzayanii, Geum Iranicum, Rhus coriaria, Commiphora myrrha, Heracleum persicum, Trachyspermum amm, Artemisia absinthium, Glycyrrhiza glabra L, Olea europaea and Punica granatum are the most affected plants against Helicobacter pylori in vitro condition. Discussion and conclusion: The observed antibacterial effects of the tested herbs in this study suggest that these herbs have the potential to be used as a viable alternative treatement for of the H. pylori infections but antibacterial activity evaluation of herbal extracts against H. pylori should be evaluated both in vitro and in vivo conditions. Also, determining the effective ingredient can help further research in this regard. The effectiveness of the same plant species should be evaluated in the different regions and ultimately concluded in the field of their effect. It is clear that the obtain outcome of the antibacterial effect of the same herbal extract on different strains of a bacterial species might be different so the standard strain of H. pylori must be use.

Introduction: Phenol is considered to be an important pollutant in the environment and is steadier than other aromatic compounds in industrial treatment. There are several methods for detecting phenol in the wastes. In spite of the high accuracy of these methods, they are time consuming and complex. The utilization of enzymatic biosensors for the identification of phenolic compounds is one of the options and successful techniques. However, the weaknesses of enzymes and high financial expenses cannot be ignored. One of the alternative solutions to overcome the shortcomings of working with enzymes is the utilization of microbial cells in biosensors. In this study, microbial cells were used to design a reasonable and accurate biosensor. Materials and Methods: In this survey, designing of a biosensor was examined using a phenol consuming bacterium. Pseudomonas. GSN23 was acclimatized to high phenol concentrations and immobilized by forming physical and chemical links on working electrodes (glassy carbon and gold interdigitated microelectrodes). Two electrochemical methods (square wave voltammetry and conductometric) were utilized to measure the phenol. Results: In the presence of 1 gram per liter phenol, as the only source of carbon and energy, Pseudomonas. GSN23 consumed 73% of the initial phenol concentration at 32 hours and phenol consumed completely at 72 hours. This bacterium had positive and repeatable responses in conductometric method for phenol detection in the range of 1-300 milligram per liter. The phenol selectivity of the designed biosensor was estimated 5 times more than other aromatic compounds. Conclusion: Microbial biosensors are practical, stable and resistant to the changes of the experimental media. In this study, Pseudomonas. GSN23 was utilized as a phenol consuming bacterium and by conductivity measurement; repeatable responses were acquired in detecting this contaminant.

Introduction: Common zinnia (Zinnia elegans), canna (Canna sp. ), petunia (Petunia hybrida), compacta (Dracaena Compacta), dahlia (Dahlia sp. ), gazania (Gazania sp. ), marigold (Tagetes sp. ), rose moss (Portulaca grandiflora) and nasturtium (Tropaeolum majus) are common ornamental plants in Ahvaz. The identification of fungi associated with these plants will contribute to improving the future managment of their cultivation. Members of the genera Amesia and Chaetomium are widely distributed in soil, water, plants, animals and humans. In this study, 12 isolates from Chaetomium and Amesia genera, obtained from herbaceous ornamentals, were identified based on morphology and phylogenetic analysis. Materials and methods: During 2017-2018, 40 symptomatic plants, showing root rot, stem canker and leaf spot, were collected and their associated fungi were isolated. Among those, 12 chaetomiaceae-like isolates were obtained, which their morphological and molecular characterizations were surveyed. Mycelial biomass of the isolates, produced into potato-dextrose-broth (PDB), was collected by passing through filter paper and freeze-dried. ITS and partial regions of the 28s-D1/D2 (for 4 isolates) and tub2 (for 9 isolates) were amplified using appropriate primers and sequenced. Results: The isolates under survey were compared with known strains using BLASTn search and phylogenetic analysis beased on ITS, 28S and tub2 regions. Accordingly, the isolates under study were identified as follow: Amesia atrobrunnea, Chaetomium rectangulare, C. globosum, C. ascotrichoides and C. olivaceum. The morphological characteristics of these isolates were in accordance with the type strains of each species. Discussion and conclusion: To our knowledge, this is the first record of C. ascotrichoides in Iran and the association of C. rectangulare on compacta, C. globosum on zinnia and canna, C. ascotrichoides on petunia, C. olivaceum on common zinnia, nasturtium and marigold throughout the world.

Introduction: Mycotoxins or toxic fungi are primary or secondary metabolic products. A wide variety of mold fungi such as Aspergillus, Fusarium and other fungi are capable of producing large amounts of dangerous mycotoxins in human and animal food. Materials and methods: In this study, samples of animal and poultry feed were transferred to the laboratory and cultured on potato dextrose agar (PDA) medium. After isolation, purification, and identification, the toxicity of fungi was performed on the corn media, and coconut agar medium was used for toxicity assessment. Then, they were evaluated using standard toxin on the TLC plate in the TLC tank under ultraviolet (UV) light. Also, the quantitative evaluation of toxins was performed using high performance liquid chromatography (HPLC). Results: The results showed that the samples were infected with Aspergillus flavus, A. parasiticus, A. ochraceous, A. niger, Penicilliun glabrum, Fusarium verticillioides, F. proliferatum, F. fujikuroi, F. concentricum, Rhizopus oreyzae, Absidia corymbifera, Rhizomucor sp., Trichothecium sp. and Alternaria alternata. Rhizomucor, Absidia and Fusarium (15 and 27. 5%) were most infected in poultry and F. prolifratum (62. 1%) in animal feed, respectively. Also, according to TLC, F. prolifratum and F. verticillioides fungi emitted the highest light, while Rhizomucor received the least light and, consequently, the least toxicity. Based on HPLC results of F. verticillioides and A. flavus isolates, Fumonisin B1 and A. niger had the highest amount of aflatoxin G1. Discussion and conclusion: In the present study, Aspergillus, Rhizomocor and Fusarium fungi showed fluorescence in coconut-agar medium. After puncturing on the TLC plate, the toxincontaining dots had a higher fluorescence intensity, which the overall results of this toxin assay by HPLC also confirmed this.

ntroduction: Lactobacillus bacteria are known as living microorganisms in the stomach, biliary secretions, and pancreas. They attach to the epithelial cells and colonize the human intestines. Many probiotics belong to a large group of bacteria called lactic acid bacteria. Due to immunomodulatory effect of probiotics and the impact of these bacteria on the performance of immune responses, the aim of this study was to evaluate the effect of Lactobacillus reuteri cell wall and cytoplasmic extract effects on the stimulation of IL-4 and IFN γ cytokines production. Materials and methods: For this purpose, 20 samples of traditional dairy and pasteurized dairy products were collected. Molecular identification was performed using molecular-specific primers. Bacterial DNA was extracted and the identification of bacterial species was determined by genetic sequencing of PCR product. Human heparin blood was then prepared and peripheral mononuclear blood cells were isolated. To evaluate immune stimulation, IL-4 and IFN γ cytokines production were measured by ELISA method. Results: The results of this study showed that from 20 dairy samples, 7 isolates of Lactobacillus reuteri were identified. The immune system for the production of interleukin-4 and IFN γ in the presence of cell wall and cytoplasmic cell extracts of Lactobacillus reuteri was not stimulated. Lactobacillus casei extract compared to other two bacteria has the greatest effect on immune stimulation and increased IL-4 production. Discussion and conclusion: The level of cytokines produced in human monocular cells did not increase after stimulating the immune system. The Lactobacillus reuteri bacterium will not be used in immunotherapy.

Introduction: Due to the advantages of biosurfactants such as low environmental toxicity, biological degradation, and effectiveness in wide ranges of pH and temperature, the industrial production of them has been significantly increased. Bioremediation is the strategy of reducing or eliminating petroleum compounds using microorganisms that are capable of decomposing petroleum hydrocarbons by producing biosurfactants. The purpose of this study was to investigate the biosurfactant production and bioremediation of crude oil by the isolated bacterium from Isfahan Oil Recovery plant activated sludge. Materials and methods: Quantitative and qualitative methods of screening such as hemolysis in blood agar medium, oil distribution, oil degradation, oil emulsification and surface tension reduction measurements were used for the detection of biosurfactant production. The bacterium was identified by biochemical tests and 16S rRNA sequencing. Residual petroleum hydrocarbons were analyzed using gas chromatography (GC-MS) analysis. Results: The results from analysis of the composition by thin layer chromatography and Fiore infrared analysis showed that the produced biosurfactant had rhamnolipid content. The isolated bacterium was identified Pseudomonas Sp. The Pseudomonas sp. that was isolated from activated sludge of the oil refinery plant in Isfahan was able to produce rhamnolipid biosurfactant and decreased the surface tension of crude oil down to 27 mN/m. Gas chromatography analysis showed the removal of 80. 45% of petroleum hydrocarbons within 20 days by the isolate. Methanoic acid accounts for 23% of the remarkable produced compounds. Discussion and conclusion: The results of this study showed that the BA3 isolate was capable of producing the most biosurfactant and also the decomposition of crude oil hydrocarbons. Therefore, it has the ability to be used in bioremediation, crude oil decomposition and elimination of the environmental pollutions from oil industries. Also, the produced methanoic acid can be used as an antibacterial substance in animal feed.