JOURNAL OF MICROBIAL BIOTECHNOLOGY
Year:2012 | Volume:4 | Issue:14|Papers Count:8

Background and Objective: Species of Aeromonas are gram negative, facultative anaerobic and opportunistic pathogens that are found in water system. In this study aimed was performed to determine of Aeromonas prevalence in water sources and water supply Network in Qom.Materials and Methods: 150 samples of water sources which were derived from 15 khordad barrier and other urban water sources during 6 months from April 2009 to September 2009 by memberane filteration in particular environment with presence of amplicilin dextrin agar with vancomycin, were taken under evaluation.Results: Culture experiments and Determination of biochemical showed that only in 20 samples to 15 khordad barrier were positive for presumptive Areomonas with an average count 9 CFU/100ml water sample and the most of isolates belonged to the A. hydrophila, A. veronii biovar sobria and A. sobria species. Antibiotic Sensitivity test and tolerance evaluation of NaCl and cl presented some differences compared with E.coli and vibro that Aeromonas comparing with E.coli and vibro are less tolerant than NaCl (max 3%) and cl (max (37.5ppm) but more tolerant observed with antibiotics include ampicilin, erythromycin, amoxycilin, nalidixic acid, tetracycline and trimetoprim.Conclusion: The low abundance of bacteria in the water can be attributed to high chlorine residual (Average 8/0 ppm) and relatively high percentage of minerals and salt water network Qom.

Background and Objective: This Research done in medical microbiology. Lemon is a ripe fruit of C. Limonum plant from the Rutaceae family that the essence and extract (juice) of this fruit has extraordinarily antimicrobial effects against microorganisms. The purpose of this research is replacement of a natural substance with antimicrobial drugs and prevents their side effects and also reduces the resistance of various microorganisms to antibiotics.Materials and Methods: In this project, antimicrobial effects of essence and extract of Lemon were researched on mouth microorganisms (contain: S. sanguis, S. mutans, S.pyogenes, Streptococcus group B, L.casei, L. fermentum, S.aureus, C.albicans and C.glabrata) with determining of diameter of growth inhibition zone in disc diffusion method and MIC and MBC in broth microdilution method on Moller hinton medium. At first the mouth microorganisms were formed as pure colonies. Lemon's essence was purchased from "Zardband e Yasudj company and its extract was also produced by a juicer's out of a whole Lemon. Both substances' antimicrobial effects against these microorganisms were taken into consideration in Disk diffusion and Broth microdilution methods.Results: In view of the results, it seems that there is no significant difference between the extract and essence but its essence showed a better antimicrobial effect on mouth microorganisms.Conclusion: Considering that, therefore, we can use Lemon's essence as a powerful anti-microbial substance in treating oral infections. As a result, considering the universal approach to biological pharmaceutics, Lemon's essence as antibiotics can be an appropriate alternative to the treatment of many infections.

Background and Objective: Micro-organisms that accumulate lipid more than 20% of their biomass are introduced as oleaginous strains. Oleaginous yeast accumulates tri acyl glycerol rich in unsaturated fatty acids. These lipophylic microbial compounds, because of their special characteristics, are considered from industrial point of view. Microbial oil has potential for biodiesel production. Biodiesel compared to fossil fuel is very peaceful to the environment.Materials and Methods: In this investigation 70 yeast strains were isolated from soil of different regions and 23 of them were oleaginous. Screening of oleaginous strains was done by enrichment in Glycerin medium and sudan black staining. Then the amount of lipid production was measured by Bligh & Dyer method. Among the isolates one of them with Aa2 ID was selected for identification and further investigations.Results: After optimization in medium containing 95 g/l Glucose, 1.5g/l (NH4)2SO4, 3g/l KH2PO4, 1.5 g/l MgSO4.7H2O & 2g/l NaH2PO4 and 1g/l yeast extract for 96h at 150 rpm with a pH of 5.5, the strain (Aa2) had lipid production, dry biomass & lipid quantity of 5.44g/L, 14.39 g/L & 37.8%.Conclusion: The results obtained in this study indicate that there are valuable native strains in our country that by isolation and optimization of lipid production in them, they can be used in different industrial cases such as biodiesel production without needing foreign strains.

Background and Objective: Antibiotic resistance which is different in Gram-negative bacteria is increasingly growing up. Pseudomonas aeruginosa is a major cause of serious bacterial infections. Metallobetalactamase (MBL) enzyme plays an important role in developing resistance to different antimicrobial agents, especially betalactams and carbapenems. In this study, it is aimed to determine antibiotic susceptibility pattern in isolated Pseudomonase aeruginosa in an educational hospital Dezful and to investigate phenotypic frequency of MBL.Materials and Methods: A total of 150 isolates of Pseudomonas eaeruginosa from various specimens included 72 samples of urine cultures, 55 Tracheal cultures, 12 blood cultures and 11 wound cultures, were subjected to susceptibility testing against various antibiotics by disc diffusion test (Kirby-Bauer method) according to CLSI guidelines. MBL producing isolates were recognized by E- test strip method. Statistical analysis of the findings was done by SPSS-18 software, and the chi-square test was run.Results: It was found that out of the 150 strains, 27(18%) and 22(14.7 %) were non susceptible to imipenem and meropenem, respectively. Isolates showed the highest antibiotic resistance to Ceftriaxone (41.3%) and ceftazidime (28.7%). It was found that 21(14%) isolates were MBL producers confirmed by E-Test strip method. The highest frequency of isolates of positive phenotype was in pulmonary secretions (23.6%).Conclusion: Due to the high resistance of Pseudomonas aeruginosa isolates producing MBL enzymes to multiple antibiotics; development of such resistance is a concern in hospitals. So to prevent the spread of infectious diseases, the diagnosis of MBL-producing isolates is recommended.

Background and Objective: Staphylococcus epidermidisand Pseudomonas aeruginosa are important infectious agents acquired from community health centers. The aim of this study isto evaluate and comparethe antibacterial activity of Malvaneglecta extracts and nanosilver particles against resistant Staphylococcus epidermidis and Pseudomonas aeruginosa.Materials and Methods: In this study the extracts of Malvaneglecta leaves in aqueous and alcoholic (ethanol) solvents were prepared, then MIC and MBC of extracts and nanosilver particles on Staphylococcus epidermidis and Pseudomonas aeruginosawere calculated by broth macrodilution and agar well diffusion methods. Consequently, theantimicrobial effects of extracts were investigated on animal model.Results: Results showed that MIC and MBC amounts of aqueous extract on Staphylococcus epidermidis were 1.6 and 3.2 mg/ml, respectively, while the values calculated as 3.2 and 6.5 mg/ml, respectively for alcoholic extracts. The aforementioned parameters for aqueous extract on Pseudomonas aeruginosa were 6.5 and 13 mg/ml and for alcoholic extract 13 and 26.1 mg/ml, respectively. The results for nanosilver particles on these bacteria were 1.6 and 3.1 ppm (Staphylococcus epidermidis) and 3.1 and 6.2 ppm (Pseudomonas aeruginosa), respectively. In animal model study, drastic decrease of bacteria in all experimental groups was observed (p<0.05).Conclusion: Overall in vitro and animal model the results indicated that aqueous extract of Malvaneglectacontributed the most effective antimicrobial activity on Staphylococcus epidermidis and Pseudomonas aeruginosarather that alcoholic extract. However these nanoparticles showed the best antimicrobial activity even better than aqueous extract. These results would be useful in production of new drugs.

Background and Objective: Recently, among the oil-producing fungi, Cunninghamella echinulata due to the production of larger quantities of single cell oil and fatty acid of gamma linolenic acid has been special attention. The main objective of current study was optimization of culture conditions for production of biomass, single cell oil and gamma-linolenic acid by C. echinulata in submerged fermentation.Materials and Methods: Eeffect of different amounts of carbon source (glucose) and nitrogen source (lipid free soybean meal) was studied on production of biomass, oil and gamma-linolenic acid from the fungus of C. echinulata using statistical methods of Response Surface Methodology (RSM). Carbon and nitrogen sources during the submerged fermentation were in 5 levels and were using central composite rotatable design with 13 experiments.Results: The highest amount of oil production in glucose and soybean concentration was 60, 4.31g/l as 25% and the highest biomass production in glucose and soybean concentration was 80, 20 g/l as 2.53%, respectively. The highest amount of gamma-linolenic acid in glucose and soybean concentration was 31.72, 13.5g/l, respectively as 6.5%.Conclusion: The optimized conditions for oil accumulation in C. echinulata are restricting nitrogen source concentration and increase of carbon source. The increase process of biomass and oil production showed that when growth is stopped, oil production is increased considerably and when biomass destruction is started, oil accumulation is reduced.

Background and Objective: Infectious diseases are the leading cause of death worldwide. The clinical efficacy of many existing antibiotics is being threatened by the emergence of multidrug-resistant pathogens. Emergence of resistance against antibiotics and adverse effects of synthetic antibiotics increases the importance of identifying natural antibiotics. Hairy root is an unusual plant tissue developed by Agrobacterium rhizogenes activity nearby plant wounded sites. Hairy roots have two specific properties in relation to secondary metabolites: higher secondary metabolite production and new substance production versus original plant. Based on these characteristics, the effects of aqueous and methanolic extracts of hairy root, root and aerial parts of Artemisia vulgaris was studied against four bacterial and two yeast species.Materials and Methods: Hairy root induction was carried out using Agrobacterium rhizogenes strain A4 from leaf samples. Primers for rolb gene were designed and PCR reactions were conducted to investigate the transformation of hairy roots. Methanolic and aqueous extracts were prepared and their antimicrobial activity was investigated by disc diffusion method.Results: In all experiments aqueous and methanolic extracts of hairy roots exhibited remarkable antibacterial and anti yeast effects. Extracts of aerial parts and roots presented no antimicrobial activity. Antibacterial activity of hairy root aqueous extracts was higher in methanolic extract. Maximum inhibition diameter was against obtained Bacillus subtilis. Antibacterial activity of hairy root extracts was more than anti yeast activity.Conclusion: Hairy roots of Artemisia vulgaris produce antimicrobial substances that are not produced in other parts of the plant. These substances that cause antimicrobial activity in hairy roots can be recognized using chemical-analytical methods and have the potential to be introduced as new natural antimicrobial compounds.

Background and Objective: Reef-building corals associate with unicellular symbionts which belong to the genus Symbiodinium. So far, 9 clades of Symbiodinium have been identified using molecular method that among all of them clade D is the most tolerant clade. However, coral`s type plays an important role in the resistance of corals to environmental stress. The aim of this study is identification of Symbiodinium clades in hard corals off Hengam Island.Materials and Methods: Samples were collected from depth 5-7 meters in north of Hengam Island including: Cyphastrea microphthalma, Lepthastrea transversa, Platygyra daedalea and Siderastrea savignyana. Specimens were kept in 20% Dimethyl sulfoxide (DMSO) saturated by NaCl. DNA was extracted using Cethyl trimethyl ammonium Bromide (CTAB)/chloroform method. Using a combination of the internal transcribed spacer-2 and Denaturing Gradient Gel Electrophoresis with GC-clamp primer, the variables clades and subclades of Symbiodinium were assessed.Results: The excised bands were purified by DNA Gel Extraction Kit (K0513). Sequencing results showed that clade C was detected from Siderastrea savignyana, while various subclades D were found in Cyphastrea microphthalma, Platygyra daedalea and Leptastrea transversa.Conclusion: As clade D is the most thermal tolerant clade among other clades of Symbiodinium, dominance of this clade in northern parts of the Persian Gulf may be due to high fluctuation in temperature and other stressful conditions of this area.