جستجوی مقالات مرتبط با کلیدواژه « بیوسورفکتانت » در نشریات گروه « پزشکی »

Probiotics are common and well-known microorganisms in human and animal microflora and have been widely studied for medical and food productions. The present research was conducted with the aim of isolating and identifying probiotic bacteria and the ability to produce biosurfactant and magnesium oxide nanoparticles from local dairy products in Rafsanjan, Iran.

In this laboratory study, the local dairy samples were transported to the laboratory under sterile conditions, observing the cold chain, and cultured in MRS (de Man Rogosa Sharpe) agar medium. In order to isolate biosurfactant-producing isolates, oil spreading and emulsification tests were performed, then the isolates were further studied in terms of the production of magnesium oxide nanoparticles. The size and morphology of nanoparticles, antioxidant activity, FTIR (Fourier Transform Infrared Spectroscope), and their antibacterial effects were determined. Then polymerase chain reaction, sequencing, and phylogeny tree drawing were performed for the identification of superior strain.

Nine probiotic isolates had the ability to produce biosurfactants, all of which had a significant emulsifying activity. The produced biosurfactants had antibacterial properties. One of the biosurfactant-producing isolates was able to produce magnesium oxide nanoparticles, which was named Enterococcus faecium L8 based on the molecular identity. The size of 90% of nanoparticles was 107 nm, which showed significant antibacterial and antioxidant effects.

Enterococcus faecium L8 has a favorable probiotic ability, and this native strain can be used in the formulation of multipurpose foods by conducting more tests.

Biosurfactants are compounds that are produced by different microorganisms and have an emulsifying property. This study aimed to investigate extractive biosurfactant from bacillus subtilis (PTCC1720) against the biofilms of Staphylococcus aureus (PTCC 1112), Staphylococcus saprophyticus (PTCC 1440) and Staphylococcus epidermidis (PTCC 1435). This study was conducted in vitro to examine the effect of biosurfactant produced by Bacillus subtilis in prevention of biofilm formation and removal of biofilms produced by different staphylococcal species. First, bacillus subtilis was cultured in suitable culture media for producing biosurfactant. Then, extraction of produced biosurfactant was done and anti-biofilm properties were assessed by determination of optical density at 570 nm by ELISA reader equipment. Statistical analysis was performed by SPSS software version 16 and ANOVA. The means were compared at 95% confidence level by Duncan's method. According to the results, the biosurfactant produced by bacillus subtilis had emulsification index equal to 40% and oil replacement area was 1.8 ± 0.3 cm-2. Produced biosurfactant by bacillus subtilis had a significant effect on preventing microbial formation with the highest effect on biofilm of staphylococcus aureus and Staphylococcus saprophyticus. Also, the results showed that the biofilm of staphylococcus epidermidis had the highest resistance in this respect. According to this study, the antibiofilm activity of biosurfactant extracted from Bacillus subtilis against the biofilm of staphylococcus aureus, epidermidis and saprophyticus was shown. In addition, this type of biosurfactant can be effective in removing biofilms formed by staphylococcal strains.

Biosurfactants are amphiphilic molecules produced by microorganisms that due to  surfactant activity, have several applications in different industries such as cleaning, emulsification, foaming and dispersion. The aim of this study was to investigate the effect of biosurfactant extracted from saccharomycess cerevisiae on biofilm formation of staphylococcus aureus (PTCC 1112), staphylococcus saprophyticus (PTCC 1440) and staphylococcus epidermidis (PTCC 1435). The effect of this biosurfactant on the removal of the mentioned bacteria’s biofilms was also assessed. In this laboratory study, after Saccharomycess cerevisiae cultivation for producing biosurfactant  and extraction of the produced biosurfactant , the effect of the extracted biosurfactant in preventing the formation of biofilms of staphylococcus aureus, staphylococcus saprophyticus and staphylococcus epidermidis was assessed using  96-well polystyrene microplate and absorbance reader at 570nm by ELISA reader. The same method was used for determining the ability of biosurfectant in removal of biofilms. Statistical analysis was performed by ANOVA. The means of treatments were compared with Duncan's method at a confidence level of 99%. The results showed that biosurfactant of saccharomycess cerevisiae had an emulsification index equal to 55%. The biosurfactant activity was determined via  the oil displacement method and the area of displaced oil was 2.5±0.5 cm2. The results showed  the biosurfactant produced by saccharomycess cerevisiae had the most effect on preventing biofilm formation by staphylococcus aureus and staphylococcus saprophyticus. Biosurfactant caused the all tested bacteria’s biofilms to be removed.  Biosurfactant produced by saccharomycess cerevisiae has strong  anti-biofilm activity against biofilms of Staphylococcus aureus, epidermidis and saprophyticus.

PAHs was producted from incomplete combustion of fossil fuels and due to nature of publishing, it was categorized as the soil and beaches pollutant. These compounds are considered in pollutants which have priority, carcinogenic and certain mutagenic. The main difficulty of clearing contaminated areas to PAHs is the nature of highly water repellent of these pollutants and a strong attraction to the soil texture. The main objective of this current study was to determine the efficiency of phenanthrene removal from contaminated soil and beaches by using biosurfactant produced by a bacterium isolated from Persian Gulf.
with primary screening, a Bacillus sp strain with surfactin production capability was isolated and purified in laboratory. A mixed bacterial consortium isolated which was consists of three bacterial species with of capable of metabolism of phenanthrene from Khark contaminated beaches and was used as a microbial seed. The synthetic soil samples with initial phenanthrene concentration of 100 mg/kg and also natural contaminated samples were subjected to bioremediation during 9 weeks.
The phenanthrene removal efficiency in the samples containing biosurfactants and with artificial and natural pollution were 82% and 39% respectively. The removal efficiency for samples without biosurfactant was 11%.
The bioremediation process is considered an efficient, eco-friendly and operational for remediation of beache and soil polluted by petroleum hydrocarbons by using bacterial biosurfactant.

Probiotics are live micro-organisms that if are consumed in sufficient numbers, will been beneficial effects on the health of their host. Probiotics have inhibitori effects on the pathogenic bacteria and the expression of their virulence gene. Studies have shown that probiotic bacteria reduce chronic inflammation of the bowel disease, prevention and treatment of diarrhea disease, necrotizing enterocolitis, urinary tract infection and infections are caused by Helicobacter pylori. Lactic acid bacteria can settle site of adhesin of pathogenic bacteria in the gastrointestinal tract and prevent them. Also produce antimicrobial factors such as bacteriocins, organic acids and biosurfactant. Today, researchers use probiotics to prevent and remove biofilms for example L.plantarum has inhibitori effect on the production molecular signals, homoserine lactone and elastase production in P. aeruginosa. Different strains of Lactobacillus inhibited swarming and urease activity of Proteus. Also have been proven inhibitori effect of bacteriocin of L. plantarum on biofilm formation and antibiotic resistance of S. marcescens. It has been found effect of biosurfactant of L. acidophilus on S. mutans biofilm formation. Prebiotics are indigestible nutrition that caused increase the number and activity of limeted bacteria in the colon. A prebiotic must improve growth of Bifidobacterium and lactic acid bacteria and can be increase antimicrobial activity of probiotics. At the result can say that probiotic bacteria use for treatment pathogenic bacteria with antibiotics or their prebiotics and they inhibitori expression of virulence genes by defferent mechanism and metabolite.

Contamination of soil by diesel fuel can pose serious problems to ecosystems. For this reason some ways to remove diesel fuel from soil were developed by a number of researchers. The aim of this research is to extract bio-surfactant for treating soil contaminated with diesel fuel. In this study, 4 soil samples were taken from fields that had been exposed to diesel fuel over the years. The microorganisms that were able to produce bio-surfactant and remove diesel fuel were isolated from these samples. Ability of microorganisms to produce bio-surfactant was evaluated by emulsification test (E24). Finally solved bio-surfactant into nutrients culture was extracted and measured. Four strains of bacteria were isolated in this study. Results indicated that all bacteria were gram negative. The highest emulsification index was obtained from bacteria isolated from gas fuel station soil. In this study 1.1 gram of bio-surfactant was extracted per one liter of nutrients culture containing bacteria. The results showed that, some special bacteria are able to product enough bio-surfactant to treat soil contaminated diesel fuel.

Biosurfactants are amphipathic molecules with both hydrophilic and hydrophobic moieties that allow them to reduce surface tension. Biosurfactants have several advantages over the chemical surfactants, such as lower toxicity, higher biodegradability and better environmental compatibility. A promising group of glycolipid biosurfactants are sophorolipids that are produced by a group of yeasts. So the aim of this study was isolation of yeasts from bee bread of honey bees. The samples were prepared from bee bread of honey bee, Apis mellifera. The yeasts were isolated on YMG culture medium. Hemolysis and oil spreading techniques were performed for screening of biosurfactant-producing isolates. The extracted biosurfactants were characterized by thin layer chromatography (TLC) and infrared spectroscopy (FTIR). From a total of 35 isolated yeast strains, 10 isolates had positive oil spreading test. The HG12 isolate showed the highest level of oil spreading character.The TLC and FTIR examinations of the purified Glycolipid biosurfactant confirmed its structure as sophorolipid. This is the first report of production of a sophorolipid biosurfactant from yeast in Iran.

Biosurfactants are amphiphilic biological compounds produced extracellularly by a variety of microorganisms. Because their use in various industries are of a particular importance. The aim of this study was to identify a strain of bacteria of the genus Bacillus Cereus biosurfactant producers and investigate the antibacterial effects of biosurfactant produced. In this study، different samples of oil، water and soil contaminated with oil were prepared. Hemolytic activities، emulsification and measurement of surface tension were used and selected strains were identified by biochemical tests. The nature and effect of antibacterial biosurfactant were evaluated for strain selection. In this study، eighty eight bacterial strains were isolated. Among them، 24 strains were hemolytic activity. Among them، 14 strains have emulsification activity more than 70% and finally from among them four strains were able to convey to the surface tension of less than 40 mN/m. On the basis of biochemical tests، a strain selective in this study as B. cereus 43 strain، were identification and selection. The results of investigating the nature biosurfactant determined that the type of lipopeptide. Also، the produced biosurfactant has antibacterial activity against six bacterial infectious. The most sensitive and the most resistant bacteria than the impact of biosurfactant extract، of S. aureus PTCC1112 and of the Proteus mirabilis ATCC 2601 respectively. Also، the results of MIC، MBC showed that MIC extract were effective in a dilution of 63 mg /ml on S. aureus PTCC1112 and S. epidermidis ATCC 2405 and the MBC extract had the greatest effect in a dilution of 125mg/ml on Staphylococcus aureus، Staphylococcus epidermidis and Pseudomonas aeruginosa PTCC 1074 respectively. Bacillus Cereus 43 had high potential in reducing the surface tension and biosurfactant extracted had high antibacterial effects. Therefore، Frequency of potential has for applications of biotechnology and the environment.

Dental caries is a worldwide health problem involving almost all age groups in underdeveloped as well as developed countries. So for no considerable progress achieved in the disease prevention, so new preventive/thrapeutique measures are urgently needed. Probiotic bacteria and their biproducts, like biosurfactants, are cost-effective with no considerable side effects for dental caries prevention. The aim of the present study was to evaluate the effects of biosurfactants purified from Lactobacillus casei (ATCC39392) and Lactobacillus reuteri (DSM20016) on ftf and gtf B/C gene expression level of the standard strains of streptococcus mutans (ATCC35668). Lactobacillus species purchased from the bacterial collection center of Iran. For biofilm production, microtiter plate assay in presence of 1% glucose was used. For biosurfactant production, lactobacillus species were cultured in MRS broth medium, dialyzed and lyophilized using freeze-dryer. To evaluate the effects of biosurfactant on gene expression, bacterial cells were cultured in presence of the appropriate biosurfactant (2.5 mg/ml); after four hours incubation, total cellular RNA was then extracted and used for cDNA synthesis. Expression of ftf and gtf B/C genes of the standard strains of Streptococcus mutans (ATCC35668) was considerably down regulated by the application of the biosurfactants. The reduction in gene expression was statistically significant (P < 0.05). Considerable down regulation of all genes in presence of biosurfactants was observed. Therefore, it is concluded that the biosurfactants prepared in this study is very successful in dental caries prevention.

Water poluted with crude oil or oil materials are one of the life enviorenment.Bioremedation is a simple method and economical for cleaning poluted water.the aim of this survey is to check the degradation of crude oil power with separated Bacillus from crude oil in Isfahan oil refinery. For this purpose polluted water with crude oil is used in Isfahan oil refinery.choosing cases were cultured in the MSM medium and 10000 ppm oil are used in this as an only carbonated bacteries sources.this cultured medium was incubated in a shaker with 150 rpm and 35ₒ tempreture. For separating generating biosurfactant bacterias,checking hemolytic activity as the first norm of separating and isolating.for checking the strength of crude oil degradation purified three strains and this three strain, s consortium put IR (infrared rey) test and GC-MS(gas chromatography - spectrometry). Purified Bacillus are reganized with biochemical and molecular diagnostic methods. Among twelve strains separating,eight strains were been able to lysis sheep erythrocytes and make hemolysis halo on medium blood agar.strains that had hemolytic activity were choosen for later studying. Surface tension of three strains were acceptable.the consortium of this three strains was surveyed on Biosurfactant out put and purified three strains got numbers of 38,30,34 mN/m and consortium got 28 mN/m.when sequences above put in the BLAST program,the results showed similarity of 99.8 percent of separated bacterias with Bacillus subtilis and Bacillus cereus. Identified two Bacillus were only defferent in to six nucleotid. The surveys showed that consortium function in the biodegradation is more effective of Bacillus culture was alone,in fact consortium worked effectively in comparison with only Bacillus in the crude oil biodegradation on the polluted waters.

Biosurfactants are unique amphipathic molecules with extensive application in removing organic and metal contaminants. The purpose of this study was to isolate the biosurfactant-producing bacteria and characterize the surface-active properties of the metabolites produced.

This study was conducted in three Caspian Sea coastal regions in Babolsar during 2007-8. In primary screening, hemolytic and emulsifying activities were performed on blood agar plates and in culture medium, respectively and then the reduction in the surface tension, as a biosurfactant-producing index, was determined quantitatively by captive drop cell instrument. The isolated strain was also investigated for its ability to use different hydrocarbon pollutants using the surface tension measurement.

One out of 10 different strains exhibited high ability to produce biosurfactant. This strain called Caspian petroleum A1 (CPA1). Biochemical tests showed that CPA1 classified in aerobic gram-negative cocci, neisseriaceae family and acinetobacter genus. CPA1 utilized crude oil and gasoline, as carbon and energy sources, to reduce the surface tension of culture medium from 71 to 42 and 39 mN/m.

CPA1, as a biosurfactant-producer, was isolated and identified based on potential for biodegradation of hydrocarbon pollutants (e.g. crude oil, gasoline, anthracen and naphthalene).