جستجوی مقالات مرتبط با کلیدواژه « لاکتوباسیل » در نشریات گروه « زیست شناسی »

Probiotics are a solution of living microorganisms and if are administered in adequate quantities, will be beneficial to the host's health. Probiotics have positive effects on the gastrointestinal tract; hence, these microorganisms must be resistant to the process of producing and storage in order to survive in the commercial product at the completion of their useful life, higher than the threshold of 106 CFU / g. We have examined several ways in order to increase the stability and activity of probiotics in commercial products: Selecting species resistant to acid and bile acids, compatibility to stress, and absorbing micronutrients. Microencapsulation.

in this case, Probiotic cultures were isolated from different randomly cheese samples. the using garam stain and biochemichal test and Bergey's Manual of Determinative Bacteriology, we isolated probiotic lactobacilli. then we microencapsulated them.to reach a high density and high concentration network of low-fat milk solution as a gel forming solution.

Based on past internal and external research, we witnessed successful microencapsulation. In this research, we could produce spherical capsules and moreover saw very high microcapsulation effectiveness about 100%. we applied the special characteristics of milk and capsules produced in this approach gives very high characteristics to the product.

insoluble microcapsules in water with milk protein can be a very good alternative to encapsulation of probiotics from herbal gels by ionotropic or polysaccharides like alginate. In addition to the considerable functional features of milk protein, it can also be efficient to decrease the size of capsules, as the size of capsules produced due to sensory taste features is very significant not to touch under the tongue.

Lactobacilli are Gram-positive, catalase-negative, non-spore forming, rod-shaped organisms. So far, more than 90 species of these bacteria have been identified. There are several strains of probiotic Lactobacilli in a wide range of human food products. Identification of these bacteria in traditional dairy products makes it possible to use them in the production of delicious industrial dairy products. The selection of reliable methods for the identification of Lactobacilli is of a particular importance. Biochemical methods are time consuming and ambiguous. Molecular methods are more appropriate and precise and can be a substitute for previous methods. The purpose of this study is the isolation of Lactobacilli from bacterial flora in Bandar Abbas traditional cheese and identification these bacteria by using PCR as an effective tool for the recognizing the isolated strains.

Fifty samples of traditional cheese were collected from Bandar Abbas and strains were obtained by phenotypic methods.16 s rRNA primers were used to identify their molecular identity. Then the PCR product was sent to Poya Gene Gostar for sequencing. Obtained sequences were blasted in NCBI GenBank.

3 strains of Lactobacillus include Lactobacillus murinus, Lactobacillus helviticus and Lactobacillus planatrum were identified.

These three strains improve the quality of dairy products in this area and can be used in products manufactured in the industry.

In this study, the effects of fish liquid fertilizer (Fish Hydrosylate) and aqueous extract of green-algae (chactomopha gracilis), from cladophorales order were evaluated on growth properties of tomato. The fish liquid fertilizer obtained from Persian Gulf fish waste contained P2O5 (0.48 %), K2O (0.14 %), Fe (30.60 ppm), Zn (20.50 ppm), and N (2%). The variance analysis of the traits including shoot length, shoot diameter, radicle length, leaf width and chlorophyll content revealed a significant difference among treatments (p<0.01). The mean comparisons of traits using Duncan's multi-domain test indicated that the fish liquid fertilizer treatments with concentrations of 0.001 and 0.0001 had the highest effects on entire traits. The green-algae extract treatments showed positive effects on studied traits and improved tomato performance and growth parameters. Although, the effects of green macroalgae extract (chactomophora gracilis) were less than that those of fish liquid fertilizer.

Lactobacilli are a group of lactic acid bacteria that their final product of fermentation is lactic acid. The objective of this research is selection of local Lactobacilli producing L (+) lactic acid. In this research the local strains were screened based on the ability to produce lactic acid. The screening was performed in two stages. The first stage was the titration method and the second stage was the enzymatic method. The superior strains obtained from titration method were selected to do enzymatic test. Finally, the superior strains in the second stage (enzymatic) which had the ability to produce L (+) lactic acid were identified by biochemical tests. Then, molecular identification of strains was performed by using 16S rRNA sequencing. In this study, the ability of 79 strains of local Lactobacilli in terms of production of lactic acid was studied. The highest and lowest rates of lactic acid production was 34. 8 and 12. 4 mg/g. Superior Lactobacilli in terms of production of lactic acid ability of producing had an optical isomer L (+), the highest levels of L (+) lactic acid were with 3. 99 and the lowest amount equal to 1. 03 mg/g. The biochemical and molecular identification of superior strains showed that strains are Lactobacillus paracasei. Then the sequences of 16S rRNA of superior strains were reported in NCBI with accession numbers KF735654، KF735655، KJ508201and KJ508202. Discussion and The amounts of lactic acid production by local Lactobacilli were very different and producing some of these strains on available reports showed more products. The results of this research suggest the use of superior strains of Lactobacilli for production of pure L (+) lactic acid.

Probiotics have some beneficial effects on health so these microorganisms are added to dairy products and other foods as well. Lactobacillus bacteria are the most commonly used for this purpose. The aim of this study was to find native Lactobacillus bacteria which has the potentiality for using as probiotic. For isolating lactobacilli، gram strain reaction and catalase test were performed on separated bacteria from 40 local yoghurt samples: after isolating، the acid resistance ability of isolates were evaluated by placing isolates in pH=2. 5 for 2 hours and culturing samples on medium and colony counts. Then، among 18 acid resistant bacteria، by gel diffusion method the inhibitory effect of isolates on pathogens bacteria such as E. coli and Pseudomonas aeruginosa were investigated. The results were compared to the results of investigated commercial strains. The results revealed that S4 isolate had the most inhibitory effect، it showed %80 good-inhibitory and %20 strong-inhibitory effect on pathogenic bacteria، which were completely consistent with results for commercial Lactobacillus gasseri strain. Also، the lowest inhibitory effect against pathogens was related to (Y4-Y5-Y11-Y14-Y15) isolates that all of them had weak-inhibitory effect on pathogens. Other strains were classified in good-inhibitor group. Discussion and Considering daily increasing of drug resistance relating to pathogenic bacteria، today، the use of probiotics، especially lactobacilli as an appropriate alternative of antibiotics is important. The investigated bacteria in this study were able to inhibit pathogens’s growth to some extent، but for investigating the results more accurately، some methods with more sensitivity، for instance، two layers method and MIC method can be used as well.

Aim and background. The genus Lactobacillus encompasses a diverse assemblage of Gram-positive، catalase-negative، non-spore-forming، rod-shaped organisms. Over 90 species are currently described. Several strains of probiotic lactobacilli have been incorporated in a wide range of products for human. As the probiotic capacities are strain-dependent، methods for reliable identification of lactobacilli at the strain level are of great importance. Regarding biochemical methods are time-consuming and often very ambiguous the molecular methods are more accurate. The aim of present study is typing of lactobacillus species isolated from different traditional dairy products by RAPD markers. Materials and Methods. The 20 strains used in this study were isolated from different sources. Samples were grown in MRS broth then total genomic DNA was extracted. RAPD markers were used for the detection of genetic diversity. Results. Out of 20 primers used 19 primers produced reproducible bands. The primers generated 225 RAPD loci، of which 219 were polymorph، 6 were monomorph and 63 were unique. NJ and UPGMA clustering methods performed on molecular data by NTSYS-PC software. Similar results are obtained by two methods. Conclusion. UPGMA clustering methods were performed on molecular data. Two genotypes of k2l3 and y1m4 are grouped together in two dendrograms. In UPGMA dendrogram two major clusters A and B were observed. Cluster A was divided in to2 subcluster by c6m3، y1l4، y2f3 and c1d2 genotypes. In cluster B، 2 subclusters by 6 genotypes (c2h1، d3b1، y2c4، k2l3 و y1m4 and p) were observed.