ABSTRACT
Considering the ever increasing population and industrialization of the developmental trend of human life, we are no longer able to detect the toxins produced in food products using the traditional techniques. This is due to the fact that the isolation time for food products is not cost-effective, and even in most of the cases, the precision of practical techniques like bacterial cultivation and other techniques suffers from operator errors, or the errors of the mixtures used. Hence, with the advent of nanotechnology, the design of selective and smart sensors has turned into one of the greatest industrial revelations of the quality control of food products that, in few minutes time and with a very high precision, can identify the volume and toxicity of the bacteria. In this research, based on the bacterial antibody's connection to nanoparticles, a sensor was used. In this part of the research, as the basis for absorption for the recognition of bacterial toxin, medium sized silica nanoparticles of 10 nm in the form of solid powder were utilized with Notrino brand. Then the suspension produced from the agent-linked nanosilica, which was connected to the bacterial antibody, was positioned near the samples of distilled water, which were contaminated withStaphylococcus aureus bacterial toxin with the density of 10[-3] molar, so that in case any toxin exists in the sample, a connection between the toxin antigen and the antibody would be formed. Finally, the light absorption related to the connection of antigen to the particle-attached antibody was measured using spectrophotometry. The 23S rRNA gene that is conserved in allStaphylococcus spp. was used as the control. The accuracy of the test was monitored by using the serial dilution [l0[-6]] of overnight cell culture of Staphylococcus spp. bacteria [OD[600]: 0.02 = 107 cell]. It showed that the sensitivity of PCR is 10 bacteria per ml of cells within few hours. The results indicated that the sensor detects up to 10-[4] molar density. Additionally, the sensitivity of the sensor was examined after 60 days; by the 56 day, it had confirmatory results, which started to decrease after this time. Comparison of practical nanobiosensory method with the conventional methods including culture and bio-technology methods [such as polymerase chain reaction] confirmed its accuracy, sensitiveness and uniqueness. It also reduces the time from hours to 30 minutes
Subject(s)
Exotoxins , Silicon Dioxide , Nanoparticles , Genotyping Techniques , Multiplex Polymerase Chain ReactionABSTRACT
We are no longer able to detect the toxins produced in food products using the traditional techniques. This is due to the fact that the isolation time for food products is not cost-effective and even in most of the cases. Hence with the advent of nanotechnology, the design of selective and smart sensors is one of the greatest industrial revelations of the quality control of food products. This was an laboratory experimental study. In this technique, based on the bacterial antibody connection to nanoparticle, a sensor was used. In this part of the research, as the basis for absorption for the recognition of bacterial toxin, medium sized silica nanoparticles of 10 nano meter in form of solid powder were utilized with Notrino brand. Then the suspension produced from agent-linked nanosilica which was connected to bacterial antibody was positioned near the samples of distrilled water, that were contaminated with Staphylococcus aureus bacterial toxin with the density of 10-3, so that in case any toxin exists in the sample, a connection between toxin antigen and antibody would be formed. Finally, the light absorption related to the connection of antigen to the particle attached antoibody was measured using spectrophotometry. The results indicate that the sensor, up to 10-4 of density is detectable. Additionally, the sensitivity of the sensors were examined after 60 days, the sensor by the 56 day had confirmatory results and started to decrease after those time periods. Nano-particles have unique property in bioanalysis. They have high speed and high sensitivity along with cost effectiveness
Subject(s)
Exotoxins , Biosensing Techniques , Nanotechnology , Silicon DioxideABSTRACT
BACKGROUND: Nowadays, Microencapsulation of probiotic bacteria is the newest method for increasing the survival ability of probiotics in Food products. The Lactobacillus acidophilus as a probiotic bacterium has more beneficial effects and the low survival of this bacterium under food processing conditions and adverse environment have been studied by many researchers
OBJECTIVES: In this study, Lactobacillus acidophilus was added to mayonnaise sauce as either free cells or encapsulated and the survival of probiotic was evaluated during storage for 30 days at 4oC.
METHODS: The emulsion method was performed for the microencapsulation process of Lactobacillus acidophilus. A morphological characteristic of capsules was indicated by optical microscope and scanning electron microscope
RESULTS: The microencapsulation with calcium alginate-resistant starch significantly affected [p<0.05] the survival of Lactobacillus acidophilus compared to free state in mayonnaise sauce. No differences were detectable in the morphological of capsules with resistant starch by scanning electron microscope and Sensory properties of mayonnaise sauce were improved by the addition of encapsulated Lactobacillus acidophilus
CONCLUSIONS: The microencapsulation significantly increased the survival of Lactobacillus acidophilus
ABSTRACT
Nanotechnology offers numerous opportunities for invention of new and reformed applicable products for the benefit of human society. In spite of a vast application of nanomaterials there is little information about their impact on human health. This study examines the biological activity of nanosilver on mesenchymal, natural fibroblast [HF2], and osteoblast [G292] cells. The effects of nanosilver on the cells were observed by a light microscope and the amplification of the cells was assayed by using a standard cell toxicity test. The results show that the cytotoxicity depends on nanosilver concentration. The amount of IC50 on mesenchymal stem was 6.33; and on HF2 was 6.68; and on G292 cells was 3.42 micro g/L. The results show that nanosilver has two times more of an inhibition effect on cancerous cells' growth as compared to the normal cells. This phenomenon is due to the direct effect of nanosilver on the cell oxidation system. Due to the extraordinary activation of the mitochondorial respiration system in cancer cells, when compared to the normal cells, it can provide suitable opportunity for nanosilver to cause cell disruption