Showing 7 results for Mn
Volume 8, Issue 2 (10-2009)
Abstract
Propolis or bee-glue is a natural sticky material gathered in the hives by worker honey bees (Apis mellifera L. ,Apidae) from the growing parts of trees and shrubs (e.g., leaf buds, trunk wounds). Typical propolis has approximately 50 constituents, primarily resins and vegetable balsams (50%), waxes (30%), essential oils (10%), and pollen. At least, 180 different compounds have been identified so far in propolis. The aim of this study is to examaine antimutagenesis effects of cosmetic creams containing ethanolic extract of propolis (EEP) against two mutagenic substances named sodium azide (NaN3) and potassium permanganate (KMnO4) by Ames test and microsome. In this test, various strains of Salmonella typhymurium TA100 and TA97 were used each having selective mutation in their operon histidine. Mutant strains (His-) were grown on culture media containing minimum salt and glucose in the presence of mutagen substances above. So, only those bacteria that reversed by mutation (His+) could grow and form colonies on culture media. If antimutagen (EEP) and mutagen substances are gathered, the rate of reversed mutation is reduced and the percentage of mutation inhibition can be calculated by means of the formula. In addition, the significant difference between the average of revertants per plate of the sample in relation to the mutagens was assessed by using statistical software SPSS and interpreted by one-way variant statistical test. Finally the results of in vitro antimutagenicity tests revealed that propolis in 0.1-4% concentrations could inhibit mutagenicity of two mutagens mentioned above in a dose-dependent manner. Also the results of microsomal assay (S9) revealed that propolis has a very high potential for inhibition of mutation and cancer. For these reason, ethanolic extract of propolis in defined concentrations can be used in cream formulation due to these reason
Volume 8, Issue 4 (11-2010)
Abstract
Biosurfactants are surface active agents which are widely used in industries. One of the important varieties of biosurfactants are widely produced by Pseudomonas aeruginosa. In this paper. P. aeruginosa MM1011 was obtained from Persian Type Culture Collection (Biotechnology Department, IROST). The aim of this investigation is to optimize the mineral salts medium with whey to produce rhamnolipid. Since P. aeruginosa is Lac (-), the whey hydrolysed by lactase in order to produc glucose as carbon source. The results assayed by phenol-sulfuric acid method and crude oil emulsification activity. Depicted results showed that the best medium is 3M which contained whey (that hydrolysed by lactase completely at temp.: 40° C ,pH: 6.5, time: 3 hours) . The product obtained at temp.: 33 ° C, pH:7, shaking rate: 200 rpm , nitrogen concentration, 0.36 %, and inoculum size, 2 %. The results of rhamnolipid production by usig whey as a source of carbon and energy is more or less comparable with the results obtained when molasses was used as carbon and energy source.
Volume 9, Issue 3 (10-2010)
Abstract
Biosurfactants are products of broad range of microorganisms. These compounds are surface active. Glycolipids, Phospholipids & Fatty acids, Lipopeptids and Lipoproteins, Polymeric biosurfactants and Special Biosurfactants are main types of biosurfactants. Rhamnolipid is a type of Glycolipids that is produced by Pseudomonas aeruginosa. In the present paper, P. aeruginosa MM1011 was obtained from Persian Type Culture Collection (Biotechnology Center, IROST). The aim of this investigation was optimization of mineral salts medium with sugar beet molasses to produce rhamnolipid considering specific parameters. such as: C/N, Temperature, pH, shaking rate, and Inoculation size. Since P. aeruginosa is Suc.(-), it was mutated to be able to use the sucrose as carbon source. The molasses treated chemically, then used by the bacterium. The results assayed by phenol-sulfuric acid method, and crude oil emulsification capability. Results of ANOVA. Depicted results showd that the optimum conditions without molasses is: temp.:33˚c, pH 7, C/N:18, shaking rate: 200 rpm and inoculom: 2% in 96 hours and the best medium is 3M which contained sugar beet molasses. Further investigation proved that the best production temperature is 33°c when pH is 6.8, shaking rate: 200 rpm, C/N: 16, inoculom: 2%. Using the above mentioned factors, the obtained results showed that the produced rhamnose was 0.22 g/L (rhamnolipid = 0.66 g /L) and crude oil emulcification was 55.5 %.
H Amani,
Volume 14, Issue 1 (4-2014)
Abstract
The petroleum industry generates large amounts of solid and semisolid wastes known as oily sludges. Oily sludges can be generated in several steps of the petroleum production and refining in the bottom of tanks. The accumulation of oily residues in petroleum industry poses aserious environmental problem.The aim of this research was to evaluate an alternative process of removal of oily sludge from storage tanks that can be carried out by using biosurfactants. One of the most important properties of biosurfactants is reduction of surface tension and formation of oil/water emulsions. In this research, the ability of Pseudomonas aeruginosa PTCC 1570 to produce rhamnolipid was shown and the production of rhamnoilipd was confirmed by TLC and HPLC analysis. The rhamnolipid production started at exponential growth phase and continued during the stationary phase. During investigation of rhamnolipid production on sunflower oil as sole carbon, the results showed that the maximum rhamnolipid reached about 0.5 g/l. Finally, crude oil recovery from an oil storage tank using produced rhamnolipd was also demonstrated at CMC concentration. An oil recovery of up to 70 % was obtained in a storage tank using this method.
Seyed Lotfollah Sharifi, Hadi Sadeghi, Akbar Mirzaei,
Volume 14, Issue 1 (4-2014)
Abstract
In this study, manganese dioxide nanoparticles were synthesized in the pores of zeolite 13X by supporting method and its morphology and structure were characterized by SEM, XRD, IR and AAS techniques. Decontamination reaction of 2-chloroethyl ethyl sulfide (a mustard agent simulant) was investigated by GC technique. The results of GC analysis showed that 2-CEES was completely absorbed by Nano-MnO2/Zeolite13X composite after 168 hours and converted to less toxic chemical product. Decontamination products formed via hydrolysis were hydroxyl ethyl ethyl sulfide and ethyl vinyl sulfide. Destruction reaction of DMMP nerve agent simulant via 31P NMR analysis showed that this composite after 36 hours demolished almost 32 percent of nerve agent simulant
H Amani,
Volume 14, Issue 4 (6-2015)
Abstract
In this research, the ability of Pseudomonas aeruginosa NP2to produce rhamnolipid biosurfactant was investigated. Rhamnolipid has various applications in oil industry including cleaning oil sludge filters, cleaning oil storage tanks and biological treatment of oil wastes.The purpose of this paper was optimization of biosurfactant production for reduction of costs using taguchi experimental design methods. Source of carbon, salt concentration, phosphorus concentration and nitrogen concentration at three levels were investigated. The best condition for biosurfactant production was observed when sucrose was used as carbon source, 50 g/l Nacl as salt source, 6.75 g/l NaH2PO4 as phosphorus source, and 1g/l (NH4)2SO4 as nitrogen source. The highest rhamnoliopd production among different experiments was 2.8 g/l. Also the evaluation of emulsification index (E24) of the produced rhamnolipid was studied and the emulsification index value of 80% was reached for crude oil (API=34).
Volume 18, Issue 56 (9-2006)
Abstract
Manganese (Mn) is a micronutrient that is essential for plant growth and develop-ment. Meanwhile, an excess amount of Mn is one of the most important growth limiting factors in acid soils. The present study was undertaken to identify the effects of excessive Mn on the physiological aspects of tea plant. To this end, 2-year old rooted cuttings of tea (Camellia sinensis L. assamica × sinensis) were grown in a modified Hoagland solution with pH=4.2 for 1 month with aeration in green house, with temperature of 27 ± 3 ˚C and photosynthetic photon flux of 101.5 µmol. m-2 s-1 (400-700 nm) at the plant level. After emergence of new, white roots with 5 to 10 cm in length, the plants were treated for 1 week with excessive Mn to a final concentration of 0.9 mM. After 1 week, the white roots were harvested and frozen in liquid N2 and kept at -80 ˚C until used for determination of PO activity, lignin and sugar as well as chlorophyll content. The activities of soluble peroxidase (SPO), covalently wall-bound peroxidase (CPO) and lignin content decreased by Mn treatment. On the other hand, the activities of ionically wall-bound peroxidase (IPO), sugar and chlorophyll contents increased by Mn treatment. These results suggest that excessive Mn may have beneficial effects on tea plant via lowering lignin content and increasing extensibility of the walls.
