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Rhodotorula glutinis is an aerobic yeast with particular metabolic characteristic that can produce large amount of carotenoids during the stationary growth phase. Carotenoid is an important natural pigment with antioxidant properties, which is used in food, pharmaceutical and cosmetics industry as additives. The aim of this work is to study the production of carotenoid with antioxidant activity by R.glutinis R12 in different media conditions. The selected strain was cultivated in three different culture media such as YM broth, Basal and MS3 medium at 28°C for 72–120 hours. After fermentation, cells were harvested by centrifugation and freeze-dried. Carotenoid from the biomass was extracted as a mixture of DMSO, acetone and petroleum ether with a ratio of 1:2:2 and cells were ruptured using ultrasonic wave. The carotenoid content in the supernatant was measured by spectrophotometric method. The highest content of carotenoids extracted from R.glutinis R12 was 283.71µg/g dry biomass. The maximum antioxidant activity of carotenoid by DPPH assays were achieved 52.09 ± 0.4% (IC50= 536.02) and at a concentration of 600 µg ml-1. This study revealed that the R.glutinis R12 strain has the ability to produce carotenoid and has shown antioxidant activity in Basal and MS3 medium. For further study, it is necessary to investigate the improvement of carotenoid yield from R.glutinis R12 strains.

Essential oils from aromatic plants of Ledum palustre L. and Mentha piperita L. were extracted using steam distillation and the antimicrobial effects were evaluated alone and in combinations against food-borne pathogens of Gram-positive and Gram-negative bacteria and food related-yeasts (Bacillus subtilis, Escherichia coli, Saccharomyces cerevisiae, Schizosaccharomyce spombe, and Geotrichum candidum). Essential oils from two aromatic plants used in this study showed the antimicrobial activity against bacteria and yeast, which was found to be concentration dependent. The effects of Ledum palustre L. and Mentha piperita L. plants essential oils against yeast and Gram-negative bacteria at concentrations of 0.5 ul/ml and 0.25 ul/ml extended lag phase or adaptation phase by 48 hours, respectively. Gram-positive bacteria were found to be susceptible to the studied two plants essential oils. When the effects of antimicrobial activity of two essential oils were tested in combination against bacteria and yeast in vitro, the MIC value was in the range of 0.125-0.5 ul/ml and showed synergistic activity against E.coli and additive values against B.subtilis and S.cerevisiae.

The symbiotic system of Legumes and root-nodule bacteria is a significant process for enriching barren and dry soils and supporting plant growth. The aim of this study was to isolate root-nodule bacteria from Medicago falcate and to select high activity strains with resistance to environmental stress. As a result, only MSZ-25 strain grew in the medium containing 0.8M NaCl, with pH4.8-9.8 and at temperatures of 4-45°С. All rhizobial isolates were tolerant to the concentrations of 0.01-0.1% Pb(NO3)2, 0.01% ZnSO4, CdCI2, CuCI2 and NiCI2. The strains were also resisted to penicillin 10μ/ml, erythromycin 10μ/ml, and chlorampenicol 10μ/ml but the growths of all isolates were inhibited by kanamycin 30μ/ml, novobiocin 30μ/ml and tetracycline 10μ/ml.

Pinus sylvestris. var mongolica is a major source of timber in Mongolia. The logging process makes many kinds of valuable biomass including bark, cones, and needles, which can be used for obtaining essential oil. The essential oil from the needles of wild growing Pinus sylvestris. var mongolica growing in Mongolia was chemically analyzed and its antibacterial, antifungal and cytotoxic activities were evaluated. The chemical analyses identified 101 compounds in the essential oil with the major compounds of α-pinene (29.87 %), limonene + β-phellandrene (16.15 %), camphene (4.95 %), bornylacetate (4.34 %), and β-pinene (3.88 %). This oil possessed the inhibitory activity against B. subtilis, S. cerevisiae, S. aureus and E. coli, successively with minimum inhibition concentration of 0.125, 0.1, 3.0, and 10.0 µg/mL. Importantly, the oil at 50 µg/mL and 100 µg/mL inhibited the growth of MCF-7 cells by 45.3 % and 99.7 %. The half of inhibition concentration of DPPH (2,2-Diphenyl-1-picrylhydrazyl) radical scavenging was 14.36 ± 0.28 mg/mL. The results, therefore, suggested that the essential oil of a Mongolian Scotch pine could potentially be used as a preservative material in cosmetic and food products, as a bioactive agent in anti-inflammatory and wound healing products in view of its antibacterial activity. Given our findings that this essential oil has such profound activity against MCF-7 cancer cells, a further investigation concerning the full extent of this essential oil’s anticancer activities seems warranted. Furthermore, given the promising antimicrobial effects of this essential oil against various bacterial species, an investigation concerning its effect against drug-resistant bacteria would be of immense interest.

Although inorganic fertilizers are known to raise environmental and health problems, the current agricultural practices are heavily dependent on the application of synthetic fertilizers and pesticides. In this study, we examined the effect of Chlorella vulgaris strain on germination of tomato and cucumber seeds. Seeds were germinated in culture medium containing algal strain and grown for 3, 6, 9 and 12 days to study its effect on growth parameters. As results, C. vulgaris suspension increased the seed growth compared to those of the control (sterilized culture medium) of seed germination. The best treatments were 0.17 and 0.25 g/L of algal suspension for the root and shoot lengths of tomato and cucumber seeds, respectively.