Showing 4 results for Cyanobacteria
Volume 4, Issue 2 (9-2015)
Abstract
The antibiotic properties of eight cyanobacteria (blue-green algae) species from Anzali Wetland was investigated on several bacterial species through vacuum distillation and simple mechanical methods. The result showed that Anabaena sp., A. variabilis, A. flos-aquae and Aphanizomenonflos-aquaehad negative effect on the growth of Staphylococcus aureusandA. flos-aquaeand A. oscillaroideshad negative effects on the growth of E. coli. The growth of Candida albicans yeast was greatly reduced by Aphanizomenonflos-aquae, A. variabilis, and A. oscillaroides. Among the investigated algae only A. oscillaroides could reduce the growth of Pseudomonassp.
R. Mohammadi , J. Zahiri , M.j. Niroomand,
Volume 9, Issue 2 (9-2018)
Abstract
Aims: The production of biofuels has been one of the promising efforts in biotechnology in the past decades. Unicellular cyanobacteria are widespread phototrophic microorganisms that can be suitable chassis for production of valuable organic materials like biofuels. The aim of this study was the reconstruction and modeling of integrated metabolic network of a cyanobacterium to increase the production of biofuels.
Materials and Methods: In the present computational study, a software for integrating reconstructed metabolic networks was developed to optimize and increase their efficiency and was named as iMet. First, iMet was used to integrate the 3 pre-reconstructed metabolic networks of Synechocystis PCC6803. In the next step, the reconstructed network was modeled to produce 4 types of biofuels, including ethanol, propanol, butanol, and isobutanol.
Findings: The new merged model had 808 reactions and 560 metabolites. The amount of flux or flow in the integrated model was calculated to be 0.0295 hours per hour. This showed a remarkable increase compared to the previous three models. The cells were divided once every 24 hours. The amount of flux of 4 types of alcohol and their maximum theoretical efficiency increased in the integrated model compared to the previous 3 models. The flux of ethanol production was greater in all models than flux of 3 other alcohols, and the ethanol production reactions were closer to the flow or the central flux of carbon.
Conclusion: The analyses of flow equilibrium in the metabolic network coverage show an increase in the production of biofuels and a decrease in the number of blocked reactions in the new model, thereby the efficiency of the developed iMet software is proved.
Asieh Bahrami, Samaneh Zolghadri, Ehteram Deilami,
Volume 11, Issue 2 (6-2020)
Abstract
Abstract. Phycocyanine (PC) belongs to a group of protein receptor proteins called phycobiliprotein. All of the phycobiliprotein are multi-chain proteins made up of apoproteins. Which are covalently attached to the phyclobilins. This experimental study was carried out on strain of native Anabaena doliolum, Isolated from soils and waters of south Iran were Masjed Soleyman area. The cyanobacteria were grown and stored in BG11 medium. Then, the amount of phycocyanin produced under different light treatment and the amount of phycocyanin extracted using different ratios of multi-buffer and at two different temperatures were evaluated. The results of this study showed that the highest growth rate is when the sample is exposed to green light for three to five days. The best amount of extraction for distilled water and at a refrigerator temperature (0◦C) with a ratio of 3:1 biomass/solvent is equal to 0.03 ± 15 µg/ml. Also, at the environment temperature, phosphate buffer is a more suitable solvent for extracting phycocyanine at a ratio of one to two with a value of 0.05 ± 8 µg/ml. In general, it can be said that the growth rate, pigment production and optimum extraction conditions for each species are quite different, and the optimal extraction of phycocyanin in a species is also dependent on various factors such as time, temperature, solvent and the ratio of biomass to solvent.
Volume 22, Issue 2 (3-2020)
Abstract
The flavonoid and phenolic compounds are among the main pharmaceutical components of medicinal plants. These compounds are considered as effective anti-oxidant sources. Five cyanobacterial extracts were used to stimulate the plant growth and increase production of specific secondary metabolites in Plantago major as a medicinal plant. These cyanobacteria were isolated from the growth bed of the plant in its natural habitats. Nitrate-free BG11 medium was used for preparing axenic monoalgal cultures. Pot experiments were performed by spraying cyanobacterial extracts on the soil of treated plants every 20 days from the time of planting. Growth of plants was evaluated by measuring growth parameters such as plant height, root length, dry and fresh weight of plant, leaf number, leaf area, as well as inflorescence characteristics 60 days after planting. In addition to growth factors, the total amount of phenol and flavonoid of plants was also assessed. Statistical analysis showed that there was a significant difference in the vegetative and reproductive characteristics compared to the control plants. Also, the methanolic extraction of treated and control plants displayed the highest total phenolic and flavonoid content 77.23±3.21 µg of GA mg-1 and 389.67±34.43 µg of RU mg-1 in plants treated with Cylindrospermum michailovskoence. Based on the obtained results, cyanobacterial fertilizers are suggested as the biological elicitors to improve the quantity and quality of medicinal plants products. As a result of this study, chemical content of cyanobacterial extracts and the production of plant growth stimulating substances such as phytohormones can be proposed as factors affecting plant growth parameters and metabolites production.
