To study the abilities of Chlorella sorokiniana CS-01 on using CO2 from flue gases to produce biodiesel,the microaglae was cultured with different simulated flue gases containing 5%-15%(volume fraction) of CO2.The res...To study the abilities of Chlorella sorokiniana CS-01 on using CO2 from flue gases to produce biodiesel,the microaglae was cultured with different simulated flue gases containing 5%-15%(volume fraction) of CO2.The results show that strain CS-01 could grow at 15% CO2 and grow well under CO2 contents ranging from 5%-10%.The maximal biomass productivity and lipid productivity were obtained when aerating with 10% of CO2.The lipids content ranged from 28% to 43% of dry mass of biomass.The main fatty acid compositions of strain CS-01 were C14-C18(>72%) short-chain FAMEs(known as biodiesel feedstocks).Meanwhile,the biodiesel productivity was over 60%,suggesting that Chlorella sorokiniana CS-01 has a great potential for CO2 mitigation and biodiesel production.Furthermore,differential expression of three genes related to CO2 fixation and fatty acid synthesis were studied to further describe the effect of simulated flue gases on the growth and lipid accumulation of strain CS-01 at molecular level.展开更多
The effect of microwave （MW） heating on the dielectric properties and oxidation processes of virgin olive oil and refined sunflower oil were determined by dielectric and UV- spectroscopy. Samples were heated in the ...The effect of microwave （MW） heating on the dielectric properties and oxidation processes of virgin olive oil and refined sunflower oil were determined by dielectric and UV- spectroscopy. Samples were heated in the microwave oven （850 W, 2.450 MHz） for 0 to 14 minutes. The results show degradation of dielectric characteristics, conductivity and oxidative stability of investigated oils, increasing with the exposure time. UV spectrum shows only one defined peak at 206 nm for olive oil confirming the dominant presence of monounsaturated fats and four peaks for sunflower oil （203 nm, 230 nm, 269 nm and 278 nm） dependent on polyunsaturated acid fats contents. Increasing of absorbance at all peak wave lengths indicates production of lipid oxidation, due to formation of conjugated monoenes and dienes and in small amounts due to trienes and secondary products like ketoaldehydes. Dielectric constant for olive oil is stable and almost unchangeable with MW radiation while sunflower oil＇s c＇ oscillates around the origin value in greater rate. Dielectric loss e＂ decreases with increasing time of MW radiation and its maximum shifts towards higher frequencies for sunflower oil indicating shortening of the relaxation times, while for olive oil it is unchanged. Cole-Cole analysis show the presence of only one relaxation process in the oils. Conductivity of oils is increasing in similar way with increasing frequency following the Jonscher＇s power law and is not changed with MW exposure time. Olive oil has conductivity higher for four orders of magnitude than sunflower oil, which is connected to the high content of monounsaturated fats. The differences between sunflower and olive oil characteristics are discussed.展开更多
基金Project(50621063) supported by the National Natural Science Foundation for Distinguished Group of ChinaProjects(2010bsxt05,2010ssxt246) supported by the Innovation Foundation of Science and Technology of Central South University,China
文摘To study the abilities of Chlorella sorokiniana CS-01 on using CO2 from flue gases to produce biodiesel,the microaglae was cultured with different simulated flue gases containing 5%-15%(volume fraction) of CO2.The results show that strain CS-01 could grow at 15% CO2 and grow well under CO2 contents ranging from 5%-10%.The maximal biomass productivity and lipid productivity were obtained when aerating with 10% of CO2.The lipids content ranged from 28% to 43% of dry mass of biomass.The main fatty acid compositions of strain CS-01 were C14-C18(>72%) short-chain FAMEs(known as biodiesel feedstocks).Meanwhile,the biodiesel productivity was over 60%,suggesting that Chlorella sorokiniana CS-01 has a great potential for CO2 mitigation and biodiesel production.Furthermore,differential expression of three genes related to CO2 fixation and fatty acid synthesis were studied to further describe the effect of simulated flue gases on the growth and lipid accumulation of strain CS-01 at molecular level.
文摘The effect of microwave （MW） heating on the dielectric properties and oxidation processes of virgin olive oil and refined sunflower oil were determined by dielectric and UV- spectroscopy. Samples were heated in the microwave oven （850 W, 2.450 MHz） for 0 to 14 minutes. The results show degradation of dielectric characteristics, conductivity and oxidative stability of investigated oils, increasing with the exposure time. UV spectrum shows only one defined peak at 206 nm for olive oil confirming the dominant presence of monounsaturated fats and four peaks for sunflower oil （203 nm, 230 nm, 269 nm and 278 nm） dependent on polyunsaturated acid fats contents. Increasing of absorbance at all peak wave lengths indicates production of lipid oxidation, due to formation of conjugated monoenes and dienes and in small amounts due to trienes and secondary products like ketoaldehydes. Dielectric constant for olive oil is stable and almost unchangeable with MW radiation while sunflower oil＇s c＇ oscillates around the origin value in greater rate. Dielectric loss e＂ decreases with increasing time of MW radiation and its maximum shifts towards higher frequencies for sunflower oil indicating shortening of the relaxation times, while for olive oil it is unchanged. Cole-Cole analysis show the presence of only one relaxation process in the oils. Conductivity of oils is increasing in similar way with increasing frequency following the Jonscher＇s power law and is not changed with MW exposure time. Olive oil has conductivity higher for four orders of magnitude than sunflower oil, which is connected to the high content of monounsaturated fats. The differences between sunflower and olive oil characteristics are discussed.
