Strontium-induced stress in growth and chlorophyll contents of Platymonas subcordiformis was investigated under laboratory condition. The results showed that strontium exposure had little influ- ences in general on gr...Strontium-induced stress in growth and chlorophyll contents of Platymonas subcordiformis was investigated under laboratory condition. The results showed that strontium exposure had little influ- ences in general on growth and chlorophyll contents of the algae except for very high Sr concentrations. The maximum biosorption capacity of strontium ranged from 69.62 to 269.18 mg Sr2+/g dry weight. The algal biomass exhibited high uptake capacity of strontium. Total superoxide dismutase (SOD) activity and the content of lipid peroxidation products malondialdehyde (MDA) were significantly different in differ- ent treatments. SOD activity reached the highest level at 0.09 mmol/L that was about 55.8 % higher than that in the control. The MDA content increased significantly at 0.36 mmol/L, which was 2.15 times higher than that in the control, indicating a state of oxidative stress. With the increase of strontium concentration, the amount of fatty acids decreased.展开更多
Platymonas (Tetraselmis) subcordiformis is a unicellular marine green alga. It was found to be very sensitive to the herbicide Basta through a sensitivity test indicating it could be employed as a selective agent. The...Platymonas (Tetraselmis) subcordiformis is a unicellular marine green alga. It was found to be very sensitive to the herbicide Basta through a sensitivity test indicating it could be employed as a selective agent. The bar gene is a practicable and selectable marker gene. The vector containing the expression cassette of the bar gene was transferred to P. subcordiformis by both particle bombardment and glass-bead agitation and transformants were then selected using Basta. Finally, Southern blotting analysis indicated that the bar gene had been successfully integrated into the nuclear genome of P. subcordiformis using both of the transgenic techniques, with the transformation efficiency of the glass-bead method being slightly higher than that of particle bombardment. This is the first report on stable transformation of P. subcordiformis, and will improve fundamental research and enlarge application of this alga.展开更多
In the present paper, the unicellular green alga Platymonas subcordiformis was entrapped in 2% (W/V) alginate, treated with CaCl2 at different concentrations (0. 5, 0.75, 1. 0, 1. 5 and 2. 0 mol/dm3), cultured at 15℃...In the present paper, the unicellular green alga Platymonas subcordiformis was entrapped in 2% (W/V) alginate, treated with CaCl2 at different concentrations (0. 5, 0.75, 1. 0, 1. 5 and 2. 0 mol/dm3), cultured at 15℃ and 25℃. The growth rate and morphology were studied and photosynthesis and respiration rates were measured. The optimum conditions of immobilized culture is in 0. 5 mol/dm3 of CaCl2, at 25℃. Photosynthesis rate of immobilized cells is higher than free cultivated cells, and that at 15℃ than at 25℃. Under scanning electronic microscope, it was shown that the immobilized cells had larger size and rougher surface. The relationship between growth of immobilized cells and abiotic factors and the prospects of applying immobilized cultivation are also discussed.展开更多
Short term uptake experiments and long term semicontinuous culture experiments were performed under the condition of phosphorus (P) limitation to estimate and compare the P uptake and growth kinetics of the microalga ...Short term uptake experiments and long term semicontinuous culture experiments were performed under the condition of phosphorus (P) limitation to estimate and compare the P uptake and growth kinetics of the microalga Tetraselmis subcordiformis and the macroalga Ulva pertusa. Two new parameters, the maximum specific uptake rate ( V sp m) and the maximal growth efficiency ( β ), are introduced to achieve uniformity for the comparison of nutrient uptake and growth efficiency between microalgae and macroalgae. T. subcordiformis possesses 3 times lower half saturation uptake constant, 4 times higher maximal growth rate and 20 times higher maximum specific uptake rate than U. pertusa, while U. pertusa possesses 4 times higher maximal growth efficiency than T. subcordiformis.展开更多
Microalgae Tetraselmis subcordiformis and Nannochloropsis oculata were cultured at 15,20,25,30,and 35℃ and their properties as potential biofuel resources were examined.The results indicate that T.subcordiformis and ...Microalgae Tetraselmis subcordiformis and Nannochloropsis oculata were cultured at 15,20,25,30,and 35℃ and their properties as potential biofuel resources were examined.The results indicate that T.subcordiformis and N.oculata grew best at 20℃ and 25℃ and yielded the highest total lipids at 20℃and 30℃,respectively.With increased temperature,neutral lipid and polyunsaturated fatty acids(FAs)decreased while saturated FAs increased,accompanied by increased monounsaturated FAs(MUFAs) in T.subcordiformis and decreased MUFAs in N.oculata;meanwhile,the predicted cetane number of FA methyl esters increased from 45.3 to 47.6 in T.subcordiformis and from 52.3 to 60.3 in N.oculata.Therefore,optimizing culture temperatures is important for improving microalgal biodiesel production.展开更多
The green alga Tetraselmis subcordiformis has been widely used as a quality live food for aquaculture species, and also has been studied as a model organism for the photo-biological production of hydrogen. We attempte...The green alga Tetraselmis subcordiformis has been widely used as a quality live food for aquaculture species, and also has been studied as a model organism for the photo-biological production of hydrogen. We attempted to quantify the relationship between T. subcordiformis specific growth rate(SGR) and three important environmental factors(temperature, salinity, and p H) using the central composite design and response surface method under laboratory conditions. The results showed that the linear effects of temperature and salinity were significant( P< 0.05), and they were equally important in impacting T. subcordiformis specific growth; the linear effect of p H was not significant( P >0.05); the interactive effect of temperature and p H was significant( P <0.05), whereas the temperature ′ salinity and salinity ′ p H interactions were not significant( P >0.05); all of the quadratic effects of the three factors were significant( P< 0.05). A model equation for specific growth rate with the three factors was established, with the unadjusted and predictive R^2 as high as 0.990 and 0.921, respectively, suggesting that the model was a very good fit and that it could be used to predict SGR. Through optimizing the reliable model, an optimal 3-factor combination of 25 ° C/35 of salinity/p H 7.9 was obtained, at which the maximum specific growth rate(0.65) was recorded, with a desirability value of 93.8%. These experimental results could serve as guidelines for increasing T. subcordiformis production efficiency.展开更多
研究了 CO2 加富对两种海洋微绿藻小球藻和亚心形扁藻的生长、光合作用和抗氧化酶活性的影响。实验结果表明 ,CO2加富 (含 5 0 0 0 μl/ L CO2 的空气 )促进小球藻和亚心形扁藻的生长。但两种藻对 CO2 加富的敏感性不同。CO2 加富对小...研究了 CO2 加富对两种海洋微绿藻小球藻和亚心形扁藻的生长、光合作用和抗氧化酶活性的影响。实验结果表明 ,CO2加富 (含 5 0 0 0 μl/ L CO2 的空气 )促进小球藻和亚心形扁藻的生长。但两种藻对 CO2 加富的敏感性不同。CO2 加富对小球藻生物量影响的敏感性小于亚心形扁藻。CO2 加富使两种藻的干重和光合速率显著增加 ;可溶性蛋白含量显著下降 ;但两种藻的 Chla含量和 Car含量与对照相比变化不明显。高浓度 CO2 生长的小球藻和亚心形扁藻的 MDA含量比对照低 ,表明 CO2 升高可以减轻微藻的膜脂过氧化损伤 ,有利于膜脂稳定性的保持 ;在正常浓度 CO2 (36 0μl/ L )条件下 ,抗氧化酶 SOD、POD、CAT、GR的活性因藻种不同而存在很大差异 ,高浓度 CO2 (5 0 0 0μl/ L )培养条件使得这些抗氧化酶中的 SOD、CAT、GR的活性显著降低 ,而POD活性变化则不明显。 CO2 浓度升高可能导致抗氧化酶活性需求的减少 ,从而对藻的氧化损伤具有一定的保护能力。另外 ,光合速率、Chla含量和展开更多
基金This work was supported by Natural Science Foundation of Jiangsu Province (No. 95021301).
文摘Strontium-induced stress in growth and chlorophyll contents of Platymonas subcordiformis was investigated under laboratory condition. The results showed that strontium exposure had little influ- ences in general on growth and chlorophyll contents of the algae except for very high Sr concentrations. The maximum biosorption capacity of strontium ranged from 69.62 to 269.18 mg Sr2+/g dry weight. The algal biomass exhibited high uptake capacity of strontium. Total superoxide dismutase (SOD) activity and the content of lipid peroxidation products malondialdehyde (MDA) were significantly different in differ- ent treatments. SOD activity reached the highest level at 0.09 mmol/L that was about 55.8 % higher than that in the control. The MDA content increased significantly at 0.36 mmol/L, which was 2.15 times higher than that in the control, indicating a state of oxidative stress. With the increase of strontium concentration, the amount of fatty acids decreased.
基金Supported by the National Basic Research Program of China (973 Program) (No. 2011CB200902)the National High Technology Research and Development Program of China (863 Program) (Nos. 2009AA10Z106,2009AA064401)+2 种基金the Promotive Research Fund for Excellent Young and Middle-aged Scientists of Shandong Province (No. 2010BSB02009)the National Natural Science Foundation of China (Nos. 40876082,30870247)the Science and Technology Project of Qingdao City (No.09-1-3-59-jch)
文摘Platymonas (Tetraselmis) subcordiformis is a unicellular marine green alga. It was found to be very sensitive to the herbicide Basta through a sensitivity test indicating it could be employed as a selective agent. The bar gene is a practicable and selectable marker gene. The vector containing the expression cassette of the bar gene was transferred to P. subcordiformis by both particle bombardment and glass-bead agitation and transformants were then selected using Basta. Finally, Southern blotting analysis indicated that the bar gene had been successfully integrated into the nuclear genome of P. subcordiformis using both of the transgenic techniques, with the transformation efficiency of the glass-bead method being slightly higher than that of particle bombardment. This is the first report on stable transformation of P. subcordiformis, and will improve fundamental research and enlarge application of this alga.
文摘In the present paper, the unicellular green alga Platymonas subcordiformis was entrapped in 2% (W/V) alginate, treated with CaCl2 at different concentrations (0. 5, 0.75, 1. 0, 1. 5 and 2. 0 mol/dm3), cultured at 15℃ and 25℃. The growth rate and morphology were studied and photosynthesis and respiration rates were measured. The optimum conditions of immobilized culture is in 0. 5 mol/dm3 of CaCl2, at 25℃. Photosynthesis rate of immobilized cells is higher than free cultivated cells, and that at 15℃ than at 25℃. Under scanning electronic microscope, it was shown that the immobilized cells had larger size and rougher surface. The relationship between growth of immobilized cells and abiotic factors and the prospects of applying immobilized cultivation are also discussed.
基金supported by the Project under Major State Basic Research of China(G1999012011).
文摘Short term uptake experiments and long term semicontinuous culture experiments were performed under the condition of phosphorus (P) limitation to estimate and compare the P uptake and growth kinetics of the microalga Tetraselmis subcordiformis and the macroalga Ulva pertusa. Two new parameters, the maximum specific uptake rate ( V sp m) and the maximal growth efficiency ( β ), are introduced to achieve uniformity for the comparison of nutrient uptake and growth efficiency between microalgae and macroalgae. T. subcordiformis possesses 3 times lower half saturation uptake constant, 4 times higher maximal growth rate and 20 times higher maximum specific uptake rate than U. pertusa, while U. pertusa possesses 4 times higher maximal growth efficiency than T. subcordiformis.
基金Supported by the National High Technology Research and Development Program of China(863 Program)(No.2009AA064401)the Special Fundation for Marine Renewable Energy from the State Oceanic Administration of China(No.SHME2011SW02)the Shanghai Universities First-class Disciplines Project of Fisheries(A)
文摘Microalgae Tetraselmis subcordiformis and Nannochloropsis oculata were cultured at 15,20,25,30,and 35℃ and their properties as potential biofuel resources were examined.The results indicate that T.subcordiformis and N.oculata grew best at 20℃ and 25℃ and yielded the highest total lipids at 20℃and 30℃,respectively.With increased temperature,neutral lipid and polyunsaturated fatty acids(FAs)decreased while saturated FAs increased,accompanied by increased monounsaturated FAs(MUFAs) in T.subcordiformis and decreased MUFAs in N.oculata;meanwhile,the predicted cetane number of FA methyl esters increased from 45.3 to 47.6 in T.subcordiformis and from 52.3 to 60.3 in N.oculata.Therefore,optimizing culture temperatures is important for improving microalgal biodiesel production.
基金Supported by the Guangdong Province Science and Technology Project(No.2010B020201014)the Guangdong Province South China Sea Invertebrates Healthy Culture Engineering Technology Research Center(No.GCZX-A0909)+2 种基金the Guangdong Province Ocean and Fisheries Science and Technology Extension Project(No.20120980)the Guangdong Province Industry-University-Science Partnership Project(No.20110908)the Sci&Tech Plan of Huaiyin Normal University(No.WH0031)
文摘The green alga Tetraselmis subcordiformis has been widely used as a quality live food for aquaculture species, and also has been studied as a model organism for the photo-biological production of hydrogen. We attempted to quantify the relationship between T. subcordiformis specific growth rate(SGR) and three important environmental factors(temperature, salinity, and p H) using the central composite design and response surface method under laboratory conditions. The results showed that the linear effects of temperature and salinity were significant( P< 0.05), and they were equally important in impacting T. subcordiformis specific growth; the linear effect of p H was not significant( P >0.05); the interactive effect of temperature and p H was significant( P <0.05), whereas the temperature ′ salinity and salinity ′ p H interactions were not significant( P >0.05); all of the quadratic effects of the three factors were significant( P< 0.05). A model equation for specific growth rate with the three factors was established, with the unadjusted and predictive R^2 as high as 0.990 and 0.921, respectively, suggesting that the model was a very good fit and that it could be used to predict SGR. Through optimizing the reliable model, an optimal 3-factor combination of 25 ° C/35 of salinity/p H 7.9 was obtained, at which the maximum specific growth rate(0.65) was recorded, with a desirability value of 93.8%. These experimental results could serve as guidelines for increasing T. subcordiformis production efficiency.
文摘研究了 CO2 加富对两种海洋微绿藻小球藻和亚心形扁藻的生长、光合作用和抗氧化酶活性的影响。实验结果表明 ,CO2加富 (含 5 0 0 0 μl/ L CO2 的空气 )促进小球藻和亚心形扁藻的生长。但两种藻对 CO2 加富的敏感性不同。CO2 加富对小球藻生物量影响的敏感性小于亚心形扁藻。CO2 加富使两种藻的干重和光合速率显著增加 ;可溶性蛋白含量显著下降 ;但两种藻的 Chla含量和 Car含量与对照相比变化不明显。高浓度 CO2 生长的小球藻和亚心形扁藻的 MDA含量比对照低 ,表明 CO2 升高可以减轻微藻的膜脂过氧化损伤 ,有利于膜脂稳定性的保持 ;在正常浓度 CO2 (36 0μl/ L )条件下 ,抗氧化酶 SOD、POD、CAT、GR的活性因藻种不同而存在很大差异 ,高浓度 CO2 (5 0 0 0μl/ L )培养条件使得这些抗氧化酶中的 SOD、CAT、GR的活性显著降低 ,而POD活性变化则不明显。 CO2 浓度升高可能导致抗氧化酶活性需求的减少 ,从而对藻的氧化损伤具有一定的保护能力。另外 ,光合速率、Chla含量和
