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
This study investigated whether increased solar UV-B radiation (280-315 nm) could suppress the growth of marine microalgae through effects on their antioxidant systems. Two marine microalgae species, Platymonas subcor...This study investigated whether increased solar UV-B radiation (280-315 nm) could suppress the growth of marine microalgae through effects on their antioxidant systems. Two marine microalgae species, Platymonas subcordiformis (Wille) Hazen and Nitzschia closterium (Ehrenb.) W. Sm, were exposed to a range of UV-B radiation and both showed reductions in their growth rates, and the chlorophyll a (Chl a) and carotenoid (Car) contents when UV-B radiation dose increased. Superoxide anion radical (O2)production and the concentration of hydrogen peroxide (H2O2) and malodiadehyde (MDA) also increased with the increasing of UV-B radiation. Antioxidant systems, non-enzymic components (Car and glutathione content) and enzymic components (superoxide dismutase (SOD) and catalase (CAT) activity), decreased as a result of enhanced UV-B radiation. When the exogenous glutathione (GSH) was added, the effects of UVB radiation on the growth of the two species were alleviated. These results suggest that enhanced UV-B radiation suppressed the antioxidant systems and caused some active oxygen species to accumulate, which in turns retarded the development of the marine microalgae.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
The cultures of Platymonas subcordiformis and Isochrysis zhangjiangensis which had preserved for long time was irradiated by Nd:YAG laser(1.06 μm,5 W)with different dose.Then,the effects of laser on algae growth,phys...The cultures of Platymonas subcordiformis and Isochrysis zhangjiangensis which had preserved for long time was irradiated by Nd:YAG laser(1.06 μm,5 W)with different dose.Then,the effects of laser on algae growth,physiological and biochemical characteristic were investigated.The feasibility to utilize laser in the activation and rejuvenation of microalgae were discussed.The results showed that the optimal dosage to rejuvenate I.zhangjiangensis is 60 s,which the growth rate,cell biomass,the contents of chlorophyll,polysaccharides and protein increased by 27.59%-43.44% after Nd:YAG radiation.For P.subcordiformis,the better results of rejuvenation by Nd:YAG laser was got when irradiation dose at both 60 s and 90 s.It is favourable to the growth of P.subcordiformis by using lower irradiation dose of Nd:YAG laser,which the growth rate and the contents of chlorophyll increased by 12.5% and 17.5% respectively.By contrast,the higher irradiation dose was favourable to the increase of other biomass of P.subcordiformis,which the contents of carotenoids,protein and polysaccharides increased by 87.7%,15.5% and 36.8% respectively.The results of Laser Scanning Confocal Microscope(LSCM)showed that the fluorescence spectra of the irradiated group is similar to control group with the maximum peak located at 682 nm which can be attributed to photosystemⅡ.While the irradiated group which the growth had be promoted has a higher intensity at 682 nm than control group.In this paper,the possible mechanism of activation and rejuvenation effects on microalgae induced by laser irradiation was also discussed.These results can offer a theoretical foundation to utilize laser in breeding of microalgae species for aquiculture.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.
基金国家自然科学基金，Encouraging Foundation for Outstanding Youth Scientists of Shandong Province
文摘This study investigated whether increased solar UV-B radiation (280-315 nm) could suppress the growth of marine microalgae through effects on their antioxidant systems. Two marine microalgae species, Platymonas subcordiformis (Wille) Hazen and Nitzschia closterium (Ehrenb.) W. Sm, were exposed to a range of UV-B radiation and both showed reductions in their growth rates, and the chlorophyll a (Chl a) and carotenoid (Car) contents when UV-B radiation dose increased. Superoxide anion radical (O2)production and the concentration of hydrogen peroxide (H2O2) and malodiadehyde (MDA) also increased with the increasing of UV-B radiation. Antioxidant systems, non-enzymic components (Car and glutathione content) and enzymic components (superoxide dismutase (SOD) and catalase (CAT) activity), decreased as a result of enhanced UV-B radiation. When the exogenous glutathione (GSH) was added, the effects of UVB radiation on the growth of the two species were alleviated. These results suggest that enhanced UV-B radiation suppressed the antioxidant systems and caused some active oxygen species to accumulate, which in turns retarded the development of the marine microalgae.
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
文摘The cultures of Platymonas subcordiformis and Isochrysis zhangjiangensis which had preserved for long time was irradiated by Nd:YAG laser(1.06 μm,5 W)with different dose.Then,the effects of laser on algae growth,physiological and biochemical characteristic were investigated.The feasibility to utilize laser in the activation and rejuvenation of microalgae were discussed.The results showed that the optimal dosage to rejuvenate I.zhangjiangensis is 60 s,which the growth rate,cell biomass,the contents of chlorophyll,polysaccharides and protein increased by 27.59%-43.44% after Nd:YAG radiation.For P.subcordiformis,the better results of rejuvenation by Nd:YAG laser was got when irradiation dose at both 60 s and 90 s.It is favourable to the growth of P.subcordiformis by using lower irradiation dose of Nd:YAG laser,which the growth rate and the contents of chlorophyll increased by 12.5% and 17.5% respectively.By contrast,the higher irradiation dose was favourable to the increase of other biomass of P.subcordiformis,which the contents of carotenoids,protein and polysaccharides increased by 87.7%,15.5% and 36.8% respectively.The results of Laser Scanning Confocal Microscope(LSCM)showed that the fluorescence spectra of the irradiated group is similar to control group with the maximum peak located at 682 nm which can be attributed to photosystemⅡ.While the irradiated group which the growth had be promoted has a higher intensity at 682 nm than control group.In this paper,the possible mechanism of activation and rejuvenation effects on microalgae induced by laser irradiation was also discussed.These results can offer a theoretical foundation to utilize laser in breeding of microalgae species for aquiculture.
