The vertical fluxes and molar ratios of carbon, nitrogen and phosphorus of suspended particulate matter in the Yellow Sea were studied based on the analysis of suspended particulate matter, sediments and sinking parti...The vertical fluxes and molar ratios of carbon, nitrogen and phosphorus of suspended particulate matter in the Yellow Sea were studied based on the analysis of suspended particulate matter, sediments and sinking particles obtained by use of moored sediment traps. The POC:PON ratios indicate that most of the particulate organic matter in the Yellow Sea water column comes from marine life rather than the continent. The vertical fluxes of SPM, POC, PON and POP in the Yellow Sea are much higher than those in other seas over the world, and present a typical pattern in shallow epicontinental seas. The estimated residence time of the bioactive elements showed that the speed of the biogeochemical process of materials in the Yellow Sea is much shorter than that in the open ocean as there was high primary productivity in this region.展开更多
This study investigate the effect of the concentration of nitrate and phosphate, present in the culture medium, on the chemical and biochemical composition of the products from the marine microalgae, Nannochloropsis s...This study investigate the effect of the concentration of nitrate and phosphate, present in the culture medium, on the chemical and biochemical composition of the products from the marine microalgae, Nannochloropsis sp.. Experimental design allowed the assessment, in a systematic way, of the response of the microalgae to the nitrate and phosphate concentrations, and the way they lead to changes in the total amount of carotenoids, chlorophyll a, iron and magnesium produced or uptaken. The total carotenoids presented a higher yield when cultivated under lower phosphate concentrations, but showed no change with nitrate concentration. Chlorophyll a yield increased in the presence of higher concentrations of nitrogen and lower concentrations of phosphorus. There was an increase in the amount of iron absorbed by cells when higher levels of nitrates were present, but the effect is insignificant with phosphates. The magnesium content was not significantly affected by culture manipulation. The results also showed that the biomass yield of the microalgae Nannochloropsis sp. was negatively affected by the N/P ratio. The antioxidative potential of the microalgae, in contrast, was found to increase with the N/P ratio.展开更多
文摘The vertical fluxes and molar ratios of carbon, nitrogen and phosphorus of suspended particulate matter in the Yellow Sea were studied based on the analysis of suspended particulate matter, sediments and sinking particles obtained by use of moored sediment traps. The POC:PON ratios indicate that most of the particulate organic matter in the Yellow Sea water column comes from marine life rather than the continent. The vertical fluxes of SPM, POC, PON and POP in the Yellow Sea are much higher than those in other seas over the world, and present a typical pattern in shallow epicontinental seas. The estimated residence time of the bioactive elements showed that the speed of the biogeochemical process of materials in the Yellow Sea is much shorter than that in the open ocean as there was high primary productivity in this region.
文摘This study investigate the effect of the concentration of nitrate and phosphate, present in the culture medium, on the chemical and biochemical composition of the products from the marine microalgae, Nannochloropsis sp.. Experimental design allowed the assessment, in a systematic way, of the response of the microalgae to the nitrate and phosphate concentrations, and the way they lead to changes in the total amount of carotenoids, chlorophyll a, iron and magnesium produced or uptaken. The total carotenoids presented a higher yield when cultivated under lower phosphate concentrations, but showed no change with nitrate concentration. Chlorophyll a yield increased in the presence of higher concentrations of nitrogen and lower concentrations of phosphorus. There was an increase in the amount of iron absorbed by cells when higher levels of nitrates were present, but the effect is insignificant with phosphates. The magnesium content was not significantly affected by culture manipulation. The results also showed that the biomass yield of the microalgae Nannochloropsis sp. was negatively affected by the N/P ratio. The antioxidative potential of the microalgae, in contrast, was found to increase with the N/P ratio.
