Nutrient stimulation of carbon fixation in summertime English Channel phytoplankton assemblages

1981 ◽  
Vol 61 (3) ◽  
pp. 551-563 ◽  
Author(s):  
Anthony G. Davies ◽  
Jillian A. Sleep
Keyword(s):  
Carbon Fixation ◽  
Phosphorus Compounds ◽  
English Channel ◽  
Summer Period ◽  
Nitrogen And Phosphorus ◽  
Phytoplankton Assemblages ◽  
Nutrient Additions ◽  
Low Levels ◽  
Zooplankton Excretion ◽  
Stimulation Of

The effects of nutrient additions and zooplankton excretion products upon carbon fixation rates in the phytoplankton present at Station L 4 in the English Channel during the summer and autumn of 1979 have been studied. Nitrate, ammonium, urea, phosphate, glucose-6-phosphate and the excretion products when added individually all caused photosynthesis to be stimulated, and the result of the simultaneous addition of nitrate and phosphate indicated that their effects were additive. Germanic acid, which inhibits photosynthesis mainly in diatoms, removed the stimulatory effect of the nitrogen supplements, indicating that they were utilized mostly by the diatoms; the higher fixation rates caused by the phosphate enrichments were, however, decreased by the same proportion as the unenriched controls when germanic acid was present, suggesting that the whole of the phytoplankton population was phosphorus-limited. This was supported by the finding that glucose-6-phosphate stimulated carbon fixation in all of the phytoplankton.The excretion products, even at concentrations likely to be produced in the sea, stimulated carbon fixation, and it has been calculated that zooplankton-regenerated nitrogen and phosphorus compounds could supply the amounts needed to maintain primary production during the summer period.Nutrient additions and zooplankton excretion products had little effect upon carbon fixation in the autumn samples, presumably because the higher nutrient levels then present in the water exceeded the requirements of the phytoplankton.It has been concluded that the predominance of the sub-10 μ microflagellates in the summertime is probably due to their ability to utilize more efficiently than the other types of phytoplankton the low levels of nutrients which become available due to regeneration.

Copper inhibition of carbon fixation in coastal phytoplankton assemblages

1980 ◽  
Vol 60 (4) ◽  
pp. 841-850 ◽  
Author(s):  
Anthony G. Davies ◽  
Jillian A. Sleep
Keyword(s):  
Primary Production ◽  
Metal Concentration ◽  
Water Samples ◽  
Metal Pollution ◽  
Carbon Fixation ◽  
Plant Cells ◽  
English Channel ◽  
Phytoplankton Assemblages ◽  
Effect Of Copper ◽  
Coastal Phytoplankton

The effect of copper upon carbon fixation in coastal phytoplankton assemblages has been studied in relation to both the metal concentration in the water and the levels taken up by the plant cells. The phytoplankton populations were those present in water samples collected from Station L4 in the English Channel in the late autumn of 1979. The lowest copper concentrations causing detectable inhibition of photosynthesis lay in the range 1–25 μg/1, well below the levels which have been reported to be present in some sea areas around the British Isles; metal pollution may thus be influencing primary production in these contaminated regions.

Inhibition of carbon fixation as a function of zinc uptake in natural phytoplankton assemblages

1979 ◽  
Vol 59 (4) ◽  
pp. 937-949 ◽  
Author(s):  
Anthony G. Davies ◽  
Jillian A. Sleep
Keyword(s):  
Carbon Fixation ◽  
Natural Populations ◽  
Plant Cells ◽  
Toxic Metal ◽  
Vitamin B ◽  
Phytoplankton Assemblages ◽  
Metal Contents ◽  
Rate Limiting ◽  
Natural Phytoplankton

There is now a substantial body of evidence that the growth rates of phytoplankton in culture are more closely related to the cellular levels of the rate-limiting constituent, be it a nutrient, micronutrient or toxic metal, than to the concentrations in the supporting medium; nitrate, Caperon (1968); phosphate, Fuhs (1969); silicate, Paasche (1973); vitamin B12, Droop (1968); iron, Davies (1970); mercury, Davies (1974); cadmium, Davies (1978a). This has suggested the requirement for a technique which would allow the determination of comparable relationships for natural populations of phytoplankton - how, for instance, their carbon fixation rates depend upon the metal contents of the plant cells. Although the effects of metals upon carbon fixation in phytoplankton assemblages from several different sea areas have already been examined (Knauer & Martin, 1972; Patin et al. 1974; Zingmark & Miller, 1975; Ibragim & Patin, 1976) no data seem to have been obtained on the levels of the metals present in the phytoplankton at the time of the measurements.

Hydrographic and nutrient chemistry surveys in the western English channel during 1963 and 1964

1972 ◽  
Vol 52 (4) ◽  
pp. 915-930 ◽  
Author(s):  
F. A. J. Armstrong ◽  
E. I. Butler ◽  
G. T. Boalch
Keyword(s):  
Suspended Matter ◽  
Low Temperatures ◽  
English Channel ◽  
Nitrogen And Phosphorus ◽  
Mean Values ◽  
Average Temperature ◽  
Significant Difference ◽  
Nutrient Chemistry ◽  
Phosphate Silicate ◽  
Made In

Three surveys were made in 1963 and five in 1964 in the area of the English Channel between the English and French coasts and between 3° 40' W and 5°10' W. This area had been surveyed in 1961 and 1962. Temperature and salinity were determined at o, to and 50 m and phosphate silicate and nitrate at 10 and 50 m. The results are presented graphically. Temperature and salinity were compared with Lumby's 25–year averages. The year 1963 started with unusually low temperatures and salinities higher than average. Temperature remained low in the spring, but salinity decreased. The year 1964 started with temperatures and salinities above normal, but during the rest of the year values were close to average. Nitrate in January 1964 was higher than in January 1963. Analyses of suspended matter at 12m were made for carbon, nitrogen and phosphorus on most surveys, and mean values for the whole area are given. Suspended carbon was 67 /ig C/l. in January 1963 and 51 /*g C/l. in January 1964, a significant difference. Increases in sus-pended carbon, nitrogen and phosphorus were found in spring and summer 1964.

scholarly journals WASTEWATER TREATMENT WITH BIOCONVERSION FOR MOTOR FUEL PRODUCTION

ScienceRise ◽  
2020 ◽  
pp. 66-72
Author(s):  
Sergii Shamanskyi ◽  
Sergii Boichenko ◽  
Lesia Pavliukh
Keyword(s):  
Wastewater Treatment ◽  
Culture Medium ◽  
Motor Fuel ◽  
Biofuel Production ◽  
Phosphorus Compounds ◽  
Biogenic Elements ◽  
Fuel Production ◽  
Nitrogen And Phosphorus ◽  
Phosphorous Compounds ◽  
Technological Product

The object of research: the process of wastewater treatment using bioconversion for subsequent motor fuel production. Investigated problem: improving the efficiency of bioconversion process for biofuel production with simultaneous wastewater treatment by removing nitrogen and phosphorous compounds. The main scientific results: providing the possibility of biofuel production with energy and economic inefficiency. It is done by combining the process of motor biofuel production with the process of treating wastewater from biogenic elements makes it perspective for commercial use. Traditional technology for the production of motor biofuels from microalgae includes cultivation, harvesting, dehydration and drying of biomass, extraction of oils from them and subsequent production of methyl esters and glycerol. Such technology is often not economically effective. It requires significant amount of energy for carrying out all necessary processes. In addition, it requires significant expenditures of water and nutrients. The use of nutrient-rich wastewater as a culture medium for the cultivation of microalgae allows not only to reduce costs, but also to purify wastewater from nitrogen and phosphorus compounds, which makes this process economically effective. The area of practical use of the research results: Sewage and gray water treatment plants. Industrial and agricultural effluents treatment plants. Different types of enterprises, which have wastewater enriched with nitrogen and phosphorous compounds. Innovative technological product: The technology of microalgae cultivation using wastewater as a culture medium. The technology allows effectively purifying used wastewaters from nitrogen and phosphorous compounds with no waste at the end. Scope of the innovative technological product: Improved technology of motor biofuel production with simultaneous wastewater purification, which is economically effective and environmentally safe.

scholarly journals Autosomal dominant polycythemia

Blood ◽  
1985 ◽  
Vol 66 (5) ◽  
pp. 1208-1214 ◽  
Author(s):  
JT Prchal ◽  
WM Crist ◽  
E Goldwasser ◽  
G Perrine ◽  
JF Prchal
Keyword(s):  
Autosomal Dominant ◽  
Oxygen Affinity ◽  
Colony Growth ◽  
Blood Oxygen ◽  
Autosomal Dominant Trait ◽  
Volume Measurements ◽  
Blood Oxygen Affinity ◽  
Low Levels ◽  
Stimulation Of

Two families with polycythemia inherited as an autosomal dominant trait are described. Serial hemoglobin determinations in multiple family members and RBC volume measurements in selected affected subjects documented their polycythemia. Measurements of arterial p02s, p50s, and blood oxygen affinity were normal in all affected individuals from each family who were tested. Erythropoietin (EPO) levels were low in affected individuals from family 1 and normal in affected members of family 2. Stimulation of in vitro CFU-E colony growth by low levels of EPO was significantly increased in subjects from family 1, but normal in those affected from family 2. We conclude that although the inheritance pattern for the polycythemia in both of these families appeared to be the same, the biologic defect leading to the disorder in each of these unique families was different. The precise mechanism of the increased EPO sensitivity noted in affected subjects from family 1 awaits elucidation.

scholarly journals Responses of soil microbial communities and enzyme activities to nitrogen and phosphorus additions in Chinese fir plantations of subtropical China

2015 ◽  
Vol 12 (13) ◽  
pp. 10359-10387 ◽  
Author(s):  
W. Y. Dong ◽  
X. Y. Zhang ◽  
X. Y. Liu ◽  
X. L. Fu ◽  
F. S. Chen ◽  
...  
Keyword(s):  
Microbial Community ◽  
Microbial Communities ◽  
Enzyme Activities ◽  
Microbial Community Composition ◽  
Soil Microbial Communities ◽  
Chinese Fir ◽  
Subtropical China ◽  
Nitrogen And Phosphorus ◽  
Soil Microbial ◽  
Nutrient Additions

Abstract. Nitrogen (N) and phosphorus (P) additions to forest ecosystems are known to influence various above-ground properties, such as plant productivity and composition, and below-ground properties, such as soil nutrient cycling. However, our understanding of how soil microbial communities and their functions respond to nutrient additions in subtropical plantations is still not complete. In this study, we added N and P to Chinese fir plantations in subtropical China to examine how nutrient additions influenced soil microbial community composition and enzyme activities. The results showed that most soil microbial properties were responsive to N and/or P additions, but responses often varied depending on the nutrient added and the quantity added. For instance, there were more than 30 % greater increases in the activities of β-Glucosidase (βG) and N-acetyl-β-D-glucosaminidase (NAG) in the treatments that received nutrient additions compared to the control plot, whereas acid phosphatase (aP) activity was always higher (57 and 71 %, respectively) in the P treatment. N and P additions greatly enhanced the PLFA abundanceespecially in the N2P treatment, the bacterial PLFAs (bacPLFAs), fungal PLFAs (funPLFAs) and actinomycic PLFAs (actPLFAs) were about 2.5, 3 and 4 times higher, respectively, than in the CK. Soil enzyme activities were noticeably higher in November than in July, mainly due to seasonal differences in soil moisture content (SMC). βG or NAG activities were significantly and positively correlated with microbial PLFAs. There were also significant relationships between gram-positive (G+) bacteria and all three soil enzymes. These findings indicate that G+ bacteria is the most important microbial community in C, N, and P transformations in Chinese fir plantations, and that βG and NAG would be useful tools for assessing the biogeochemical transformation and metabolic activity of soil microbes. We recommend combined additions of N and P fertilizer to promote soil fertility and microbial activity in this kind of plantation.

Interaction of ethylaluminum dichloride with organic nitrogen and phosphorus compounds in three-component polyolefin catalysts

1965 ◽  
Vol 3 (6) ◽  
pp. 2135-2147
Author(s):  
Richard L. McConnell ◽  
Marvin A. McCall ◽  
G. O. Cash ◽  
F. B. Joyner ◽  
H. W. Coover
Keyword(s):  
Organic Nitrogen ◽  
Phosphorus Compounds ◽  
Nitrogen And Phosphorus
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