The Phosphorus-containing Fractions of Sterile Lingcod Muscle During Storage at 0 °C

1960 ◽  
Vol 17 (3) ◽  
pp. 371-376 ◽  
Author(s):  
Neil Tomlinson ◽  
Vera M. Creelman ◽  
K. G. Reid

During refrigerator storage of sterile lingcod muscle for up to 3 weeks at 0 °C no significant changes occurred in the P content of the phospholipid, ribonucleic acid, or deoxyribonucleic acid fractions, but in the acid-soluble fraction the portion of total P accounted for by inorganic P increased to 96% from 75%. The P-containing fractions from the fish held in ice for the same period did not differ appreciably from those of the sterile muscle. An aqueous extract of lingcod muscle was shown to be able to form orthophosphate from a variety of phosphorylated compounds.

1985 ◽  
Vol 65 (3) ◽  
pp. 467-473 ◽  
Author(s):  
V. K. BHATNAGAR ◽  
M. H. MILLER

A series of laboratory experiments was conducted to determine the mechanism(s) responsible for a previously reported observation that addition of liquid manure to soil increased the NaHCO3-extractable P (Ext-P) of large aggregates (> 2 mm) more than that of smaller aggregates whereas addition of an inorganic P solution did not. Application of liquid poultry manure increased the total P, Ext-P and total C concentrations in large aggregates (> 2 mm) much more (> 2.5 ×) than that in small aggregates (< 1 mm). Addition of inorganic P solution or of supernatant liquid from a centrifuged manure slurry increased the P content of the large aggregates only slightly (1.2 ×). A greater increase in Ext-P in large aggregates was observed even when the smaller aggregates were purposely layered on top of the larger ones prior to addition of the liquid manure. A similar but less pronounced effect of aggregate size on increase in P or C concentration was observed when different sized aggregates were left in contact with an effectively infinite source of liquid manure for 24 h. It is concluded that the larger aggregates absorbed more of the bulk manure slurry than smaller aggregates. A partial sealing of small aggregates by particulates is suggested as a possible mechanism. Key words: Carbon, phosphorus, liquid manure, soil aggregates


1957 ◽  
Vol 35 (1) ◽  
pp. 721-728 ◽  
Author(s):  
R. Daoust ◽  
Catherine E. Stevens Hooper

The DNA phosphorus fraction of tissues was isolated by the method of Schmidt and Thannhauser modified so that the DNA phosphorus fraction attains a state of purity satisfactory for studies with radiophosphorus. This procedure was submitted to a series of test experiments. The results suggested that the DNA isolated by the procedure is practically free from contamination by other phosphorus-containing fractions, namely acid-soluble phosphorus, phospholipids, ribonucleic acid, and phosphoproteins. The modified method seems reliable for estimating the specific activity of DNA phosphorus following the administration of radiophosphorus to animals.


1957 ◽  
Vol 35 (9) ◽  
pp. 721-728 ◽  
Author(s):  
R. Daoust ◽  
Catherine E. Stevens Hooper

The DNA phosphorus fraction of tissues was isolated by the method of Schmidt and Thannhauser modified so that the DNA phosphorus fraction attains a state of purity satisfactory for studies with radiophosphorus. This procedure was submitted to a series of test experiments. The results suggested that the DNA isolated by the procedure is practically free from contamination by other phosphorus-containing fractions, namely acid-soluble phosphorus, phospholipids, ribonucleic acid, and phosphoproteins. The modified method seems reliable for estimating the specific activity of DNA phosphorus following the administration of radiophosphorus to animals.


1956 ◽  
Vol 28 (1) ◽  
pp. 142-167
Author(s):  
Armi Kaila

In the present paper the total and organic P content of virgin peat soils is studied on the basis of 217 peat samples mostly collected from Northern Finland and consisting of 32 Sp, 34 CSp, 62 SCp, 12 EuSCp, 36 BCp, and 41 Cp samples. The material was found to be satisfactorily typical for a study of Finnish peat soils as to the pH, ash and N contents. Only the BCp samples were, in some respect, of a poorer quality than in general. The total P content of the 217 samples ranged from 190 to 2350 ppm or from 30 to 2440 kg/ha. In the Sp and BCp groups the mean P content was equal, 580 ± 80 ppm and 560 ± 90 ppm resp., and significantly lower than the corresponding value in all the other groups which was 950 ±120 ppm in the Cp-group, 980 ± 290 in the EuSCp-group, 800 ± 60 in the SCp-group, and 800 ± 120 ppm in the CSp-group. A low but significant correlation was found to exist between the degree of land quality estimated on the basis of the surface vegetation and the P content of the surface samples: r = 0.361***. When the BCp samples were excluded an even closer correlation was detected: r = 0.481***. The correlation coefficient between the total P content and the degree of humification was r = 0.317***, that between the total P and the ash contents r = 0.289**, and that between the total P and N contents r = 0.206*. The organic P content of the 217 samples ranged from 130 to 1950 ppm with an average of 600 ± 40 ppm. The Sp and BCp groups showed significantly lower means, 430 ± 60 ppm and 440 ±7O ppm resp., than the other groups with averages of 630 ± 120 ppm in the CSp-group, 620 ± 50 ppm in the SCp-group, 770 ± 100 ppm in the Cp-group and 820 ± 280 in the EuSCp-group. The organic P content was very closely correlated with the total P content; the total correlation coefficient was r = 0.934***. The connection with the degree of humification was not distinct: the total correlation coefficient was r = 0.336***, but the partial correlation coefficient after the elimination of the effects of total P and N contents was only r = 0.136. No significant correlation existed between the organic P content and the N content, r = 0.184. The organic P content of the 217 samples expressed as a percentage of the total P content ranged from 55 to 95 per cent with an average of 78 ± 1 per cent. The proportion of organic P of total P was correlated with the degree of humification, the total correlation coefficient was r = 0.504***, the partial correlation coefficient after the elimination of the effect of the sampling depth was r = 0.427***. No correlation with the sampling depth existed after the elimination of the effect of the degree of humification: the partial correlation coefficient was r = 0.159, whereas the total correlation coefficient was r = 0.334***. A low correlation existed between the percentage of organic P of total P and the pH value even after the elimination of the effect of the degree of humification, r = 0.228*, but the connection with the total P content appeared to be only indirect and arised from the effect of the degree of humification, the total correlation coefficient was r = 0.222*, the partial correlation coefficient r = 0.076. The amount of organic P expressed as a percentage of the organic dry matter ranged from 0.01 to 0.25 per cent with an average of 0.07 ± 0.004. The ratio of N/org.P ranged from 12 to 133 with an average of 45 ± 3. Owing to the low P content of the BCp-group its mean ratio was significantly higher than that of the other groups. The degree of humification did not show any correlation with the ratio of N/org.P. The solubility of inorganic P in 0.5 N acetic acid and in 0.2 N sulphuric acid was highest in the Sp-group. On the average approximately from 15 to 30 per cent of total inorganic P was extracted by the latter solution. The acetic acid extracted only about 2 per cent of the inorganic P in the Cp-group but about 15 per cent in the Sp-group. The phosphorus conditions in virgin peat soils was discussed and it was attempted to explain the results obtained on the basis of the supposition that phosphorus is a minimum factor in the metabolism of peat.


1999 ◽  
Vol 39 (12) ◽  
pp. 63-67 ◽  
Author(s):  
B. L. Turner ◽  
P. M. Haygarth

Phosphorus (P) transfer from agricultural land to surface waters can contribute to eutrophication, excess algal growth and associated water quality problems. Grasslands have a high potential for P transfer, as they receive P inputs as mineral fertiliser and concentrates cycled through livestock manures. The transfer of P can occur through surface and subsurface pathways, although the capacity of most soils to fix inorganic P has meant that subsurface P transfer by leaching mechanisms has often been perceived as negligible. We investigated this using large-scale monolith lysimeters (135 cm deep, 80 cm diameter) to monitor leachate P under four grassland soil types. Leachate was collected during the 1997–98 drainage year and analysed for a range of P fractions. Mean concentrations of total P routinely exceeded 100 μg l−1 from all soil types and, therefore, exceeded P concentrations above which eutrophication and algal growth can occur. The majority of the leachate P was in algal-available Mo-reactive (inorganic) forms, although a large proportion occurred in unreactive (organic) forms. We suggest that subsurface transfer by leaching can represent a significant mechanism for agricultural P transfer from some soils and must be given greater consideration as a potential source of diffuse P pollution to surface waters.


1966 ◽  
Vol 241 (12) ◽  
pp. 2933-2943 ◽  
Author(s):  
Abraham Novogrodsky ◽  
Moshe Tal ◽  
Abraham Traub ◽  
Jerard Hurwitz

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