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261.
A total of 8579 Salmonella strains received during 1973–1982 were tested for their antibiogram patterns against nine routinely used antibiotics including gentamicin. Of these, 380 strains (4.4%) showed resistance to gentamicin at levels of 10 g/ml and above. A high degree of resistance to gentamicin was recorded in 1979 (18.7%) and 1980 (9.4%). M.I.C. levels of strains received during 1982 were determined and it was found that some strains had levels as high as 160 g/ml. The comparative results of gentamicin resistance from 1973 to 1982 are presented and the public health significance of the alarming increase in two years (1979–1980) is discussed. 相似文献
262.
Identification of active-site residues of sheep liver serine hydroxymethyltransferase. 总被引:1,自引:1,他引:0
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Chemical modification of amino acid residues with phenylglyoxal, N-ethylmaleimide and diethyl pyrocarbonate indicated that at least one residue each of arginine, cysteine and histidine were essential for the activity of sheep liver serine hydroxymethyltransferase. The second-order rate constants for inactivation were calculated to be 0.016 mM-1 X min-1 for phenylglyoxal, 0.52 mM-1 X min-1 for N-ethylmaleimide and 0.06 mM-1 X min-1 for diethyl pyrocarbonate. Different rates of modification of these residues in the presence and in the absence of substrates and the cofactor pyridoxal 5'-phosphate as well as the spectra of the modified protein suggested that these residues might occur at the active site of the enzyme. 相似文献
263.
S. V. Rao B. G. S. Rao 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1984,67(5):419-426
Summary Cytogenetic studies involving six species of spinous Solanums have been made using the parameters of crossability/fertility relationships and chromosome pairing in parental and derived hybrid genomes. These studies have made it possible to integrate hybrid reproductive performance with observed cytological phenomena and draw inferences on concerned intergenomic homeologies. It has been found that species' differences, as they exist, are ascribable to chromosome repatterning, in their divergence and maintenance as distinct taxa. In the light of these studies, the grouping of these species has to be reconsidered. 相似文献
264.
Summary A field experiment on N turnover in rotations of groundnut, sorghum and pigeonpea crops was conducted in an Indian Alfisol during 1978–80.15N-labelled urea N was applied @ 40 kg ha–1 in 1978. In the first year, the groundnut utilized 19.5% of the applied labelled N, sorghum 25.5%, and pigeon pea 10.3%. More fertilizer N was removed through weeding than by crop uptake in sorghum and pigeon pea. The fertilizer N left behind in soil upto 40 cm depth was 44.4% in groundnut plots, 35.1% in sorghum plots and 40.1% in pigeon pea plots.The uptake in 1979 of the residual fertilizer N in the soil was 8.9% in sorghum, 8.3% in groundnut and 2.8% in pigeon pea. In 1980, it declined to less than 2% for pigeon pea and groundnut and to about 4% for sorghum.A balance sheet drawn at the end of each rotation showed that about 51.3% of the applied labelled N was accounted for in groundnut-sorghum-pigeon pea rotation, 70.9% in sorghumpigeon pea-groundnut, and 43.5% in pigeon pea-groundnut-sorghum. 相似文献
265.
Summary In a greenhouse study the influence of alternate flooded and nonflooded conditions on the N2-ase activity of rice rhizosphere soil was investigated by C2H2 reduction assay. The soil fraction attached to roots represent the rhizosphere soil. Soil submergence always accelerated N2-ase and this effect was more pronounced in planted system. Moreover, rice plant exhibited phase-dependent N2-ase with a maximum activity at 60 days after transplanting. The alternate flooded and nonflooded regimes resulted in alterations of the N2-ase activity. Thus, the N2-ase activity increased following a shift from nonflooded to flooded conditions, but the activity decreased when the flooded soil was returned to nonflooded condition by draining. However, the differential influence of the water regime on N2-ase was not marked in prolonged flooded-nonflooded cycles. Microbial analysis indicated the stimulation of different groups of free-living and associative N2-fixing microorganisms depending on the water regime. 相似文献
266.
Summary Elevating the pH of two extremely acid tropical soils from an initial pH of 4 to 5 with Ca(OH)2 and NaOH solutions resulted in a sharp decrease in urea adsorption. Further increases in pH to 9 caused only slight further decrease in urea adsorption. Ca treatment resulted in slightly higher adsorption than Na treatment over the full range of pH values studied for a clay soil with high smectite content, and for a loam with kaolinite mineralogy below pH 7. Above pH 7 a kaolinitic loamy soil gave slightly higher adsorption with Na treatment than with Ca. 相似文献
267.
Summary Relative efficiency of Hup+ and Hup–
R. japonicum strains with Pusa 16 cultivar of soybean was studied. Inoculation with the Hup+ strain (A 1014) reduced the protein content in grain as compared to uninoculated control. 相似文献
268.
269.
Transmission Studies with Cucumber Green Mottle Mosaic Virus 总被引:2,自引:0,他引:2
Cucumber green mottle mosaic virus may spread in bottlegourd under field conditions through soil contaminated with infected plant debris followed by contact. No seed transmission was noticed in bottlegourd (Lagenaria siceraria) or vegetable marrow (Cucurbita pepo) although pollen grains and cotyledons from infected bottlegourd flowers or seeds, respectively, contained negliginle amounts of virus. Cucumber leaf beerles (Raphidopalpa fevicollis) are probable vectors since their regurgitated fluid and excretes contained infective virus particles. No vector fungi were found in the soil around infected bottlegourd plants. 相似文献
270.
Tween-80 supplementation in submerged culture ofAspergillus fumigatus resulted in an increase of phosphate uptake. The uptake system was characterized as saturable, energy-dependent and operating
against the concentration gradient. Control and Tween 80 cultures showed similarK
m
values for phosphate uptake (50 μm). Cold osmotic shock treatment of the cultures was found to cause considerable reduction
in the ability to take up phosphorus with concomitant release of the binding protein into the shock fluid. Binding protein
preparation from Tween-80 supplemented cells showed more activity than that from control cells. 相似文献