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The aim of the study was to present antibacterial properties of bacteria found in sugar beet silage against Shigella. The experiment involved bullocks, from which the pathogenic bacteria were isolated, and microorganisms obtained from silage (without additives). It was found that pathogenic bacteria are inhibited by bacteria present in the silage. Experimental subjects included 10 bullocks (crosses of Limousine with Black and White Lowland (BWL) of 700 kg mean body weight. Silage was prepared from sugar beet leaves contaminated with soil. Plant material was ensiled in 6 PCV containers (barrels) of 200 dm3 in volume closed with a cover allowing the release of gaseous products. The ensiling process lasted 120 days. Samples for chemical and microbiological analyses were collected from three barrel depths (15, 30 and 45 cm) and were subsequently pooled to make a representative sample of 0.9 kg weight. The basic composition of the silage was determined in accordance with AOAC. The strain antagonistic to Shigella was identified by the molecular method: after isolating bacterial DNA, a PCR reaction was performed. The PCR analysis and the DNA sequence analysis showed that the organism which naturally occurs in sugar beet leaf silage and exhibits antagonistic properties to Shigella bacteria was Bacillus subtilis. Shigella spp., a pathogenic microorganism that is of particular concern to humans, was found in the mouth of cattle.
The presented investigations were conducted on a group of 60 porkers of crossbreed Polish Landrace x Large White Polish. The animals were divided into two equal experimental groups. The control group (K) was fed diets without supplementation with probiotics, group (P) - diets with the addition of probiotic (0.2 kg t⁻¹ feed). The aim of the study was to determine the effect of probiotic preparation on total numberof lactic acid rods from the Lactobacillus genus and those forming hydrogen oxide. The second part of experiment concerned the influence of probiotic preparation on the number, haemolytic ability and changes in drug resistance of Escherichia coli isolated from animal faeces. The significantly highest number of Lactobacillus sp. were determined in the saliva of porkers fed diets with the addition of probiotic, while the lowest in the control group. Lactobacillus sp. rods capable of forming hydrogen peroxide were isolated from 17 animals in group K and from three animals in group P. E. coli was determined in each examined sample of faeces. In groups K and P, counts of these bacteria were similar and did not differ statistically. High numbers of haemolytic isolates (haemolysis ß) were found in faeces of animals fed diets with the addition of probiotic. Number and proportions of resistant isolates in groups K and P were different. Gentamicin was characterised by exceptionally high in vitro effectiveness. The used probiotic increased drug resistance of E. coli and increased frequency of incidence of haemolysis ß.
As reported in the paper by Grzebisz et al. (this issue), maize crop treated foliarly with fertilizer zinc at early stages of growth produced significantly high yields. Growth analysis procedures were applied to explain various effects of fertilizer zinc on grain yield increase and zinc accumulation and redistribution among maize organs in the course of the growing season. Therefore, based on the obtained zinc uptake characteristics, two major and one minor, but time-separated hot spots of zinc accumulation by maize plants have been distinguished. The first one, as described by RUR-Zn data, extended from the BBCH7 to BBCH9 stages. The second one, as expressed by CUR-Zn data, appeared during the milk stage of kernels growth and could be decisive for kernels sink capacity for accumulating carbohydrates. A minor hot spot, which occurred at tasselling may be responsible for pollen production and activity. The first zinc hot spot has also revealed the diagnostic problem of soil and plant tests for zinc. Current tests tend to overestimate plant zinc nutritional status, and therefore need to be urgently revised. Vegetative organs such as leaves and stems were only the minor sources of zinc for developing maize kernels. During grain filling period, most zinc absorbed by maize plants originated from soil resources.
Transcription is the main step in the regulation of gene expression. To study this process in vitro, it is necessary to obtain highly purified RNA polymerases. Here, we describe a method of RNA polymerase purification using a Mono Q FPLC column. Using Mono Q column chromatography accelerates the purification process and separates RNA polymerase II from RNA polymerase III with good yield.
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