Search
Search Results
-
Comparison of the sample preparation methods worked out for the examination of the element content of wine
77-82Views:174The examination of the potentially toxic elements content of the wines is not easy task, because the most elements are in little concentration (mg kg-1 or μg kg-1) in the wine and the wines contain great amount of organic matrix. The efficient sample preparation is essential for the accurate determination of element content. The eim of our research was to determine which sample preparation method will be the most efficient in examination of wines with ICP technology. The examined wine sample was a 2008 Chardonnay from the Eger wine region. We did the sample preparation and analysis examination in University of Debrecen, Centre for Agricultural and Applied Economic Sciences, Institute of Food Science, Quality Assurance and Microbiology.
We did the analysis examinations with ICP- MS (inductively coupled plasma mass spectroscopy). We always did the sample preparations and the examinations in three times rehearsal. The applied sample preparation methods: dilution with distilled water, open digestion and microwave digestion.
We were able to measure B, Al, Mn, Fe and Zn with only dilution and open sample preparation. In the smaller quantity present Sr and Ba were measurable in the wine in the case of all three methods well. We were able to measure the Co with dilution and open digestion method, while Cr, Ni, and Te with only dilution method. In the case of arsenic we were not able to measure reliable result with dilution and open digestion method because of organic matrix and other components
(alcohols, monosaccharides, polysaccharides, polyalcohols and inorganic salts). On the whole we are able to say that in the case of certain elements (B, Mn, Fe, Zn, Sr, Ba) the open digestion and dilution sample preparation is applicable well, however, in the case of certain elements (As, Al, V, Cr, Se, Mo, Cd, Hg, Pb) we have to develop the methods. It may be development of one of the way, if we develop sample preparation methods to examined element specifically and not
to wine generally. -
The applicability of 10 ml cryotubes for sperm cryopreservation in a Hungarian carp landrace (Cyprinus carpio carpio morpha accuminatus)
93-97Views:245In our study, the comparison of 5 ml straw and 10 ml cryotube during sperm cryopreservation in a Hungarian carp landrace (Cyprinus carpio carpio morpha accuminatus) was carried out. Three different dilution ratios (1:1, 1:4 and 1:9) were also tested using the cryotube. A significantly higher pMOT was recorded using the cryotube in comparison with the straw. VCL and STR were similar in both groups. Cryopreservation had a negative effect on pMOT and VCl using the cryotube and also the straw where, STR was not reduced significantly. An increasing tendency was observed using higher dilution of sperm during cryopreservation; however, significant difference was not recorded between the three groups. VCL and STR were similar in all groups. Cryotube was applicable for the sperm cryopreservation of the Hungarian carp landrace. However, the standardization for the freezing method specified for this volume is recommended. The different dilution ratios needed be tested also during fertilization.
-
The effect of lead and copper heavy metal salts on soil microorganisms under laboratory circumstances
55-59Views:165he population dynamics of calcareous chernozem soils polluted with different concentrations of lead and copper heavy metal saline solutions was examined.
The experiment was carried out in the soil biological laboratory of the Institute of Agricultiral Chemistry and Soil Science at DE AGTC MÉK in 2012. For the determination of the concentration of the undiluted stock solutions we multiplied the smallest toxic concentration values of the MSZ 08-1721/1-86 Hungarian standard by forty. The intermediary concentrations of the treatments were produced with adequate dilution of the stock solutions until a dilution level equal to the values of the standard. The statistical evaluation of the data was performed with ANOVA (Analysis of Variance) including the determination of the standard deviation and significant difference. Investigating the effects of the different treatments on the soil microbes we established that both heavy metal saline solutions had a negative effect on the population dynamics of bacteria and microscopic fungi living in the soils. The negative effect of copper – as a potential toxic micro nutrient – turned out to be less strong than the negative effect of the toxic lead. According to our results the correction of the treatment levels is recommended in order to further tolerance examinations and the determination of the tolerance levels.
-
The effect of different herbicide on the number and activity of living microorganisms in soil
76-82Views:136Sustainable plant growth, considering the difficulties of weed elimination, cannot be effective without the application of herbicides. However, these chemicals have enormous ecological implications, including effects on the microbiological communities of soils. It is advisable to use herbicides that have minimal secondary effects on the environment and soil-living microorganisms. In contrast, herbicides with prolonged growth stimulating or inhibiting effects are not suitable, because both types have strong influences on the number and activity of bacteria, thus causing changes in the ecological equilibrium.
Preceding small plot experiments, laboratory tests were carried out to study the effect of herbicides used in maize cultures on the number of bacteria and growth of microscopic fungi.
Substances that were observed to have stronger influences were applied in small plot experiments set up in the experimental garden of the Department of Plant Protection of the University of Debrecen. We studied the effects of four herbicides (Acenit A88EC, Frontier 900 EC, Merlin SC and Wing EC) on the microbiological properties of the soil. These herbicides were used in different concentrations in maize culture, and we investigated the effects in different soil layers.
In the laboratory experiments, we determined the total number of bacteria and microscopic fungi and examined the growth of Aspergillus niger, Trichoderma sp. and Fusarium oxysporum on peptone-glucose agar containing herbicides.
During the small plot experiments, soil samples were collected 3 times a year from 2-20 cm depth. The total numbers of bacteria and microscopic fungi were determined by plate dilution method, while the method of most probable number (Pochon method) was used to determine the numbers of nitrifying bacteria and cellulose decomposing bacteria. To evaluate the microbiological activity of the soil samples we measured carbon-dioxide release (after 10 days incubation), nitrate production (after 14 days incubation) and the concentration of C and N in the biomass.
We can summarize our results as follows:
• In laboratory experiments, herbicides caused a decrease in the number of bacteria and inhibited the growth of microscopic fungi.
• Frontier 900 EC and Acenit A 880 EC had the strongest inhibiting effect on microorganisms.
• In small plot experiments, herbicide treatment decreased the total number of bacteria and microscopic fungi.
• Herbicides caused a significant increase in the number of nitrifying and cellulose decomposing bacteria.
• Different herbicides containing the same active compound had similar influences on soil microoorganisms.
• A significant increase was observed in the physiological processes of tolerant microorganisms surviving the effects of herbicides -
Utility of Winter Wheat According to Visual and Microbiological Fusarium Infection, as Well as Toxin Examination
26-34Views:105In 1998 the Fusarium infection was studied visually and microbiologically and also F-2, T-2, HT-2, DAS and DON contamination were measured using 22 winter wheat samples. The correlation between the different parameters of 22 wheat samples were determined by regression analysis. According to our results we can state the following.
There is no significant connection between the results of visual, microbiological and toxicological examinations. This means that no certain conclusion can be drawn about the toxin contamination of samples – which is a determining factor of its utility – based on the visual symptoms and the plate dilution method.
Our results indicate however – though it is not proven statistically – that those samples in which the Fusarium infection did not exceed the limit of the standard, also had low toxin contamination, therefore they can be used as components of forage.
It is a considerable problem, however, that according to the visual qualification, such samples are excluded from the later utilisation, wherein the toxin contamination does not justify such action. Therefore, it is necessary to examine the toxin content of those samples which show high infection by visual symptoms. To reducing the number of expensive toxin examinations it would be advisable to change the currently used 0,5% limit which is indicated in the standard for a higher value of infection, for example to 2%, as recommended by Mesterházy (1998). -
A tárolási feltételek hatása a kukorica Fusarium fertőzöttségére és toxin szennyezettségére
28-32Views:290Corn samples harvested in 1997, 1998 and 1999 from different soil types were stored at different conditions (temperature, moisture content, state of kernels) for six months. The Fusarium contamination was examined by plate dilution method and the amount of mycotoxins (F-2, T-2, HT-2, DON, DAS) were determined applying HPLC method immediately after harvesting and in the third and sixth month of storage. The aim of our study was to find correlation between the ecological factors, storage conditions and the examined parameters mentioned above, as well as to prove them statistically. According to the examinations carried out after harvesting we could state that the soil type had no effect on the parameters. Analysing the effect of the years we found considerable differences. The Fusarium infection of corn samples in 1998, while the toxin contamination in 1999 was the highest. The results of storage experiment show that year (number of microscopic fungi, F-2, T-2, HT-2, DAS and total toxin content) and moisture content of kernels (F-2, T-2, and total toxin content) have a significant effect on the examined parameters. We could prove the effect of temperature on the T-2 content (samples with natural moisture content) and DON content (samples with 14% moisture content). Higher values were found at higher temperature storage. The ratio of damaged kernels influenced the DON concentration in the non- wetted samples and the number of microscopic fungi in the wetted samples.
-
Experiments for Isolating and Culturing Soil-borne Mycobacteria (Contemporary Publication)
107-110Views:71On grounds of the several thousand tests performed in the field of this topic, the following conclusions may be arrived at:
1. The informations available and the experimental data on soil mycobacteria are very incomplete.
2. Of the 77 strains isolated from similar soil types so far, and adaptable for pure basic culture, 47 strains are confusingly similar, from morphological aspects, to the mycobacteria isolated from clinical material.
3. The apparently homogeneous cultures isolated from the soil are generally co-infected and, therefore, the morphological, biochemical, and other physiological characteristics of the isolated strains can be studied only on base cultures after purification.
4. For the isolation of the soil mycobacteria experiments qualified hitherto as most suitable processes the 4 or 1 per cent NaOH neutralized with H2SO4, and the 1 per cent NaOH or 1 per cent Na3PO4 treatments, on Gottsacker agar medium with plate or top pouring, at a temperature of 29 to 37 C°, in a soil suspension sequence of 1:500 to 1:5000 final dilution.
5. The Ziehl-Nielsen staining of the isolated mycobacteria composed to sub-cultures is best performed by heating with an infra red radiator from above, instead of the gas flame used so far to heat from below.
The repetition of the biochemical test of the hitherto isolated 77 purified strains is under progress, and will be reported on in our next scientific publication. -
The recent state of cryopreservation techniques for ex-situ gene conservation and breeding purposes in small ruminants: A review
81-87Views:319The viewpoint of the recent cryopreservation techniques (CT) suggests the use of a reduced volume of cryopreservation solution, high concentration of cryoprotectants and ultra-rapid cooling and warming rates help to reduce cryo-injury and maximize the viability of the preserved animal genetic resources (AnGR). The CT had now become widely accepted as one of the best methods of choice for the ex-situ conservation of AnGR due to its high success rate recorded and no-invasive nature as compared to the conventional slow rate freezing (CSRF). Rapid advances and wide acceptability of the use of assisted reproductive technologies (ART’s) particularly artificial insemination (AI) in animal breeding had resulted in a greater loss of a large number of good quality genes in virtually almost all the native breeds of animals across the globe. Small ruminant (SR) animals are not an exception in such present predicaments situation of erosion and dilution of the valuable AnGR among the native breeds. As a result of this, 148 and 16 breeds of sheep and goats respectively have already become extinct in Europe and the Caucasus. In view of the aforementioned situation, the present review aimed at exploring some of the current states of development, roles played and potentials of CT in the conservation of SR genes and genome for the immediate and future breeding purposes for sustainable development. It basically covers; animal genetic resource, the need to conserve AnGR, tools for ex situ in vitro conservation of AnGR and recent developments in breeding and cryopreservation of SR AnGR.
Cryopreservation is playing a pivotal role in ex-situ gene conservation of AnGR. Decline in genetic diversity among SR breed population was high in Europe and the Caucasus. There is therefore, need for improvent on current stringent measures on conservation of AnGR in this region of the world.