The transfer of POPs in food of animal origin has been studied by a meta-analysis of 28 peer-reviewed articles using transfer rate (TR) for milk and eggs and bioconcentration factors (BCF) for eligible tissues after establishing an adapted methodology. TRs of the most toxic PCDD/Fs into milk were generally elevated and even higher into eggs. BCFs in excreting adult animals varied widely between studies complicating to hierarchize tissues or congeners, even if liver and fat seemed to bioconcentrate more than lean tissues. Short time studies have clearly shown low BCFs contrarily to field studies showing the highest BCFs. The BCFs of PCDD/Fs in growing animals were higher in liver than in fat or muscle. In contrast to easily bioconcentrating hexachlorinated congeners, octa-and heptachlorinated congeners barely bioconcentrate. PCB transfer into milk and eggs was systematically high for very lipophilic congeners. Highly ortho-chlorinated PCBs were transferred >50% into milk and eggs and even >70% for congeners 123 and 167 into eggs. BCFs of the most toxic PCBs 126 and 169 were significantly higher than for less toxic congeners. BCFs seem generally low in PBDEs except congeners 47, 153 and 154. DDT and its metabolites showed high bioconcentration. Differences between tissues appeared but were masked by a study effect. In addition to some methodologic recommendations, this analysis showed the high transfer of POPs into eggs, milk and liver when animals were exposed justifying a strong monitoring in areas with POP exposure.
In Kazakhstan where Bactrian camel, dromedary camel and their hybrids are cohabiting within same farms, the consumption of camel milk is very popular because its medicinal and dietary properties. This milk is consumed under fermented form, called shubat. Shubat is still very often made on a small scale in the steppe with a fermentation step driven by wild bacteria. Camel milk and shubat were sampled from 4 regions with high number of camel population. As the whole, 26 samples were obtained from 13 selected farms representing the variability of the farming system. Isolated LAB strains were identified by method of a polymorphism determination of 16S ribosome DNA. PCR with using two different pairs of amorces (338f/518r; W001/23S1) was done. Majority of microflora were cocci in a both milk products. Yeast biodiversity in shubat was studied by using denaturing gradient gel electrophoresis (DGGE). Target DNA bands were identified according to the reference species scoring. Comigrating bands present in the DGGE profiles were resolved by species-specific PCR. The dominant yeasts in both products included Kazakhstania unispora, Saccharomyces cerevisiae and Kluyveromyces marxianus. Frequently isolated yeast species were Dekkera bruxellensis and more rarely Galactomyces geotrichum. The results of microflora identification in these products provide a theoretical foundation for developing starter cultures.
The effectiveness of the fermented milk product for decreasing the absorption of Lead (Pb) in vivo by testing several combinations of different strains and individual strains of LAB isolated from camel milk and shubat (fermented camel milk) was determined. During 4 weeks 0.5 ppm of Pb was given to cavies in fermented milk product and water. Control group and groups treated only by fermented milk products, also, were observed. Faeces, Blood, Heart, Lungs, Liver, Kidneys, and Spleen were analyzed. The lead concentrations in faeces of Control group and lead nitrate treated group were nearly the same. The quantity of Pb in faeces of fermented milk treated groups was higher than in Control and Water Pb groups. In the different cavies' organs of Water Pb group, the higher concentration of heavy metal (ppm) was observed in spleen (1.04), heart (0.65), kidneys (0.58), and blood (0.46) to be compared to 0.82, 0.2, 0.58 and 0.31 respectively in control group. In groups treated with fermented milk without/with Pb, the lead concentration decreased in target organs. Quantity of lead in blood samples of Control group and groups treated fermented milk products without/with Pb is nearly same. Highest concentration of blood Pb was observed for Water Pb group.
The environmental situation concerning pollution by (eco)toxic and persistent trace elements in Kazakhstan has been investigated by analytical reviews of scientific studies published over the past 20 years reporting concentrations of 10 toxic trace elements (TTE) observed in soil, sediments or surface water. A database of 62 articles published in Kazakh, Russian or English covered the majority of the territory of the country for soil and water samples but to a lesser extent for sediments. Reported concentrations were summarized using statistical parameters, then spatialized and finally classified in contamination classes according to local legislation. This analysis revealed some hotspots of TTE in surface waters (Cd and Pb), soil (As) and sediments (Cd and As). Hotspots of less toxic Cu, Zn and Mn were also detected. Spatialization of results allowed localization of these hotspots close to industrial sites, such as smelters or mining and metallurgic combines. Others have been shown to be close to disused mining sites or landfills with municipal waste. Methodological improvements for further studies have been suggested, such as to integrate more West Kazakhstan or remote areas in sampling campaigns, but also to describe more exhaustively the used analytical methods and to be more attentive to the speciation of the analyzed form of the element. Finally, a management strategy to strengthen a sustainable food policy has been proposed: to reduce emissions by modernization of industrial facilities and better waste management, to organize land use depending on the contamination levels and to reduce the bioavailability of the toxic elements.
Shubat and Koumiss are traditional fermented products widely consumed in Kazakhstan and Central Asia. Microflora of those fermented products is composed of bacteria and yeasts, which could have deep impacts on beverages quality. Although, the known presence of yeast in such fermented foods, few studies on yeast microflora of Shubat and Koumiss were available. The aim of the study was to identify the main indigenous yeasts in these traditional beverages and additionally, the differences between these 2 types of fermented products. Five samples of fresh and fermented camel and mare's milk from tank were collected in 5 different farms, located in South of Kazakhstan. Farms were selected because of their importance of production of fermented milk at the regional level and the reputation of these products among the consumers. Yeast biodiversity in Shubat and Koumiss was studied using denaturing gradient gel electrophoresis (DGGE). Target DNA bands were identified according to the reference species ladder, constructed in this study. Co-migrating bands present in the DGGE profiles were resolved by species-specific PCR. Galactomyces geotrichum, Kluyveromyces marxianus, Kazachstania unispora, Saccharomyces cerevisiae, Dekkera anomala, Dekkera bruxellensis yeast were identified. Some yeasts were not identified by used primers. In all samples of Shubat and Koumiss the dominant yeast species were Kazakhstania unispora, Kluyveromyces marxianu. Other species were not present in all samples. (Résumé d'auteur
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