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Bacterial communities in buffalo rumen were characterized using a culture-independent approach for a pooled sample of rumen fluid from 3 adult Surti buffaloes. Buffalo rumen is likely to include species of various bacterial phyla, so 16S rDNA sequences were amplified and cloned from the sample. A total of 191 clones were sequenced and similarities to known 16S rDNA sequences were examined. About 62.82% sequences (120 clones) had >90% similarity to the 16S rDNA database sequences. Furthermore, about 34.03% of the sequences (65 clones) were 85-89% similar to 16S rDNA database sequences. For the remaining 3.14%, the similarity was lower than 85%. Phylogenetic analyses were also used to infer the makeup of bacterial communities in the rumen of Surti buffalo. As a result, we distinguished 42 operational taxonomie units (OTUs) based on unique 16S r DNA sequences: 19 OTUs affiliated to an unidentified group (45.23% of total OTUs), 11 OTUs of the phylum Firmicutes, also known as the low G+C group (26.19%), 7 OTUs of the Cytophaga-Flexibacter-Bacteroides phylum (16.66%), 4 OTUs of Spirochaetes (9.52%), and 1 OTU of Actmobacteria (2.38%). These include 10 single-clone OTUs, so Good's coverage (94.76%) of 16S rRNA libraries indicated that sequences identified in the libraries represent the majority of bacterial diversity present in rumen.
Nowadays, genetically modified plants are cultivated in many countries and it is important to consider their safety for surrounding environment. So, the environmental risk assessments of genetically modified plants are evaluated. This assessment consists of an objective evaluation of risk and involves generating; collecting and assessing of information on a GM plant with the aim to determine its impact on human or animal health and the environment relative to non-genetically modified organisms. One of the numerous methods used to investigate the impact of GM plants on the environment is the Terminal Restriction Fragment Length Polymorphism. This method was used for comparison of genetic variation in populations of bacteria isolated from rhizosphere of genetically modified maize MON810 carrying the gene cry1Ab and genetically non-modified maize. Rhizosphere samples were collected in Slovakia during two years (2008, 2009) in July and September and 16S rRNA gene was amplified from metagenomic DNA using universal eubacterial primers. Differences in the number of terminal restriction fragments between control and GM maize hybrids were not detected. Additionally, variation within bacterial communities composition from rhizosphere of MON810 and non-GM hybrids was not observed, nevertheless negligible differences in composition of bacterial community were observed between two sampling periods (July and September). These changes were observed in non-GM as well as in GM maize hybrids and reflected effects of environment and conditions, no influence of genetic modification. The 16S rDNA clone library creation from rhizosphere sample of MON810 maize followed by DNA sequencing revealed that the Proteobacteria were major group of bacteria and Actinobacteria, Firmicutes, and Chloroflexi were less represented. This study did not confirm any changes in the soil ecosystem, which would have been larger than normal variations caused by external conditions.
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