Analysis of Diversity of Reindeer Rumen Bacteria Involved in the Cellulose Decomposition. & Search and Isolation of Microorganisms from the Rangifer Tarandus Rumen Possessing Mycotoxin Biodegradation Potential and Cellulolytic Activity.
Ilina L., Filippova V., Yildirim E., Laishev K. Analysis of Diversity of Reindeer Rumen Bacteria Involved in the Cellulose Decomposition. // Advances in Social Science, Education and Humanities Research, volume 393. / The Fifth Technological Order: Prospects for the Development and Modernization of the Russian Agro-Industrial Sector. 2019. C 210-214.
Analysis of Diversity of Reindeer Rumen Bacteria Involved in the Cellulose Decomposition.
Publication Date 16 January 2020
ISBN 978-94-6252-886-4
Abstract—Bacteria involved in the cellulose decomposition are dominant in the community of microorganisms of the rumen of various ruminants, including reindeer. Reindeer (Rangifer tarandus) is a unique ruminant adapted to live in adverse conditions of meager diet of the Far North. As a result of the study, it was shown that the proportion of bacteria phyla of Firmicutes and Bacteroidetes, which includes the overwhelming majority of cellulolytic bacteria, comprised from 84.3% to 86.9% of the rumen bacterial community: not more than 4% of Proteobacteria; Cyanobacteria, Spirochaetes, Verrucomicrobia and Actinobacteria – not more than 5.6%, the rest – in a minor amount. Phylum Bacteroidetes was dominant among representatives of other phyla; their share ranged from 45.6% to 52.1%. The largest proportion of cellulolytic bacteria was detected in young deers at the age of 0.5 years (52.5%). Animals showed a tendency to decrease in the share of these bacteria with age. The smallest relative abundance of cellulolytic bacteria was detected in animals at the age of 9 years (44.7%). Bacteria of the genus Prevotella dominated among cellulolytic rumen bacteria. Bacteroides sp., Ruminococcus sp., Blautia sp., Clostridium sp., Butyrivibrio sp. and Paraprevotella sp. ranked next in relative abundance among rumen bacteria. Their share averaged from 3% to 6%. Our analysis showed the presence of two clusters uniting the microbial communities of the reindeer rumen into groups by the age characteristics. The first cluster included individuals under the age of 5 years, and the second group was older than 6 years. This is consistent with the data of biodiversity indices, which showed that bacterial diversity in the reindeer rumen increases with the age.
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Search and Isolation of Microorganisms from the Rangifer Tarandus Rumen Possessing Mycotoxin Biodegradation Potential and Cellulolytic Activity.
Abstract—Rumen content of the Rangifer tarandus is a promising source for the search for bacteria with high biological activity. Our objective was to screen isolates with high biological activity from the rumen content of reindeer in the Nenets and Yamalo-Nenets Autonomous Okrug of Russia. A total of 63 associations of microorganisms were investigated. Most of the studied associations showed the ability to decompose cellulose in the form of filter paper on the 3rd-6th day of incubation. 52 isolates demonstrated decomposition properties of carboxymethyl cellulose (according to data on the 3rd day of incubation). The results of the analysis of the cellulolytic activity of ten isolates that were selected as a result of screening according to the method of Henderson, Horvath and Block in the Churlis modification showed the level of cellulose decomposition from 4.0±0.34 to 62.0±4.1%. Four promising isolates selected at the next stage had the ability to biodegrade at least three mycotoxins. The highest level of biodegradation was observed for aflatoxins and reached 75.1±3.9%. The obtained experiments led to the conclusion that the isolates of microorganisms isolated from the reindeer rumen are capable of synthesizing cellulases and enzymes that biodegrade mycotoxins, which probably allows them to gain a competitive advantage in the rumen of a deer that consumes diets with an abundance of indigestible fiber and secondary metabolites with toxic properties. These strains are of undoubted interest for livestock (including dairy cattle and reindeer husbandry) with the aim of using them as environmentally friendly and safe probiotic feed additives.
Keywords—rangifer tarandus, rumen, mycotoxin biodegradation, cellulolytic microorganisms.