Archaea in the microbial community of the reindeer rumen in the Russian Arctic

Larisa Ilina,Elena Yildirim,Kasim Layshev,Valentina Filippova,A Valiev,F Nezhmetdinova,A Taylan,R Nizamov,B Ziganshin

doi:10.1051/bioconf/20202700066

Abstract

Archaea is the least studied group of the reindeer rumen microbiocenosis. Although the functional load performed by this group of microorganisms in the rumen is large. Methane-forming archaea play a key role in the process of anaerobic decomposition of organic substances, the formation of methane. This study for the first time analyzed the composition of the archaeal part of the microbial community of the reindeer rumen using the T-RFLP method from various regions of the Russian Arctic. As a result, it was found that according to the estimates of the number of archaea by quantitative PCR in the reindeer rumen in the winter-spring period, on average, 108 genomes/g of archaea were observed in individuals of the Yamalo-Nenets Autonomous District, and 109 genomes/in animals from the Nenets Autonomous District Archean. Thus, in the winter-spring period, a lower number of archaea in the rumen was observed in the Yamalo-Nenets Autonomous District. According to the results of the T-RFLP method, 44 to 134 phylotypes were detected in the archaeal community of the reindeer rumen, the Shannon index was 2.02–3.80. The lowest content (up to 11.10 %) of methanogenic archaea of the Methanomicrobia class (including the families Methanosarcinaceae and Methanocorpusculaceae) was revealed in the Nenets Autonomous District, while their presence in individuals of the Yamalo-Nenets Autonomous District reached 36.33 %. Interestingly, in adults of the Yamalo-Nenets and Nenets Autonomous Districts, a significant decrease in the representation of methanogenic archaea of the Methanomicrobia class was noted by 1.38 (P <0.05) and 2.70 times (P <0.01), respectively, compared with young individuals (up to 2 years).

Highlights

Among all ruminants, reindeers are unique animals
In the archaeological community of the reindeer rumen using the T-RFLP method, from 44 to 134 phylotypes were detected depending on the sample; the Shannon index was 2.02–3.80
When analyzing the archaeal taxonomic affiliation, a significant number of sequences could not be identified up to the phyla level (57.30–96.03 %), which indicates the presence of absolutely unknown microorganisms in the rumen of reindeer, whose nucleotide sequences have no analogues with the described filaments

Summary

Introduction

They have adaptive devices that help them successfully survive in the Far North [1]. Ruminants are characterized by the presence of a rumen in their digestive system, an organ populated by a large number of microorganisms (bacteria, archaea, fungi, protozoa) that provide fiber digestion. This is a symbiosis that has formed over a long period of co-evolution. The diversity of microorganisms in the ruminant rumen reaches several thousand species, less than 100 of which have been studied in detail. Most of them are strictly anaerobic uncultivated species [2]

Methods

Results

Conclusion