In:
Molecular Ecology, Wiley, Vol. 24, No. 6 ( 2015-03), p. 1236-1247
Abstract:
Studies on the active rare biosphere at the RNA level are mainly focused on Bacteria and Archaea and fail to include the protists, which are involved in the main biogeochemical cycles of the earth. In this study, the richness, composition and activity of the rare protistan biosphere were determined from a temporal survey of two lakes by pyrosequencing. In these ecosystems, the always rare OTU s represented 77.2% of the total OTU s and 76.6% of the phylogenetic diversity. From the various phylogenetic indices computed, the phylogenetic units ( PU s) constituted exclusively by always rare OTU s were discriminated from the other PU s. Therefore, the rare biosphere included mainly taxa that are distant from the reference databases compared to the dominant ones. In addition, the rarest OTU s represented 59.8% of the active biosphere depicted by r RNA and the activity (r RNA :r DNA ratio) increased with the rarity. The high r RNA :r DNA ratio determined in the rare fraction highlights that some protists were active at low abundances and contribute to ecosystem functioning. Interestingly, the always rare and active OTU s were characterized by seasonal changes in relation with the main environmental parameters measured. In conclusion, the rare eukaryotes represent an active, dynamic and overlooked fraction in the lacustrine ecosystems.
Type of Medium:
Online Resource
ISSN:
0962-1083
,
1365-294X
DOI:
10.1111/mec.2015.24.issue-6
Language:
English
Publisher:
Wiley
Publication Date:
2015
detail.hit.zdb_id:
2020749-9
detail.hit.zdb_id:
1126687-9
SSG:
12
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