摘要
This study explores the diversity and structure of prokaryotic communities (Archaea and Bacteria) of 2 tropical volcanic lakes (Nyos and Monoun) in Cameroon, using 16SrRNA sequences. Metagenomics analysis of sequences showed that most OTUs (Operational Taxonomic Units) were associated with 26 phyla (23 for Bacteria and 3 for Archaea) in Nyos and 36 phyla (33 for Bacteria and 3 for Archaea) in Monoun. In both lakes, Proteobacteria for Bacteria and Crenarchaea for Archaea were predominant and present at all depths but in different proportions. Bacterial community compositions were generally dominated by members of Proteobacteria, Firmicutes, Actinobacteria, Chloroflexi and Bacteroidetes covering about 98% of the sequences. Crenarchaea, Thaumarchaea and Euryarchaea were the three main phyla of Archaea common to both lakes. The amount of virus and total bacteria was determined by flow cytometry technic and the evaluated ratio ranged from 0.2 to 1.2 at Nyos and from 0.6 to 2.6 at Monoun. For both lakes, the correlation was very significant between viruses and total bacteria. The depth-dependent variability is discussed with chemical and physical environmental parameters. These could significantly influence virus-mediated bacterial lysis and abundance and vertical stratification of the prokaryotic community.
This study explores the diversity and structure of prokaryotic communities (Archaea and Bacteria) of 2 tropical volcanic lakes (Nyos and Monoun) in Cameroon, using 16SrRNA sequences. Metagenomics analysis of sequences showed that most OTUs (Operational Taxonomic Units) were associated with 26 phyla (23 for Bacteria and 3 for Archaea) in Nyos and 36 phyla (33 for Bacteria and 3 for Archaea) in Monoun. In both lakes, Proteobacteria for Bacteria and Crenarchaea for Archaea were predominant and present at all depths but in different proportions. Bacterial community compositions were generally dominated by members of Proteobacteria, Firmicutes, Actinobacteria, Chloroflexi and Bacteroidetes covering about 98% of the sequences. Crenarchaea, Thaumarchaea and Euryarchaea were the three main phyla of Archaea common to both lakes. The amount of virus and total bacteria was determined by flow cytometry technic and the evaluated ratio ranged from 0.2 to 1.2 at Nyos and from 0.6 to 2.6 at Monoun. For both lakes, the correlation was very significant between viruses and total bacteria. The depth-dependent variability is discussed with chemical and physical environmental parameters. These could significantly influence virus-mediated bacterial lysis and abundance and vertical stratification of the prokaryotic community.
作者
Paul-Alain Nana
Moïse Nola
Geneviève Bricheux
Zéphyrin Fokam
Pierre Ngassam
Dickson Achuo Enah
Jonathan Colombet
Agnès Vellet
Anne Mone
Viviane Ravet
Didier Debroas
Télesphore Sime-Ngando
Paul-Alain Nana;Moïse Nola;Geneviève Bricheux;Zéphyrin Fokam;Pierre Ngassam;Dickson Achuo Enah;Jonathan Colombet;Agnès Vellet;Anne Mone;Viviane Ravet;Didier Debroas;Télesphore Sime-Ngando(Department of Oceanography, Institute of Fisheries and Aquatic Sciences, University of Douala, Douala, Cameroon;Laboratory of Hydrobiology and Environment, Faculty of Science, University of Yaoundé I, Yaoundé, Cameroon;Laboratory Microorganisms: Genome and Environment, UMR CNRS 6023, Clermont Auvergne University, Clermont-Ferrand, France;Department of Biology, Higher Teacher Training College, University of Bamenda, Bamenda, Cameroon)
