A Comparative Study of the Dynamics and Diversity of and Like Organisms in Lakes Annecy and Geneva.

and like organisms (BALOs) are obligate bacterial predators of other Gram-negative bacteria. Here, we used quantitative PCR (qPCR) and recently developed specific primers which target the 16S rRNA gene to explore the abundance and distribution of three families of BALO belonging to the Oligoflexia class (i.e., , and over one year in the epilimnion and hypolimnion of Lakes Annecy and Geneva. was the dominant group at all sampling points except at the bottom of Lake Geneva, where was found in higher number. In addition, the abundance of BALOs increased significantly during the warmer months. Using high-throughput sequencing (Illumina Miseq), hundreds of OTUs were identified for and . Phylogenetic analysis suggests that are more diverse than and that some OTUs belong to new species of . We also found that dominant OTUs were present simultaneously in the two lakes, while some others were specific to each lake, suggesting an adaptive pattern. Finally, both abundance and diversity of BALOs were poorly associated with abiotic factors except temperature, suggesting the importance of studying biotic relationships, assumed to play a greater role than physico-chemical variables in BALOs' dynamics and distribution.