This observation is concordant with the parallel increment in specificity, and indicates that environmental selectivity manifests mainly at genus or species level. Focusing in families, Figure 2 illustrates their representation in the

diverse environments. It is apparent that most families can be found in many different environments, with only a few presenting a clear-cut specificity. According to the specificity criterion cited above, just 3 out of the 211 families (1.4%, see Figure 2) will be specific for environmental types: two Clostridia (Lachnospiraceae and Oscillospiraceae), SB-715992 research buy and the gamma-proteobacterial family Succinivibrionaceae, all of them specific for the gastro-intestinal tract of animals (Additional file 1, Table S1). These are strictly anaerobic chemoorganotrophs that are found in the rumen

of cattle, SAR302503 purchase sheep and other animals. The distribution of different species within these families can nevertheless be quite heterogeneous depending on the diet of the animal, according to the available carbon and energy sources [24]. When using the broader classification of environmental supertypes with the same criteria, we found specificity for 13 families (6.1%), mainly from thermal and host-associated habitats (Figure 2, and Additional file 1, Table S1). No specific families were found, however, when using the most detailed classification of environmental subtypes. Hence, we can say that under this criterion, specificity is a rare event in taxonomic families. If we relax Monoiodotyrosine the specificity criterion,

the number of putative specific families increases, but such criteria are probably too loose and inadequate for determining specificity. Figure 2 Distribution of individual taxonomic families in the different environment types. The phylogenetic tree shown in the inner circle was created by taking one representative sequence from each family, and was arbitrarily rooted in the branch separating bacteria from archaea. Families are coloured by its corresponding phyla, and only families with 10 or more observations have been considered. The bars in the outer circle indicate the number of times that each family has been observed in a sample from a particular environment. The bars marked with stars have been reduced to one third of their original size, for clarity purposes. This figure was done using iTOL server[42]. In contrast, cosmopolitanism seems to be more common for families, with their members well distributed in most environments. Two clear examples can be found in Pseudomonadaceae or Flavobacteriaceae. By defining a cosmopolitan family as having five or more observations in 90% of the environments, we found that 111, 23 and 4 families met these criteria for environmental supertypes, types and subtypes, respectively (Figure 2 and Additional file 1, Table S1). Therefore, for that taxonomic level, there is more likelihood of https://www.selleckchem.com/products/ABT-888.html finding instances of cosmopolitanism than of specificity.