A new niche for anoxygenic phototrophs as endoliths.

A new niche for anoxygenic phototrophs as endoliths. Appl Environ Microbiol. 2017 Dec 08;: Authors: Roush D, Couradeau E, Guida B, Neuer S, Garcia-Pichel F Abstract Anoxygenic phototrophic bacteria (APBs) occur in a wide range of aquatic habitats, from hot springs to freshwater lakes and intertidal microbial mats. Here we report the discovery of a novel niche for APBs: endoliths within marine littoral carbonates. In a study of 40 locations around Isla de Mona, Puerto Rico, and Menorca, Spain, 16S rRNA high-throughput sequencing of endolithic community DNA revealed the presence of abundant phylotypes potentially belonging to well-known APB clades. An ad hoc phylogenetic classification of these sequences allowed us to refine the assignments more stringently. Even then, all locations contained such putative APBs, often reaching a significant proportion of all phototrophic sequences. In fact, in some 20% of samples, their contribution exceeded that of oxygenic phototrophs, previously regarded as the major type of endolithic microbe in carbonates. The communities contained representatives of APBs in the Chloroflexales, various Proteobacterial groups, and Chlorobi. The most abundant phylotypes varied with geography: on Isla de Mona, Roseiflexus and Chlorothrix-related phylotypes dominated, whereas those related to Erythrobacter were the most common in Menorca. The presence of active populations of APBs was corroborated through an analysis ...
Source: Applied and Environmental Microbiology - Category: Microbiology Authors: Tags: Appl Environ Microbiol Source Type: research