New phylotypes of mesophilic filamentous anoxygenic phototrophic bacteria enriched from sulfide‐containing environments

Abstract

Agar-based solid media with increasing concentrations of organic matter were used to isolate new members of the Chloroflexaceae (phylum Chloroflexi) from mesophilic environments containing sulfide. Inorganic media yielded less than 10% positive enrichments, which were not able to be maintained after repetitive inoculations in fresh medium. The use of casaminoacids and complex organic acid mixtures increased the number of positive enrichments (up to 45%) from both water and sediment samples. Two different green filamentous bacteria, SisoF2 and SalF, could be stably maintained as co-cultures for long periods and their phylogeny inferred from the analysis of complete sequences of the 16S rRNA gene. Ribotype SalF showed a high homology (95-98%) to previously isolated Oscillochloris trichoides strains. The 16S rRNA gene sequence retrieved from culture SisoF2 was largely divergent (< 92% similarity) from any sequence derived from either cultured representatives or environmental samples, suggesting that ribotype SisoF2 may constitute a new genus within the phylum. The presence of the new morphotypes in the environment from where they were enriched was analysed by high-resolution phylogenetic fingerprinting.

Short and direct science: Environmental Microbiology Reports

“…The paper presented by Bañeras and colleagues (2009) also represents a relevant milestone for the study of currently unculturable microbes. The article presents new ways to facilitate the culture of anoxygenic phototrophic bacteria, which is of particular importance when considering that our current knowledge of filamentous green bacteria is mainly derived from in situ ecophysiology in microbial mats (Klatt et al.…”

New phylotypes of mesophilic filamentous anoxygenic phototrophic bacteria enriched from sulfide‐containing environments

“…In the article ‘New phylotypes of mesophilic filamentous anoxygenic phototrophic bacteria enriched from sulfide‐containing environments’ (Bañeras et al ., 2009), the following error was published on page 91, under ‘Nucleotide sequence accession numbers’ (Results):…”