Physiological and genomic analyses of novel filamentous anoxygenic phototrophs using Type I photosynthetic reaction centers
Filamentous anoxygenic phototrophs (also called "green nonsulfur bacteria") belong to the Chloroflexota (formerly Chloroflexi) phylum and have remained cryptic in their evolutionary origins. Although phototrophic Chloroflexota members use a Type II photosynthetic reaction center, many members also contain chlorosomes, a light-harvesting apparatus only otherwise associated with Type I reaction center-containing phototrophs. Here we report the cultivation of 'Candidatus Chlorohelix allophototropha', a highly novel filamentous anoxygenic phototroph that contains a Type I reaction center and chlorosomes. 'Ca. Chx. allophototropha' represents the first cultured member of a novel order within the Chloroflexota phylum that we have provisionally named the 'Ca. Chloroheliales'. With the cultivation of 'Ca. Chx. allophototropha', the Chloroflexota now represents the only known microbial phylum where both known types of photosynthetic reaction center are utilized separately in members of the phylum.This BioProject contains raw metagenome sequencing reads (generated by the Illumina HiSeq platform with 2x125 base reads) from early enrichment cultures of both 'Ca. Chx. allophototropha' and a second related organism, 'Ca. Chloroheliales L227-5C', which was lost after the first subculture. This BioProject also contains read-cloud metagenome sequencing reads (generated by the Illumina MiSeq platform with 2x150 base reads) representing a later and more highly purified version of the 'Ca. Chx. allophototropha' culture. The read cloud sequencing library was prepared using the TELL-Seq WGS Library Prep Kit. High-completeness and low-contamination genome bins recovered from these metagenomes are also included in the BioProject. Note that only genome bins of the two 'Ca. Chloroheliales' members have been manually curated.