# Apolloniradiicaulis salifontis gen. nov., sp. nov., a New Prosthecate Aerobic Anoxygenic Phototroph Isolated from Lake Winnipegosis Region Salt Springs

## TL;DR

A new type of bacteria that uses light for energy was discovered in a salt spring in Canada and classified as a new species.

## Contribution

The discovery and classification of a new genus and species of aerobic anoxygenic phototrophic bacteria with unique photosynthetic features.

## Key findings

- The strain produces high amounts of bacteriochlorophyll a compared to carotenoids.
- The strain shows low genetic similarity to other Maricauaceae members.
- The new genus Apolloniradiicaulis is proposed based on distinct physiological and genomic traits.

## Abstract

A pink colored, rod-shaped, prosthecate, Gram-negative bacterial strain MS644T was discovered in saline spring water near Lake Winnipegosis, Manitoba, Canada. It produces bacteriochlorophyll a, which is incorporated into its reaction center and light harvesting I complex. Alongside no anaerobic or photoautotrophic growth, these features support its designation as an aerobic anoxygenic phototroph (AAP). Unlike most AAP, the photosynthetic apparatus is produced in significantly greater amounts compared to carotenoids. Sequence of the 16S rRNA gene identified relatedness to Glycocaulis albus (96.19%), Glycocaulis alkaliphilus (96.12%) and Glycocaulis abyssi (96.07%). The DNA G + C content was 66.01 mol %. Differences in salt tolerance and photosynthesis capability, alongside low average nucleotide identity, average amino acid identity and digital DNA-DNA hybridization compared to other Maricauaceae, support the designation of the strain as a representative of a new genus. Therefore, we propose that strain MS644T (=NCIMB 15625T = DSM 121292T) be classified as the type species of a new genus Apolloniradiicaulis in Maricaulaceae with the name A. salifontis gen. nov., sp. nov.