It is not every day that an entire bacterial genus is discovered and reclassified. We are lucky when occasionally we find a new species, but that alone certainly does not redefine an entire genus. It took the sequencing and comparative analysis of eight new genomes, in addition to the three known genomes of heliobacteria, to come to this discovery.

Dayana Montano Salama, an undergraduate research student at BU, sequenced the Heliomicrobium genomes using the in-house Illumina MiniSeq.

The family of heliobacteria are a small group of phototropic bacteria that were serendipitously found while Dr. Howard Gest was teaching a lab class in microbiology some 38 years ago. It is therefore suiting that an undergraduate student, Dayana Montano Salama, was a key player in this new research that led to new genus of Heliomicrobium.

“A combination of genome sequencing, whole genome comparison and detailed genetic analysis of the 11 species was performed to reclassify them into the Heliobacterium and Heliomicrobium genera.” says Dr. John Kyndt, who was the lead on this research project. “In the end, the new genus Heliomicrobium includes four unique species, although more will undoubtedly be discovered in the future with growing metagenomic efforts.”

The new genus name comes from the Greek words helios sun; micros small; bios life, so Heliomicrobium literally means ‘sun microbe’. Heliobacteria have been recognized as the ancestors of photosynthesis in the evolution of photosynthetic bacteria. All heliobacteria are strictly anaerobic, endospore-forming bacteria, and the ability to form endospores is unlike all other phototrophic bacteria, but similar to species of Clostridium and Bacillus. An improved understanding of the taxonomic classification of these bacteria will ultimately lead to a better understanding of the evolution of photosynthesis in bacteria in general.

The research was an international collaboration with Dr. Johannes Imhoff from the GEOMAR institute in Germany, and was recently published in the International Journal of Systematic and Evolutionary Microbiology, which is the flagship scientific journal for bacterial taxonomy.

A link to the publication can be found here:  https://www.microbiologyresearch.org/content/journal/ijsem/10.1099/ijsem.0.004729