A new study in Nature Biotechnology published by a team at the University of Queensland in Australia reports an updated version of the phylogenetic tree for microbial species.
Using recent metagenomic data published by teams around the world, the Australian group said it was able to make changes to the taxonomy of 58 percent of the 94,759 genomes comprising the Genome Taxonomy Database.
The study was led by Professor Philip Hugenholtz from UQ's School of Chemistry and Molecular Biosciences and the Australian Centre for Ecogenomics. In a press release, Hugenholtz says the scientific community generally agrees that evolutionary relationships are the most natural way to classify organisms, but that bacterial taxonomy is full of errors.
"This is mainly because microbial species have very few distinctive physical features, meaning that there are thousands of historically misclassified species," he adds. "It's also compounded by the fact that we can't yet grow the great majority of microorganisms in the laboratory, so have been unaware of them until quite recently."
The team used newly published bacterial genomes -- specifically looking at 120 genes that are highly conserved across the bacterial domain -- to construct an evolutionary tree and create a standardized model that reclassified many previously misclassified microbes and made evolutionary timelines between bacterial groups more consistent, according to the press release.
"For example, the genus Clostridium has been a dumping ground for rod-shaped bacteria that produce spores inside their cells, so we reclassified this group into 121 separate genus groups across 29 different families," researcher Donovan Parks says in the statement. "We've given bacterial classification a complete makeover."