Researchers submit recommendations for revised Lactobacillus taxonomy

By Mary Ellen Sanders PhD, Executive Science Officer, ISAPP

A team of researchers has submitted their recommendations for new classification for the heterogeneous group of species currently considered to belong to the genus Lactobacillus. The paper is under review by the International Journal of Systematic and Evolutionary Microbiology, the premier journal for bacterial taxonomy.

Three research teams that were independently working on comparative genomics and taxonomic inconsistencies among lactobacilli (see here, here, here, here, here, and here) came together to openly collaborate on this publication. These teams included scientists from Italy, Canada, Belgium, Germany, China, Ireland, and Japan.

Several species important from a commercial perspective will be impacted, including Lactobacillus casei, Lactobacillus plantarum, Lactobacillus sakei, Lactobacillus salivarius, Lactobacillus reuteri and Lactobacillus brevis. New genus names are expected for these. Lactobacillus delbrueckii, Lactobacillus acidophilus, Lactobacillus gasseri, Lactobacillus johnsonii, Lactobacillus helveticus and Pediococcus are not expected to undergo name changes. Since L. delbrueckii (which includes the subspecies L. delbrueckii subspecies bulgaricus, the yogurt starter culture) was the first Lactobacillus named, convention in naming bacterial genera requires that species from this taxonomic clade will keep the Lactobacillus name.

Driving this effort is the pressing need to apply modern phylogenetic methods to establishing relationships among the many species of Lactobacillus (see previous post). The genus Lactobacillus currently comprises more than 240 species, and has been growing rapidly for decades. In 1980, 36 Lactobacillus species were recognized. By 2012, there were 152. Scientists recognized the need to reorganize the phylogenetic assignments of this genus; they are proposing splitting the Lactobacillus genus into more than 20 genera.

Once the paper is published, the task of disseminating the message about new genus names for commercially important species will begin.

See here for a detailed article on this topic.