Annamia dubia sp. nov. with a description of a new family, Geminocystaceae fam. nov. (Cyanobacteria)

Abstract

Our environmental DNA analysis identified Annamia-like operational taxonomic units (OTUs) from Lake Kasumigaura, Japan every summer season during the period from June 2012-May 2015. A strain from Lake Kasumigaura that agreed with an Annamia-like OTU (NIES-4383) was established with a cell-sorting machine. Based on the differences in morphology and 16S rRNA sequences, a new taxon is described: Annamia dubia Tuji, Yamaguchi et Niiyama sp. nov. A. dubia produces a microcystins that is also produced by A. toxica. Our 16S rRNA phylogenetical analysis reveals that the genus Annamia makes a monophyletic clade with the genera Geminocystis, Geminobacterium, and 'Cyanobacterium.' Although this clade agrees with Cyanobacteriaceae Komarek et al. (2014), this family is invalid based on the invalid genus Cyanobacterium and the type species Cyanobacterium stanieri. We propose the alternative name Geminocystaceae Tuji, Yamaguchi et Niiyama fam. nov. based on the genus Geminocystis.