“Candidatus Laterigemmans baculatus” gen. nov. sp. nov., the first representative of rod shaped planctomycetes with lateral budding in the family Pirellulaceae

Abstract

Two axenic cultures of Planctomycetes were isolated from distinct geographical regions of the east coast of India. The two closely related strains (JC640 and CH01) showed < 93.3% 16S rRNA gene sequence identity with members of the genus Roseimaritima followed by Rhodopirellula ( < 91%). Both strains displayed non-canonical cell morphology of Planctomycetes, such as rod shaped cells with division by lateral budding. Both strains showed crateriform structures on their surfaces and cells lack fimbriae. The genomes have a size of about 5.76 Mb and DNA G + C content of 63.6 mol%. Phylogenetic analysis based on 16 S rRNA gene sequence and 92 core genes based RAxML phylogenetic tree place both the strains in the family Pirellulaceae and indicated Roseimaritima sediminicola as their closest relative. The AAI and POCP values differentiate both strains from rest of the members of the family Pirellulaceae. The axenic cultures of both strains were able to grow up to 8–10 passages and subsequently the cells became non-viable with pleomorphic shapes. Supported by genomic, phylogenetic and morphological differences, we conclude that both strains belong to a novel genus. However, since the new isolates lost their viability on passaging, we propose the novel genus as “Candidatus Laterigemmans” gen. nov. and the novel species as “Candidatus Laterigemmans baculatus” sp. nov.