Fictibacillus fluitans sp. nov., isolated from freshwater pond.

Abstract

A Gram-positive, aerobic, rod-shaped, spore-forming bacterium, designated NE201T, was isolated from a freshwater pond in Village Nerur, India. Growth was observed in the range of 15-45°C temperature with optimum at 30°C, pH range of 5-9 (optimum at 7.0), and at concentrations of NaCl ranging between 0 and 14% (optimum 0%, w/v). The 16S rRNA gene sequence showed the highest similarity with Fictibacillus enclensis NIO-1003T (JF893461) at 99.01% followed by F. rigui WPCB074T (EU939689) at 98.9% and F. solisalsi CGMCC 1.6854T (EU046268) at 98.66%. The digital DNA-DNA hybridization (dDDH) and orthoANI values for strain NE201T against F. enclensis NIO-1003T (GCA_900094955.1) were 33.7% and 87.68%, respectively. The phylogenetic analysis based on the 16S rRNA gene, 92 core genes derived from the genome, and 20 proteins involving over 20,236 amino acid positions revealed the distinct phylogenetic position of strain NE201T and the formation of a clearly defined monophyletic clade with F. enclensis. The strain NE201T showed a unique carbon utilization and assimilation pattern that differentiated it from F. enclensis NIO-1003T. The major fatty acids were anteiso -C15:0 (51.42%) and iso-C15:0 (18.88%). The major polar lipids were phosphatidylglycerol (PG), phosphatidylethanolamine (PE, and diphosphatidylglycerol (DPG). The antiSMASH analyzed genome of NE201T highlighted its diverse biosynthetic potential, unveiling regions associated with terpene, non-ribosomal peptide synthetases (NRPS), lassopeptides, NI-siderophores, lanthipeptides (LAP), and Type 3 Polyketide Synthases (T3PKS). The overall phenotypic, genotypic, and chemotaxonomic characters strongly suggested that the strain NE201T represents a novel species of genus Fictibacillus for which the name Fictibacillus fluitans sp. nov. is proposed. The type strain is NE201T(= MCC 5285 = JCM 36474).