Pontiella desulfatans gen. nov., sp. nov., and Pontiella sulfatireligans sp. nov., Two Marine Anaerobes of the Pontiellaceae fam. nov. Producing Sulfated Glycosaminoglycan-like Exopolymers

Abstract

Recently, we isolated two marine strains, F1T and F21T, which together with Kiritimatiella glycovorans L21-Fru-ABT are the only pure cultures of the class Kiritimatiellae within the phylum Verrucomicrobiota. Here, we present an in-depth genome-guided characterization of both isolates with emphasis on their exopolysaccharide synthesis. The strains only grew fermentatively on simple carbohydrates and sulfated polysaccharides. Strains F1T, F21T and K. glycovorans reduced elemental sulfur, ferric citrate and anthraquinone-2,6-disulfonate during anaerobic growth on sugars. Both strains produced exopolysaccharides during stationary phase, probably with intracellularly stored glycogen as energy and carbon source. Exopolysaccharides included N-sulfated polysaccharides probably containing hexosamines and thus resembling glycosaminoglycans. This implies that the isolates can both degrade and produce sulfated polysaccharides. Both strains encoded an unprecedently high number of glycoside hydrolase genes (422 and 388, respectively), including prevalent alpha-L-fucosidase genes, which may be necessary for degrading complex sulfated polysaccharides such as fucoidan. Strain F21T encoded three putative glycosaminoglycan sulfotransferases and a putative sulfate glycosaminoglycan biosynthesis gene cluster. Based on phylogenetic and chemotaxonomic analyses, we propose the taxa Pontiella desulfatans F1T gen. nov., sp. nov. and Pontiella sulfatireligans F21T sp. nov. as representatives of the Pontiellaceae fam. nov. within the class Kiritimatiellae.

Hydrodynamic disturbance controls microbial community assembly and biogeochemical processes in coastal sediments

“…3 ; Table S10 ), nirS and nirK genes were primarily associated with facultatively anaerobic habitat generalists such as Woeseiaceae, Flavobacteriaceae, and Rhodobacteraceae, whereas nrfA is encoded by few MAGs (Fig. 3 ), including relatively rare families Ignavibacteriaceae (Bacteroidota) and Pontiellaceae (Verrucomicrobiota) [ 91 ]. Also notable is the patchwork distribution of nitrate, nitrite, nitric oxide, and nitrous oxide reductases between families, with no MAGs (even those with >95% completeness) encoding complete denitrification pathways (Table S6 ).…”

Dietary shifts and social interactions drive temporal fluctuations of the gut microbiome from wild redfronted lemurs

“…Higher precipitation resulting in water sources with lower microbial loads decreased alpha diversity and correlated to changes in β-diversity. Thus, taxa with higher abundances in the dry season could be ingested from drinking at the river waterholes like Kiritimatiellae —WCHB1–41, which was impacted negatively by higher precipitation and has been previously isolated from environmental water suggesting transmission from water sources [ 104 ].…”

Enrichable consortia of microbial symbionts degrade macroalgal polysaccharides inKyphosusfish

“…This hypothesis is supported by the fact that Kyphosid gut community Bacillota from the genus Vallitalea appear more closely related to marine sediment bacteria (80,89) than any previously reported examples from seawater or terrestrial gut microbiota ( Table S3 ). Likewise, sediment-dwelling Verrucomicrobiota from the order Kiritimatiellales similar to those in Kyphosus fish guts have also been shown to degrade sulfated macroalgal polysaccharides (90), with genomes rich in both glycoside hydrolases and sulfatases (91). It is possible that consumption of sediment by Kyphosus fish improves polysaccharide digestion not only through physical breakdown of seaweed, but also by the contribution of additional enzyme capabilities originally derived from sediment bacteria that likely encounter highly diverse recalcitrant organic substrates including macroalgae biomass (92).…”