Rosistilla oblonga gen. nov., sp. nov. and Rosistilla carotiformis sp. nov., isolated from biotic or abiotic surfaces in Northern Germany, Mallorca, Spain and California, USA

Abstract

Planctomycetes are ubiquitous bacteria with fascinating cell biological features. Strains available as axenic cultures in most cases have been isolated from aquatic environments and serve as a basis to study planctomycetal cell biology and interactions in further detail. As a contribution to the current collection of axenic cultures, here we characterise three closely related strains, Poly24 T , CA51 T and Mal33, which were isolated from the Baltic Sea, the Pacific Ocean and the Mediterranean Sea, respectively. The strains display cell biological features typical for related Planctomycetes, such as division by polar budding, presence of crateriform structures and formation of rosettes. Optimal growth was observed at temperatures of 30-33°C and at pH 7.5, which led to maximal growth rates of 0.065-0.079 h-1 , corresponding to generation times of 9-11 h. The genomes of the novel isolates have a size of 7.3-7.5 Mb and a G ? C content of 57.7-58.2%. Phylogenetic analyses place the strains in the family Pirellulaceae and suggest that Roseimaritima ulvae and Roseimaritima sediminicola are the current closest relatives. Analysis of five different phylogenetic markers, however, supports the delineation of the strains from members of the genus Roseimaritima and other characterised genera in the family. Supported by morphological and physiological differences, we conclude that the strains belong to the novel genus Rosistilla gen. nov. and constitute two novel species, for which we propose the names Rosistilla carotiformis sp. nov. and Rosistilla oblonga sp. nov. (the type species). The two novel species are represented by the type strains Poly24 T

Analysis of Bacterial Communities on North Sea Macroalgae and Characterization of the Isolated Planctomycetes Adhaeretor mobilis gen. nov., sp. nov., Roseimaritima multifibrata sp. nov., Rosistilla ulvae sp. nov. and Rubripirellula lacrimiformis sp. nov.

“…When reviewing 16S rRNA gene sequence- as well as MLSA-based phylogeny of strain EC9 T and its close neighbors ( Figure 8 and Supplementary Figure S1 ), it became apparent that the novel strain belongs to the only recently described genus Rosistilla, which comprises R. oblonga and R. carotiformis [ 31 ]. The assessment that these species and strain EC9 T belong to the same genus is confirmed by AAI and POCP values distinctly above the genus thresholds ( Supplementary Figure S4 ).…”

“…Maximum likelihood 16S rRNA gene sequence-based phylogeny was computed for the novel strains, all described planctomycetal species of the order Pirellulales [ 28 , 29 , 30 , 31 , 40 , 42 , 61 , 62 , 63 , 64 , 65 , 66 , 67 , 68 , 69 , 70 , 71 , 72 , 73 ] and an outgroup of three strains from the order Planctomycetales (acc. no.…”

“…Nevertheless, the first two described planctomycetal isolates from macroalgae belong to the class Phycisphaerae [ 24 , 25 , 26 ]. In recent years, single-cell genomes [ 27 ] and axenic cultures from macroalgae were also obtained for the families Pirellulaceae [ 28 , 29 , 30 , 31 ], Lacipirellulaceae [ 32 ], Planctomycetaceae [ 33 , 34 , 35 ], and Isosphaeraceae [ 36 ].…”

Updates to the recently introduced family Lacipirellulaceae in the phylum Planctomycetes: isolation of strains belonging to the novel genera Aeoliella, Botrimarina, Pirellulimonas and Pseudobythopirellula and the novel species Bythopirellula polymerisocia and Posidoniimonas corsicana

“…Members of the class Planctomycetia have been found to occur ubiquitously but are predominant in aquatic environments (Wiegand et al 2018). They have been isolated from numerous algal surfaces (Bengtsson et al 2012;Boersma et al 2019;Bondoso et al 2014Bondoso et al , 2015Bondoso et al , 2017Kallscheuer et al 2019a, d; Lage and Bondoso 2014;Peeters et al 2019;Vollmers et al 2017;Waqqas et al 2020), on which they sometimes even dominate the microbial community (Bengtsson and Øvreås 2010;Wiegand et al 2018). Planctomycetes are considered important players in global carbon cycling (Wiegand et al 2018) as they possess the metabolic ability to degrade complex carbon substrates (Jeske et al 2013;Lachnit et al 2013).…”

“…Planctomycetes are considered important players in global carbon cycling (Wiegand et al 2018) as they possess the metabolic ability to degrade complex carbon substrates (Jeske et al 2013;Lachnit et al 2013). Planctomycetes are suspected to produce small bioactive molecules (Graca et al 2016;Jeske et al 2016;Waqqas et al 2020). Recently, stieleriacines, one of the first small molecules elucidated from planctomycetes, were shown to be involved in alteration of community compositions in biofilms (Kallscheuer et al 2020a).…”