Kiloniella laminariae gen. nov., sp. nov., an alphaproteobacterium from the marine macroalga Laminaria saccharina

Abstract

A novel alphaproteobacterium, strain LD81 T , was isolated from the marine macroalga Laminaria saccharina. The bacterium is mesophilic and shows a typical marine growth response. It is a chemoheterotrophic aerobe with the potential for denitrification. Growth optima are 25 6C, pH 5.5 and 3 % NaCl. Strain LD81 T has a unique phylogenetic position, not fitting any of the known families of the Alphaproteobacteria. The 16S rRNA gene sequence revealed a distant relationship to species of several orders of the Alphaproteobacteria, with less than 90 % sequence similarity. Phylogenetically, strain LD81 T is related to the type strains of Terasakiella pusilla (88.4 % 16S rRNA gene sequence similarity) and the three Thalassospira species (88.9-89.2 %). It forms a cluster with these bacteria and a novel as-yet undescribed isolate (KOPRI 13522; 96.6 % sequence similarity). Strain LD81 T has a relatively low DNA G+C content (51.1 mol%) and, due to its distant phylogenetic position from all other alphaproteobacteria, strain LD81 T (5NCIMB 14374 T 5JCM 14845 T ) is considered as the type strain of a novel species within a new genus, for which the name Kiloniella laminariae gen. nov., sp. nov. is proposed. The genus Kiloniella represents the type of the new family Kiloniellaceae fam. nov. and order Kiloniellales ord. nov.The Alphaproteobacteria is one of the most well-represented bacterial groups observed in marine habitats (Giovannoni & Rappé, 2000), with members of the orders Caulobacterales, Sphingomonadales, Rhizobiales, Rickettsiales, Rhodobacterales, Rhodospirillales, Kordiimonadales and 'Parvularculales' being reported (Garrity et al., 2005;Kwon et al., 2005). In a study concerning the phylogenetic analysis of bacteria that are associated with the marine brown alga Laminaria saccharina from the Baltic Sea, strain LD81 T was isolated.Pieces of Laminaria saccharina tissue were suspended in sterile seawater and homogenized using an Ultraturrax T25 (IKA Werke). The suspension was diluted in sterile seawater and plated on TSB medium (l 21 : 3 g Difco tryptic soy broth, 7 g NaCl, 15 g Bacto agar; pH 7.2). The plates were incubated at 22 u C in the dark for 20 days. After good growth was obtained, an overlay containing TSB medium (with 8 g l 21 Bacto agar) and 10 % (v/v) overnight culture of Candida glabrata DSM 6425 was poured onto the plates and incubated for 24 h at 22 u C in order to detect inhibition zones against C. glabrata by individual colonies. Antibiotically active colonies were repeatedly streaked on agar plates with TSB medium to obtain pure cultures. One of the pure cultures obtained was strain LD81 T , which was stored at 280 u C using the Cryobank System (Mast Diagnostica GmbH) for maintenance.Cell morphology was examined by scanning electron microscopy. Strain LD81 T was cultivated for 24 h in marine broth (MB; Difco 2216) at 28 u C on a rotary shaker with shaking at 95 r.p.m., followed by fixation with a final concentration of 1 % formol and filtration through 0.2 mm polycarbonate filters (Sarstedt). The filte...

Chemical interactions between marine macroalgae and bacteria

“…Considering all available evidence, including our own observations (Staufenberger et al 2008, Lachnit et al 2009, Wiese et al 2009a, it is reasonable to conclude that a highly specific association of bacterial communities with marine macroalgae exists. It has been proposed that the physiological and biochemical properties of macroalgae predetermine the composition of the adhering microbial communities (Beleneva & Zhukova 2006).…”

Lesion bacterial communities in American lobsters with diet-induced shell disease

“…The 16S rDNA sequence determined for the Kiloniella sp. was 96% identical to that of Kiloniella laminariae LD81 T , the only cultured Kiloniellaceae member and an aerobic chemoheterotrophic spirillum isolated from the marine brown alga Laminaria saccharina in the Baltic sea (Wiese et al 2009). It was also 99% identical to 'Kopriimonas byanusanensis', a novel species not described formally, and from this high sequence similarity we propose the name 'Candidatus Kopriimonas aquarianus' for this newly identified Kiloniella relative.…”

Bacterial community analysis of marine recirculating aquaculture system bioreactors for complete nitrogen removal established from a commercial inoculum

“…Colwelliaceae include marine aerobic and facultative anaerobic marine members that reduce nitrate to nitrite (Ivanova et al, 2004) and have been shown to inhabit industrial saline wastewater (Yoshie et al, 2004; Yoshie et al, 2006) and marine RAS denitrification systems (Interdonato, 2012; Martins et al, 2013). Thalassospira include members possessing aerobic or facultative anaerobic metabolism that use nitrate as electron acceptor (Wiese et al, 2009) and have been identified in denitrification bioreactor for saline water with poly butylene succinate as carbon source (Luo et al, 2013) and in the Mediterranean Sea (Hütz et al, 2011; Cortés-Lara et al, 2015). Finally, in addition to bacteria involved in nitrogen cycling, bacteria capable of sulfur metabolism were identified in the DBRs, including a representative of the genus Arcobacter , which oxidizes sulfide to sulfur (Vandamme et al, 2005).…”