Labilibaculum manganireducens gen. nov., sp. nov. and Labilibaculum filiforme sp. nov., Novel Bacteroidetes Isolated from Subsurface Sediments of the Baltic Sea

Abstract

Microbial communities in deep subsurface sediments are challenged by the decrease in amount and quality of organic substrates with depth. In sediments of the Baltic Sea, they might additionally have to cope with an increase in salinity from ions that have diffused downward from the overlying water during the last 9000 years. Here, we report the isolation and characterization of four novel bacteria of the Bacteroidetes from depths of 14–52 m below seafloor (mbsf) of Baltic Sea sediments sampled during International Ocean Discovery Program (IODP) Expedition 347. Based on physiological, chemotaxonomic and genotypic characterization, we propose that the four strains represent two new species within a new genus in the family Marinifilaceae, with the proposed names Labilibaculum manganireducens gen. nov., sp. nov. (type strain 59.10-2MT) and Labilibaculum filiforme sp. nov. (type strains 59.16BT) with additional strains of this species (59.10-1M and 60.6M). The draft genomes of the two type strains had sizes of 5.2 and 5.3 Mb and reflected the major physiological capabilities. The strains showed gliding motility, were psychrotolerant, neutrophilic and halotolerant. Growth by fermentation of mono- and disaccharides as well as pyruvate, lactate and glycerol was observed. During glucose fermentation, small amounts of electron equivalents were transferred to Fe(III) by all strains, while one of the strains also reduced Mn(IV). Thereby, the four strains broaden the phylogenetic range of prokaryotes known to reduce metals to the group of Bacteroidetes. Halotolerance and metal reduction might both be beneficial for survival in deep subsurface sediments of the Baltic Sea.

Temporal and Spatial Characterization of Sediment Bacterial Communities From Lake Wetlands in a Plain River Network Region

“…They can t into the changing redox conditions of an aquifer and participate in the degradation of organics, and this action may lead to the low OM content in the sediment (LA et al, 2013, Huang et al, 2017). Bacteroidetes is widespread in a variety of environments such as surface sediments (Vandieken et al, 2017, Orsi et al, 2013, Inagaki, 2015. It is thought to play a vital role in ecosystems because its members process complex molecules into simpler compounds in predominantly anaerobic habitats (Liu et al, 2009, Rosselló-Mora et al, 1999.…”

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

“…AQDS is known to be reduced by lactic acid bacteria growing fermentatively, although not by Escherichia coli [80]. The reduction of metals during fermentative growth has been reported for members from various phyla [81,82]. The reduction of AQDS and metals can proceed through periplasmic or outer membrane c-type cytochromes that deliver electrons from quinones to these electron acceptors [83,84].…”

Sunxiuqinia indica sp. nov., isolated from deep sea

“…Other oxidative stress-related enzymes including gutathione peroxidase, iron-dependent superoxide dismutase, copper and zinc-dependent superoxide dismutase and manganese-dependent superoxide dismutase were also present in the novel strain as well as in the other two type strains (Table S2). The ability of production of acid, such as acetate and formate, was confirmed either by the presence of the enzyme pyruvate-formate lyase or pyruvate-flavodoxin oxidoreductase [17]. In the novel strain genome, we found two genes encoding pyruvate-formate lyase and one encoding pyruvate-flavodoxin oxidoreductase, as well as in genomes of two type strains (Table S2).…”