How to grow your cable bacteria: Establishment of a stable single-strain culture in sediment and proposal of Candidatus Electronema aureum GS

Thorup, Charlotte Brun; Petro, Caitlin; Bøggild, Andreas; Ebsen, Tine Sneibjerg; Brokjær, Signe; Nielsen, Lars Peter; Schramm, Andreas; Bjerg, Jesper Jensen

doi:10.1016/j.syapm.2021.126236

Cited by 28 publications

(31 citation statements)

References 37 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Before inoculation, sediment was homogenized, sieved (pore size: 0.5 mm) and autoclaved in 2 L bottles for 20 min as described in Thorup et al (2021) and Marzocchi et al (2022). Cooled down sediment (15°C) was distributed into 20 and 10 ethanol-cleaned Plexiglas core liners that were closed with a rubber stopper at the bottom.…”

Section: Sediment Preparation Inoculation and Incubationmentioning

confidence: 99%

“…The sulfide oxidizers were found to be active below the oxic zone and were proposed to connect with the cable bacteria's electron transport through the oxidation of sulfide and subsequent transfer of the gained electrons to cable bacteria (Vasquez-Cardenas et al, 2015). Another example of association are flocking bacteria, which were discovered to swim around cable bacteria as a nimbus, in enrichments with the freshwater cable bacteria Candidatus Electronema aureum GS (Thorup et al, 2021;Bjerg et al, in press). These flocking bacteria, or flockers, displayed chemotactic behavior toward the cable bacteria, without clearly touching or attaching to the filaments (Bjerg et al, in press).…”

Section: Introductionmentioning

confidence: 99%

“…To test this hypothesis, we set out to elucidate the occurrence of flocking and its relationship to cable bacteria succession, activity, and geochemical changes. We combined microsensor measurements in sediment cores with sequencing, to describe the biogeochemical succession of a single strain enrichment of Candidatus Electronema aureum GS (Thorup et al, 2021), including their activity (inferred from an electric potential (EP) microsensor), changes in pH profile, and relative abundance of cable bacteria. This was compared to microscopy observations of flocking behavior around cable bacteria from the profiled cores, in two replicate time series (TS1 and TS2) each lasting 3 months to resolve how often flocking appears and to determine the amount of flockers and their morphology.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Persistent flocks of diverse motile bacteria in long-term incubations of electron-conducting cable bacteria, Candidatus Electronema aureum

Lustermans

Bjerg²,

Burdorf³

et al. 2023

Front. Microbiol.

Self Cite

View full text Add to dashboard Cite

Cable bacteria are centimeters-long filamentous bacteria that oxidize sulfide in anoxic sediment layers and reduce oxygen at the oxic-anoxic interface, connecting these reactions via electron transport. The ubiquitous cable bacteria have a major impact on sediment geochemistry and microbial communities. This includes diverse bacteria swimming around cable bacteria as dense flocks in the anoxic zone, where the cable bacteria act as chemotactic attractant. We hypothesized that flocking only appears when cable bacteria are highly abundant and active. We set out to discern the timing and drivers of flocking over 81 days in an enrichment culture of the freshwater cable bacterium Candidatus Electronema aureum GS by measuring sediment microprofiles of pH, oxygen, and electric potential as a proxy of cable bacteria activity. Cable bacterial relative abundance was quantified by 16S rRNA amplicon sequencing, and microscopy observations to determine presence of flocking. Flocking was always observed at some cable bacteria, irrespective of overall cable bacteria rRNA abundance, activity, or sediment pH. Diverse cell morphologies of flockers were observed, suggesting that flocking is not restricted to a specific, single bacterial associate. This, coupled with their consistent presence supports a common mechanism of interaction, likely interspecies electron transfer via electron shuttles. Flocking appears exclusively linked to the electron conducting activity of the individual cable bacteria.

show abstract

Section: Sediment Preparation Inoculation and Incubationmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Persistent flocks of diverse motile bacteria in long-term incubations of electron-conducting cable bacteria, Candidatus Electronema aureum

Lustermans

Bjerg²,

Burdorf³

et al. 2023

Front. Microbiol.

Self Cite

View full text Add to dashboard Cite

show abstract

“…Ca . Electronema aureum GS enrichment sample and manual processing of all samples was performed as detailed in a previous study 15 .…”

Section: Methodsmentioning

confidence: 99%

Closed genomes uncover a saltwater species ofCandidatusElectronema and shed new light on the boundary between marine and freshwater cable bacteria

Sereika

Petriglieri

Jensen

et al. 2022

Preprint

Self Cite

View full text Add to dashboard Cite

Cable bacteria of the Desulfobulbaceae family are centimeter-long filamentous bacteria, which are capable of conducting long-distance electron transfer. Currently, all cable bacteria are classified into two candidate genera: Candidatus Electronema, typically found in freshwater environments, and Candidatus Electrothrix, typically found in saltwater environments. This taxonomic framework is based on both 16S rRNA gene sequences and metagenome-assembled genome (MAG) phylogenies. However, most of the currently available MAGs are highly fragmented, incomplete, and thus likely miss key genes essential for deciphering the physiology of cable bacteria. To address this, we performed Nanopore long read (total 162.4 Gbp) and Illumina short read (total 148.3 Gbp) shotgun sequencing of selected environmental samples and a single-strain enrichment of Ca. Electronema aureum. We recovered multiple cable bacteria MAGs, including two circular and one single-contig. Phylogenomic analysis, also confirmed by 16S rRNA gene-based phylogeny, classified one circular MAG and the single-contig MAG as novel species of cable bacteria, which we propose to name Ca. Electronema halotolerans and Ca. Electrothrix laxa, respectively. The Ca. Electronema halotolerans, despite belonging to the previously recognized freshwater genus of cable bacteria, was retrieved from brackish-water sediment. Metabolic predictions showed several adaptations to a high salinity environment, similar to the ''saltwater'' Ca. Electrothrix species, indicating how Ca. Electronema halotolerans may be the evolutionary link between marine and freshwater cable bacteria lineages.

show abstract

“…As a second limitation, all species of cable bacteria lack a pure culture so far, making upscaling difficult. Although some attempts have been made toward it, only a single-strain sediment culture was achieved until this point ( Thorup et al, 2021 ). Finally, the conductive periplasmic fibers are yet to be extracted properly from cable bacteria, as it is expected that the pure fibers rather than the full filaments will be used in future electronics ( Cosert et al, 2019 ).…”

Section: Conclusion Challenges and Outlookmentioning

confidence: 99%

Biomaterials and Electroactive Bacteria for Biodegradable Electronics

et al. 2022

View full text Add to dashboard Cite

The global production of unrecycled electronic waste is extensively growing each year, urging the search for alternatives in biodegradable electronic materials. Electroactive bacteria and their nanowires have emerged as a new route toward electronic biological materials (e-biologics). Recent studies on electron transport in cable bacteria—filamentous, multicellular electroactive bacteria—showed centimeter long electron transport in an organized conductive fiber structure with high conductivities and remarkable intrinsic electrical properties. In this work we give a brief overview of the recent advances in biodegradable electronics with a focus on the use of biomaterials and electroactive bacteria, and with special attention for cable bacteria. We investigate the potential of cable bacteria in this field, as we compare the intrinsic electrical properties of cable bacteria to organic and inorganic electronic materials. Based on their intrinsic electrical properties, we show cable bacteria filaments to have great potential as for instance interconnects and transistor channels in a new generation of bioelectronics. Together with other biomaterials and electroactive bacteria they open electrifying routes toward a new generation of biodegradable electronics.

show abstract

How to grow your cable bacteria: Establishment of a stable single-strain culture in sediment and proposal of Candidatus Electronema aureum GS

Cited by 28 publications

References 37 publications

Persistent flocks of diverse motile bacteria in long-term incubations of electron-conducting cable bacteria, Candidatus Electronema aureum

Persistent flocks of diverse motile bacteria in long-term incubations of electron-conducting cable bacteria, Candidatus Electronema aureum

Closed genomes uncover a saltwater species ofCandidatusElectronema and shed new light on the boundary between marine and freshwater cable bacteria

Biomaterials and Electroactive Bacteria for Biodegradable Electronics

Contact Info

Product

Resources

About