Author(s): Jackson VLN; Grevesse T; Kilias ES; Onda DFL; Young KF; Allen MJ; Walsh DA; Lovejoy C; Monier A;

The Arctic Ocean (AO) is changing at an unprecedented rate, with ongoing sea ice loss, warming and freshening impacting the extent and duration of primary productivity over summer months. Surface microbial eukaryotes are vulnerable to such changes, but basic knowledge of the spatial variability o ...

Article GUID: 39572565

Author(s): Lawruk-Desjardins C; Storck V; Ponton DE; Amyot M; Walsh DA;

Methyl mercury, a toxic compound, is produced by anaerobic microbes and magnifies in aquatic food webs, affecting the health of animals and humans. The exploration of mercury methylators based on genomes is still limited, especially in the context of river ecosystems. To address this knowledge gap, we developed a genome catalogue of potential mercury-meth ...

Article GUID: 38922750

Author(s): Kraemer SA; Ramachandran A; Onana VE; Li WKW; Walsh DA;

Climate change is profoundly impacting the Arctic, leading to a loss of multiyear sea ice and a warmer, fresher upper Arctic Ocean. The response of microbial communities to these climate-mediated changes is largely unknown. Here, we document the interannual variation in bacterial and archaeal communities across a 9-year time series of the Canada Basin tha ...

Article GUID: 38282643

Author(s): Garner RE; Kraemer SA; Onana VE; Fradette M; Varin MP; Huot Y; Walsh DA;

No abstract

Article GUID: 37821571

Author(s): Garner RE; Kraemer SA; Onana VE; Fradette M; Varin MP; Huot Y; Walsh DA;

Lakes are heterogeneous ecosystems inhabited by a rich microbiome whose genomic diversity is poorly defined. We present a continental-scale study of metagenomes representing 6.5 million km2 of the most lake-rich landscape on Earth. Analysis of 308 Canadian lakes resulted in a metagenome-assembled genome (MAG) catalogue of 1,008 mostly novel bacterial geno ...

Article GUID: 37524802

Author(s): Oliva A; Onana VE; Garner RE; Kraemer SA; Fradette M; Walsh DA; Huot Y;

Lakes are sentinels of environmental changes within their watersheds including those induced by a changing climate and anthropogenic activities. In particular, contamination originating from point or non-point sources (NPS) within watersheds might be reflected in changes in the bacterial composition of lake water. We assessed the abundance of potentially ...

Article GUID: 36653256

Author(s): Grevesse T; Guéguen C; Onana VE; Walsh DA;

Background: The Arctic Ocean receives massive freshwater input and a correspondingly large amount of humic-rich organic matter of terrestrial origin. Global warming, permafrost melt, and a changing hydrological cycle will contribute to an intensification of terrestrial organic matter release to the Arctic Ocean. Although considered recalcitrant to degrada ...

Article GUID: 36566218

Author(s): Kraemer SA; Barbosa da Costa N; Oliva A; Huot Y; Walsh DA;

Our decreasing ability to fight bacterial infections is a major health concern. It is arising due to the evolution of antimicrobial resistance (AMR) in response to the mis- and overuse of antibiotics in both human and veterinary medicine. Lakes integrate watershed processes and thus may act as receptors and reservoirs of antibiotic resistance genes (ARGs) ...

Article GUID: 36338036

Author(s): MacKeigan PW; Garner RE; Monchamp MÈ; Walsh DA; Onana VE; Kraemer SA; Pick FR; Beisner BE; Agbeti MD; da Costa NB; Shapiro BJ; Gregory-Eaves I;

Accurately identifying the species present in an ecosystem is vital to lake managers and successful bioassessment programs. This is particularly important when monitoring cyanobacteria, as numerous taxa produce toxins and can have major negative impacts on aquatic ecosystems. Increasingly, DNA-ba ...

Article GUID: 35287928

Author(s): O' Malley MA; Walsh DA;

The 'principle of microbial infallibility' was a mainstay of microbial physiology and environmental microbiology in earlier decades. This principle asserts that wherever there is an energetic gain to be made from environmental resources, microorganisms will find a way to take advantage of the situation. Although previously disputed, this claim was ...

Article GUID: 34160589

Author(s): Ramachandran A; McLatchie S; Walsh DA;

Bacteria inhabiting polar oceans, particularly the Arctic Ocean, are less studied than those at lower latitudes. Discovering bacterial adaptations to Arctic Ocean conditions is essential for understanding responses to the accelerated environmental changes occurring in the North. The Methylophilaceae are emerging as a model for investigating the genomic ba ...

Article GUID: 34154421