Microbial Life in a Fjord: Metagenomic Analysis of a Microbial Mat in Chilean Patagonia

Abstract

The current study describes the taxonomic and functional composition of metagenomic sequences obtained from a filamentous microbial mat isolated from the Comau fjord, located in the northernmost part of the Chilean Patagonia. The taxonomic composition of the microbial community showed a high proportion of members of the Gammaproteobacteria, including a high number of sequences that were recruited to the genomes of Moritella marina MP-1 and Colwellia psycherythraea 34H, suggesting the presence of populations related to these two psychrophilic bacterial species. Functional analysis of the community indicated a high proportion of genes coding for the transport and metabolism of amino acids, as well as in energy production. Among the energy production functions, we found protein-coding genes for sulfate and nitrate reduction, both processes associated with Gammaproteobacteria-related sequences. This report provides the first examination of the taxonomic composition and genetic diversity associated with these conspicuous microbial mat communities and provides a framework for future microbial studies in the Comau fjord.

Natural and Human Influences on Marine Processes in Patagonian Subantarctic Coastal Waters

“…Moreover, evidence of active geological processes (e.g., surface hydrothermal vents; Försterra et al, 2014) in Comau Fjord is relevant ecologically and biogeochemically (high methane and sulfide-enriched water), as these processes support trophic webs sustained by giant methanogenic bacteria (chemosynthetic communities) and diverse benthic species (Muñoz et al, 2014;Quiroga et al, 2016). Although the number of cold seeps in the fjord system remains unknown, patches of microbial mats, which obtain energy from the reduction of nitrate and sulfate, may play a key role in supporting a trophic link to invertebrate grazers (chitons, gastropods, mussels, and coldwater scleractinian corals) (Ugalde et al, 2013;Muñoz et al, 2014).…”

The response of nitrifying microbial assemblages to ammonium (NH4+) enrichment from salmon farm activities in a northern Chilean Fjord

“…The fjord is 41 km long, 4. 5 km wide and the average depth is 250 m. The fjord is characterized by a seasonal variability associated with freshwater input derived mainly from the Vodudahue and Lloncochaigua rivers,precipitation (5,435mm) and ice thawing (Galea et al, 2007;Sánchez et al, 2011;Fillinger and Richter, 2013), which generates a variation in the pycnocline depth of up to 10 meters during the rainy season (Ugalde et al, 2013;Försterra, 2009). …”

Environmental issues in Chilean salmon farming: a review

“…The area is important for microbial (Ugalde et al . ), invertebrate (Hernández et al . ; Mutschke ; Häussermann & Försterra ) and vertebrate biodiversity (Schlatter & Simeone ; Valenzuela et al .…”

“…Patagonian fjords and channels have been recognized as having high conservation value due to their biodiversity and uniqueness (Fern andez et al 2000;Hucke-Gaete et al 2006;H€ aussermann & F€ orsterra 2009). The area is important for microbial (Ugalde et al 2013), invertebrate (Hern andez et al 2005Mutschke 2008; H€ aussermann & F€ orsterra 2009) and vertebrate biodiversity (Schlatter & Simeone 1999;Valenzuela et al 2008;Skewgar et al 2014), and is a hotspot for cetacean diversity (Hucke-Gaete et al 2006;Buchan & Quiñones 2016;Viddi et al 2016) This region is a transitional marine system, influenced by oceanic deep waters of high salinity/nutrients and surface freshwater of low salinity/nutrients. The estuarine waters are relatively poor in nutrients, with the oceanic Sub-Antarctic Waters (SAAW) being the main source of nutrients (Silva & Neshyba 1979).…”