Uncovering the Prokaryotic Diversity of the Bathyal Waters above the Kuril–Kamchatka Trench

• Published in: Journal of Marine Science and Engineering
• Main Authors: Gorrasi, Susanna, Brandt, Angelika, Pittino, Francesca, Franzetti, Andrea, Pasqualetti, Marcella, Muñoz Palazón, Barbara, Novello, Giorgia, Fenice, Massimiliano
• Format: Article in Journal/Newspaper
• Language: English
• Published: MDPI 2023
• Subjects: Bacterial communities; Archaeal communities; Deep sea; Kamchatka
• Online Access: https://hdl.handle.net/10481/90408; https://doi.org/10.3390/jmse11112145

The Kuril–Kamchatka Trench (North-West Pacific Ocean) is included in the deepest trenches (>9000 m). This study is the first that aims at uncovering the bathyal prokaryotic diversity (1000–2000 m) of this fascinating extreme environment. The analysis of -diversity revealed that bacterial communities showed greater diversity than archaeal communities and that both communities were characterized by poor evenness (indicative of the presence of few dominant OTUs). The metabarcoding analysis showed that Proteobacteria (65.5–90.7%), Bacteroidetes (2.4–10.7%), and Actinobacteria (2.5–9.6%) were the highly represented phyla of bacteria, with Acinetobacter (21.5–62.5%) as the most abundant genus. Moreover, the recently described Pseudofrancisella genus, which has been isolated from estuarine environments, has been found among the major bacterial taxa. This work represents the first report stating the presence of this genus in bathyal waters. The archaeal communities were dominated by the phylum Thaumarchaeota (53.6–94.0%), with Nitrosopumilus (53.6–94%) as its representative genus. The functional diversity analysis revealed that overall, the bacterial communities had a higher involvement in the carbon and nitrogen biogeochemical cycles, with chemoheterotrophy (mostly aerobic), aromatic compound degradation, and nitrate reduction as the most represented functions. In the archaeal communities, the most represented ecological function was the aerobic oxidation of ammonia (first stage of nitrification), a functional feature characteristic of Nitrosopumilus. KuramBio II project supported by the PTJ (German Ministry for Science and Education), grant 03G0250A National Recovery and Resilience Plan (NRRP), Mission 4 Component 2 Investment 1.4—Call for tender No. 3138 of 16 December 2021, rectified by Decree n.3175 of 18 December 2021 of Italian Ministry of University and Research funded by the European Union—Next Generation EU Project code CN_00000033, Concession Decree No. 1034 of 17 June 2022 adopted by the Italian ...