Ecogenomics reveals viral communities across the Challenger Deep oceanic trench

Abstract

Despite the environmental challenges and nutrient scarcity, the geographically isolated Challenger Deep in Mariana trench, is considered a dynamic hotspot of microbial activity. Hadal viruses are the least explored microorganisms in Challenger Deep, while their taxonomic and functional diversity and ecological impact on deep-sea biogeochemistry are poorly described. Here, we collect 13 sediment cores from slope and bottom-axis sites across the Challenger Deep (down to ~11 kilometers depth), and identify 1,628 previously undescribed viral operational taxonomic units at species level. Community-wide analyses reveals 1,299 viral genera and distinct viral diversity across the trench, which is significantly higher at the bottom-axis vs. slope sites of the trench. 77% of these viral genera have not been previously identified in soils, deep-sea sediments and other oceanic settings. Key prokaryotes involved in hadal carbon and nitrogen cycling are predicted to be potential hosts infected by these viruses. The detected putative auxiliary metabolic genes suggest that viruses at Challenger Deep could modulate the carbohydrate and sulfur metabolisms of their potential hosts, and stabilize host’s cell membranes under extreme hydrostatic pressures. Our results shed light on hadal viral metabolic capabilities, contribute to understanding deep sea ecology and on functional adaptions of hadal viruses for future research.

Exploring virus-host-environment interactions in a chemotrophic-based underground estuary

“…This represents a greater degree of novelty than other reported marine-associated environments, including seawater (comprising ~ 15% known viruses) [ 83 ], or marine biofilms (9% known viruses) [ 84 ]. Rather, this degree of novelty is consistent with more extreme and less sampled marine environments, such as deep ocean trenches [ 85 , 86 ], which comprise 1–2% known viruses. Such novelty is also reflected among the prokaryotic community characterised in previous studies of the sinkhole [ 20 , 25 ], likely driven by adaptation to the distinctive physicochemical properties of anchialine ecosystems.…”

Isolation and Structure Elucidation of New Metabolites from the Mariana-Trench-Associated Fungus Aspergillus sp. SY2601

“…Based on their NMR spectroscopic analyses, optical rotation values, co-HPLC analysis with authentic samples, and comparison to reported data, 23 known compounds were identified: 2-deisoprenyl-neoechinulin A (4) [19], dipodazine (5) [20], cyclo-L-tryptophan-L-alanine (6) [21], cyclo-L-proline-L-tyrosine (maculosin, 7) [22], cyclo-L-proline-L-methionine (8) [22], cyclo-L-proline-L-valine (9) [22], (6S)-3-methylene-6-benzyl-2,5-piperazinedione (10) [23], (6S)-3-methylene-6-(2-methylpropyl)-2,5-piperazinedione (11) [24], (6S,8S)-3-methylene-6-(1methylpropyl)-2,5-piperazinedione (12) [25], azonazine (13) [26], aspergillipeptide A ( 14) [27], isoasteltoxin (15) [28], asteltoxin (16) [28], asteltoxins C (17) and B (18) [29], dihydroaspyrone (19) [30], aspyrone (20) [31], diorcinol (22) [32], aspinonediol (23) [30], aspertetranones A (24) and D (25) [33], insolicolide A (27) [34], and 9-deoxyinsolicolide (28) [34]. The 13 C and 1 H NMR data of these known compounds are listed in Tables S2 The absolute configuration at C-14, the only chiral carbon, was determined through optical rotation (OR) calculations [35,36].…”

“…The Mariana Trench is well known for being the deepest site in the Earth’s oceans, and a number of investigations showed that the Mariana Trench is rich in microorganisms [ 9 , 10 , 11 , 12 ]. Previously reported metabolites from the Mariana Trench microorganisms included phenazines [ 13 , 14 ], aniline-tetramic acids [ 15 ], phenylbutenote and nocapyrone [ 16 ], and n -acetylglutaminyl glutamine amide and desferrioxamine B [ 17 ].…”

Viruses in deep-sea cold seep sediments harbor diverse survival mechanisms and remain genetically conserved within species

“…SAM is the methyl donor for methyltransferases that modify DNA, RNA, histones, and other proteins; decarboxylation of SAM to S-adenosylmethioninamine might reduce the SAM required for methylation by host enzymes [ 52 ]. These AMGs have been also reported to be encoded by viruses in other deep-sea settings, including seawater and sediments of oceanic trenches, and free-living and particle-attached fractions from the bathypelagic ocean [ 45 , 53 – 55 ], suggesting their importance roles in increasing viral adaptability in deep oceans.…”