Distribution and Succession of Microbial Communities Along the Dispersal Pathway of Hydrothermal Plumes on the Southwest Indian Ridge

Abstract

The distribution and succession of microbial communities along the dispersion path of hydrothermal plumes has not been well investigated. In this study, we collected several types of samples from the Longqi hydrothermal field located on the Southwest Indian Ridge, including hydrothermal plumes at different stages of formation, a suite of water column samples across the non-buoyant hydrothermal plumes above this field, and a background seawater column approximately 350 km away from the hydrothermal field. Using CH 4 concentration anomalies, three non-buoyant plume samples between 2,535 and 2,735 m were identified within the water column. Microbial community compositions within these plumes and background seawater samples were examined based on the 16S rRNA genes and revealed significant variations and successions in community composition between different portions of the hydrothermal plumes. Near the vent orifice, representing the initial stage of plume formation, microbial populations were characterized by abundant and diverse putative vent-associated communities including (hyper)thermophiles such as Aquificaceae and Hydrogenothermaceae within the phylum Aquificae, and some epsilonproteobacterial chemolithoautotrophs such as Sulfurovum, Sulfurimonas, and Caminibacter. By contrast, in the rising buoyant plumes and adjacent seawaters, most vent-associated microbial taxa were still present but made only minor contributions to community composition. Some microbial taxa that are common in seawater columns such as alphaproteobacterial Sphingomonadaceae and SAR11 clade, deltaproteobacterial SAR324 clade, and gammaproteobacterial Pseudomonas, together with Sulfurimonas and SUP05 clade, became predominant. Members within the Sulfurimonas and SUP05 clade flourished with considerable abundance in the non-buoyant plumes, although these plumes were mainly composed of alphaproteobacterial Rhodobacteraceae, gammaproteobacterial Alteromonadaceae and Saccharospirillaceae putatively derived from the surrounding ambient seawater. We also analyzed archaeal components in the initial discharge and rising buoyant plume stages, with both primarily consisting of thaumarchaeal Nitrosopumilales

Hydrothermal trace metal release and microbial metabolism in the northeastern Lau Basin of the South Pacific Ocean

“…An additional TonB protein was ninefold more abundant in the hydrothermal plume (FDR = 0.006), belonging to the Alteromonadales family within Gammaproteobacteria and containing the BtuB domain. Although TonB genes are highly expressed in Gammaproteobacteria from the Guaymas Basin hydrothermal plume (Li et al, 2014), we did not find evidence for overall enrichment, with only these 3 out of 83 TonB transporter proteins identified as differentially abundant in the plume, suggesting that these transporters are broadly utilized by deep-sea bacterial communities. The The horizontal purple lines mark a log 2 fold change of 2 or −2 for a fourfold increase or decrease in protein abundance, respectively.…”

“…Trace metal transformations in hydrothermal plumes are heavily driven by biological communities (Gartman and Findlay, 2020;Toner et al, 2009Toner et al, , 2016. Prior microbiological and meta-omic studies have offered insights into plume microbial community dynamics, with many studies focusing on near-field ecosystems (Huber et al, 2007;Jeanthon, 2000;Li et al, 2014;Reveillaud et al, 2016;Sylvan et al, 2012;Takai et al, 2008) and fewer, more recent explorations into distal plumes (Djurhuus et al, 2017;Haalboom et al, 2020;Li et al, 2020). Microbial communities in plumes may be sourced from seafloor vent sites themselves or seeded from background seawater (Dick et al, 2013;Reed et al, 2015;Sheik et al, 2015).…”

Structure and Connectivity of Hydrothermal Vent Communities Along the Mid-Ocean Ridges in the West Indian Ocean: A Review

“…Only a handful of studies have examined the biodiversity of Indian HTV microorganisms in various microhabitats. These genetic surveys revealed that microbial vent communities are distinct from those of the Atlantic or Pacific vents (Ding et al, 2017;Li et al, 2020;Yang Z. et al, 2020), are highly specialized to their local environment, and may hold great biological novelty. In the SWIR, the microbial community structures on active chimneys (Ding et al, 2017) and vent sediments (Xu et al, 2018;Yang Z. et al, 2020) vary within a single vent field or a single chimney structure according to the temperature and chemical composition of the substrates.…”

Development of chemosynthetic microbial communities in organic falls deployed in the deep Southwest Atlantic Ocean

“…We also detected Gammaproteobacteria S-oxidisers, mainly from the family Thiomicrospiraceae. This family has been reported in hydrothermal vent communities (Li et al 2020) and comprises groups that live in symbiosis with vent-associated fauna (Tourova et al 2006).…”