Seagrass vegetation affect the vertical organization of microbial communities in sediment

The Seagrass Holobiont: What We Know and What We Still Need to Disclose for Its Possible Use as an Ecological Indicator

“…Only a small fraction of the bacterial species can be readily cultivated in microbiology laboratories, hence, studies assessing the composition of different microbial communities, including those growing on seagrass, have gradually moved away from the culture related approaches [37,105,199,200], to culture-independent molecular based techniques [35,36,99,161,162,201] and, ultimately, to next-generation sequencing (NGS) approaches [23][24][25][27][28][29]31,32,38,39,96,97,191,202]. This paradigm change has been necessary because bacterial growth is inhibited in vitro, if crucial factors of their natural environment are not properly replicated in the laboratory.…”

“…Ettinger et al [96] found a significant correlation between sediment microbial community structure and seagrass density, with an enrichment of microbes involved in the sulfur-cycle in the densest area of the meadow. On the contrary, Bourque et al [188] found that the complexity of the seagrass sediment microbial community seems to be influenced by the ecological condition of the seagrass meadows that was lower in the disturbed sediment, while, similarly Sun et al [191] found that seagrasses caused a decrease in sediment microbial diversity. Another interesting insight is the observation that the microbial community within the sediment surrounding the native Zostera capricorni is able to hinder the growth of the invasive seaweed Caulerpa taxifolia, contributing to the capacity to resist the settling of this invasive macroalgal species [192].…”

“…In addition to being affected by their environments, seagrasses-defined as ecosystem engineers-are also able to modify their surroundings environments, including the microbial communities [84,89,95,[187][188][189][190][191][192]. Indeed, vegetated sediments host high abundance of nitrogen-fixing bacteria [95,189], and the seagrass rhizosphere hosts high abundance of microbial genes related to putative phosphorus and sulfur pathways [26,190].…”

“…Indeed, vegetated sediments host high abundance of nitrogen-fixing bacteria [95,189], and the seagrass rhizosphere hosts high abundance of microbial genes related to putative phosphorus and sulfur pathways [26,190]. In this perspective, the biogeochemical cycles are undoubtedly influenced by seagrass meadows, which, in turn, have been found to influence the sediment microbial taxonomic profile [96,97,99,191,192], with a larger extent than environmental factors like the seasonal seawater temperature fluctuation [21]. Ettinger et al [96] found a significant correlation between sediment microbial community structure and seagrass density, with an enrichment of microbes involved in the sulfur-cycle in the densest area of the meadow.…”

Spatial and Species Variations of Bacterial Community Structure and Putative Function in Seagrass Rhizosphere Sediment

“…Inorganic nutrients in seawater, including ammonium, nitrate, nitrite, and phosphate, and total phosphorus (TP) in sediment were measured in triplicate according to the standard oceanography methods (General Administration of Quality Supervision, Inspection, and Quarantine of the People’s Republic of China, 2002). Total carbon (TC), total organic carbon (TOC), and total nitrogen (TN) were measured by CHNS Vario E1 III elemental analyzer (Hanau, Germany), according to Sun et al (2020) [ 30 ].…”