Prokaryotic community structure and diversity in the sediments of an active submarine mud volcano (Kazan mud volcano, East Mediterranean Sea)

Abstract

We investigated 16S rRNA gene diversity at a high sediment depth resolution (every 5 cm, top 30 cm) in an active site of the Kazan mud volcano, East Mediterranean Sea. A total of 242 archaeal and 374 bacterial clones were analysed, which were attributed to 38 and 205 unique phylotypes, respectively (> or = 98% similarity). Most of the archaeal phylotypes were related to ANME-1, -2 and -3 members originating from habitats where anaerobic oxidation of methane (AOM) occurs, although they occurred in sediment layers with no apparent AOM (below the sulphate depletion depth). Proteobacteria were the most abundant and diverse bacterial group, with the Gammaproteobacteria dominating in most sediment layers and these were related to phylotypes involved in methane cycling. The Deltaproteobacteria included several of the sulphate-reducers related to AOM. The rest of the bacterial phylotypes belonged to 15 known phyla and three unaffiliated groups, with representatives from similar habitats. Diversity index H was in the range 0.56-1.73 and 1.47-3.82 for Archaea and Bacteria, respectively, revealing different depth patterns for the two groups. At 15 and 20 cm below the sea floor, the prokaryotic communities were highly similar, hosting AOM-specific Archaea and Bacteria. Our study revealed different dominant phyla in proximate sediment layers.

Viral infections stimulate the metabolism and shape prokaryotic assemblages in submarine mud volcanoes

“…We found the same pattern in the control sediments, whereas euryarchaea were dominant in the surface and subsurface sediments of the mud volcanoes. The dominance of euryarchaea over crenarchaea has been previously reported for gas-hydrate-bearing and methane-bearing sediments, and this was related to the exploitation of the methane released by the seeps (Inagaki et al, 2006;Parkes et al, 2007;Pachiadaki et al, 2010).…”

“…At present, we know that microbial assemblages in cold-seep ecosystems are typically dominated by sulphatereducing bacteria and methanotrophic archaea, which mediate anaerobic oxidation of methane with sulphate (Jørgensen and Boetius, 2007). This process represents one of the major global sinks for methane (Michaelis et al, 2002;Niemann et al, 2006;Pachiadaki et al, 2010).…”

Bacterial Diversity of the Deep Sea of Sangihe Talaud, Sulawesi

“…Several Proteobacteria phyla (α-, δ-, and γ-proteobacteria classes) dominated in marine sediments associated with carbon and nitrogen cycles (Hunter et al, 2006;Pachiadaki et al, 2010). Rhodobacterales bacterium belonging to the class of α-proteobacteria that is known living in a low temperature and high pressure (Psychropiezophiles) were f ound in site II, while Aphanothece sp.…”

“…This species is known able to degrade a wide range of hydrocarbons such as C10-35 which is potential for marine bioremediation (Harwati et al, 2007). Pachiadaki et al (2010) reported a diversity of bacteria of Kazan mud volcano, East Mediterranean Sea which found some classes of bacteria such as Acidobacteria, Actinobacteria, α-proteobacteria, Bacteroidetes, -proteobacteria, Chlorobi, Chloroflexi, δ-proteobact eria, γ-prot eobacteria, Epsi lon proteobacteria, Def erribacteres, Firmicutes, Fusobacteria, Planctomycetes, Spirochaetes. According to Takai et al (2006) microbes that inhabit in the mountain areas of marine microbial groups are dominated by chemoautotrophic.…”

“…These species are belong There were several species that play a role on the cycle of sulfate, sulfite, sulfur, methyl found in this site such as: Desulfatimicrobium mahresensis, Desulfovibrio desulfuricans, Methylarcula marina, Methylobacillus flagellates, Methylotenera mobilis, Sulfitobacter sp., Sulfobacillus sp., and Sulfobacillus thermosulfidooxidan. γ-proteobacteria were related to phylotypes involved in methane cycling and δ-proteobacteria was grouped included in to sulphatereducers related to anaerobic oxidation of methane (AOM) (David et al, 2005;Pachiadaki et al, 2010).…”