On and sulfide generation, and they revealed thiotrophic microbial mats related with higher fluxes of sulfide [22,25,26]. Nevertheless, the total microbial abundance at the bottom on the Barents Sea could depend on the alter of seasons, and it was shown that bacterio- and virioplankton have been much more abundant in coastal marine regions in late autumn than in winter [27]. This higher abundance of microorganisms within the uppermost layers of sediments is linked to the aerobic nature of microbial processes along with the availability of reactive organic carbon [28]. The majority of the above-mentioned studies have focused either around the methane cycle at only some methane seep web sites, or on geomicrobiological processes unrelated towards the methane cycle in the sediments from the Barents Sea. The study of microbial communities and methane cycle processes inside the sediments can assist in understanding the methane cycle processes in the Arctic seas. Right here we report the results of studying microbial processes and molecular evaluation of microbial communities in the sediments collected at five Resazurin Epigenetics stations in the northern part of the Barents Sea.Microorganisms 2021, 9,3 of2. Materials and Approaches two.1. Site Description and Sampling Sediment samples have been collected at 5 stations at depths from 101 to 1514 m in August 2020 during the 80th cruise of R/V Akademik Mstislav Keldysh [29]. Samples have been taken with a multi-corer or Van Veen grab sampler (0.1 m2 sampling region, station 6840) into sterile flasks. Sediment samples had been represented by aleurite-pelitic silt with many contents of coarse fraction. 3 horizons were investigated at station 6841, even though at other stations only the surface sediment (0 cm) was analyzed (Table 1).Table 1. The sampling stations. Sampling Station 6840 6841 Sea Depth (m) 1514 385 Coordinates 75.21990 N 13.11843 E 76.06437 N 15.57961 E Sediment Depth (cm) 0 0 6 169 6844 6849 merged study pairs.16S rRNA Gene Sequences 10,140 19,649 16,146 17,395 174,986 23,286 22,101 30777.03582 N 25.58852 E 78.59960 N 35.39939 E 80.59010 N 40.45922 E0 0 0Immediately immediately after lifting the sampler with sediments for the deck, undisturbed sediment samples from each layer of sediment (2.5 cm3) have been taken into sterile cut-edged plastic syringes and sealed using a butyl rubber septum stopper devoid of air access. All radioisotope measurements have been began within two hours right after sampling directly in the laboratory on the study vessel. To analyze the methane content material, two cm3 with the sediment sample was transferred into glass serum vials employing a syringe without a needle. About 0.1 g of KOH was added to each and every vial to stop microbial activity. Seawater, filtered by way of filters using a pore size of 0.two , was added to a sign marking the volume of your tube’s head space, plus the vials had been closed with gas-tight butyl rubber stoppers and crimped with aluminum seals. All samples have been stored upside down at 4 C and analyzed for CH4 concentrations inside 1 month. For molecular genetic research, syringes with sediment samples had been frozen at -18 C and delivered to the laboratory with the Research Center of -AG 99 In Vitro Biotechnology in the Russian Academy of Sciences, Moscow. two.2. Chemical Evaluation The pH and eH values in freshly collected sediments had been measured having a portable ionometer WTW pH 3110 (Germany) with electrodes WTW Electrode Sen Tix ORP and WTW pH-Electrode Sen Tix 41. The pore water was squeezed out by centrifugation with the sediment samples at 8000 g for ten min. Alkalinity on the pore water was determined onboa.