Composition of the Fe-Mn nodules and associated microbial communities of the Kara Sea, Arctic Ocean

2021 ◽  
Author(s):  
Natalia Shulga ◽  
Sergej Abramov ◽  
Sergej Gavrilov ◽  
Konstantin Ryazantsev
Keyword(s):  
Organic Matter ◽  
Microbial Communities ◽  
Organic Matter Content ◽  
Matter Content ◽  
Ore Deposits ◽  
Kara Sea ◽  
Rrna Gene ◽  
Anaerobic Oxidation Of Methane ◽  
Terrestrial Organic Matter ◽  
Russian Science

<p>This work is based on ferromanganese nodules, crusts and underlying sediments collected from the different parts of the Kara Sea shelf (Arctic). The geochemistry, morphology and organic matter content of nodules, crusts and sediments were determined with ICP-MS, SEM-EDS and GC/MS. The associated microbial communities were identified with 16S rRNA (gene) sequencing. Nodules from the Kara Sea shelf significantly differ from their more common abyssal analogues. These shelf nodules have an irregular tabular morphology and relatively low abundances of Mn (up to 19 wt.%), Fe (up to 24 wt.%), other trace metals and the REYs. The Kara Sea nodules show concentric layering that is also typical of deep-sea diagenetic nodules. Samples subdivided into two groups: Mn-rich (Mn/Fe = 0.35 on av.) and Fe-rich (Mn/Fe = 1.65 on av.). The negative Ce anomaly suggests a diagenetic origin of the nodules and crusts. The input of organic matter to the ore deposits in the study area has three main sources (according to n-alkane composition): 1) marine (planctonogenic); 2) low-transformed terrestrial organic matter derived from river run-off; 3) microbial-derived source. Microbial communities of nodules and crusts are substantially different from benthic microbial communities in sediments. They dominated by taxa involved in N cycle, particularly responsible for denitrification (<em>Cyclobacteriaceae</em> and <em>Kiloniellaceae</em>), nitrification (“<em>Candidatus Nitrosopumilus</em>” and <em>Nitrosomonas</em>), comammox (<em>Nitrospira</em>) and anammox (<em>Nitrosococcaceae</em>) [1]. Dissimilatory Fe(III)- and Mn(IV)-reducing Geopsychrobacter was identified in Fe-rich ore samples. This taxon can be involved in Fe(III)- and Mn(IV)-dependent anaerobic oxidation of methane [2]. In contrast, microbial community of underlying sediments dominated by sulfate-reducing bacteria (SRB). Some of the identified SRB (e.g. <em>Desulfobulbaceae</em> and <em>Desulfosarcinaceae</em>) are able to form syntrophic associations with anaerobic methanotrophic archaea [3]. Identified n-alkanes can be oxidized by <em>Anaerolineaceae</em> growing in syntrophic association with methanogens. Furthermore, we revealed that manganese nodules and crusts can be used potentially as important electron acceptors for oxidation of organic compounds by <em>Geopsychrobacter</em>, <em>Desulfuromonadales</em> and <em>Colwellia</em>. Applied multi-disciplinary approach to the study of the Fe-Mn nodules and crusts will help to determine their contribution in formation of unique biogeochemical environments in the Kara Sea.</p><p>This work was supported by the Russian Science Foundation (grant 19-77-00107).</p>

Organic matter content controls the N and P degradation process on biogeochemical interfaces: A micro-ecosystem scale study based on SoilChips-XPS-Zymography integrated technique in paddy soils

2020 ◽  
Author(s):  
Liang Wei
Keyword(s):  
Organic Matter ◽  
Dissolved Organic Matter ◽  
Photoelectron Spectroscopy ◽  
Organic Matter Content ◽  
Degradation Process ◽  
Matter Content ◽  
Microbial Production ◽  
Paddy Soils ◽  
Rrna Gene ◽  
Degradation Processes

<p>The biogeochemical interfaces are hotspots for organic matter (OM) transformation. However, direct and continuouxiacis tracing of OM transformations and N and P degradation processes are lacking due to the heterogeneous and opaque nature of soil microenvironment. To investigate these processes, a new soil microarray technology (SoilChips) was developed and used. Homogeneous 2-mm-diameter SoilChips were constructed by depositing a dispersed paddy soils with high and low soil organic carbon (SOC) content. A horizon suspension on a patterned glass. Dissolved organic matter from the original soil was added on the SoilChips to mimic biogeochemical processes on interfaces. The chemical composition of biogeochemical interfaces were evaluated via X-ray photoelectron spectroscopy (XPS) and the two-dimensional distribution of enzyme activities in SoilChips were evaluated by zymography. Over 30 days, soil with high SOC content increases microbial nutrition (N and P) requirements than soil with low SOC evidenced by higher hotspots of β-1,4-N-acetaminophen glucosidase, and acid phosphomonoesterases and higher 16S rRNA gene copies. The degree of humification in dissolved organic matter (DOM) was higher and the bioavailability of DOM was poorer in soil with high SOC than soil with low SOC. The poorest bioavailability of DOM was detected at the end of incubation in soil with high SOC. Molecular modeling of OM composition showed that low SOC mainly facilitated the microbial production of glucans but high SOC mainly facilitated the microbial production of proteins. We demonstrated that SOC content or DOM availability for microorganisms modifies the specific OM molecular processing and N and P degradation processes, thereby providing a direct insight into biogeochemical transformation of OM at micro-scale.</p>

scholarly journals Soil macroaggregates and organic-matter content regulate microbial communities and enzymatic activity in a Chinese Mollisol

2019 ◽  
Vol 18 (11) ◽  
pp. 2605-2618
Author(s):  
Xu CHEN ◽  
Xiao-zeng HAN ◽  
Meng-yang YOU ◽  
Jun YAN ◽  
Xin-chun LU ◽  
...  
Keyword(s):  
Organic Matter ◽  
Enzymatic Activity ◽  
Microbial Communities ◽  
Organic Matter Content ◽  
Matter Content

Gas seepage pockmark microbiomes suggest the presence of sedimentary coal seams in the Öxarfjörður graben of northeastern Iceland

2020 ◽  
Vol 66 (1) ◽  
pp. 25-38 ◽  
Author(s):  
Guðný Vala Þorsteinsdóttir ◽  
Anett Blischke ◽  
M. Auður Sigurbjörnsdóttir ◽  
Finnbogi Òskarsson ◽  
Þórarinn Sveinn Arnarson ◽  
...  
Keyword(s):  
Organic Matter ◽  
Carbon Isotope ◽  
Isotope Composition ◽  
Organic Matter Content ◽  
Matter Content ◽  
Rrna Gene ◽  
Bacterial Strains ◽  
Bacterial Phyla ◽  
Methane Gas ◽  
Gas Seepage

Natural gas seepage pockmarks are found off- and onshore in the Öxarfjörður graben, Iceland. The bacterial communities of two onshore seepage sites were analysed by 16S rRNA gene amplicon sequencing; the geochemical characteristics, hydrocarbon content, and the carbon isotope composition of the sites were also determined. While one site was found to be characterised by biogenic origin of methane gas, with a carbon isotope ratio (δ13C (‰)) of −63.2, high contents of organic matter and complex hydrocarbons, the other site showed a mixed origin of the methane gas (δ13C (‰) = −26.6) with geothermal characteristics and lower organic matter content. While both sites harboured Proteobacteria as the most abundant bacterial phyla, the Deltaproteobacteria were more abundant at the geothermal site and the Alphaproteobacteria at the biogenic site. The Dehalococcoidia class of phylum Chloroflexi was abundant at the geothermal site while the Anaerolineae class was more abundant at the biogenic site. Bacterial strains from the seepage pockmarks were isolated on a variety of selective media targeting bacteria with bioremediation potential. A total of 106 strains were isolated and characterised, including representatives from the phyla Proteobacteria, Bacteroidetes, Firmicutes, and Actinobacteria. This article describes the first microbial study on gas seepage pockmarks in Iceland.

HEAVY METAL SPECIATION IN BOTTOM SEDIMENTS OF THE VYSHNEVOLOTSKY RESERVOIR

2018 ◽  
pp. 46-54
Author(s):  
O. A. Lipatnikova
Keyword(s):  
Heavy Metal ◽  
Organic Matter ◽  
Bottom Sediments ◽  
Metal Speciation ◽  
Organic Matter Content ◽  
Water Reservoir ◽  
Matter Content ◽  
Heavy Metal Speciation ◽  
Mobile Forms ◽  
Manganese Hydroxides

The study of heavy metal speciation in bottom sediments of the Vyshnevolotsky water reservoir is presented in this paper. Sequential selective procedure was used to determine the heavy metal speciation in bottom sediments and thermodynamic calculation — to determine ones in interstitial water. It has been shown that Mn are mainly presented in exchangeable and carbonate forms; for Fe, Zn, Pb и Co the forms are related to iron and manganese hydroxides is played an important role; and Cu and Ni are mainly associated with organic matter. In interstitial waters the main forms of heavy metal speciation are free ions for Zn, Ni, Co and Cd, carbonate complexes for Pb, fulvate complexes for Cu. Effects of particle size and organic matter content in sediments on distribution of mobile and potentially mobile forms of toxic elements have been revealed.

Physico-Chemical Properties of Soil Collected from Chandrabhaga River in Kalmeshwar, Nagpur, Maharashtra

2020 ◽  
Vol 07 (02) ◽  
pp. 1-3
Author(s):  
Amita M Watkar ◽  
Keyword(s):  
Organic Matter ◽  
Soil Quality ◽  
Agricultural Land ◽  
Organic Matter Content ◽  
Chemical Properties ◽  
Matter Content ◽  
Soil Attributes ◽  
Essential Components ◽  
Agricultural Land Management ◽  
Physical And Chemical

Soil, itself means Soul of Infinite Life. Soil is the naturally occurring unconsolidated or loose covering on the earth’s surface. Physical properties depend upon the amount, size, shape, arrangement, and mineral composition of soil particles. It also depends on the organic matter content and pore spaces. Chemical properties depend on the Inorganic and organic matter present in the soil. Soils are the essential components of the environment and foundation resources for nearly all types of land use, besides being the most important component of sustainable agriculture. Therefore, assessment of soil quality and its direction of change with time is an ideal and primary indicator of sustainable agricultural land management. Soil quality indicators refer to measurable soil attributes that influence the capacity of a soil to function, within the limits imposed by the ecosystem, to preserve biological productivity and environmental quality and promote plant, animal and human health. The present study is to assess these soil attributes such as physical and chemical properties season-wise.

scholarly journals Soil nitrogen supply of peat grasslands estimated by degree days and soil organic matter content

2020 ◽  
Vol 117 (3) ◽  
pp. 351-365
Author(s):  
J. Pijlman ◽  
G. Holshof ◽  
W. van den Berg ◽  
G. H. Ros ◽  
J. W. Erisman ◽  
...  
Keyword(s):  
Organic Matter ◽  
Soil Organic Matter ◽  
Soil Nitrogen ◽  
Organic Matter Content ◽  
Matter Content ◽  
Nitrogen Supply ◽  
Degree Days ◽  
Soil Organic Matter Content ◽  
Soil Nitrogen Supply

scholarly journals Effect of Clay, Soil Organic Matter, and Soil pH on Initial and Residual Weed Control with Flumioxazin

Agronomy ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1326
Author(s):  
Calvin F. Glaspie ◽  
Eric A. L. Jones ◽  
Donald Penner ◽  
John A. Pawlak ◽  
Wesley J. Everman
Keyword(s):  
Organic Matter ◽  
Soil Organic Matter ◽  
Weed Control ◽  
Soil Ph ◽  
Organic Matter Content ◽  
Amaranthus Retroflexus ◽  
Matter Content ◽  
Weed Species ◽  
Soil Organic Matter Content ◽  
Field Soils

Greenhouse studies were conducted to evaluate the effects of soil organic matter content and soil pH on initial and residual weed control with flumioxazin by planting selected weed species in various lab-made and field soils. Initial control was determined by planting weed seeds into various lab-made and field soils treated with flumioxazin (71 g ha−1). Seeds of Echinochloa crus-galli (barnyard grass), Setaria faberi (giant foxtail), Amaranthus retroflexus (redroot pigweed), and Abutilon theophrasti (velvetleaf) were incorporated into the top 1.3 cm of each soil at a density of 100 seeds per pot, respectively. Emerged plants were counted and removed in both treated and non-treated pots two weeks after planting and each following week for six weeks. Flumioxazin control was evaluated by calculating percent emergence of weeds in treated soils compared to the emergence of weeds in non-treated soils. Clay content was not found to affect initial flumioxazin control of any tested weed species. Control of A. theophrasti, E. crus-galli, and S. faberi was reduced as soil organic matter content increased. The control of A. retroflexus was not affected by organic matter. Soil pH below 6 reduced flumioxazin control of A. theophrasti, and S. faberi but did not affect the control of A. retroflexus and E. crus-galli. Flumioxazin residual control was determined by planting selected weed species in various lab-made and field soils 0, 2, 4, 6, and 8 weeks after treatment. Eight weeks after treatment, flumioxazin gave 0% control of A. theophrasti and S. faberi in all soils tested. Control of A. retroflexus and Chenopodium album (common lambsquarters) was 100% for the duration of the experiment, except when soil organic matter content was greater than 3% or the soil pH 7. Eight weeks after treatment, 0% control was only observed for common A. retroflexus and C. album in organic soil (soil organic matter > 80%) or when soil pH was above 7. Control of A. theophrasti and S. faberi decreased as soil organic matter content and soil pH increased. Similar results were observed when comparing lab-made soils to field soils; however, differences in control were observed between lab-made organic matter soils and field organic matter soils. Results indicate that flumioxazin can provide control ranging from 75–100% for two to six weeks on common weed species.

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