scholarly journals Microbial population genomes from the Amazon River reveal possible modulation of the organic matter degradation process in tropical freshwaters

2021 ◽  
Author(s):  
Célio Dias Santos‐Júnior ◽  
Ramiro Logares ◽  
Flávio Henrique‐Silva
Keyword(s):  
Organic Matter ◽  
Microbial Population ◽  
Degradation Process ◽  
Amazon River ◽  
Organic Matter Degradation ◽  
Tropical Freshwaters

scholarly journals Timescales for the development of methanogenesis and free gas layers in recently-deposited sediments of Arkona Basin (Baltic Sea)

2012 ◽  
Vol 9 (5) ◽  
pp. 1915-1933 ◽  
Author(s):  
J. M. Mogollón ◽  
A. W. Dale ◽  
H. Fossing ◽  
P. Regnier
Keyword(s):  
Organic Matter ◽  
Baltic Sea ◽  
Reactive Transport ◽  
Reaction Pathway ◽  
Organic Matter Degradation ◽  
Muddy Sediment ◽  
Transport Models ◽  
Methane Gas ◽  
Geochemical Profiles ◽  
Arkona Basin

Abstract. Arkona Basin (southwestern Baltic Sea) is a seasonally-hypoxic basin characterized by the presence of free methane gas in its youngest organic-rich muddy stratum. Through the use of reactive transport models, this study tracks the development of the methane geochemistry in Arkona Basin as this muddy sediment became deposited during the last 8 kyr. Four cores are modeled each pertaining to a unique geochemical scenario according to their respective contemporary geochemical profiles. Ultimately the thickness of the muddy sediment and the flux of particulate organic carbon are crucial in determining the advent of both methanogenesis and free methane gas, the timescales over which methanogenesis takes over as a dominant reaction pathway for organic matter degradation, and the timescales required for free methane gas to form.

Beneficial effect of mixture of additives amendment on enzymatic activities, organic matter degradation and humification during biosolids co-composting

2018 ◽  
Vol 247 ◽  
pp. 138-146 ◽  
Author(s):  
Mukesh Kumar Awasthi ◽  
Quan Wang ◽  
Hongyu Chen ◽  
Sanjeev Kumar Awasthi ◽  
Meijing Wang ◽  
...  
Keyword(s):  
Organic Matter ◽  
Beneficial Effect ◽  
Enzymatic Activities ◽  
Organic Matter Degradation

Tracing soil organic carbon in the lower Amazon River and its tributaries using GDGT distributions and bulk organic matter properties

2012 ◽  
Vol 90 ◽  
pp. 163-180 ◽  
Author(s):  
Jung-Hyun Kim ◽  
Claudia Zell ◽  
Patricia Moreira-Turcq ◽  
Marcela A.P. Pérez ◽  
Gwenaël Abril ◽  
...  
Keyword(s):  
Organic Matter ◽  
Organic Carbon ◽  
Soil Organic Carbon ◽  
Amazon River ◽  
Bulk Organic Matter

scholarly journals Effects of pH on aquatic biodegradation processes

2009 ◽  
Vol 6 (1) ◽  
pp. 491-514 ◽  
Author(s):  
R. F. Krachler ◽  
R. Krachler ◽  
A. Stojanovic ◽  
B. Wielander ◽  
A. Herzig
Keyword(s):  
Organic Matter ◽  
Lake Water ◽  
Decomposition Rate ◽  
Degradation Mechanism ◽  
Ph Dependence ◽  
Degradation Process ◽  
Plant Litter ◽  
Lake Basin ◽  
Causal Connection ◽  
Ph Values

Abstract. To date, little is known about the pH-stimulated mineralization of organic matter in aquatic environments. In this study, we investigated biodegradation processes in alkaline waters. Study site is a large shallow soda lake in Central Europe (Neusiedler See/Ferto). The decomposition rate of plant litter was measured as a function of pH by incubating air-saturated lake-water samples in contact with Phragmites litter (leaves) from the littoral vegetation. All samples showed high decomposition rates (up to 32% mass loss within 35 days) and a characteristic two-step degradation mechanism. During the degradation process, the solid plant litter was dissolved forming humic colloids. Subsequently, the humic colloids were mineralized to CO2 in the water column. The decomposition rate was linearly related to pH. Increasing pH values accelerated significantly the leaching of humic colloids as well as the final degradation process. The observed two-step mechanism controls the wetland/lake/air carbon fluxes, since large quantities of humic colloids are currently produced in the reed belt, exported through wind-driven circulations and incorporated into the open lake foodweb. At present, the lake is rapidly shrinking due to peat deposition in the littoral zone, whereas it has been resistant to silting-up processes for thousands of years. In order to investigate the cause of this abrupt change, the chemical composition of the lake-water was measured during 1995–2007. A thorough analysis of these data revealed that major lake-water discharges through the lake's artificial outlet channel led to a decline in salinity and alkalinity. According to our estimates, the lake's original salinity and alkalinity was 70–90% higher compared to the present conditions, with the consequence of substantially lower pH values in the present lake. The observed pH dependence of reed litter biodegradation rates points to a causal connection between low pH values and accumulation of peat in the lake basin. Our results suggest that the pH stimulated remineralisation of organic matter plays a major role in maintaining the long-term integrity of saline lake/wetland systems.

scholarly journals Nitrogen mineralization and microbial activity as influenced by sulfur sources in an alkaline calcareous soil

1970 ◽  
pp. 14-18
Author(s):  
Tufail Shah ◽  
Zahir Shah ◽  
Syed Atizaz Ali Shah ◽  
Nazir Ahmad
Keyword(s):  
Organic Matter ◽  
Sulfuric Acid ◽  
Microbial Activity ◽  
Calcareous Soil ◽  
Bacterial Population ◽  
Elemental Sulfur ◽  
Microbial Population ◽  
Organic Matter Content ◽  
Matter Content ◽  
Fungal Population

A study was performed to check the effects of various sources of sulfur on microbial activity, microbial population, N mineralization and organic matter content in an alkaline calcareous soil by using soil samples collected from Malakandher Farm at 0-20 cm depth, and analyzed for microbial activity, total mineral nitrogen, bacterial and fungal population and organic matter content. The results showed that the rate of CO2 evolution and cumulative CO2 production were higher in soils amended with elemental sulfur followed by sulfuric acid and gypsum treated soils. The microbial activity decreased with incubation period in all treatments, and the microbial population was greatly affected by sulfur sources. Generally, the bacterial population decreased in soils amended with elemental sulfur, but the population was higher in soils amended with gypsum. Bacterial population was suppressed in soils treated with sulfuric acid. However, the fungal population was higher in soils amended with sulfuric acids was less in soil amended with elemental sulfur. The sulfur amendments promoted immobilization of N. The net N immobilized was higher in soil amended with gypsum followed by soils amended with sulfuric acid and elemental sulfur. The percent organic matter was higher in soils amended with gypsum and was decreased compared with that amended with elemental sulfur or sulfuric acid. These results suggested that soil microbiological properties changed with sulfur amendments during laboratory incubation.

scholarly journals Uncovering the gene machinery of the Amazon River microbiome to degrade rainforest organic matter

2019 ◽  
Author(s):  
Célio Dias Santos ◽  
Hugo Sarmento ◽  
Fernando Pellon de Miranda ◽  
Flávio Henrique-Silva ◽  
Ramiro Logares
Keyword(s):  
Organic Matter ◽  
Lignin Degradation ◽  
Amazon River ◽  
Spatial Distributions ◽  
Gene Repertoire ◽  
Terrestrial Organic Matter ◽  
Incubation Experiments ◽  
Degradation Rates ◽  
Redundant Genes ◽  
Gene Functions

ABSTRACTThe Amazon River receives, from the surrounding rainforest, huge amounts of terrestrial organic matter (TeOM), which is typically resistant to microbial degradation. However, only a small fraction of the TeOM ends up in the ocean, indicating that most of it is degraded in the river. So far, the nature of the genes involved in TeOM degradation and their spatial distributions are barely known. Here, we examined the Amazon River microbiome gene repertoire and found that it contains a substantial gene-novelty, compared to other environments (rivers and rainforest soil). We predicted ~3.7 million non-redundant genes, affiliating mostly to bacteria. The gene-functions involved in TeOM degradation revealed that lignin degradation correlated to tricarboxylates and hemicellulose processing, pointing to higher lignin degradation rates under consumption of labile compounds. We describe the biochemical machinery that could be speeding up the decomposition of recalcitrant compounds in Amazonian waters, previously reported only in incubation experiments.

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