scholarly journals Enhanced biotic degradation of terrestrial POM in an estuarine salinity gradient: interactive effects of organic matter pools and changes of bacterial communities

2019 ◽  
Vol 83 (2) ◽  
pp. 147-159
Author(s):  
P Bonin ◽  
AH Prime ◽  
MA Galeron ◽  
S Guasco ◽  
JF Rontani
Keyword(s):  
Organic Matter ◽  
Bacterial Communities ◽  
Salinity Gradient ◽  
Interactive Effects ◽  
Biotic Degradation ◽  
Estuarine Salinity

scholarly journals DOM degradation by light and microbes along the Yukon River-coastal ocean continuum

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Brice K. Grunert ◽  
Maria Tzortziou ◽  
Patrick Neale ◽  
Alana Menendez ◽  
Peter Hernes
Keyword(s):  
Organic Matter ◽  
Dissolved Organic Matter ◽  
Salinity Gradient ◽  
Coastal Ocean ◽  
Interactive Effects ◽  
The Arctic ◽  
Yukon River ◽  
Spring Freshet ◽  
Dom Composition

AbstractThe Arctic is experiencing rapid warming, resulting in fundamental shifts in hydrologic connectivity and carbon cycling. Dissolved organic matter (DOM) is a significant component of the Arctic and global carbon cycle, and significant perturbations to DOM cycling are expected with Arctic warming. The impact of photochemical and microbial degradation, and their interactive effects, on DOM composition and remineralization have been documented in Arctic soils and rivers. However, the role of microbes, sunlight and their interactions on Arctic DOM alteration and remineralization in the coastal ocean has not been considered, particularly during the spring freshet when DOM loads are high, photoexposure can be quite limited and residence time within river networks is low. Here, we collected DOM samples along a salinity gradient in the Yukon River delta, plume and coastal ocean during peak river discharge immediately after spring freshet and explored the role of UV exposure, microbial transformations and interactive effects on DOM quantity and composition. Our results show: (1) photochemical alteration of DOM significantly shifts processing pathways of terrestrial DOM, including increasing relative humification of DOM by microbes by > 10%; (2) microbes produce humic-like material that is not optically distinguishable from terrestrial humics; and (3) size-fractionation of the microbial community indicates a size-dependent role for DOM remineralization and humification of DOM observed through modeled PARAFAC components of fluorescent DOM, either through direct or community effects. Field observations indicate apparent conservative mixing along the salinity gradient; however, changing photochemical and microbial alteration of DOM with increasing salinity indicate changing DOM composition likely due to microbial activity. Finally, our findings show potential for rapid transformation of DOM in the coastal ocean from photochemical and microbial alteration, with microbes responsible for the majority of dissolved organic matter remineralization.

Elevated temperatures drive abiotic and biotic degradation of organic matter in a peat bog under oxic conditions

2022 ◽  
Vol 804 ◽  
pp. 150045
Author(s):  
Roya AminiTabrizi ◽  
Katerina Dontsova ◽  
Nathalia Graf Grachet ◽  
Malak M. Tfaily
Keyword(s):  
Organic Matter ◽  
Elevated Temperatures ◽  
Peat Bog ◽  
Biotic Degradation

scholarly journals Spatio-Temporal Variation of the Bacterial Communities along a Salinity Gradient within a Thalassohaline Environment (Saline di Tarquinia Salterns, Italy)

Molecules ◽  
2021 ◽  
Vol 26 (5) ◽  
pp. 1338
Author(s):  
Susanna Gorrasi ◽  
Andrea Franzetti ◽  
Roberto Ambrosini ◽  
Francesca Pittino ◽  
Marcella Pasqualetti ◽  
...  
Keyword(s):  
Bacterial Diversity ◽  
Generalized Linear Models ◽  
Bacterial Communities ◽  
Linear Models ◽  
Salinity Gradient ◽  
Sampling Site ◽  
Α Diversity ◽  
Spatio Temporal ◽  
Abundance Variation ◽  
Microbiological Aspects

The “Saline di Tarquinia” salterns have been scarcely investigated regarding their microbiological aspects. This work studied the structure and composition of their bacterial communities along the salinity gradient (from the nearby sea through different ponds). The communities showed increasing simplification of pond bacterial diversity along the gradient (particularly if compared to those of the sea). Among the 38 assigned phyla, the most represented were Proteobacteria, Actinobacteria and Bacteroidetes. Differently to other marine salterns, where at the highest salinities Bacteroidetes dominated, preponderance of Proteobacteria was observed. At the genus level the most abundant taxa were Pontimonas, Marivita, Spiribacter, Bordetella, GpVII and Lentibacter. The α-diversity analysis showed that the communities were highly uneven, and the Canonical Correspondence Analysis indicated that they were structured by various factors (sampling site, sampling year, salinity, and sampling month). Moreover, the taxa abundance variation in relation to these significant parameters were investigated by Generalized Linear Models. This work represents the first investigation of a marine saltern, carried out by a metabarcoding approach, which permitted a broad vision of the bacterial diversity, covering both a wide temporal span (two years with monthly sampling) and the entire salinity gradient (from the nearby sea up to the crystallisation ponds).

Interaction of dissolved organic matter with Hg(II) along salinity gradient in Boston Lake

2014 ◽  
Vol 52 (12) ◽  
pp. 1072-1077 ◽  
Author(s):  
Rehemanjiang Wufuer ◽  
Ying Liu ◽  
Shuyong Mu ◽  
Wenjuan Song ◽  
Xue Yang ◽  
...  
Keyword(s):  
Organic Matter ◽  
Dissolved Organic Matter ◽  
Salinity Gradient
Sign in / Sign up

Export Citation Format

Share Document