Trophic status and metabolic rates of threatened shallow saline lakes in Central Spain: Providing diagnostic elements for improving management strategies.

Shallow saline lakes in the La Mancha Húmeda Biosphere Reserve in Central Spain show diverse degrees of cultural and natural eutrophication, prompting urgent conservation measures. This study focuses on 17 representative lakes from the site to assess seasonal nutrient dynamics and their connection to plankton metabolism (photosynthesis and respiration) during two successive hydrological periods. Effect of environmental factors was evaluated on a combination of several response variables, demonstrating that source of the nutrient inputs (ranging from natural to anthropic) had the highest influence on the nutrients stoichiometry and metabolic rates.

Ecological status and type of alteration determine the C-balance and climate change mitigation capacity of Mediterranean inland saline shallow lakes.

Saline shallow lakes may play an important role in carbon exchange with the atmosphere, but their alteration may change carbon balance and greenhouse gas emissions patterns. This study investigated the relationship between carbon metabolic processes and environmental factors, focusing on alterations in salinity, hydroperiod length, and trophic status. The results revealed that disruptions to natural salinity patterns, driven by hydrological changes and ecological degradation, enhanced carbon greenhouse gas emitting metabolisms.

Naturalization of treated wastewater by a constructed wetland in a water-scarce Mediterranean region.

The effluents from conventional wastewater treatment plants (WWTP), even if accomplishing quality regulations, substantially differ in their characteristics with those of waters in natural environments. Constructed wetlands (CWs) serve as transitional ecosystems within WWTPs, mitigating these differences and restoring natural features before water is poured into the natural environment. Our study focused on an experimental surface-flow CW naturalizing the WWTP effluent in a semiarid area in Eastern Spain.

A Deep Insight into the Diversity of Microfungal Communities in Arctic and Antarctic Lakes.

We assessed fungal diversity in water and sediment samples obtained from five Arctic lakes in Ny-Ålesund (Svalbard Islands, High Arctic) and five Antarctic lakes on Livingston and Deception Islands (South Shetland Islands), using DNA metabarcoding. A total of 1,639,074 fungal DNA reads were detected and assigned to 5980 ASVs amplicon sequence variants (ASVs), with only 102 (1.7%) that were shared between the two Polar regions.

Effect of experimentally increased nutrient availability on the structure, metabolic activities, and potential microbial functions of a maritime Antarctic microbial mat.

The role of competitive interactions based on resource utilisation was explored in a phototrophic microbial mat from Byers Peninsula (Maritime Antarctica). Shotgun metagenomic profiling of the mat showed a taxonomic and functionally diverse microbial community. The heterotrophic bacterial community was dominated by Proteobacteria, where genera typically found in polar habitats, such as , , and , were highly prevalent.

Effects of Soil Quality on the Microbial Community Structure of Poorly Evolved Mediterranean Soils.

Physical and chemical alterations may affect the microbiota of soils as much as the specific presence of toxic pollutants. The relationship between the microbial diversity patterns and the soil quality in a Mediterranean context is studied here to test the hypothesis that soil microbiota is strongly affected by the level of anthropogenic soil alteration. Our aim has been to determine the potential effect of organic matter loss and associated changes in soil microbiota of poorly evolved Mediterranean soils ( and ) suffering anthropogenic stress (i.

Functional Metabolic Diversity of Bacterioplankton in Maritime Antarctic Lakes.

A summer survey was conducted on the bacterioplankton communities of seven lakes from Byers Peninsula (Maritime Antarctica), differing in trophic and morphological characteristics. Predictions of the metabolic capabilities of these communities were performed with FAPROTAX using 16S rRNA sequencing data. The versatility for metabolizing carbon sources was also assessed in three of the lakes using Biolog Ecoplates.

Carbon metabolic rates and GHG emissions in different wetland types of the Ebro Delta.

Deltaic wetlands are highly productive ecosystems, which characteristically can act as C-sinks. However, they are among the most threatened ecosystems, being very vulnerable to global change, and require special attention towards its conservation. Knowing their climate change mitigating potential, conservation measures should also be oriented with a climatic approach, to strengthen their regulatory services.

Bacterioplankton Community Composition Along Environmental Gradients in Lakes From Byers Peninsula (Maritime Antarctica) as Determined by Next-Generation Sequencing.

This study comprises the first attempt to describe the planktonic bacterial communities of lakes from Byers Peninsula, one of the most significant limnological districts in the Maritime Antarctica, leveraging next-generation sequencing (NGS) technologies. For the survey, we selected 7 lakes covering the environmental gradient from inland to coastal lakes, some of them sampled both in surface and deep waters. Analysis provided just over 85,000 high quality sequences that were clustered into 864 unique Zero-radius Operational Taxonomic Units (ZOTUs) (i.

Effect of wastewater management on phosphorus content and sedimentary fractionation in Mediterranean saline lakes.

The La Mancha Húmeda Biosphere Reserve is the largest wetland district in the Iberian Peninsula, containing many temporary saline lakes undergoing different anthropogenic pressures. Eleven of these lakes were selected to assess phosphorus (P) burial, fractionation and mobilization in their sediments. Wastewater inputs, wherever they occurred, favored accumulation of all P sedimentary fractions, which took place mainly via precipitation with divalent cations (i.

Efficiency in hydrocarbon degradation and biosurfactant production by Joostella sp. A8 when grown in pure culture and consortia.

Joostella strains are emerging candidates for biosurfactant production. Here such ability was analyzed for Joostella strain A8 in comparison with Alcanivorax strain A53 and Pseudomonas strain A6, all previously isolated from hydrocarbon enrichment cultures made of polychaete homogenates. In pure cultures Joostella sp.

Temperature Effects Explain Continental Scale Distribution of Cyanobacterial Toxins.

Insight into how environmental change determines the production and distribution of cyanobacterial toxins is necessary for risk assessment. Management guidelines currently focus on hepatotoxins (microcystins). Increasing attention is given to other classes, such as neurotoxins (e.

Prokaryotic assemblages in the maritime Antarctic Lake Limnopolar (Byers Peninsula, South Shetland Islands).

The potentially metabolically active components within the prokaryotic assemblages inhabiting the Antarctic Lake Limnopolar (Byers Peninsula, Maritime Antarctica) were investigated by a polyphasic approach which included culture-dependent and culture-independent methods (based on RNA molecules). Results support previous observations on the Proteobacteria and Bacteroidetes dominance, followed by Actinobacteria, in Antarctic lakes. In particular, Alpha-, Betaproteobacteria and Bacteroidetes were mainly detected by CARD-FISH and cDNA cloning, whereas Gammaproteobacteria and Actinobacteria dominated within the cultivable fraction.

Prokaryotic Community in Lacustrine Sediments of Byers Peninsula (Livingston Island, Maritime Antarctica).

Byers Peninsula (Livingston Island, Antarctica), the largest seasonally ice-free region of the Maritime Antarctica, holds a large number of lakes, ponds, and streams. The prokaryotic structure and bacterial diversity in sediment samples collected during the 2008-2009 austral summer from five inland lakes, two coastal lakes, and an estuarine site were analyzed by Catalyzed Reporter Deposition Fluorescence In Situ Hybridization (CARD-FISH) and 16S rRNA 454 tag pyrosequencing techniques, respectively. Differently from inland lakes, which range around the oligotrophic status, coastal lakes are eutrophic environments, enriched by nutrient inputs from marine animals.

Total mercury and methyl-mercury contents and accumulation in polar microbial mats.

Although polar regions are considered isolated and pristine areas, the organisms that inhabit these zones are exposed to global pollution. Heavy metals, such as mercury, are global pollutants and can reach almost any location on Earth. Mercury may come from natural, volcanic or geological sources, or result from anthropogenic sources, in particular industrial or mining activities.

A close link between bacterial community composition and environmental heterogeneity in maritime Antarctic lakes.

Seven maritime Antarctic lakes located on Byers Peninsula (Livingston Island, South Shetland Islands) were surveyed to determine the relationship between planktonic bacterial community composition and environmental features. Specifically, the extent to which factors other than low temperature determine the composition of bacterioplankton assemblages of maritime Antarctic lakes was evaluated. Both deep and shallow lakes in the central plateau of the Peninsula, as well as a coastal lake, were studied in order to fully account for the environmental heterogeneity of the Peninsula's lakes.

Community structure and physiological characterization of microbial mats in Byers Peninsula, Livingston Island (South Shetland Islands, Antarctica).

The community structure and physiological characteristics of three microbial mat communities in Byers Peninsula (Livingston Island, South Shetland Islands, Antarctica) were compared. One of the mats was located at the edge of a stream and was dominated by diatoms (with a thin basal layer of oscillatorian cyanobacteria), whereas the other two mats, located over moist soil and the bottom of a pond, respectively, were dominated by cyanobacteria throughout their vertical profiles. The predominant xanthophyll was fucoxanthin in the stream mat and myxoxanthophyll in the cyanobacteria-dominated mats.

Spatial dominance and inorganic carbon assimilation by conspicuous autotrophic biofilms in a physical and chemical gradient of a cold sulfurous spring: the role of differential ecological strategies.

The community composition and ecophysiological features of microbial autotrophic biofilms were studied in Fuente Podrida, a cold sulfur spring located in East Spain. We demonstrated how different ecophysiological strategies, such as resistance and/or utilization of sulfide and oxygen, light adaptation, or resistance to high water flow, allow each of the microorganisms described to efficiently colonize several areas within the environmental gradient. In the zone of the spring constantly influenced by sulfide-rich waters, biofilms were formed by purple bacteria, cyanobacteria, and filamentous colorless sulfur bacteria.