Effect of nitrogen and phosphorus additions on a benthic microbial mat from a hypersaline lake

Camacho, Antonio; Wit, Rutger de

doi:10.3354/ame032261

Cited by 44 publications

(41 citation statements)

References 48 publications

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“…Stal (2002) observed a strong increase in nitrogenase activity after phosphate fertilization, together with a decrease in oxygen concentration probably due to other metabolic processes. Moreover, phosphorus additions, either alone or supplemented with nitrogen, increased the relative abundance of cyanobacteria with respect to diatoms in intertidal microbial mats (Camacho & de Wit, 2003). However, in other experiments, SRP enrichment did not stimulate N 2 fixation (Paerl et al, 1993).…”

Section: Factors Influencing Cyanobacterial Abundance and Nitrogenasementioning

confidence: 68%

Factors influencing microbial mat composition, distribution and dinitrogen fixation in three western Indian Ocean coral reefs

Charpy

Palińska

Abed

et al. 2012

European Journal of Phycology

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Cyanobacteria have been found to be important for primary production and nitrogen supply on coral reefs. Here, the distribution of cyanobacteria that dominate microbial mats (identified by using microscopic and molecular tools), their abundance, and specific contributions and timing of N 2 fixation, were studied in two coral reef systems of the western Indian Ocean: Mayotte (Comoros) and Tulear (Toliara, Madagascar). The results were compared with previously published data from the reefs of La Re´union Island (Mascarenes). Variations in nutrient levels, temperature and light penetration (Secchi) were also measured and compared. The reefs in Mayotte are situated in oligotrophic ocean waters and support coral reefs in good condition. The reef of Tulear was overgrown by algae. The shallow lagoon and reef in La Re´union showed signs of eutrophication and coral degradation. All three reefs maintained a diverse population of benthic cyanobacterial mats. A total of 13 different cyanobacterial morphotypes were encountered, belonging mainly to the genera Anabaena, Hydrocoleum, Leptolyngbya and Lyngbya (as identified by morphotypes and 16 S RNA analyses), but with variable abundances. Twelve of the 13 dominant cyanobacteria observed in the three sites fixed dinitrogen with daily rates of up to 42 nmol N 2 mg À1 Chl a.Maximum values were achieved by the heterocystous Anabaena sp. during daylight in Mayotte, which exhibited strongly lightstimulated nitrogenase activity. Mats dominated by non-heterocystous cyanobacteria fixed both during daylight and the night, with daily rates up to 38 nmol N 2 mg À1 Chl a (by Lyngbya majuscula, Mayotte). Hydrocoleum-dominated mats fixed N 2 at rates between 0 (H. glutinosum, Tulear) and 23.4 nmol N 2 mg À1 Chl a (H. coccineum, Mayotte). Cyanobacteria are normal constituents of the benthic microflora in tropical regions, but their abundance, diversity and species composition changes with environmental conditions and so do the rates of N 2 fixation on the lagoon floors.

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Section: Factors Influencing Cyanobacterial Abundance and Nitrogenasementioning

confidence: 68%

Factors influencing microbial mat composition, distribution and dinitrogen fixation in three western Indian Ocean coral reefs

Charpy

Palińska

Abed

et al. 2012

European Journal of Phycology

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“…Calm, protected conditions and clear, shallow waters provide ideal environments for the prolific growth of structurally and functionally well-developed microbial mats (Black 1933, Neumann et al 1970, Pinckney et al 1995. These systems are frequently nitrogen depleted, and primary productivity relies on inputs of nitrogen through the activity of nitrogen-fixing diazotrophs (Cyanobacteria and diverse members of Alpha-, Beta-, and Gammaproteobacteria) as well as allochthonous sources in rainfall and runoff (Stal 1995, Camacho & de Wit 2003, Omoregie et al 2004, Yannarell et al 2006.…”

Section: Introductionmentioning

confidence: 99%

Structural and functional responses of microbial mats to reductions in nutrient and salinity stressors in a Bahamian hypersaline lagoon

Pinckney¹,

Long²,

Paerl³

2011

Aquat. Microb. Ecol.

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Microbial mats in Bahamian hypersaline lagoons are affected by the combination of salinity fluctuations and external nutrient inputs, both of which are seasonally variable. The purpose of this study was to examine the singular and combined effects of salinity and nutrient (N+P) stress on primary production, extracellular enzyme activity, and the composition of the photoautotroph community in this episodically varying extreme environment. Anoxygenic phototrophic bacteria were able to increase their relative abundance when nutrients were supplied under hypersaline conditions (300 g l -1). When salinities were lowered (38 g l -1) and nutrients added, extracellular enzyme activity (aminopeptidase, α-glucosidase, and β-glucosidase), rates of oxygenic photosynthesis, and phototroph biomass increased in the oxic surface layers of the mat. Once salinity stress had been lowered, oxygenic photosynthesis allowed the proliferation of Cyanobacteria, heterotrophic activity, and a corresponding reduction in the abundance of anoxygenic phototrophic bacteria. On reduction of nutrient stress, mat phototrophs responded by increasing biomass (using either anoxygenic or oxygenic photosynthesis, or both). In this hypersaline system, seasonal as well as short-term (days) variations in environmental conditions may promote structural changes in the mat community which alter the rates of major processes such as oxygenic photosynthesis and heterotrophy, and illustrate the cyclic behavior of microbial dormancy and proliferation in this extreme environment. Cycles in nutrient input and salinity are primary forcing factors for the maintenance of a dynamic and diverse (both structurally and functionally) benthic microbial community in a small hypersaline lagoon, Salt Pond, on San Salvador Island, Bahamas. KEY WORDS: Cyanobacteria · Photopigments · HPLC · Enzymes · Productivity Resale or republication not permitted without written consent of the publisherAquat Microb Ecol 62: 289-298, 2011 (Paerl et al. 1993, Pinckney et al. 1995, Yannarell et al. 2006. Maximum rates of production and nitrogen fixation occur in a <10 mm thick surface layer during the daytime and nighttime, respectively . Purple anoxygenic photosynthetic bacteria (Chromatium sp.) and chemolithotrophic bacteria (Beggiatoa sp.) migrate from deeper layers to the surface during periods of anoxia in the sediments (Paerl et al. 2003). In the dry months, evaporation leads to hypersaline conditions in which Cyanobacteria are the primary nitrogen-fixers. During wet periods, a more diverse community of bacterial diazotrophs develops within the mat (Yannarell et al. 2006). On annual time scales, the primary environmental control on microbial activity in this lagoon appears to be salinity, which may range from as low as 60 to 90 g l -1 in the wet season (September-January) to a maximum of 340 g l -1 at the end of the dry season in July and August (see Fig. 1) (Yannarell et al. 2006). Lower salinity generally promotes higher metabolic activity, and experimental reduction in salini...

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“…In addition, diatoms sometimes occurred in the mat, particularly on the top surface layer, particularly during spring. These diatoms are favored by high inputs of inorganic nitrogen, i.e., NO 3 -and NH 4+ [20]. In contrast, the cyanobacteria were stimulated by the combined addition of inorganic nitrogen end phosphate [20].…”

Section: Lake Sciences and Climate Change 52mentioning

confidence: 97%

Lake La Salada de Chiprana (NE Spain), an Example of an Athalassic Salt Lake in a Cultural Landscape

Wit¹

2016

Lake Sciences and Climate Change

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On a global scale, athalassic inland salt lakes are abundant, albeit restricted to semiarid and arid climates. La Salada de Chiprana is unique in Western Europe, because it is a permanent and relatively deep (up to 5.6 m) hypersaline lake (40-90 g total dissolved salt L -1 ) since 1700 AD. It forms part of a cultural landscape, which imposes a challenge for management. The aim of this paper is to describe the specific microbial biota and how they interacted with both animals and plant species during the last 25 years. The deeper parts regularly showed salinity stratification with an anoxic sulfide-rich hypolimnion and a bloom of green sulfur bacteria (Prosthecochloris aestuarii and Chlorobium vibrioforme) at the pycnocline. Despite highly eutrophic conditions, often the top water layer is transparent due to top-down control of phytoplankton populations by the brine shrimp, Artemia parthenogenetica. This allows for the development of submerged aquatic vegetation of the endemic foxtail stonewort Lamprothamnium papulosum var. papulosum f. aragonense, and microbial mat communities build by the cyanobacterium Coleofasciculus (Microcoleus) chthonoplastes coexisting with green filamentous nonsulfur bacteria (Chloroflexaceae). The microbial mats show photosynthetically induced precipitation of high-Mg calcite, which by incorporating viruses represents a mechanism for their fossilization.

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Effect of nitrogen and phosphorus additions on a benthic microbial mat from a hypersaline lake

Cited by 44 publications

References 48 publications

Factors influencing microbial mat composition, distribution and dinitrogen fixation in three western Indian Ocean coral reefs

Factors influencing microbial mat composition, distribution and dinitrogen fixation in three western Indian Ocean coral reefs

Structural and functional responses of microbial mats to reductions in nutrient and salinity stressors in a Bahamian hypersaline lagoon

Lake La Salada de Chiprana (NE Spain), an Example of an Athalassic Salt Lake in a Cultural Landscape

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