Growth and phosphatase activities of Ostreopsis cf. ovata biofilms supplied with diverse dissolved organic phosphorus (DOP) compounds

It is becoming increasingly evident that the use of organic nutrients is widespread among many aquatic phototrophic organisms. Simultaneously, incidents of eutrophication of coastal waters are becoming more common due to rises in organic nutrient loads deriving from anthropogenic activities and natural terrestrial processes. In the northern Adriatic Sea, blooms of the toxic dinoflagellate Ostreopsis cf. ovata are reported as a frequent phenomenon linked to particular environmental conditions, including increased organic nutrient loads. Ostreopsis blooms typically produce a mucilaginous biofilm that can cover all benthic substrata. In order to clarify the role of dissolved organic phosphorus (DOP) in the onset and maintenance of an O. cf. ovata bloom, we investigated the growth rates in the presence of a range of phosphomonoesters (PMEs) (D-fructose 1,6-disphosphate, β-glycerophosphate, α-D-glucose 1-phosphate, guanosine 5’-monophosphate and phytic acid) and phosphodiesters (PDEs) (DNA and RNA). Levels of both phosphomonoesterase (PMEase) and phosphodiesterase (PDEase) activities were assessed in the O. cf. ovata biofilms. The results showed that O. cf. ovata growth is not inhibited in media containing a wide range of DOP and diverse ratios of PME:PDE compared to those containing inorganic phosphorus. Much of the hydrolytic activity was associated with bacteria and with extracellular polymeric substances (EPSs). Our findings suggest that the success of O. cf. ovata stems from the collective participation of all components of the biofilm (O. cf. ovata, EPSs and bacteria) that allows it to thrive in phosphorus-limited environments, but where the main source of phosphorus is organic.

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Mechanisms of production and fate of organic phosphorus in the northern Adriatic Sea

Marine Biology ◽

10.1007/bf00392904 ◽

1987 ◽

Vol 94 (1) ◽

pp. 117-125 ◽

Cited By ~ 13

Author(s):

I. Ivančić ◽

D. Degobbis

Keyword(s):

Adriatic Sea ◽

Organic Phosphorus ◽

Northern Adriatic Sea ◽

Northern Adriatic

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Processing of Metals and Metalloids by Actinobacteria: Cell Resistance Mechanisms and Synthesis of Metal(loid)-Based Nanostructures

Microorganisms ◽

10.3390/microorganisms8122027 ◽

2020 ◽

Vol 8 (12) ◽

pp. 2027

Author(s):

Alessandro Presentato ◽

Elena Piacenza ◽

Raymond J. Turner ◽

Davide Zannoni ◽

Martina Cappelletti

Keyword(s):

Extracellular Polymeric Substances ◽

Anthropogenic Activities ◽

Resistance Mechanisms ◽

Biological Properties ◽

Ecological Niches ◽

Economic Interests ◽

Natural Processes ◽

Technological Value ◽

Inorganic Substances ◽

Wide Range

Metal(loid)s have a dual biological role as micronutrients and stress agents. A few geochemical and natural processes can cause their release in the environment, although most metal-contaminated sites derive from anthropogenic activities. Actinobacteria include high GC bacteria that inhabit a wide range of terrestrial and aquatic ecological niches, where they play essential roles in recycling or transforming organic and inorganic substances. The metal(loid) tolerance and/or resistance of several members of this phylum rely on mechanisms such as biosorption and extracellular sequestration by siderophores and extracellular polymeric substances (EPS), bioaccumulation, biotransformation, and metal efflux processes, which overall contribute to maintaining metal homeostasis. Considering the bioprocessing potential of metal(loid)s by Actinobacteria, the development of bioremediation strategies to reclaim metal-contaminated environments has gained scientific and economic interests. Moreover, the ability of Actinobacteria to produce nanoscale materials with intriguing physical-chemical and biological properties emphasizes the technological value of these biotic approaches. Given these premises, this review summarizes the strategies used by Actinobacteria to cope with metal(loid) toxicity and their undoubted role in bioremediation and bionanotechnology fields.

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Mechanisms of production and fate of organic phosphorus in the northern Adriatic Sea

Deep Sea Research Part B Oceanographic Literature Review ◽

10.1016/0198-0254(87)90134-8 ◽

1987 ◽

Vol 34 (9) ◽

pp. 750

Keyword(s):

Adriatic Sea ◽

Organic Phosphorus ◽

Northern Adriatic Sea ◽

Northern Adriatic

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Climatic and Anthropogenic Impacts on Environmental Conditions and Phytoplankton Community in the Gulf of Trieste (Northern Adriatic Sea)

Water ◽

10.3390/w12092652 ◽

2020 ◽

Vol 12 (9) ◽

pp. 2652 ◽

Cited By ~ 1

Author(s):

Stefano Cozzi ◽

Marina Cabrini ◽

Martina Kralj ◽

Cinzia De Vittor ◽

Massimo Celio ◽

...

Keyword(s):

Management Practices ◽

Phytoplankton Community ◽

Anthropogenic Impacts ◽

Nutrient Balance ◽

Environmental Data ◽

Data Series ◽

Nutrient Loads ◽

Northern Adriatic Sea ◽

Northern Adriatic ◽

Gulf Of Trieste

During the last century, human activities have exerted an increasing pressure on coastal ecosystems, primarily inducing their eutrophication, with a more recent partial mitigation of this phenomenon where improvements of environmental management practices were adopted. However, a reanalysis of the pressures on coastal zones and surrounding drainage basins is needed because of the alterations induced nowadays by the climate changes. A comparative analysis of long-term oceanographic and environmental data series (1986–2018) was performed, in order to highlight the effects of anthropogenic and climatic disturbances on the phytoplankton community in the Gulf of Trieste (GoT). After the 1980s, the decline in phytoplankton abundance was matched to increasing periods of low runoff, an overall deficit of the precipitation and to a decrease in phosphate availability in the coastal waters (−0.003 µmol L−1 yr−1), even in the presence of large riverine inputs of nitrogen and silicates. This trend of oligotrophication was reversed in the 2010s by the beginning of a new and unexpected phase of climatic instability, which also caused changes of the composition and seasonal cycle of the phytoplankton community. Beyond the management of nutrient loads, it was shown that climatic drivers such as seawater warming, precipitation and wind regime affect both nutrient balance and phytoplankton community in this coastal zone.

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Ecological Importance of Alkaline Phosphatase Activity in Changing Marine Environmental Conditions

Water ◽

10.3390/w13192750 ◽

2021 ◽

Vol 13 (19) ◽

pp. 2750

Author(s):

Ingrid Ivančić ◽

Romina Kraus ◽

Mirjana Najdek ◽

Stefano Cozzi

Keyword(s):

Alkaline Phosphatase ◽

Phosphatase Activity ◽

Alkaline Phosphatase Activity ◽

Climatic Conditions ◽

Nutrient Loads ◽

Northern Adriatic Sea ◽

Po River ◽

Coastal System ◽

Northern Adriatic ◽

P Limitation

The effects of changing hydrological and climatic conditions on the dynamics of phosphorus (P) were studied in the Northern Adriatic Sea (NA), a coastal system currently affected by these changes. P limitation is one of the key stresses in the NA and it is a globally important phenomenon in aquatic ecosystems. Therefore, the response to P stress by inducing alkaline phosphatase activity (APA) was studied in characteristic water types in the NA, formed by the changing freshwater input in different thermic conditions. APA was important in providing P for microbial growth in upper waters dominated by assimilation during the warmer part of the year in stratified conditions. Contrarily, APA was not important during mixing in the colder part of the year, as well as in waters dominated by regeneration. In waters influenced by freshwater, temperature had no effect on APA, while in high-salinity waters, temperature was an important factor for APA increase. The highest APA occurred during riverine nutrients supply, indicating that the alteration of anthropogenic nutrient loads might strongly change P status in this coastal system. Furthermore, predicted increases in winter sea temperature and summer Po River discharge could delay the water column mixing, prolonging periods of P limitation.

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Trends of Nitrogen and Phosphorus in Surface Sediments of the Lagoons of the Northern Adriatic Sea as a Study Case

Water ◽

10.3390/w13202914 ◽

2021 ◽

Vol 13 (20) ◽

pp. 2914

Author(s):

Adriano Sfriso ◽

Alessandro Buosi ◽

Yari Tomio ◽

Abdul-Salam Juhmani ◽

Michele Mistri ◽

...

Keyword(s):

Surface Sediments ◽

Adriatic Sea ◽

Organic Phosphorus ◽

Anthropogenic Impacts ◽

Venice Lagoon ◽

Nutrient Concentrations ◽

Nitrogen And Phosphorus ◽

Northern Adriatic Sea ◽

Northern Adriatic ◽

Po Delta

The analysis of nutrient concentrations in surface sediments is a reliable tool for assessing the trophic status of a water body. Nitrogen and phosphorus concentrations are strongly related to the sediment characteristics but are mainly driven by anthropogenic impacts. The results of the determination of total nitrogen and total inorganic and organic phosphorus in surface sediments of the lagoons and ponds of the northwestern Adriatic Sea (Marano-Grado, Venice, Po Delta, Comacchio Valleys, Pialassa della Baiona) show the merit of this approach. Indeed, when previous data are available, the ratio between the actual and background values can provide useful information on the trophic changes that have occurred in the most recent times, and the results can also explain the conditions present in less studied environments. In this context, numerous studies performed in the Venice lagoon since the second half of the 20th century during different environmental scenarios provide mean concentration ranges and propose the main causes of changes. The results of single datasets available for the other lagoons fall into scenarios that occurred in the Venice lagoon. At present, the most eutrophic basins are Pialassa della Baiona, the Po Delta lagoons and ponds and the Comacchio valleys due to industrial effluents, fish farming and clam harvesting, respectively, whereas the Venice lagoon is now experiencing environmental recovery.

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Natural Recovery and Planned Intervention in Coastal Wetlands: Venice Lagoon (Northern Adriatic Sea, Italy) as a Case Study

The Scientific World JOURNAL ◽

10.1155/2014/968618 ◽

2014 ◽

Vol 2014 ◽

pp. 1-15 ◽

Cited By ~ 14

Author(s):

Chiara Facca ◽

Sonia Ceoldo ◽

Nicola Pellegrino ◽

Adriano Sfriso

Keyword(s):

Organic Phosphorus ◽

Sustainable Use ◽

Venice Lagoon ◽

Detailed Knowledge ◽

Nutrient Inputs ◽

Anthropogenic Pressures ◽

Northern Adriatic Sea ◽

Northern Adriatic ◽

Seagrass Meadows ◽

Carbon Concentrations

The goals of conservation and sustainable use of environmental ecosystems have increased the need for detailed knowledge of ecological evolution and responses to both anthropogenic pressures and recovery measures. The present study shows the effects of natural processes and planned intervention in terms of reducing nutrient inputs in a highly exploited coastal lagoon, describing its evolution over a 16-year period from the late 1980s (when eutrophication was at its peak) until 2003. Changes in nutrient and carbon concentrations in the top layer of sediments were investigated in parallel with macroalgal and seagrass biomass in the most anthropized basin of Venice Lagoon in four surveys conducted in accordance with the same protocols in 1987, 1993, 1998, and 2003. A pronounced reduction in trophic state (mainly total nitrogen, organic phosphorus, and organic carbon concentrations) and macroalgal biomass was recorded, together with the progressive expansion of seagrass meadows. General considerations are also made on the effects of Manila clam farming and the shift from illegal to managed clam farming.

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Spatial distribution of microphytobenthos, meiofauna and macrofauna in the north-western Adriatic Sea: a synoptic study

Advances in Oceanography and Limnology ◽

10.4081/aiol.2015.5470 ◽

2015 ◽

Vol 6 (1/2) ◽

Cited By ~ 4

Author(s):

Annalisa Franzo ◽

Tamara Cibic ◽

Paola Del Negro ◽

Cinzia De Vittor

Keyword(s):

Adriatic Sea ◽

Multiple Stressors ◽

Inorganic Nitrogen ◽

Benthic Communities ◽

Nutrient Loads ◽

Northern Adriatic Sea ◽

Sediment Grain Size ◽

Coastal System ◽

Northern Adriatic ◽

Station Grid

In view of the general paucity of integrated information on offshore benthic communities in the Adriatic Sea and given the vulnerability of this particular coastal system, microphytobenthos, meiofauna and macrofauna were synoptically investigated in front of the Emilia-Romagna coast (northern Adriatic Sea) in September 2010 and March 2011. As required by the Marine Strategy Framework Directive, which extends its action beyond the territorial waters (within 12 nmi) of the Member States, our findings could help to fill the gap of knowledge on the environmental status in offshore areas since the study was carried out also at >12 nmi from the coastline. In fact, sediment samples for the analysis of the benthic communities were collected from a 10-point-station grid that covered an area of about 400 km2 with water depths ranging from 13 to 50 m. The variability of the sediment grain size and other chemical variables in the sediment suggests the presence of two distinct environmental contexts that enhance the proliferation of different benthic communities. At the inshore stations (depth <20 m) the higher sand percentages and the maxima of dissolved inorganic nitrogen concentrations indicate the presence of hydrodynamic perturbations and the influence of nutrient loads of terrestrial origin. Inshore, both meio- and macrofaunal communities were poorly structured and dominated by relatively more opportunistic taxa, such as nematodes and the bivalve Corbula gibba. Offshore stations (depth >20 m) had muddier sediments, which likely exerted a greater retention of sediment-bound organic matter. These conditions seemed to favour benthic deposit feeders like meio- and macrofaunal annelids. Surprisingly, a conspicuous microphytobenthic community, mainly represented by the diatom Paralia sulcata, has been observed even at remarkable depths (~50 m) opening new questions regarding the role of these organisms in dim-light conditions. Although the investigated benthic communities were, to some extent, moderately influenced by multiple stressors, the co-existence of sensitive taxa (such as meiofaunal copepods and the amphipod Ampelisca spp.) with opportunistic ones (i.e., C. gibba) suggests that the benthic domain in the investigated area is not severely impacted.

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