Search results for "algae"

Macroalgal responses to ocean acidification depend on nutrient and light levels. Frontiers in Marine Science

2015

Ocean acidification may benefit algae that are able to capitalize on increased carbon availability for photosynthesis, but it is expected to have adverse effects on calcified algae through dissolution. Shifts in dominance between primary producers will have knock-on effects on marine ecosystems and will likely vary regionally, depending on factors such as irradiance (light vs. shade) and nutrient levels (oligotrophic vs. eutrophic). Thus experiments are needed to evaluate interactive effects of combined stressors in the field. In this study, we investigated the physiological responses of macroalgae near a CO2 seep in oligotrophic waters off Vulcano (Italy). The algae were incubated in situ …

ANTIOXIDANT AND ANTIMICROBIAL ACTIVITY OF EXTRACTS FROM MARINE ALGAE

2013

Paleoecological constraints on reef-coral morphologies in the Tortonian-early Messinian of the Lorca Basin, SE Spain.

2004

Coral reefs represent one of the main carbonate factories that contributed to the control of the stratigraphic architecture of carbonate platforms, which had a widespread development during the late Miocene in the paleo-Mediterranean area. The late Miocene reef complexes of the Lorca Basin in southeastern Spain are composed of five mixed siliciclastic/carbonate units, middle Tortonian to early Messinian in age. The development of coral reefs probably ceased when the first evaporitic event occurred in the basin centre in the early Messinian. This study mainly focuses on the response of reef communities and the modifications of reef organisation to global and regional parameters. At the platf…

MODELLING OF THE GROWTH OF NANNOCHLOROPSIS GADITANA IN DIFFERENT REACTOR GEOMETRIES, EXPERIMENTAL KINETIC PARAMETERS FROM BATCH CULTURES AND BIOCHEMI…

2022

Microalgae are unicellular and photosynthetic microorganisms that grow using inorganic salts, CO2 and light, and are applied in numerous industrial sectors due to their variety and properties. Due to the lack of information on how microalgae respond to external inputs and to the different environments in which they grow, today the industrial application is not exploited as it should. It is therefore necessary to create models that allow to predict microalgal growth in different photobioreactors to improve our knowledge, still poorly investigated. In this work the Monod equation for the specific growth rate was combined with the Lambert-Beer law for the non-homogeneous light distribution in …

Civil Wastewater Remediation through Employment of Indigenous Microalgae and Sewage Sludge

2022

Microalgae are photosynthetic microorganisms that can employ some inorganic pollutant compounds as nutrients, for example nitrates and phosphates. Traditional wastewater treatment comprises oxidation ponds in which the Activated Sludge performs the oxidation of the organic matter. Microalgae may be well applied in these processes. In this work, we tested the potential of remediation of a mixture of a local microalga, Chlorella sp. Pozzillo, and activated sludge and compared it to controls of only microalga and only activated sludge. We found that the mixture of bacteria and microalgae leads to an improvement in nitrogen removal up to the 83,68%, while phosphorous removal is improved when th…

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

2007

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. The sheath pigment scytonemin was absent in the stream mat but present in the soil and pond mats. …

Influence of hydrogen cations on kinetics and equilibria of heavy-metal sorption by algae-sorption of copper cations by the alga

2012

The influence of hydrogen cations on kinetics and equilibria of sorption of copper cations by the marine alga Palmaria palmata (Linnaeus) Weber & Mohr was studied under static conditions. The competitive effect of the H+ cations is described, which influenced the uncertainty of evaluation of the alga sorption capacity. Under static conditions, the variation of the Cu2+/H+ concentration ratio during sorption was found nonmonotonic. The Langmuir isotherm model was used to determine the sorption capacity of the alga, namely 12.4 mg g−1 of dry algae mass. A similar value was determined from the kinetic parameters of the ionic exchange which is considered a pseudo-second-order chemical reaction.…

Influence of Ecklonia maxima Extracts on Growth, Yield, and Postharvest Quality of Hydroponic Leaf Lettuce

2021

Ecklonia maxima is a brown algae seaweed largely harvested over the last years and used to produce alginate, animal feed, fertilizers, and plant biostimulants. Their extracts are commercially available in various forms and have been applied to many crops for their growth-promoting effects which may vary according to the treated species and doses applied. The aim of the study was to characterize the effect of adding an Ecklonia maxima commercial extract (Basfoliar Kelp

Prospects of in vivo 31P NMR method in glyphosate degradation studies in whole cell system

2009

Abstract The degradation of the phosphonate herbicide glyphosate ( N -phosphonomethylglycine) by four taxonomically distinct microorganisms was studied in vivo in whole cell system using phosphorus nuclear magnetic spectroscopy ( 31 P NMR). The time-course of glyphosate metabolization in dense cell cultures was followed by means of 31 P NMR up to 21 days after the addition. The results obtained by this non-invasive way confirmed that the cells of Spirulina platensis and Streptomyces lusitanus biodegrade herbicide. Moreover, phosphorus starvation influenced the rate of glyphosate degradation by S. platensis . On the other hand, the results of similar measurements in the cultures of green alg…

Environmental effects of tourism and its seasonality on Mediterranean islands: the contribution of the Interreg MED BLUEISLANDS project to build up a…

2020

AbstractThe Mediterranean basin is amongst the world’s main tourist destination, and its islands are a major attraction, being sites of historical, cultural and naturalistic importance. This is beneficial for the local economies, but it may also represent a great burden on the coastal environment, where other human pressures are concentrated. The awareness of detrimental side effects of tourism together with the importance to take into account social and economic facets has led to the concept of sustainable tourism, which, however, represents a goal far from being attained. A good opportunity to promote sustainable tourism was provided by the Interreg MED BLUEISLANDS project, whose main aim…