Physiological responses of the alien macroalga Rugulopteryx okamurae (Phaeophyceae, Heterokontophyta) to changes in nutrients and temperature.

The Asian brown macroalga Rugulopteryx okamurae has invaded the oligotrophic areas of Mediterranean coasts since 2015, with drastic impacts on environmental conditions and socioeconomic activities in coastal areas in Europe. Therefore, it is intriguing how this species is able to grow and expand at the observed rates. In this context, the physiological responses of R.

Modelling bioremediation of contaminated effluents by Ulva ohnoi. - A predictive perspective.

Ulva spp. are tolerant to salinity variations and exhibit easy acclimation, playing an essential role in the depollution of aquatic ecosystems precisely due to their high efficiency in absorbing and accumulating nutrients. For this reason, Ulva spp.

Characterization and Biological Activities of the Ulvan Polysaccharide-Rich Fraction Obtained from Ulva rigida and Ulva pseudorotundata and Their Potential for Pharmaceutical Application.

Seaweed from the genus Ulva (Ulvales, Chlorophyta) has a worldwide distribution and represents a potential biomass source for biotechnological applications. In the present study, we investigated the ulvan polysaccharide-rich fraction (UPRF) isolated from two Ulva species (U. rigida and U.

Analyzing environmental factors that favor the growth of the invasive brown macroalga Rugulopteryx okamurae (Ochrophyta): The probable role of the nutrient excess.

Time series of temperature, salinity and nutrients in the Strait of Gibraltar (SoG) were researched to analyze which factors explain the invasive success of Rugulopteryx okamurare, which has colonized wide coastal areas at the Spanish and Moroccan coasts since 2016. Temperature and salinity were higher in the SoG compared to its native habitat, implying that the alga is active during the whole seasonal cycle and grows optimally at the high salinities occurring in the SoG. Nitrate removal experiments indicate that the alga is able to linearly increase its N uptake rates following boost in nitrate concentration.

Saxitoxins from the freshwater cyanobacterium Raphidiopsis raciborskii can contaminate marine mussels.

Raphidiopsis raciborskii (formerly Cylindrospermopsis raciborskii) is a freshwater cyanobacterium potentially producing saxitoxins (STX) and cylindrospermopsin. Its ecophysiological versatility enables it to form blooms in the most diverse types of environments, from tropical to temperate, and from relatively pristine to polluted. In Peri Lake, located in the subtropical south of Brazil, growing populations of STX-producing R.

Electron & Biomass Dynamics of Under Interacting Nitrogen & Carbon Limitations.

Marine diazotrophs are a diverse group with key roles in biogeochemical fluxes linked to primary productivity. The unicellular, diazotrophic cyanobacterium is widely found in coastal, subtropical oceans. We analyze the consequences of diazotrophy on growth efficiency, compared to NO -supported growth in , to understand how cells cope with N-fixation when they also have to face carbon limitation, which may transiently affect populations in coastal environments or during blooms of phytoplankton communities.

Temporal Patterns and Intra- and Inter-Cellular Variability in Carbon and Nitrogen Assimilation by the Unicellular Cyanobacterium sp. ATCC 51142.

Unicellular nitrogen fixing cyanobacteria (UCYN) are abundant members of phytoplankton communities in a wide range of marine environments, including those with rapidly changing nitrogen (N) concentrations. We hypothesized that differences in N availability (N vs. combined N) would cause UCYN to shift strategies of intracellular N and C allocation.

Cyanobacteria and Red Macroalgae as Potential Sources of Antioxidants and UV Radiation-Absorbing Compounds for Cosmeceutical Applications.

In recent years, research on natural products has gained considerable attention, particularly in the cosmetic industry, which is looking for new bio-active and biodegradable molecules. In this study, cosmetic properties of cyanobacteria and red macroalgae were analyzed. The extractions were conducted in different solvents (water, ethanol and two combinations of water:ethanol).

Short-term effects of increased CO2, nitrate and temperature on photosynthetic activity in Ulva rigida (Chlorophyta) estimated by different pulse amplitude modulated fluorometers and oxygen evolution.

Short-term effects of pCO2 (700-380 ppm; High carbon (HC) and Low carbon (LC), respectively) and nitrate content (50-5 µM; High nitrogen (HN) and Low nitrogen (LN), respectively on photosynthesis were investigated in Ulva rigida (Chlorophyta) under solar radiation (in-situ) and in the laboratory under artificial light (ex-situ). After six days of incubation at ambient temperature (AT), algae were subjected to a 4 °C temperature increase (AT+4 °C) for 3 d. Both in-situ and ex-situ maximal electron transport rate (ETRmax) and in situ gross photosynthesis (GP), measured by O2 evolution, presented highest values under HCHN, and lowest under HCLN, across all measuring systems.

Physiological and biochemical responses driven by different UV-visible radiation in Osmundea pinnatifida (Hudson) Stackhouse (Rhodophyta).

Light, or visible radiation, serves as a source of energy for photosynthesis of plants and most algae. In addition, light and ultraviolet radiation (UV-A and UV-B) act as a biological signal, triggering several cellular processes that are mediated by photoreceptors. The aim of this study was to evaluate the physiological and biochemical responses of Osmundea pinnatifida driven by different radiations through putative photoreceptors.

Microorganism-Based Larval Diets Affect Mosquito Development, Size and Nutritional Reserves in the Yellow Fever Mosquito (Diptera: Culicidae).

Background: Mosquito larvae feed on organic detritus from the environment, particularly microorganisms comprising bacteria, protozoa, and algae as well as crustaceans, plant debris, and insect exuviae. Little attention has been paid to nutritional studies in larvae.

Objectives: We investigated the effects of yeast, bacteria and microalgae diets on larval development, pupation time, adult size, emergence, survivorship, lifespan, and wing morphology.

Phytoremediation potential of Ulva ohnoi (Chlorophyta): Influence of temperature and salinity on the uptake efficiency and toxicity of cadmium.

Ulva ohnoi is a green macroalga with fast growth and high rates of nitrogen and phosphorus absorption. Recently, this species has been recorded in several places with record green tide formation in some of them. Using molecular tools, we herein report the first occurrence of this species in Brazil and demonstrate its potential for phytoremediation in typical environmental concentrations of Cd (0.

UVR and PAR absorbing compounds of marine brown macroalgae along a latitudinal gradient of the Brazilian coast.

Absorption spectra are indicative of biological sample chemical composition and can be used as a basis for the construction of descriptive and predictive models for biotechnological screening or assays. In marine algae, chemical composition can vary due to species-specific differences in biochemistry, as well as intra-specific responses to unique environmental variables. Different indices (UVi, UVi and PARi) were proposed and calculated to evaluate how photoprotective compounds vary in 18 species of Phaeophyceae.

Effects of Ocean Acidification and Temperature Increases on the Photosynthesis of Tropical Reef Calcified Macroalgae.

Climate change is a global phenomenon that is considered an important threat to marine ecosystems. Ocean acidification and increased seawater temperatures are among the consequences of this phenomenon. The comprehension of the effects of these alterations on marine organisms, in particular on calcified macroalgae, is still modest despite its great importance.

Effects of eutrophic seawater and temperature on the physiology and morphology of Hypnea musciformis J. V. Lamouroux (Gigartinales, Rhodophyta).

As both food and source of a kappa-carrageenan, Hypnea musciformis represents a species of great economic interest. It also synthesizes substances with antiviral, anti-helminthic and anti-inflammatory potential and shows promise for use as a bioindicator of cadmium. In this study, we investigated the combined effects of seawater from three urbanized areas (area 1: natural runoff, NRA; area 2: urbanized runoff and sewage with treatment, RTA; area 3: urbanized runoff and untreated sewage, RUS) and three different temperatures (15, 25 and 30 °C) on the growth rate, photosynthetic efficiency, photosynthetic pigments and cell morphology of H.

The effect of different concentrations of copper and lead on the morphology and physiology of Hypnea musciformis cultivated in vitro: a comparative analysis.

Copper and lead, as remnants of industrial activities and urban effluents, have heavily contaminated many aquatic environments. Therefore, this study aimed to determine their effects on the physiological, biochemical, and cell organization responses of Hypnea musciformis under laboratory conditions during a 7-day experimental period. To accomplish this, segments of H.

Photosynthetic performance of restored and natural mangroves under different environmental constraints.

We hypothesized that the photosynthetic performance of mangrove stands restored by the single planting of mangroves species would be lowered due to residual stressors. The photosynthetic parameters of the vegetation of three planted mangrove stands, each with a different disturbance history, were compared to reference sites and correlated with edaphic environmental variables. A permutational analysis of variance showed significant interaction when the factors were compared, indicating that the photosynthetic parameters of the restoration areas differed from the reference sites.

Salinity critical threshold values for photosynthesis of two cosmopolitan seaweed species: providing baselines for potential shifts on seaweed assemblages.

Climate change has increased precipitation in several South American regions leading to higher freshwater inputs into marine systems with potential to cause salinity declines along the coast. The current salinity profile on the southern coast of Brazil was surveyed during four years providing a baseline of the current salinity pattern in the region. Additionally, the effects of salinity decreases on the photosynthesis of the seaweeds Ulva lactuca and Sargassum stenophyllum were investigated in laboratory.