Search

Future atmospheric CO2 levels will most likely have complex consequences for marine organisms, particulary photosynthetic calcifying organisms. Corallina officinalis L. is an erect calcifying macroalga found in the inter- and subtidal regions of temperate rocky coastlines and provides important substrate and refugia for marine meiofauna. The main goal of the current study was to determine the physiological responses of C. officinalis to increased CO2 concentrations expected to occur within the next century and beyond. Our results show that growth and production of inorganic material decreased under high CO2 levels, while carbonic anhydrase activity was stimulated and negatively correlated to algal inorganic content. Photosynthetic efficiency based on oxygen evolution was also negatively affected by increased CO2. The results of this study indicate that C. officinalis may become less competitive under future CO2 levels, which could result in structural changes in future temperate intertidal communities. Federal Ministry of Education & Research (BMBF)

There is an increasing demand for natural antioxidant molecules in order to replace the synthetic additives in the food industry. Gracilaria Bursa-pastoris (Gmelin) Silva was analyzed to determine its bioactive components including; the total phenolic content, total antioxidant capacity (lipid and water-soluble), vitamins (A, E and C), total protein and total carbohydrate content. In addition, the bioactive components of Gracilaria Bursa-pastoris were compared with some plants and seaweeds having antioxidant capacity. This study showed that Gracilaria bursa-pastoris contained a high total phenolic content, vitamin E, vitamin C and the antioxidant capacity. Gracilaria Bursa-pastoris can be utilized as a source of natural antioxidant molecules and could be useful for food industry.

The genome is constantly exposed to agents, both exogenous and endogenous, that damage DNA. Consequently, it is very important that determination of this agents and the protective agents. In this work, we evaluated the antigenotoxic/antimutagenic activity of the crude ethanolic extracts of Codium tomentosurn Stackhouse (Chlorophyceae) (CTE), collected from The Coast of South East Marmara Sea, in human lymphocytes culture in vitro against genotoxic/mutagenic agents MMC, EMS and H2O2 by using chromosome aberration (CA), sister chromatid exchange (SCE) and micronuclei (MN) assays as experimental endpoints. Also, in the present study, we determined total phenolic content and total antioxidant capacity (in soluble lipid and water). In addition, total protein, total carbohydrate, vitamins (A. C and E) and pigments (chlorophyll a, chlorophyll b and carotene) contents were also determined. Results of CA, SCE and MN tests show that CTEs have not shown genotoxic effect. In CTE plus MMC-. EMS- or H2O2- treated cultures, CA, SCE and MN frequency which induced by MMC, EMS or H2O2 has been decreased significantly (p < 0.05-0.001). This is the first report on genotoxicity/antigenotoxicity and anti-oxidative capacity of Codium tomentosum. Our results have clearly shown that CTE has strong anti-oxidative and antigenotoxic effect. (C) 2009 Elsevier Ltd. All rights reserved.

Ocean acidification reduces the concentration of carbonate ions and increases those of bicarbonate ions in seawater compared with the present oceanic conditions. This altered composition of inorganic carbon species may, by interacting with ultraviolet radiation (UVR), affect the physiology of macroalgal species. However, very little is known about how calcareous algae respond to UVR and ocean acidification. Therefore, we conducted an experiment to determine the effects of UVR and ocean acidification on the calcified rhodophyte Corallina officinalis using CO2-enriched cultures with and without UVR exposure. Low pH increased the relative electron transport rates (rETR) but decreased the CaCO3 content and had a miniscule effect on growth. However, UVA (4.25 W m(-2)) and a moderate level of UVB (0.5 W m(-2)) increased the rETR and growth rates in C. officinalis, and there was a significant interactive effect of pH and UVR on UVR-absorbing compound concentrations. Thus, at low irradiance, pH and UVR interact in a way that affects the multiple physiological responses of C. officinalis differently. In particular, changes in the skeletal content induced by low pH may affect how C. officinalis absorbs and uses light. Therefore, the light quality used in ocean acidification experiments will affect the predictions of how calcified macroalgae will respond to elevated CO2 German Federal Ministry of Education and Research (BMBF) Biological Impacts of Ocean Acidification (BIOACID)

There is an increasing demand for natural antioxidant molecules in order to replace the synthetic additives in the food industry. Therefore, Ulva rigida C. Agardh was analyzed to determine its bioactive components, including the total phenolic content, antioxidant capacity (lipid and water-soluble), vitamins (A, E, and C), protein, carbohydrate, and pigments. As a result, Ulva rigida showed a high total phenolic, vitamin E, and total carotene content. Hence, U. rigida could be considered as a plant possessing natural antioxidant molecules and might be useful for the food industry. U. rigida can also be used for curing diseases arising from oxidative deterioration.

Several hazardous substances, can damage our DNA in various ways. Defining these substances and the protective ones is very important. Therefore, researches have increased on various compounds based on natural sources which keep the harmful effects of these various agents at the minimum level. In the present study, we evaluated the potential genotoxic/ antigenotoxic/ antimutagenic activity of the crude chloroform: methanol (2:1) extracts of Hypnea musciformis (Wulfen) Lamouroux (HME), in human lymphocytes culture in vitro against genotoxic/ mutagenic agents mitomycin C (MMC) and ethyl methanesulfonate (EMS) by using chromosome aberration (CA), sister chromatid exchange (SCE) and micronuclei (MN) assays, and also determined total antioxidant capacity (in soluble lipid and water), phenolic compound, protein, carbohydrate, vitamins (A, C and E) contents. The frequency of chromosome aberrations and SCE increased by MMC, were significantly decreased by HME (p < 0.05 for CA, p < 0.001 for SCE). The MN frequencies of the cells were significantly decreased by the treatment with HME plus MMC or EMS when compared with the positive controls (MMC or EMS) (p < 0.05). In conclusion, HME itself is not a clastogenic or cytotoxic substance. On the other hand, HME possesses a strong antigenotoxic, anti-clastogenic and protective effects against MMC in vitro.

Objective To determine the in vitro possible clastogenic and cytotoxic activities of Ova rigida crude extracts (URE), and identify their antigenotoxic and protective effects on chemotherapeutic agent mitomycine-C (MMC). Methods Anti-clastogenic and anti-genotoxic activities of Ulva rigida crude extracts (URE) were studied using chromosome aberration (CA), sister chromatid exchange (SCE), and micronuclei (MN) tests in human lymphocytes cultured in vitro. Results The chromosome aberration, sister chromatid exchange or micronuclei tests showed that URE at concentrations of 10, 20, and 40 mu g/mL had no clastogenic activity in human lymphocyte cell Culture. Three doses of URE significantly decreased the number of chromosomal aberrations and the frequencies of SCE and MN when compared with the culture treated with MMC (P

In this study, 12 taxa from the Chlorophyta, Phaeophyta and Rhodophyta were collected from different depths at Gemlik-Karacaali and Erdek-Ormanli. A total of 175 specimens from these divisions were used to determine Total Protein (TP), Total Soluble Carbohydrate (TSCH) and Chlorophyll a (Chl a), Chlorophyll b (Chl b), Chlorophyll c (Chl c), total carotenoid (Car) contents and Chl b/Chl a, Chl c/Chl a, Car/Chl a, Car/Chl b, Car/Chl c ratios. TP, TSCH and pigment contents varied significantly with respect to the algal taxa, stations and depth distribution. In addition, individual differences were important in all of the measured parameters. The maximum TP contents (0.94%-31.03%) were determined in some of the Rhodophyta. In some green seaweeds belonging to the genus Ulva L., the TP content was determined between 2.9%-28.1%. Lower TP contents were determined in Cystoseira barbata (Good) C. Agardh (1.1%-4.3%). In contrast to TP contents, TSCH values were very low; maximum TSCH were determined in Ulva species, as were protein contents. In conclusion, the variations in TP, TSCH and pigment in 12 taxa of macroalgae were analysed according to station, depth, and environment.