The vertical structure of the vegetative canopy of the brown algae Cystoseira(Black Sea)

In the coastal ecosystems of the Black Sea,macrophytobenthos and,in particular,the association of Cystoseira crinite,C.barbara,Cladostephus verticillatus,and Corallina mediterranea,with its thick vegetative canopy(VC),is the key contributor to primary production(PP).Though the vertical structure of the canopy,formed by the algal association,is of principal importance to the PP level,this subject has been long-neglected by researchers.The goal of our work was to compare vertical structures of the vegetative canopy of Cystoseira brown algae under diverse hydrodynamical conditions of the Crimean Peninsula coast.Samples were collected using the 50 cm×50 cm counting frame at eight stations positioned in shallow(55-60 cm deep)sites of Sevastopol Bay(Crimean Peninsula).Dry weight biomass of the VC was determined for all algae assemblage and for each algal species individually,per horizontal surface unit,at each height(Z).The study shows that:1)the VC is characterized by unimodal vertical distribution of biomass,with maximum estimate in the lower part,where the biomass increases to 85%of the total biomass;2)a series of single-peaked curves reliably describes the unimodal distribution of the biomass;thalli of different age groups are found along the canopy profile;and 3)algae found in epiphytic synusia prefer inhabiting the upper part of the VC.The role of environmental factors(seawater turbulence and solar radiation)is discussed in reference to the formation of the vertical structure,made up of the associations of the brown algae Cystoseira.

Antimicrobial and antioxidant activities of Cystoseira crinita Duby and Ulva intestinalis Linnaeus from the coastal region of Sinop,Turkey

Objective:To evaluate in vitro antimicrobial,antioxidant activities and total phenol contents of Cystoseira crinita and Ulva intestinalis species collected from the coastal region of Sinop.Methods:The antimicrobial activity of each methanolic algae sample was screened by using disc diffusion method against to 15 bacteria and 3 yeasts.The antioxidant potential of the extracts on the stable radical 1,1-diphenyl-2-picrylhydrazyl was determined.The total phenolic content of the 3 methanolic extracts of the seaweed samples were determined by the Folin-Ciocalteu method.Results:The results of antimicrobial assay showed that extracts were more effective against Gram-positive bacteria rather than Gram-negative.In addition,while the algal extracts had antifungal efficacy against Candida krusei,the other yeast strains were not affected at all.According to the findings of antioxidant activity,all methanolic extracts displayed good free radical scavenging activity ranging from IC_(50)=(32.19±0.08)mg/mL to the IC_(50)=(37.57±0.11)mg/mL.The total phenols content of the macroalgal extracts were found as between(5.10±0.16)mg gallic acid equivalent/g and(87.70±1.03)mg gallic acid equivalent/g.In this sense,our findings confirmed that there was a positive linear correlations(r=0.86)between total phenol contents and the IC_(50) values.Conclusions:The data gathered from this study suggested that the seaweeds can be used as a potential natural seafood sources owing to the antimicrobial efficiency and good antioxidant activity.