Objectives:To evaluate antifouling property of extracts from Red Sea soft corals against primary biofilm and biofouling.Methods:Seven species of soft corals Sarcophyton glaucum (a),Sinularia compressa,Sinularia cruciata (a),Heteroxenia fuscescens (a),Sarcophyton glaucum (b),Heteroxenia fuscescens (b) and Sinularia cruciata (b) were chosen to test their extracts as antibacterial and antifouling agents in Eastern Harbour of Alexandria,Mediterranean Sea.Bioactive compounds of soft corals were extracted by using methanol and concentrated under vacuum.The residues of extracts were mixed in formulation of inert paint which consisted of rosin,chlorinated robber and ferrous oxide against micro and macro fouling organisms.The formulated paints were then applied on PVC panels twice by brush,hanged in a steel frame and immersed in Eastern Harbour of Alexandria Mediterranean Sea followed by visual inspection and photographic recordings.Results:After 185 days of immersion in seawater,the antifouling results agreed with the antibactedal results where extracts of Sinularia compressa and Heteroxenia fuscescens (b) gave the best activity against marine fouling tubeworms and barnacles.The inhibition activity was correlated with the major functional groups (hydroxyl,amino,carbonyl,aliphatic (fatty acids),C=C of alkene or aromatic rings and C—Cl of aryl halites) of the extracts.Conclusions:The strong antifouling activity makes them promising candidates for new antifouling additives.After the screening and application of natural organic compounds from soft corals,marine organisms show activity against micro and macro fouling organisms.

Objectives To evaluate antifouling property of extracts from Red Sea soft corals against primary biofilm and biofouling. Methods Seven species of soft corals Sarcophyton glaucum (a), Sinularia compressa, Sinularia cruciata (a), Heteroxenia fuscescens (a), Sarcophyton glaucum (b), Heteroxenia fuscescens (b) and Sinularia cruciata (b) were chosen to test their extracts as antibacterial and antifouling agents in Eastern Harbour of Alexandria, Mediterranean Sea. Bioactive compounds of soft corals were extracted by using methanol and concentrated under vacuum. The residues of extracts were mixed in formulation of inert paint which consisted of rosin, chlorinated rubber and ferrous oxide against micro and macro fouling organisms. The formulated paints were then applied on PVC panels twice by brush, hanged in a steel frame and immersed in Eastern Harbour of Alexandria Mediterranean Sea followed by visual inspection and photographic recordings. Results After 185 days of immersion in seawater, the antifouling results agreed with the antibacterial results where extracts of Sinularia compressa and Heteroxenia fuscescens (b) gave the best activity against marine fouling tubeworms and barnacles. The inhibition activity was correlated with the major functional groups (hydroxyl, amino, carbonyl, aliphatic (fatty acids), C[dbnd]C of alkene or aromatic rings and C[sbnd]Cl of aryl halides) of the extracts. Conclusions The strong antifouling activity makes them promising candidates for new antifouling additives. After the screening and application of natural organic compounds from soft corals, marine organisms show activity against micro and macro fouling organisms.

Objective: To study the chemical profile, antimicrobial properties, and synergistic effect with known antibiotics of essential oil extracted from the marine red macroalgae Centroceras clavulatum (C. Agardh) Montagne, collected in Morocco. Methods: The chemical composition of the oil was analyzed by gas chromatography-mass spectrometry. The oil was evaluated for antibacterial (Pseudomonas aeruginosa, Escherichia coli, Bacillus subtilis, Micrococcus luteus, Staphylococcus aureus, and Klebsiella pneumoniae), and antifungal activity (Candida albicans, Candida glabrata, Candida krusei, and Candida parapsilosis), by the disc diffusion method. The minimum inhibitory and minimum microbicidal concentrations of the oil were determined, as well as the synergistic effects of its application combined with the antibiotics ciprofloxacin and fluconazole, by the checkerboard method. Results: Thirty molecules were identified in the essential oil, comprising 96.27% of the total oil composition. Monoterpenes such as carvacrol (36.06%) were the most abundant compounds, followed by caryophyllene (14.67%), endo-borneol (9.04%), pyroterebic acid (3.23%) and caryophyllene oxide (3.13%). The oil exhibited a moderate antimicrobial activity with inhibition zone diameters ranging from 9.0 to 15.0 mm. The minimum inhibitory concentration values varied between 0.9 and 14.7 mg/mL, and Bacillus subtilis and Escherichia coli were the more sensitive bacteria with 0.9 and 1.9 mg/mL, respectively. The minimum microbicidal concentration values ranged from 0.4 to 14.7 mg/mL. A significant synergic action was observed when the oil was applied in combination with ciprofloxacin and fluconazole, with fractional inhibitory concentration index values ranging from 0.31 to 0.50. Synergy was found in 80% of the combinations and a 2 to 16-fold reduction of antibiotics MIC was observed. Conclusions: Our findings suggest that the essential oil of Centroceras clavulatum should be further appraised for its potential use in the management of multi-drug resistant microorganisms, with the purpose to restore the activity of standard antimicrobial drugs.