Antifouling Activity of Lipidic Metabolites Derived from Padina tetrastromatica

Abstract

An attempt has been made to identify the potential seaweed for antifouling property due to the growing need for environmentally safe antifouling systems. The antibacterial, antimicroalgal, and antimussel foot adherence potentials of methanol, dichloromethane, and hexane extracts of the chosen seaweeds such as Padina tetrastromatica, Caulerpa taxifolia, and Amphiroa fragilissima have been compared against copper sulfate. Among the extracts, the maximum antibacterial activities were exhibited by the methanol extract of P. tetrastromatica. The minimum inhibitory concentration (MIC) of the methanolic extract of P. tetrastromatica was found to be 10 and 1 μg/ml against test biofilm bacteria and diatoms, respectively. The antimussel foot adherence assay indicated that the extract had inhibited the foot adherence of the green mussels Perna viridis with the effective concentration (EC50) of 25.51 ± 0.03 μg/ml, and lethal concentration for 50 % mortality (LC50) was recorded at 280.22 ± 0.12 μg/ml. Based on the prolific results, the crude methanolic extract of P. tetrastromatica was subjected to purification using silica gel column and thin-layer chromatography (TLC). Then, the active compounds of the bioassay-guided fraction (F13) were identified using gas chromatography coupled with mass spectroscopy (GC-MS), and it was observed that fatty acids were the major components, which may be responsible for the antifouling properties.

Antifouling and antibacterial activities of bioactive extracts from different organs of the sea cucumber Holothuria leucospilota

“…The MIC of the ethyl acetate extract of the body wall was found to be 0.062 mg/mL against C. muelleri. In a study published in 2016 [6] Suresh et al reported that three marine diatoms tested (P. elongatum, T. frauenfeldii and N. longa) showed high sensitivity to Padina tetrastromatica extract with a MIC of 0.001 mg/mL. The results of the present study also showed that all of the twelve extracts had higher inhibitory activity against C. muelleri compared to C. vulgaris.…”

“…The concentrations were obtained by serial dilution. Then, the tubes were incubated under a controlled condition at 25 °C with the illumination of 4000-5000 lx light intensity [6] with a 12:12 h light/dark cycle. Untreated tube and those containing DMSO served as controls.…”

“…The assay was conducted with six replicates. The minimum concentration of each extract, where no microalgal growth was observed in at least four of the six tubes, was recorded as the MIC [6].…”

“…However, bacteria, diatoms, barnacles and macroalgae are some of the most important marine fouling organisms. Marine biofouling is a serious worldwide problem affecting marine industries and any man-made structure exposed to marine environments [6] such as ships, pipelines, oil platforms, fish cages and fishing nets [7,8]. Biofouling can reduce the speed of vessels and increase fuel consumption.…”

“…It also increases emissions of greenhouse gases [9][10][11][12]. It has been reported that biofouling can cause huge economic losses of more than US$ 5.7 billion per year over the world [6,13].…”