ºÚÁÏÍø

Abstract

Marine algae and invertebrates are major fouling organisms causing considerable structural and economic damage to man-made structures such as ship hulls and aquaculture nets. Most antifouling techniques have relied on organotin or heavy metals based paints that act as broad spectrum toxins to target and non-target marine organisms. So, naturally occurring antifouling compounds are the most promising alternatives to prevent the attachment of fouling organisms. Therefore, in this study we have investigated the anti-attachment and enhancing activities of 18 seaweed extracts against the known fouling species of red algae, Porphyra suborbiculata. At both tested concentrations of 20 and 200 ���¼g/mL culture medium. Hizikia fusiformis extract showed the highest inhibitory effect on the rhizoid production, rhizoid growth and germinated and juvenile blade growth. Also, extracts from Ulva pertusa, Enteromorpha linza, Undaria pinnatifida, Sargassum horneri, Ecklonia cava showed significant growth inhibition activities (P<0.01). In contrast, the Codium fragile extract enhanced the rhizoid production with same concentrations. Also H. fusiformis methanol extract inhibited the growth of the spores from both U. pertusa and U. pinnatifida and reduced the attachment of the diatoms Naviculata annexa and Nitzchia pungens (P<0.05). Among the five fractions isolated from the H. fusiformis extract, ethyl acetate, chloroform-methanol and chloroforml fractions have shown significant inhibitory activities against the growth of the P. suborbiculata spore. In open silca-gel-column fractionation of this extract, among the five elutes collected the highest inhibition of the P. suborbiculata spore was found in the acetonirile fraction. The isolation of the purified inhibitory compound was done by RP-HPLC at 220 nm after choosing ethanol and acetonirile as mobile phases based on RP-TLC result.

Biography

Mehader Getachew Desta is MSc student in Pukyong National University, Fisheries College (Department of Biotechnology), Busan, Republic of Korea. She has been working on isolation of bioactive anti-fouling compounds from different seaweed species. Currently, she is purifying anti-fouling compounds from the brown seaweed H. fusiformis