ATTACHMENT ATTRACTANT FROM Ulva sp. Thallus : USEFULL SUBSTANCE FOR Ulva sp. CULTURE  

Ulva, a green algal, is high economic value algal and has been promoted to consumption as it's contain high nutrition and contains special substance could promote human health. This algal has been culture in several counties like Japan and China from its swarmer (spore, gametes, and zooid). The swarmer could choose surfaces to attach and the attached swarmer growth into gametophyte or sporophyte. This condition need to control on culture of Ulva. The unattached of swarmer also could trigger blooming algal around culture areas. In our study, the algal leaf was extracted using water and the substance was tested to check its activity to attract swarmer on its surface. Our results show that the water extracts have activity to attract spore to attach.

The dried algal (100 gr) was milled and extracted using aquades (500 ml) for 24 hour. The supernatant was collected by centrifuge and dried using freeze dryer. The extract diluted with aquades to get final concentration 50μg/ml. As much of 20 μl solution was pipetted into center of cover films and put on freezer (5^oC) until dried. For testing the activity of extracted on the attachment of the swarmer, the cover films moved in 6 well plates and swarmer was added to well plate to get final solution 1x6¹⁰ cell/ml (5 ml as final working volume). The 6 well plates incubated in the dark at in 25^oC and after two hour the spore attached observe.

In our research we got the swarmer prefer to attach on surface cover film which spotted by algal extract. This preliminary study have shown that the water extract of Ulva have activity to attract Ulva's swarmer.