Acclimatization of transformed seaweed Kappaphycus alvarezii carrying lysozyme gene in culture flask and the cultivation in floating net cage in Pangkep coastal

The in vitro transformation of the lysozyme gene in seaweed K. alvarezii has been successfully executed to increase the viability against ice-ice disease. There were two major stages in this research; (1) transformation of lysozyme gene in seaweed K. alvarezii which was carried out on laboratory scale and the cultivation of gene-transformed explants in the culture flask stored in “culture chamber”; (2) the acclimatization in floating net cages of green nets (mesh size of 1 mm) with cage size of 50 x 50 x 50 cm, the population density of 200 explants and cultivated for two weeks. The explants were then transferred to blue nets (mesh size of 2 mm) with a cage size of 50 x 50 x 50 cm for four weeks of rearing. The plants were then enlarged using a long-line method in the floating net cage, by tying the seaweed using a double line with a gap of 15 cm each. The measurement of weight, bud lengths, and water quality was carried out within 2 weeks. The result shows that the daily growth rate of the transformed seaweed during the regeneration stage in the culture flask was around 0.33-0.4%/day, meanwhile during the acclimatization stage in the green nets the was 0.65-1.6%/day, and even more, increased during the acclimatization stage in the blue nets with DGR of 2.28-2.3%/day. During the enlargement stage in the floating net cages, the lysozyme-transformed seaweed showed an even higher DGR with a value of 3.2-8.2%/day. The results of the integration of the lysozyme gene in seaweed were indicated by the presence of a 670 bp of amplification products, that is the same total length of the 35 S-F promoter fragments and Nos T-R in the expression vector. Based on these results, the lysozyme gene was successfully transformed in K. alvarezii seaweed.