Micropropagation, acclimatization and chemical composition of farmed seaweed, Kappaphycus alvarezii, in Sabah

• Auteur principal: Yong, Yoong Soon
• Format: Thèse
• Langue: anglais; anglais
• Publié: 2014
• Sujets: QH540-549.5 Ecology
• Accès en ligne: https://eprints.ums.edu.my/id/eprint/42835/1/24%20PAGES.pdf; https://eprints.ums.edu.my/id/eprint/42835/2/FULLTEXT.pdf

Under the Economic Transformation Programme (ETP), seaweed production in Malaysia is expected to increase to 150,000 metric tonnes annually by 2020. To achieve this goal, micropropagation and subsequent acclimatization of the micropropagated Kappaphycus alvarezii prior transplantation to the sea farm is an option to solve the shortage of seedlings. In a series of micropropagation experiments, the highest growth rate was achieved when the K. alvarezii micropropagagules were exposed to a salinity of 30 ± 5 ppt, pH of 8.5 ± 1, and 30 mg/L of Natural Seaweed Extract (NSE). In order to achieve the highest survival rate during transplantation, a study was carried out to determine the optimum conditions for acclimatization of micropropagated K. alvarezii seedlings prior to transfer to the sea farm. In a two-week acclimatization study, K. alvarezii showed the highest growth rate when cultured in seawater enriched with NSE in outdoor nursery tank with complete replacement of culture media daily and 0.40 g/L of culture density. Two batches of acclimatized K. alvarezii were transferred to the sea farm for four weeks and their carrageenan quality, physiochemical profile, minerals and trace elements, and fatty acid compositions were chemically analyzed upon harvesting. As compared to the farm propagated K. alvarezii, micropropagated K. alvarezii showed a significantly higher yield and viscosity of native carrageenan with similar sulphate content profile. Physiochemical profile revealed that both K. alvarezii consists of high ash content, low total protein, and low total lipids. The micropropagated K. alvarezii showed higher compositions of minerals and trace elements, and lower heavy metal contaminants, as compared to farm propagated K. alvarezii. These studies justify the rational and importance of micropropagation and acclimatization in the production of K. alvarezii seedlings.