Judul: Introduction of PaCS gene encoding Citrat Synthase to Kappaphycus alvarezii using Agrobacterium tumefaciens
Abstrak: Ice-ice is a disease that reduces the quality of seaweed. This disease is mainly caused by environmental stress rather than pathogen. This is supported by the fact that ice-ice disease is prevalent in the environment where the water have low quality, poor circulation, low salinity and changement of temperature, and high content of heavy metals. Citric acid is known to be a strong chelating agent for aluminum. Citric acid has a very important role in the Kreb cycle. The enzyme involved in the synthesis of citric acid is citrate synthase. Citrate synthase genes from Pseudomonas aeruginosa (PaCS) has been successfully introduced into genome of tobacco (Nicotiana tabacum) and Jatropha curcas using Agrobacterium tumefaciens. Tobacco transgenic plants containing PaCS gene are more tolerant to Al stress compared to non-transgenic plants. This research aims to introduce the citrate synthase gene into genome of seaweed Kappaphycus alvarezii by using Agrobacterium tumefaciens. Cutting Thallus of 0,5 cm were used as explants. Explants were inoculated by Agrobacterium tumefaciens for 15 minutes and then co-cultivated in PES media containing 0,3% agar for 3 days in the dark. The selection of putative transgenic K. alvarezii was carried out in PES agar selective medium containing 10 mg/l hygromicin. Based on hygromicin resistant explant on hygromicin selective medium, the transformation efficiency in K. alvarezii was 7.5 %. The efficiency of shoot regeneration of putative transgenic was 100%, and same as the regeneration efficiency of non transgenic ones. Molecular analysis by PCR showed that one of five putative transgenic K. alvarezii was confirmed as transgenic thallus containing PaCS transgene under the control of 35S CaMV promoter.
Keyword: Kappaphycus alvarezii, seaweed, PaCS gene, Agrobacterium tumefaciens, transformation

Judul: Transformasi Gen Kappa (K)-Carrageenase pada Rumput Laut Kappaphycus alvarezii
Abstrak: Foreign gene transformation technique have been applied to improve the valuable traits of farmed organism. Carrageenan content determines quality of seaweed Kappaphycus alvarezii. As the first step towards increasing of kappa(κ)-carrageenan content in K. alvarezii, in this study kappa(κ)-Carrageenase gene (κ-Car) from Pseudoalteromonas was transformed into K. alvarezii mediated by Agrobacterium tumefaciens method. The κ-Car gene involves in κ-carrageenan biosynthesis. This research consisted of three steps. The first steps of research purpose was to produce a cloning vector and an expression vector for transformation process. The κ-Car gene sequence was artificially synthesized, an then inserted in pMSH plasmid to generate a binary pMSH/κ-Car plasmid. The pMSH/κ-Car was controlled by 35S CaMV promoter (35S) and Nos terminator (tNos). Transformation of pMSH/κ-Car to Escherichia coli as cloning vector was performed using a heat-shock method, while into Agrobacterium tumefaciens was using triparental mating method. The result showed that the transformed E. coli and A. tumefaciens colonies could grow on the selective media. PCR analysis with DNA template from bacterial colonies using 35S-Forward primer (35S-F) and tNos-Reverse (tNos-R) produced DNA fragment with size of 2,000 bp, the same size with the total length of 35S promoter, κ-Car gene, and tNos sequences. Thus pMSH/κ-Car construct and A. tumefaciens transformant carrying pMSH/κ-Car were successed to be produced. The second steps of research purpose was to produce a transgenic K. alvarezii carrying κ-Car gene. Transfomation of κ-Car gene to K. alvarezii was conducted using A. tumefaciens mediation method. Analysis of K. alvarezii transgenic carrying κ-Car was performed by PCR method with two set primers. The result showed that survival percentage posttransformation of K. alvarezii explants was 36% and sprout was 88.9% while the percentage of transgenic was 100% out of the sprout explants samples. The size of DNA band of PCR product from K. alvarezii transformants using 35S-F and tNos-R set primers was 2,000 bp, the same size as PCR product of the positive control of pMSH/κ-Car plasmid as template, while no amplification product in non-transformated as negative control was found. Furthermore, PCR analysis using 35S-F and 35S-R set primers showed amplification product of 300 bp, the same size as the length of 35S promoter sequence. Thus, K. alvarezii transgenic carrying κ-Car gene had been generated..dst
Keyword: Kappaphycus alvarezii, Kappa(κ)-Carrageenase gene, transgenesis

Judul: Formulasi Hamiltonian untuk Menggambarkan Gerak Gelombang Soliter Dimensi Tiga di Permukaan Laut
Abstrak: Gelombang permukaan adalah gelombang yang terjadi perbedaan rapat massa antara air dan udara. Salah satu gelombang permukaan yang ditinjau adalah gelombang soliter. Formulasi gelombang soliter dilakukan dengan menggunakan formulasi Hamiltonian.
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