Judul: Karakterisasi Seluler Mutan Osmotoleran Pichia kudriavzevii.
Abstrak: Bioetanol merupakan salah satu komoditas energi terbarukan terbesar di dunia disamping biodiesel. Produksi bioetanol skala industri memanfaatkan khamir Saccharomyces cerevisiae sebagai agen fermentasi. Namun, khamir jenis ini memiliki keterbatasan yakni tidak mampu menggunakan gula jenis pentosa. Pengembangan khamir yang mampu menggunakan pentosa membuka salah satu peluang pemanfaatan limbah lignoselulosa sebagai substrat fermentasi bioetanol. Pichia kudriavzevii diketahui dapat memanfaatkan pentosa sebagai substrat fermentasi bioetanol. Cekaman osmotik dalam bioreaktor terjadi sebab tingginya konsentrasi gula sebagai substrat fermentasi. Pengembangan galur P. kudriavzevii yang tahan terhadap cekaman osmotik gula diharapkan mampu meningkatkan efisiensi sistem produksi bioetanol. Konstruksi isolat osmotoleran dilakukan menggunakan teknik mutagenesis evolusi terarah yang mana menumbuhkan isolat pada serial konsentrasi glukosa dari tingkat rendah hingga batas toleransi maksimal. Penelitian ini bertujuan mengonstruksi mutan osmotoleran P. kudriavzevii dan menganalisis karakter selulernya. Riset tentang konstruksi mutan osmotoleran P. kudriavzevii menggunakan teknik mutagenesis evolusi terarah dan analisis perubahan aktivitas seluler belum pernah dilakukan sebelumnya. Hasil penelitian menunjukkan bahwa mutan osmotoleran P. kudriavzevii (Pku RM) berhasil dikonstruksi menggunakan teknik mutagenesis evolusi terarah hingga tingkat toleransi cekaman hiperosmotik 35% glukosa (b/v) dan mampu tumbuh optimum pada konsentrasi 25% (b/v). Aktivasi mitokondria pada Pku RM tidak berbeda nyata dengan Pku RWT namun lebih tinggi dibanding Sce BY4741. Hasil-hasil ini menunjukkan bahwa Pku RM memiliki potensi untuk dikembangkan sebagai agen fermentasi bioetanol terkait kemampuannya dalam menghadapi cekaman osmotik.
Keyword: bioetanol, mutagenesis evolusi terarah, Pichia kudriavzevii, toleransi osmotik

Judul: Karakterisasi Seluler Mutan Osmotoleran Pichia kudriavzevii.
Abstrak: Bioethanol is one of the largest renewable energy commodities in the world besides biodiesel. Industrial-scale bioethanol production utilize yeast Saccharomyces cerevisiae as a fermentation agent. However, this type of yeast has a limitation of being unable to use pentose sugar. The development of yeast that is able to use pentose opens one of the opportunities for utilization of lignocellulosic waste as a bioethanol fermentation substrate. Pichia kudriavzevii is known to be able to utilize pentose as a bioethanol fermentation substrate. Osmotic stress in bioreactors occurs because of the high concentration of sugar as a fermentation substrate. The development of P. kudriavzevii strain which is resistant to sugar osmotic stress is expected to increase the efficiency of the bioethanol production system. The construction of osmotolerant isolate was carried out using directed evolutionary mutagenesis technique which grew isolate in serial glucose concentrations from low state to maximum tolerance limits. This study aimed to construct the P. kudriavzevii osmotolerant mutant and analyze its cellular characteristics. Research on the construction of P. kudriavzevii osmotolerant mutant using direct evolution mutagenesis technique and analysis of alteration in cellular activity have never been done before. The results showed that the P. kudriavzevii osmotolerant mutant (Pku RM) was successfully constructed using directed evolutionary mutagenesis technique to hyperosmotic stress for up to 35% glucose (w/v) and was able to grow optimally at concentration of 25% (w/v). Mitochondrial activation in Pku RM was not significantly different from RWT Pku but was higher than Sce BY4741. These results indicate that Pku RM has the potential to be developed as a bioethanol fermentation agent related to its ability in dealing with osmotic stress.
Keyword: bioethanol, directed evolution mutagenesis, osmotic tolerance, Pichia kudriavzevii

Judul: The Macroeconomic effects of goverment expenditure in ASEAN plus Three
Abstrak: Fiscal policy is one of the goverment policy to increase growth in a reasonable level. The impact of fiscal policy shock has different effect on each country around the world. The effect of goverment spending shocks led to increase growth in USA but decrease growth in Germany, as reflected by the decline in private investment. This study aims to analize the effect of goverment expenditure in ASEAN plus Three, by using vector error correction model (VECM), impulse respone function (IRF), forecasting error variance decomposition (FEVD) and pass-through effect.
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