Judul: The Diversity of Fermented Foods in Indonesia and Comparison of The Nutrient Content of Milk-Based Fermented Foods
Abstrak: Indonesia mempunyai kelimpahan dan keragaman komoditas pangan, termasuk pangan fermentasi. Namun, analisis metadata tentang diversitas pangan fermentasi belum dilaporkan. Selain itu, perbandingan kandungan gizi pangan fermentasi berbasis susu juga belum tersedia. Oleh karena itu, penelitian ini bertujuan mengungkap status diversitas pangan fermentasi, mengetahui kandungan gizi terutama dari pangan fermentasi berbasis susu yakni dangke dan perbandingannya di antara produk fermentasi berbasis susu. Metode penelitian meliputi studi literatur, pembuatan dangke, analisis proksimat dangke, dan analisis data secara statistika. Studi literatur menunjukkan bahwa makanan dan minuman fermentasi di Indonesia paling banyak dilaporkan oleh artikel masing-masing pada tahun 2017, 2018, dan 2019. Walaupun sebagian besar pangan fermentasi tidak diketahui daerah asalnya, namun kelompok mikroba yang terlibat dalam pengolahannya diketahui paling banyak berasal dari kelompok bakteri dibandingkan fungi, terutama melalui mekanisme fermentasi asam laktat. Peranan mikroba dalam produk fermentasi beragam dan dapat dikelompokkan ke dalam lima kelompok. Peranan mikroba utamanya, yaitu mendukung bioproses. Di antara produk fermentasi berbasis susu, dangke merupakan produk tradisional dengan kandungan lemak yang berbeda signifikan dengan yoghurt, kefir, dan dadih serta proteinnya tidak berbeda signifikan dengan yoghurt, kefir, dadih, dan keju mozzarella. Analisis kandungan gizi ini mengindikasikan terdapat perbedaan kadar lemak dan protein di antara produk pangan fermentasi berbasis susu., Indonesia has high abundance and diversity of food commodities, including fermented food. However, metadata analysis about the diversity of fermented foods has not been reported. In addition, a comparison of the nutritional content of milk-based fermented foods is also not yet available. Therefore, this study aimeds to reveal the diversity status of fermented foods, to determine the nutritional content, especially of fermented milk-based foods, namely dangke and their comparisons between milk-based fermented products. The research method included literature study, making dangke, proximate analysis of dangke, and statistical data analysis. Literature studies show that fermented foods and beverages in Indonesia were most reported in 2017, 2018, and 2019 respectively. Although most fermented foods are not known for their area of origin, the microbial groups involved in their processing are known to come from the bacterial group rather than fungi, mainly through the lactic acid fermentation mechanism. The role of microbes in fermented products are diverse and can be grouped into five groups. The main role of microbes is to support bioprocesses. Among milk-based fermented products, dangke is one of the traditional products with a fat content that is significantly different fat content from yoghurt, kefir, and dadih and the protein is not significantly different from yoghurt, kefir, dadih, and mozzarella cheese. This analysis of nutritional content indicates that there are differences in fat and protein content among fermented milk-based food products.
Keyword: dangke, fat content, metadata, protein content, proximate analysis

Judul: Memanfaatkan ragi probiotik multifungsi dari dadih, produk fermentasi tradisional dari Sumatera Barat,Indonesia
Abstrak: Fermented buffalo milk, commonly called Dadih, contains potential probiotic yeast cells. Probiotic yeast has garnered increasing attention in basic and clinical science over the past 20 years. This research aimed to isolate, characterize, and determine the biodiversity of potential probiotic yeasts obtained from Dadih. Isolation of probiotic yeast was done using Yeast Extract, Peptone, and Dextrose (YPD) media, followed by the identification of yeast using Sequence-Related Amplified Polymorphism (SRAP). Colonies relatedness was determined using the Numerical Taxonomy and Multivariate Analysis System (NTSYS). Two yeast isolates were further identified using Polymerase Chain Reaction (PCR) targeting the 18S rRNA gene. The probiotic characterization was done by determining pH resistance, bile salt resistance, proteolytic, lipolytic test, and hemolytic tests. Secondary metabolites were determined by conducting antioxidant, antidiabetic, antiinflammation, and antimicrobial tests. Interaction between secondary metabolites signals was determined by molecular docking using AutoDock software. Whole genome sequencing on Pichia kudriavzevii using Oxford Nanopore Technologies and genome annotation was performed using the Rapid Annotation using the Subsystem Technology (RAST) server. Fifty-five colonies were isolated, and their relatedness showed a minimum cutoff at a similarity level of 89% in the dendrogram. Two isolates, GBT 30 and GBT 37 were identified as Pichia occidentalis and Pichia kudriavzevii, respectively, based on the 18S rRNA sequence. Acid pH tolerance results showed both isolates survived at an acidic pH starting at pH 2 to pH 6. A bile salt resistance test showed that both isolates were able to show significant cell viability in 0.3 and 0.5% bile salt concentrations. Both isolates produced secondary metabolites, with GBT 30 showing good antimicrobial and antiinflammation properties than GBT 37. Whole-genome sequencing of P. kudriavzevii revealed a genome size of 10 906 850 bp, comprising five chromosomes with an average GC content of 38.26%, and secondary metabolites located on contig 7., Susu kerbau fermentasi yang biasa disebut Dadih mengandung sel ragi probiotik yang potensial. Ragi probiotik telah mendapatkan perhatian yang semakin besar dalam ilmu dasar dan klinis selama 20 tahun terakhir. Penelitian ini bertujuan untuk mengisolasi, mengkarakterisasi, dan mengetahui keanekaragaman hayati khamir probiotik potensial yang diperoleh dari Dadih. Isolasi ragi probiotik dilakukan menggunakan media Yeast Extract, Peptone, dan Dextrose (YPD), dilanjutkan dengan identifikasi ragi menggunakan Sequence-Related Aplified Polymorphism (SRAP). Keterkaitan koloni ditentukan dengan menggunakan Numerical Taxonomy and Multivariate Analysis System (NTSYS). Dua isolat khamir diidentifikasi lebih lanjut menggunakan Polymerase Chain Reaction (PCR) dengan sasaran gen 18S rRNA. Karakterisasi probiotik dilakukan dengan menentukan ketahanan pH, ketahanan garam empedu, proteolitik, uji lipolitik, dan uji hemolitik. Metabolit sekunder ditentukan dengan melakukan uji antioksidan, antidiabetes, antiinflamasi, dan antimikroba. Interaksi antara sinyal metabolit sekunder ditentukan dengan molekuler docking menggunakan perangkat lunak AutoDock. Pengurutan seluruh genom pada Pichia kudriavzevii menggunakan Oxford Nanopore Technologies dan anotasi genom dilakukan menggunakan Rapid Annotation menggunakan server Subsystem Technology (RAST). Lima puluh lima koloni diisolasi, dan keterkaitannya menunjukkan batas minimum pada tingkat kemiripan 89% pada dendrogram. Dua isolat, GBT 30 dan GBT 37 masing-masing diidentifikasi sebagai Pichia occidentalis dan Pichia kudriavzevii, berdasarkan urutan 18S rRNA. Hasil toleransi pH asam menunjukkan kedua isolat mampu bertahan pada pH asam mulai pH 2 hingga pH 6. Uji ketahanan terhadap
Keyword: probiotic, Whole Genome Sequencing, Pichia kudriavzevii, Pichia occidentalis, dadih, fermentation

Judul: Hamiltonian formulation for linear waves motion in two layers fluid
Abstrak: The surface wave could be considered as a wave that separates two fluids, namely water and air. Based on this assumption, it is introduced the interfacial wave, a wave between two layers of fluid with different density. The formulation of interfacial waves motion begins with deriving the base equation of irrotational ideal fluid. Furthermore, according to irrotational fluid assumption, the base equation can be stated in velocity potential. In this derivation, the fluids domain is assumed to be restricted by rigid lid boundary conditions, both at the upper and lower limit. Therefore, the interfacial waves motion can be explained in a hamiltonian formulation. In the hamiltonian formulation, total energy is defined as the sum of kinetic and potential energy. The hamiltonian system is obtained from reduction of kinetic energy by using the Dirichlet Neumann Operator. The resulted kinetic energy equation is nonlinear. Therefore, this form is linearized by first part of the Taylor expansion. This linearization gives a dispersion relation of linear wave. Based on this dispersion relation, the phase speed of the linear wave depends on the density ratio of the two layers fluid.
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