Judul: Isolation, Characterization and Identification of Hemolysin Producing Bacteria on the Leaf Surface of Pohpohan (Pilea melastomoides (Poir.) Wedd.).
Abstrak: Pohpohan umumnya dikonsumsi masyarakat sebagai lalapan. Sayuran segar yangdikonsumsi secara langsung dapat membawa bakteri patogen bawaan pangan. Penelitian ini bertujuan mengisolasi bakteri, mengarakterisasi, mengidentifikasi bakteri penghasil hemolisinpada permukaan daun pohpohan. Kuantifikasi bakteri pada media Blood Agar menunjukkan jumlah bakteri patogen sebanyak 6,2 x108 CFU/g. Koloni bakteri dengan morfologi yang berbeda dipilih dan dimurnikan untuk dianalisis karakterisasi lebih lanjut morfologi koloni danselnya. Sebanyak delapan isolat bakteri terpilih memiliki warna koloni yang sama yaitu putih,namun memiliki bentuk, tepian, elevasi, karakteristik optik, dan permukaan koloni yang bervariasi. Semua isolat bakteri tersebut tergolong bakteri Gram positif berbentuk basil denganpenataan sel berantai atau tunggal. Kedelapan isolat terpilih mampu melisiskan sel darah merah (hemolisis positif) yang tergolong ke dalam ß- hemolisin. Identifikasi molekuler berdasarkangen 16S rRNA menunjukkan empat isolat memiliki kemiripan sekuens yang tinggi (similarity:lebih dari 99%) dengan bakteri Bacillus paramycoides, dua isolat teridentifikasi sebagai Bacillus subtilis, dan dua isolat lainnya teridentifikasi dengan Bacillus cereus dan Bacillus tequilensis.
Keyword: Bacillus, sayur segar, Pohpohan, Hemolisis

Judul: Endophytic Microbiota Profile of Freshly-Consumed Vegetables of Pohpohan Leaf (Pilea melastomoides (Poir.) Wedd.) Based on Metagenomic Analysis
Abstrak: Penelitian terbaru menunjukkan bahwa sayuran segar merupakan habitat utama komunitas bakteri endofit. Di Indonesia, beberapa tanaman tropis dikonsumsi segar tanpa melalui proses memasak, sehingga dapat menimbulkan kekhawatiran terhadap kesehatan manusia dan kesadaran keamanan pangan. Pilea melastomoides merupakan makanan etnik tradisional yang dikenal dengan Traditional and Etnic Food (TEF) dan dimanfaatkan oleh masyarakat Sunda di Indonesia sebagai sayuran untuk dikonsumsi segar. Tanaman ini dapat tumbuh secara liar dan dibudidayakan dengan standar pertanian, sehingga menimbulkan pertanyaan mengenai komunitas bakteri endofit diantara kedua jenis sistem tanam tersebut. Oleh karena itu, penelitian ini bertujuan untuk menyelidiki profil komunitas bakteri pada P. melastomoides liar dan budidaya berdasarkan pendekatan metagenomik dengan menargetkan gen 16S rRNA. Sampel daun P. melastomoides diperoleh dari kawasan hutan Taman Nasional Gunung Halimun Salak, Kabupaten Bogor, Jawa Barat. Teknik pengambilan sampel dilakukan secara cluster random sampling yang terbagi menjadi tiga petak. Metode pengumpulan sampel dilakukan menggunakan sample pooling pada masing-masing petak, yaitu dengan menggabungkan atau mencampur 10 sampel daun hasil ekstraksi P. melastomoides budidaya dan liar, masing-masing kedalam satu tabung (pool) untuk dilakukan pengujian sebagai sampel tunggal. Selanjutnya, sampel hasil ekstraksi DNA diamplifikasi melalui teknik PCR dengan target daerah amplifikasi V3-V4 menggunakan dua primer universal bakteri yaitu primer 341F dan primer 806R. Konstruksi library (perpustakaan) dilakukan untuk mempersiapkan sampel metagenom sebelum dilakukan sekuensing meliputi proses fragmentasi DNA, end conversion, adapter ligation, cleanup of adapter-ligated, library amplification, dan library quantitation. Kemudian perpustakaan metagenom diurutkan pada platform pair-end sequencing Illumina NovaSeq 6000 (2×250 bp). Data mentah hasil sekuensing (RawPE) dilakukan analisis bioinformatika. Analisis data mengungkapkan sampel daun pohpohan budidaya mempunyai keanekaragaman bakteri endofit tertinggi, ditunjukkan melalui indeks keanekaragaman dengan kekayaan jenis berdasarkan indeks Chao1 (0,0244), indeks Shannon (0,0291), dan kemerataan jenis berdasarkan indeks Pielou (0,0282). Filum yang paling melimpah adalah filum Firmicutes dan Proteobacteria. Beberapa bakteri endofit spesifik pada tanaman budidaya teridentifikasi sebagai Limosilactobacillus (5,38%), Escherichia/Shigella (4,96%), Bacillus (4,76%), Salmonella (3,57%), Staphylococcus (3,57%). Sebaliknya, Escherichia/Shigella (15,59%), Bacillus (10,48%), Limosilactobacillus (9,00%), Salmonela (7,78%), Listeria (5,94%), merupakan genus dominan pada tanaman liar. Analisis lebih lanjut perlu dilakukan konfirmasi untuk memastikan virulensi patogen potensial pada tanaman P. melastomoides liar maupun budidaya. Kata kunci: mikrobioma, endofit, 16S rRNA, next-generation sequencing, Firmicutes, Recent studies exhibited that fresh vegetables are the major habitat for endophytic bacterial communities. In Indonesia, some of the tropical plants are consumed fresh without a cooking process, which may concern human health and food security awareness. Pilea melastomoides is a Traditional and Ethnic Food plant used by the Sundanese people in Indonesia as a vegetable for fresh consumption. This plant can be grown wild and cultivated in a standard plantation, thus raising the question of the endophytic bacterial communities between these two types of planting systems. Therefore, our research aimed to investigate the bacterial community profile of wild and cultivated P. melastomoides based on a metagenomic approach targeting the 16S rRNA gene. Samples of P. melastomoides leaves were obtained from the forest area of Mount Halimun Salak National Park, Bogor Regency, West Java. The sampling technique was carried out using cluster random sampling, divided into three plots. The sample collection method was carried out using sample pooling in
Keyword: next-generation sequencing, Firmicutes, mikrobioma, endofit, 16S rRNA

Judul: The Effects of Variance of Interest rate to Variance of Annuity Future Values
Abstrak: Time value of money is a concept that refers to the difference of the value of money due to time difference. The value of money for present time would not be the same as the value of money in the future. The value of money for present time is called as Present Value (PV) of the money and the value of money for future time is called Future Value (FV) of the money. Determination the value of money, for present and future time, depends on the time and rate of return. The value of money is determined by several factors such as inflation, fluctuation of interest rates, and government policy in securities and taxation. Due to fluctuation of the value of money we need a FV formulation, it is useful for knowing whether an investment can be profitable or not, and this information is useful also in budget analysis. Annuity is defined as a series of payments made for a specific period. The payment, fixed or varied, can be made at the beginning or at the end of the period. Annuity paid at the beginning of the period is called annuity-due and annuity paid at the end of the period is called immediate annuity-certain. The accumulated value of the annuity after few years later is called as a final value or a future value. Burnecki et al. (2003) have discussed about the FV of a fixed-rate annuity in which payments are made according to the arithmetic or geometric series. They have also examined FV for annuities in which payments are made according to arithmetic or geometric series with random rates of interest. This paper examines FV for annuity-due in which payments are made according to arithmetic or geometric series with interest rates as a random variable, which is normal distribution ,  . Future value formula is expressed in recursive form. FV for annuity-due which payments are made according to the arithmetic or geometric series with random rates of interest is calculated by theoretical way and simulation way. The random rates of interest is denoted as k k i  i  , where k i an independent random variable; i is a constant and k  is a random variable which has normal distribution ,  . By using the determined parameters, a sequence of random rates of interest are generated for theoretical calculation. Meanwhile for the simulation, the random rates of interest is generated 1000 times for the simulation. The generated data give mean value, variance, and standard deviation. Moreover, error of mean value, variance, and standard deviation from the theoretical and simulation results are calculated. Error calculation uses Symmetric Mean Absolute Percentage Error (SMAPE). The smaller the value of SMAPE is the more accurate the simulation. The interest rate variances are varied from 0.000036 to 0.0001 to study the relationship between variance of rates of interest and variance of future value. The theoretical and simulation results show that when the variance of random rates of interest increases, then the variance of FV increases linearly. FV of the annuity-due in
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