Judul: Formula media pertumbuhan bakteri asam laktat Pediococcus pentosaceus menggunakan substrat whey tahu
Abstrak: Bakteri asam laktat (BAL) dan asam laktat yang diproduksinya dapat digunakan untuk meningkatkan masa simpan dan pengawetan bahan pangan. Media MRS merupakan media untuk pertumbuhan BAL, namun pada skala industri tidak layak digunakan. Oleh karena itu diperlukan substitusi substrat yang berasal dari hasil pertanian yaitu whey tahu. Whey tahu mengandung komponen yang mendukung pertumbuhan BAL, namun diperlukan penambahan sumber C (glukosa 5%) dan sumber N (amonium sulfat atau urea 1%). Penelitian ini bertujuan mengkaji penambahan sumber nitrogen pada whey tahu terhadap pertumbuhan Pediococcus pentosaceus dan kemampuannya menghasilkan asam. Hasil penelitian menunjukan penambahan urea menyebabkan adanya peningkatan pH kultur selama fermentasi, sedangkan amonium sulfat sebaliknya. Laju pertumbuhan (µmaks) tertinggi dihasilkan pada media urea (0.43 jam-1), sedangkan pembentukan asam tertinggi dihasilkan pada media amonium sulfat (9.13 mg/mL). Penggunaan amonium sulfat dan urea mampu menghasilkan jumlah bakteri yang tinggi sebanyak 6.5 × 108 CFU/mL dan 5.4 × 108 CFU/mL, namun masih lebih rendah dibandingkan dengan media MRS (2.03 × 1010 CFU/mL).
Keyword: actic acid bacteria,, Pediococcus pentosaceus, nitrogen source

Judul: Potensi Limbah Cair Industri Tapioka sebagai Media Pertumbuhan Starter Bakteri Asam Laktat Pediococcus pentosaceus E.1222
Abstrak: Fermentasi bakteri asam laktat (BAL) dapat memperbaiki mutu dan daya simpan bahan pangan. Salah satu BAL yang potensial dalam memfermentasi bahan pangan adalah Pediococcus pentosaceus. Penggunaan media spesifik komersial de Man Rogosa and Sharpe (MRS) untuk pertumbuhan starter BAL dalam skala industri tidaklah efisien. Oleh karena itu, perlu dikembangkan substrat yang efisien sebagai media pertumbuhan starter. Limbah cair tapioka (LCT) masih mengandung sejumlah nutrisi yang diperlukan bagi pertumbuhan P. pentosaceus, namun sebagai penunjang pertumbuhan perlu penambahan sumber karbon (glukosa 5%) dan sumber nitrogen (amonium sulfat). Penelitian ini bertujuan memanfaatkan limbah cair industri tapioka yang diperkaya dengan penambahan glukosa dan amonium sulfat sebagai media alternatif starter bakteri asam laktat P. pentosaceus E.1222. Hasil penelitian menunjukkan bahwa glukosa 5% dan amonium sulfat tidak berpengaruh nyata terhadap jumlah bakteri. Efisiensi substrat yang tertinggi berturut-turut adalah LCT (86,81%), MRS broth (53,73%), dan LCT dengan suplementasi glukosa 5% dan amonium sulfat 1% (43,53%). Hasil pengamatan kurva pertumbuhan bakteri menunjukkan bakteri pada media LCT dengan suplementasi glukosa 5% dan amonium sulfat 1% memiliki laju pertumbuhan maksimum (μmaks) yang lebih tinggi (0,52 jam-1) dibandingkan dengan LCT (0,45 jam-1). Peningkatan skala produksi starter dengan media LCT dengan suplementasi glukosa 5% dan amonium sulfat 1% menunjukkan adanya sedikit penurunan jumlah logaritmik bakteri yaitu dari 8,836 (50 mL), 8,401 (500 mL), menjadi 8,063 (1000 mL).
Keyword: Bakteri asam laktat, limbah cair tapioka, sumber karbon, sumber nitrogen

Judul: Characteristic of Overshooting Top (OT) Based on  Himawari  8  Satellite  as  a  Convective  Cloud  Feature  that  Generates  Extreme Weather in the Java Island Region
Abstrak: Overshooting Top (OT) is a feature at the top of a convective cloud that is associated with extreme weather. Research on OT in tropical Indonesia is still very limited. The existence of geostationary satellites with wide area coverage and fast frequency observations is useful for observing the fast dynamics of the OT life cycle. Therefore, this study intends to analyze the relationship between OT and extreme weather, updraft and thermodynamic conditions of OT when extreme weather occurs, the best objective method for detecting OT in the day time and night time, and the spatiotemporal distribution of OT in the tropical region of Java Island during the 2018-2021 period. Based on visual analysis using visible channel and Himawari 8 sandwich products, 87% of extreme weather events in Java were accompanied by the appearance of OT. It indicates that the presence of the OT pattern is a convection cloud pattern or feature that is closely related to extreme weather events for the Java Island region. The existence of a time lag between the appearance of OT and extreme weather events on Java Island indicates that the OT of convection cloud can be used as a precursor or nowcasting for the appearance of extreme weather. Most of the convective cloud OT features during extreme weather events on Java Island have altitude that were only able to exceed the altitude of the equilibrium level and few were able to exceed the tropopause level of 9 km – 16 km. The difference in atmospheric conditions during extreme weather events on Java Island, which is in the tropics and subtropics, is a strong and unstable convective energy condition characterized by a larger CAPE, as well as unstable KI, LI, SI and TTI values. It is offset by kinematic factors in the form of a weak vertical wind shear (bulk wind shear 0-6 km) and a higher freezing point height. The difference between extreme weather events in the Java Island region and other tropical regions compared to subtropical regions is the strong updraft speed of convection clouds. The IRW Texture COMB algorithm based on the IRW-Texture Gradient modification and the COMB algorithm shows a significant increase in quality for detecting OT and non-OT pixels in Java. Rainy days with rainfall > 50 mm/day are very common in areas with an altitude of > 500 m. On the other hand, the level of convection activity which is indicated by the presence of OT and lightning is significantly reduced in this area. OT of convective clouds appear more frequently during the DJF season and less frequently during the JJA season. OT often appears during the day time and rarely at night time. Most OTs appear in the central part, away from the south and north coasts of Java Island during the day, while OTs that appear near the south and north coasts of Java Island can appear in the morning or afternoon.
Keyword: convective clouds, extreme weather, Overshooting Tops, Himawari 8 Satellite