Judul: Studi Potensi dan Purifikasi Parsial Enzim β- Galaktosidase dari Isolat Bakteri Asam Laktat Asal Produk Pangan Terfermentasi.
Abstrak: Enzim β-galaktosidase berperan dalam pemecahan laktosa menjadi glukosa dan galaktosa. Enzim ini digunakan dalam industri pangan untuk produkproduk rendah laktosa. Enzim β-galaktosidase bisa berasal dari beberapa sumber, seperti hewan, tumbuhan, ataupun mikroorganisme. Tujuan penelitian ini adalah untuk mempelajari potensi β-galaktosidase dari beberapa isolat bakteri asam laktat dan melakukan purifikasi parsial terhadap enzim dengan aktivitas spesifik tertinggi. Terdapat delapan isolat bakteri asam laktat yang diuji potensinya dalam menghasilkan enzim β-galaktosidase. Isolat 11M106-2 yang telah diidentifikasi sebagai Lactobacillus farciminis memiliki aktivitas spesifik β-galaktosidase tertinggi sebesar 13.90 ± 0.57 U/mg protein. Purifikasi parsial terhadap crude enzim dilakukan melalui dua tahapan, yaitu pengendapan dengan ammonium sulfat kemudian dilanjutkan dengan proses dialisis. Purifikasi parsial terhadap crude enzim isolat 11M106-2 meningkatkan aktivitas spesifiknya menjadi 19.65 ± 0.57 U/mg protein setelah pengendapan dengan ammonium sulfat dan menjadi 75.65 ± 0.64 U/mg protein setelah dilakukan proses dialisis.
Keyword: bakteri asam laktat, β-galaktosidase, laktosa, purifikasi parsial

Judul: Skrining Enzim β-galaktosidase dari Bakteri Asam Laktat Hasil Isolasi Bibit Kefir, Susu Kambing, dan Produk Kefirnya
Abstrak: β-galaktosidase banyak digunakan untuk menghidrolisis laktosa. Enzim ini banyak terdapat di alam dan dapat diturunkan dari berbagai sumber seperti tanaman, organ hewan dan mikroorganisme. Enzim β-galaktosidase secara luas digunakan dalam industri susu untuk menghidrolisis laktosa di dalam susu dan whey, menghasilkan produk yang mudah dicerna dan meningkatkan karakteristik sensori kemanisan dan kekentalan. Tujuan penelitian ini adalah untuk melihat potensi enzim β-galaktosidase bakteri asam laktat dari isolat yang diperoleh dari susu kambing, kefir kambing dan bibit kefir. Terdapat tiga belas isolat bakteri asam laktat yang diuji potensi enzim β-galaktosidasenya. Isolat K.Kam 1 memiliki aktivitas spesifik tertinggi 12.3616 ± 0.3952 U/mg. Selanjutnya isolat tersebut dilakukan purifikasi parsial. Purifikasi parsial dengan amonium sulfat 80% meningkatkan kemurniannya sebesar 1.29 kali. Sementara itu nilai aktivitas spesifik meningkat 1.3 kali dari crude enzyme nya. Namun, nilai recovery activity dan rendemen protein masih rendah yaitu 11.16% dan 11.85% setelah dialisis.
Keyword: β-galaktosidase, bakteri asam laktat, purifikasi parsial

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