Judul: Kondisi Pertumbuhan Optimum Bakteri Lactobacillus brevis LIPI13-2-LAB131 dalam Memproduksi Enzim β- galaktosidase
Abstrak: Mikroorganisme potensial sebagai penghasil enzim β-galaktosidase adalah Lactobacillus brevis LIPI13-2-LAB131. Bakteri ini menghasilkan aktivitas enzim β-galaktosidase sebesar 7.93 U/mL. Penelitian ini bertujuan mengoptimalkan kondisi pertumbuhan Lactobacillus brevis LIPI13-2-LAB131 agar menghasilkan aktivitas enzim β-galaktosidase yang maksimum. Penelitian ini terdiri dari pelaksanaan optimasi proses menggunakan aplikasi design expert 7.00 (DX7) dengan metode response surface methodology (RSM) dan purifikasi parsial enzim β-galaktosidase. Hasil penelitian menunjukkan kondisi pertumbuhan Lactobacillus brevis LIPI13-2-LAB131 optimum pada kombinasi kadar laktosa sebesar 1.48%, suhu 34.91 oC, waktu 48.48 jam, dan jumlah inokulum 2.83% dengan nilai desirability sebesar 0.839. Hasil purifikasi parsial enzim menunjukkan nilai aktivitas enzim β-galaktosidase meningkat menjadi 22.88 ± 0.29 U/mL dengan yield hasil purifikasi sebesar 11.65%.
Keyword: enzim β-galaktosidase, kondisi pertumbuhan, Lactobacillus brevis LIPI13-2-LAB131, optimasi, RSM

Judul: Optimasi produksi protease oleh Bacillus brevis hasil isolasi dari air rendaman kedelai
Abstrak: Tujuan dari penelitian ini adalah untuk meningkatkan aktivitas enzim protease yang dihasilkan oleh bakteri Bacillus brevis BK II hasil isolasi dari air rendaman kedelai dengan menggunakan limbah cair tahu (LCT) sebagai media pertumbuhannya. Disamping itu juga untuk mempelajari pengaruh penambahan glukosa dan skim pada LCT terhadap aktivitas protease yang dihasilkan. Isolat bakteri BK II telah berhasil diidentifikasikan untuk sementara ini sebagai Bacillus brevis dengan menggunakan kunci identifikasi yang disusun oleh R.E. Gordon dalam "CRC Handbook of Microbiology". Kondisi yang digunakan dalam penelitian ini adalah suhu 37°C, media dengan pH 7 dan kecepatan agitasi 200. rpm, karena dari hasil uji suhu pertumbuhan diketahui bahwa pertumbuhan pada suhu 37°C lebih baik dari pertumbuhan pada 27°C. Uji aktivitas proteolitik yang digunakan dalam penelitian ini adalah uji Hanlon dan Hodges yang mendasarkan pada hidrolisa azokasein. Analisa lain yang dilakukan adalah pengukuran massa sel dengan absorbansi pada panjang gelombang 600 nm berdasar metode Mao et al. dan pengukuran kadar glukosa menggunakan metode DNS yang disusun oleh Miller.
Keyword: 

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