Judul: Isolasi dan Seleksi Bakteri Asam Laktat yang Bersifat Antimikroba dari Pikel Ketimun dan Acar
Abstrak: Bakteri asam laktat mempunyai kemampuan untuk menghambat pertumbuhan bakteri perusak dan bakteri patogen. Penelitian ini bertujuan untuk mendapatkan isolat bakteri asam laktat yang berasal dari aear dan pikel ketimun yang efektif dalam menekan pertumbuhan baik mikroba patogen maupun pembusuk. Isolat bakteri asam laktat diseleksi berdasarkan kemampuannya didalam menghambat pertumbuhan bakteri perusak (Alcaligenes sp. OSM 30002 dan Pseudomonas fluorescens OSM 50106) dan bakteri patogen (Escherichia coli, Staphylococcus aureus, Salmonella typhimurium, Vibrio parahaemolyticus, dan Listeria monocytogenes) dengan uji difusi sumur. Senyawa antimikroba yang diidentifikasi berupa persen asam tertitrasi, hidrogen peroksida, dan bakteriosin. lsolat bakteri asam laktat unggul diuji lebih lanjut dengan melihat pengaruh waktu kontak antara isolat unggul dengan bakteri perusak dalam media ekstrak ikan rueah. Interval waktu kontak yang digunakan adalah 0, 4, 8, dan 24 jam. Analisis dilakukan terhadap jumlah bakteri asam laktat, jumlah bakteri perusak, persen asam tertitrasi, dan pengukuran pH media ekstrak ikan rueah.
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Judul: Isolasi dan seleksi bakteri asam laktat yang bersifat antimikroba dari sauerkraut
Abstrak: Sauerkraut atau kubis asam adalah suatu hasil fermentasi asam laktat dari rajangan kubis dengan penambahan garam kurang lebih 2,25%. Bakteri asam laktat diketahui memproduksi senyawa antimikroba yang dapat menekan pertum- buhan berbagai bakteri perusak makanan dan patogen. Penelitian ini bertujuan untuk memperoleh bakteri- bakteri asam laktat dari sauerkraut yang mempunyai kemampuan menekan pertumbuhan mikroba, baik mikroba patogen maupun mikroba perusak yang sering terdapat pada produk ikan segar. Isolasi bakteri asam laktat dilakukan pada fermentasi sauerkraut hari ke 2, 4, 6, 9, dan 12. Kemudian setelah identifikasi, dilakukan seleksi dengan metode difusi sumur. Bakteri penguji yang digunakan adalah Listeria monocytogenes, Staphylococcus aureus, Escherichia coli, Vibrio parahaemolyticus, Salmonella typhimurium, Alcaligenes sp., dan Pseudomonas fluorescens. Dari hasil isolasi ini diperoleh 31 isolat, namun dari semua isolat ini hanya 11 isolat yang diduga merupakan bakteri asam laktat, dilihat dari sifat-sifat dasar bakteri asam laktat, yaitu gram positif dan katalase negatif. Setelah dilakukan identifikasi, diduga ke sebelas isolat tadi adalah Lactobacillus plantarum (9 isolat), Streptococcus sp. (1 isolat), dan Lactobacillus brevis (1 isolat). Namun yang dilanjutkan pada tahap seleksi hanya 10 isolat, karena diduga Streptococcus sp. yang diperoleh disini merupakan jenis enterokokus (fekal) yang sering digunakan sebagai indikator kontaminasi kotoran pada bahan pangan. ...
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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