Judul: Tetes Tebu sebagai Alternatif Sumber Karbon untuk Produksi Asam Laktat oleh Lactobacillus delbrueckii subsp. bulgaricus
Abstrak: Lactic acid is needed as an industrial feed, especially for applications in the food sector. However, by using a microbial production still uses food material as a substrate. Alternative substrates for the production of lactic acid is needed in industry. Molasses are potential substrates due to the richness in carbon. Molasses also widely available and low-cost material. The objective of the research is molasses can be used as a carbon source needed by Lactobacillus delbrueckii subsp. bulgaricus to produce lactic acid. This study consisted of hydrolysis and detoxification of molasses, analysis qualitative test of reducing sugar from molasses, analysis of total sugar by phenol sulfuric acid, determination of bacterial growth, production and extraction of lactic acid, and analysis of lactic acid using high performance liquid chromatography. The results showed that molasses can be used as an alternative carbon source as indicated by growth of bacteria when the media were given 0.5% molasses. Concentration of total sugar molasses was 1090 g/L. The reducing sugar test showed positive results for the Selliwanoff, Benedict, and Barfoed tests. The optimum of L. delbrueckii subsp. bulgaricus growth was at temperature of 42° C and 150 rpm of agitation. Production of lactic acid was conducted in 24 hours. The result of lactic acid from the production was 2.80%. The dry cell biomass was 0.002 g/ L at pH of fermentation media was 4.0. Analysis HPLC also showed that lactic acid was the product of fermentation
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Judul: Pemanfaatan Tetes Tebu (Molasses) dan Limbah Cair Tahu sebagai Substrat untuk Produksi Manitol oleh Lactobacillus plantarum AYN4.32
Abstrak: Manitol merupakan pemanis yang aman karena memiliki kalori yang rendah dan indeks glikemik bernilai nol. Lactobacillus plantarum AYN4.32 merupakan salah satu jenis BAL yang dapat memproduksi manitol pada media MRS (DeMan’s Sharpe and Rogosa) + Fruktosa 20 g/L + (NH4)2SO4 10 g/L. Molasses tersusun atas total gula 51.36% dan kadar nitrogen yang rendah yaitu 0.39%. Kadar nitrogen yang rendah pada molasses sehingga sumber nitrogen diperkaya dari limbah cair tahu dan (NH4)2SO4. Larutan molasses dengan total padatan 600 g/L sendiri mengandung total gula 217.4 g/L dan gula pereduksi 75.78 g/L. Setelah dihidrolisis dengan asam, gula pereduksi meningkat menjadi 109.2 g/L atau tingkat inversi dari gula sukrosa yang didapatkan adalah 23.59%. Pada penelitian ini, Media MRS + Fruktosa 20 g/L + (NH4)2SO4 10 g/L merupakan kontrol positif dan empat jenis media formulasi campuran molasses dan limbah cair tahu yang didasarkan dengan total gula yaitu: (1) media 1 (total gula 35 g/L + (NH4)2SO4 10 g/L), (2) media 2 (total gula 40 g/L + (NH4)2SO4 10 g/L), (3) media 3 (total gula 45 g/L + (NH4)2SO4 10 g/L), dan (4) media 4 (total gula 35 g/L + (NH4)2SO4 47.6 g/L). media 4 merupakan media yang terbaik dalam produksi manitol karena memiliki intensitas warna spot manitol yang paling tebal yang berkorelasi dengan jumlah manitol yang dihasilkan pada pelat TLC.
Keyword: hydrolysis, Lactobacillus plantarum AYN4.32, mannitol, molasses, tofu whey

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