Judul: Penapisan Bakteri Resisten Terhadap Merkuri sebagai Alternatif Agen Bioremediasi pada Pencemaran Tanah Pertambangan
Abstrak: Heavy metal pollution of mercury (Hg) in soil and water are very harmful to the environment and human health. Mercury compounds in the form of Hg (II) can be bound to the cysteine residues of proteins of human / animal so that the protein loses its activity. This research was expected to help provide solutions to environmental problems caused by environmental pollution, especially mercury around industries that use mercury and as information on the type of bacteria that were resistant to mercury. Mercury-resistant bacteria are a biological agent that can degrade the mercury from Hg2+ to Hg which has un harmful properties to the environment and health. There are two mercury-resistant bacteria that had isolated from gold mine waste disposal areas of PT.ANTAM. The bacteria were cultivated on solid media supplemented with 1 μg/mL and 10 μg/mL HgCl2. Identification of two mercury-resistant bacteria had through the morphology test and biochemical assay, were compared with the Bergey's Manual of Determinative Bacteriology. Enterobacter sp. decreased consentration of HgCl2 in the media of 3.3 ppm after three days incubation, whereas the Bacillus sp. showed a decrease of 0.9 ppm. Bacillus sp. better than the Enterobacter sp. as a bioremediation agent for the level of resistance to antibiotics lower so it was easy to control.
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Judul: Bioremediation of mercury using indigenous bacteria with bioreactor and artificial wetland systems
Abstrak: Sulawesi Province, operated since 1998, utilizes mercury in processing gold material and creates mercury waste that pollutes rivers, soil, plants, and air in the area. Sample data of 2002 to 2006 showed that there were mercury pollution in the area. Bioremediation using microbe is a more effective and efficient technology for cleaning of mercury contaminated environment. This experiment was aimed to: (1) identify, characterize and test the mercury-reducing bacteria from SSGM Talawaan-Tatelu; (2) study the ability of bioreactor and artificial wetland using the mercury-reducing bacteria from SSGM, active carbon, aquatic plant (Typha sp. and Eichornia crassipes) in reducing mercury during 6 days biofilm formation. The experiment was carried out in Indonesian Center for Biodiversity and Biotechnology (ICBB) Laboratory, Bogor. Soil sample was taken collected from SSGM Manado. The results of the experiments revealed that there were 10 superior isolates of mercury-reducing bacteria that were able to grow in Luria Bertani medium containing 500 ppm HgCl2. Those identified as Bacillus sp. group were ICBB 9116, ICBB 9118, ICBB 9121, and ICBB 9122. There were two isolates of Brevibacillus sp. group, namely ICBB 9123 and ICBB 9124; and one isolate for each of Micrococcos luteus, Pseudomonas sp, Morganella morganii, Eschericia coli were ICBB 9120, ICBB 9115, ICBB 9119, ICBB 9117, respectively. The top four highest capability of isolates in reducing mercury, are as follows i.e. ICBB 9120 can reduce 79.42% - 98.65%, ICBB 9119 (80.10% - 97.06%), ICBB 9118 (80.60% - 98.62%), and ICBB 9121 (79.15% - 98.50%). Mercury reduction capability in bioreactor using isolate ICBB 9118 was 98.89%, ICBB 9119 was 98.73%, ICBB 9120 was 99.12%, and ICBB 9121 was 99.33%. The observation results showed that Bacillus sp. ICBB 9121 had the highest capacity in reducing mercury. Typha plant, carbon active, and water hyacinth were used simultaneously with microbes within bioreactor showed their ability in reducing mercury with the level of 98.50%, 97.96%, and 96.73, respectively. The experiment results of artificial wetland reactor demonstrated that the capacity of active carbon, typha plant, and water hyacinth, in reducing mercury without microbes were 85.34%, 82.18%, and 44.25%, respectively.
Keyword: mercury-reducing bacteria, bioreactor, artificial wetland

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