Judul: Karakterisasi Bakteri Isolat Bacillus sp. NTT 3a dan Bacillus sp. NTT 3e.
Abstrak: Quorum sensing (QS) is a bacterial communication mechanism controled by bacterial population and mediated by autoinducer (AI) molecule. AI molecule of Gram-negative bacteria generally is Acyl Homoserine Lactone (AHL). Acyl Homoserine Lactone Lactonase (AHL-lactonase) enzyme encoded by aiiA gene is an enzyme that can hydrolyze the lactone ring so that inhibiting QS process. This study aimed to characterize the AHL-Lactonase producing bacteria i.e. Bacillus sp. NTT 3a dan Bacillus sp. NTT 3e. the characterization is based on colony morphology, characteristics of growth in NB medium (growth curve, specific growth rate and generation time), and activity of AHL-lactonase. AHL-lactonase activity was observed using bioindicator Chromobacterium violaceum. Colonies of Bacillus sp. NTT 3a and Bacillus sp. NTT 3e are round, have a convex elevation and slippery ledges. The colony color of Bacillus sp. NTT 3a is white, while Bacillus sp. NTT 3e is beige. The maximum specific growth rate of Bacillus sp. NTT 3a and Bacillus sp. NTT 3e was 0,005 minute-1 and 0,0042 minute-1 respectively. The highest activity of AHL-lactonase in both of bacterial culture reached the age of 42 hours (stationary phase). Protein content of Bacillus sp. NTT 3a (0,539 mg/ml) lower than Bacillus sp. NTT 3e (0,578 mg/ml) at the 48 hours. However, the activity of AHL-lactonase in Bacillus sp. NTT 3a is higher than Bacillus sp. NTT 3e
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Judul: Isolation and Characterization of Acyl Homoserine Lactonase (AHL-lactonase) Producing Bacteria from Agricultural Field in Java
Abstrak: Quorum sensing (QS) is a bacterial communication mechanism correlating with the number of bacterial population and accumulation of autoinducer (AI). Quorum sensing in Gram-negative bacteria involves a AI group of acyl homoserine lactone (AHL) to regulate the expression of several genes, including virulence genes. Anti-quorum sensing compounds can degrade AHL so that virulence genes can not be expressed. Acyl homoserine lactonase (AHL-lactonase) encoded by the aiiA gene is one enzyme that can act as an anti-quorum sensing. This study aimed to isolate and characterize the AHL-lactonase producing bacteria isolated from agricultural field in Java. Activity of AHL degradation bioassay using Chromobacterium violaceum as a bacterial indicator. Verification the presence of AHL-laktonase was performed by gene aiiA amplification. As many as 12 bacterial isolates showed AHL degradation activity and two isolates had the aiiA gene i.e. INT1c and SGT3g isolates. These isolates had bacil cells with chain arrangement and endospores. They were grouped in Gram-positive bacteria. AiiA gene sequence analysis showed that aiiA gene of INT1c had homology with aiiA gene of Bacillus cereus ATTCC 14579 while the SGT3g isolate had homology with aiiA gene of Bacillus thuringiensis BMB171. Molecular identification based on 16S rRNA gene showed that INT1c isolate had the closest similarity with the Bacillus cereus strain GM3 (98%) while SGT3g isolate had the closest similarity with the Bacillus thuringiensis strains A1-1 (99%).
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Judul: Perencanan Lanskap Sunda Kalapa, Jakarta Utara Sebagai Kawasan W isata Sejarah
Abstrak: Perkembangan kota Jakarta dari waktu ke waktu sangatlah cepat, sehingga menyebabkan kota-kota tua banyak yang tergusur untuk dijadikan daerah baru yang lebih modern. Apabila hal tersebut tidak ditanggulangi secara dini maka keberadaan Kota Lama Jakarta akan hilang. Hal inilah yang melatar belakang untuk dilakukan tindakan perlindungan dan revitalisasi kawasan bersejarah Sunda Kalapa.
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