Electronic Theses and Dissertation

Identifikasi mikroorganisme ekstremofilik dari sumber air panas bawah laut di Pria Laot Sabang Aceh (PLS) 76 dilakukan untuk mengetahui apakah PLS 76 merupakan spesies baru. Hubungan kekerabatan PLS 76 dianalisis secara genotipik melalui analisis urutan gen 16S rRNA menggunakan sepasang primer Bact 27F-Uni 1492R dan data Whole Genome Sequencing (WGS), serta secara kemotaksonomi berdasarkan komposisi lipid membran dan persentase GC. Berdasarkan hasil analisis filogenetik menggunakan gen 16S rRNA PLS 76 menunjukkan cabang terpisah dan kekerabatan terdekat dengan Geobacillus zalihae T1, sementara hasil WGS menyatakan bahwa PLS 76 mirip dengan G. kaustophilus NRBC 102445. Namun komposisi lipid membran PLS 76 yang ditentukan dengan GC-MS dan persentase GC (guanin-sitosin) menunjukkan perbedaan dari bakteri termofilik lain. Sehingga disimpulkan bahwa PLS 76 merupakan bakteri Geobacillus kaustophilus strain baru khas Pria Laot Sabang. Karakterisasi gen penghasil antibiotik dilakukan untuk mengetahui kemampuan PLS 76 dalam memproduksi senyawa antibiotik. Data WGS dimanfaatkan untuk melihat gen tunggal dan kelompok gen penghasil antibiotik menggunakan program antiSMASH 6.1.1. Terdapat dua gen tunggal pengkode antibiotik antitoxin EndoAI dan gallidermin. Hasil identifikasi kelompok gen dengan antiSMASH 6.1.1 menunjukkan adanya dua region yang mirip dengan gen penghasil geobacillin I (region I) dan fengycin (region IV). Sehingga disimpulkan bahwa PLS 76 dapat mengekspresikan antibiotik pada kondisi yang sesuai.

Identification of extremophilic microorganisms from undersea hot springs in Pria Laot Sabang Aceh (PLS) 76 was carried out to determine whether PLS 76 is a new species. Genotypic identification through 16S rRNA gene sequence using a pair of Bact 27F-Uni 1492R primers and Whole Genome Sequencing (WGS) was used to analyze the phylogenetic relationship of PLS 76, as well as chemotaxonomy identification based on membrane lipid composition and percentage of GC (guanine-cytosine). Based on the result of phylogenetic analysis using the 16S rRNA gene, PLS 76 showed an outgroup branch and has the closest lineage with Geobacillus zalihae T1, moreover the WGS result indicated that PLS 76 similar to G. kaustophilus NRBC 102445. However, the membrane lipid composition of PLS 76 which determined by GC-MS and the GC percentage show no similarity to other thermophilic bacteria. Hence it was concluded that PLS 76 is a new strain of G. kaustophilus bacteria with unique characteristic of Pria Laot Sabang. Characterization of its antibiotic producing gene was carried out to understand the ability of PLS 76 to produce antibiotic compounds. The WGS data is used to study at single gene level and antibiotic-producing gene clusters was determined using antiSMASH 6.1.1 program. Two single genes which encode antimicrobial compound antitoxin EndoAI and gallidermin was found. The result of gene cluster identification with antiSMASH 6.1.1 showed two regions that were similar to the antimicrobial geobacillin I (region I) and fengycin (region IV) producing genes. It was conclude that PLS 76 has antibiotic producing genes and can express it in a suitable condition.