#TITLE_ALTERNATIVE#

• Main Author: YOHANDINI KUSUMAWATI (NIM 30503007), HENI
• Format: Dissertations
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/8094
• Institution: Institut Teknologi Bandung

Thermophilic microbes are unique cells due to their capability to grow optimal in high tempeature. Research on thermophilic microbes has advantages for development of fundamental science and its aplication in industrial processes. Indonesia has many volcanoes with abundant hot springs which are potential habitats for thermophilic microbes. Many of these hot springs have different physical and chemical properties. This difference makes Indonesia's hot springs a good source for high biodiversity of thermophilic microbes. Nowdays, research on biodiversity of thermophilic microbes in Indonesia are very limited. The objective of this reseach is to get information of biodiversity of thermophilic microbes in Kawah Hujan A and Kawah Hujan B, beside to obtain microbial cultures which are potential for industrial aplication. Culture-dependent and culture-independent approaches were used to analyze biodiversity of thermophilic microbes. The method was based on differences of 16S rRNA gene sequences obtained from amplification of chromosomal DNA of microbial samples. The 16S rRNA gene fragments with different sequences were separated by DGGE apparatus. Each of bands from DGGE was targeted for nucleotide sequencing. Homology of the nucleotide sequences was analyzed using computational analysis trough Phylip program combining with phylogenetic analyis. Chromosomal DNA isolation is crucial method for diversity analysis. In these research two methods of cell lysis, enzymatic and physical based methods were used to lysis the cell. The result showed that enzymatic based method has limitation to disrupt cell which trapped on the mud or spores and biofilm form cells. Meanwhile, physical disruption could lysis the trapping cell, spore, and biofilm form cell; however the chromosomal DNA often fragmented. Culture-independent strategy is used to analyze the dominant microbes in natural habitat, while culture-independent approaches are used to detect less populating microbes. The result showed that the microbes detected by culture-independent were different with detected by culture-dependent strategies. The application of additional nutrient in the culture was crucial to detect culturable microbes. In neutral hot spring (Kawah Hujan A), predominated microbes in nature have high homology with gamma Proteobacteria. Meanwhile, the predominated microbes in culture were belonged to Firmicutes and Deinococcus phyla. The highest homology for Firmicutes phylum was Geobacillus and Anoxybacillus genera, while for Deinococcus phylum, was Thermus genus. From detail alignment analysis suggested that the gamma proteobacteria from Kawah Hujan A were different with other known gamma proteobacteria. The result from Kawah Hujan B, very acidic with high sulphate content, were predominated by microbes that have closest homology with Crenorchaeota and Proteobacteria phyla, especially from class of gamma proteobacteria. Meanwhile, predominated microbes in culture were belonged to Alicyclobacillus genus from Firmicutes phylum, and Pantoea/Enterobacter and Pseudomonas genera from Proteobacteria phylum. Based on detail alignment analysis, the Crenorchaeota detected from Kawah Hujan B were also different with other Crenorchaeota known before. The pure culture isolated from Kawah Hujan A based on the sequence of the whole 16S rRNA gene were mostly belong to Geobacillus genus. In addition of Geobacillus, some colonies were identified as Pantoea/Enterobacter. Meanwhile pure culture from Kawah Hujan B has not succesfully isolated. Information on biodiversity of microbes of Kawah Hujan hot spring has not been reported yet. This information is broader our knowledge on natural potential of Indonesia, especially on biodiversity of thermophilic microbes, and provide a resource of microbes for development of science and its application in industrial processes.