Molecular Characterization of Bacterial Isolates from the Coastal Region of South Jember - Indonesia: Diversity and Carbon Substrates Utilization

Abstract

Bacteria play an important role in aquatic ecosystems decomposing organic matter which is a key process in the microbial food web i.e. nutrient and Carbon cycles. Furthermore, this decomposition process, which is basically depending on bacterial ability to hydrolyze nutrient in aquatic environment, is very important for the bioremediation process of polluted water. Indonesia is the largest archipelago in the world with sea area about 81% of the total area of the country. Many other water areas which are not included in this sea area flow throughout the country i.e. rivers, lakes and lagoons. Consequently, research on aquatic ecology and environmental protection is of utmost importance to Indonesia. Considering the important of bacteria in microbial aquatic food web, the analysis of natural bacterial assemblages and their activities would improve this area of research in indonesian microbial (aquatic) ecology which is very limited so far. This research is based on following hypothesis i.e. Carbon utilization of bacteria depend on their diversity (1), and therefore influence bacterial activity especially their hydrolytic activities (2). The objective of this research is therefore to investigate bacterial diversity related to its substrate utilization profile (Carbon substrates) in the coastal region of South Jember. Molecular diversity of isolates was studied by observing DNA profile of isolates after BOX-Polymerase Chain Reaction (BOX-PCR). The substrate utilization pattern kit BIOLOG GN2 was used to test the ability of isolates to respire in 95 substrates, incl. carbohydrates, amino acids, organic acids and selected polymers simultaneously producing a kind of metabolic fingerprint. 126 bacteria were isolated from the coastal region of South Jember Indonesia. 4 of 8 bacteria with diversity in genetic profiles showed diversity in their metabolic fingerprint as well. These 4 isolates were able to use polymer substrate in the BIOLOG GN indicating its potential used to produce hydrolytic enzymes which are important for material decomposition in the bioremediation process in aquatic ecosystem.