Metagenomics-Based Cloning of Amilase-Encoding Genes from the Uncultured Symbiotic Bacteria of a Marine Sponge Theonella swinhoei from Kapoposang Island, South Sulawesi

Abstract

Marine sponges have recently been recognized as the source of enzymes, including members of hydrolases. Hydrolytic enzymes are extracellularly produced by sponge-associated bacteria to mediate the metabolism of complex organic matters, there by assisting the sponge hosts in nutrition and metabolic processes. Among hydrolytic enzymes, amilases has attracted increasing attention due to their potential industrial applications. This research work was aimed to utilize functional metagenomics approach for the discovery of amilases derived from the uncultured symbiotic bacteria of the Indonesian marine sponge Theonella swinhoei. W e initially constructed a small-insert metagenomic library in Escherichia coli by cloning of metagenome in the size range of 5-20 kb prepared from the sponge's microbiome. Further functional screening of the resulting metagenomic library led to the isolation of two recombinant E. coli clones potentially harboring amilase genes, as indicated by the presence of clearing zones surrounding the selective medium containing 1% amilum.