Abstract:
This study aimed to isolate, characterize and identify agarase-producing
marine bacteria from a seaweed farm in Calatagan, Batangas. Several samples,
such as seawater, sediment, sea urchin, starfish, sea cucumber and seaweed, were
collected. Serial dilutions of these samples were plated into Marine Agar (MA) plates
and screened for agarolytic activities through the presence of “depression forming
units” (DFUs) that indicated agarase production. Agarolytic activities were consistent
from the isolates obtained from the sea urchin Echinotnx calamaris, as such, these
isolates were chosen for further characterization. DNA was extracted from two
isolates from sea urchin Echinotrix calamaris (SU1-4 and SU1-6) using
Xanthogenate-SDS Method and the PureGene DNA Extraction Kit (Gentra). No
DNA was successfully extracted from SU1-4 while DNA was successfully extracted
from SU1-6. The 16S rDNA of SU1-6 was PCR-amplified and sent to the Davis
Sequencing Facility in the United States for sequencing. Sequence analysis of the
partial forward sequence using BLAST showed that SU1-6 is closely matched to
Photobacterium sp. HAR72. Phylogenetic tree construction using molecular
softwares (ClustalX 1.8, BioEdit and Mega 3.0) showed that SU1-6 is closely related
to the genera Photobacterium.
