Background: Marine bacteria serve as excellent sources of therapeutic enzymes, metabolites
and natural products, which possess novel therapeutic properties. Increasing death rates due to
cardiovascular diseases urge for cost-effective production of the fibrinolytic enzyme.
Methods: In this study, marine sponge samples were screened for potent fibrinolytic producing bacteria.
The primary screening was done for protease production, and clot lysis activity. The secondary
screening was done for casein plasminogen activity and fibrinolytic activity. The strain
which had potent fibrinolytic activity among them was further subjected to morphological, biochemical
and molecular characterization. Media optimization was carried out to enhance enzyme
production. The enzyme produced was subjected to purification using ammonium sulfate precipitation,
gel filtration and characterized using HPLC and FTIR analysis.
Results: Sponge was identified to be Desmapsamma anchorata. Thirteen bacterial isolates were
isolated from the sponge sample. The 16S rRNA sequencing revealed that the potential strain had
99% similarity with Bacillus licheniformis. Amongst the isolates, most were found to be morphologically
identical to the Bacillus genus. Gram’s staining and SEM analysis of the potent isolate
were performed to identify the spore formation and rod-shaped morphology of the bacteria. The optimal
temperature and pH for the production of the enzyme were 37°C and 8, respectively. The carbon
source maltose and nitrogen sources were malt extract and yeast extract that were found to be
optimal. The optimum incubation time was found to be 4 to 5 days. The crude supernatant was purified
with ammonium sulfate precipitation and gel filtration chromatography. The retention time of
11.3 min and the presence of functional groups show the purity of the enzyme. The partially purified
enzyme showed 96.4% clot lysis in artificial clot lysis activity.
Conclusion: Although the secretion of fibrinolytic enzymes from Bacillus species is not new,
based on our investigation, there are no reports regarding Bacillus licheniformis being isolated
from marine sponges. However, there are reports of Bacillus licheniformis secreting fibrinolytic enzymes
isolated from fermented food samples. This study identifies the marine environment as a potential
source of new exploration for drug discovery.