Fermentation Shrimp Shell Waste in Solid State Using Pseudonocardia carboxydivorans 18A13O1 to Produce Bioactive Metabolites

Marine actinomycetes are prolific microorganisms; however, knowledge of their diver�sity, distribution, and secondary metabolites is limited. Marine actinomycetes represent an un�tapped source of novel bioactive compounds. In this study, we investigated shrimp shell as sub�strates for model production bioactive metabolites from actinomycetes under solid state fermenta�tion (SSF) conditions. A total of fifteen actinomycetes were isolated from six sponges and one tu�nicate. The isolated actinomycetes were grown on solid shrimp shells. Cultures of actinomycetes were extracted with ethyl acetate (EtOAc) and extracts were bioassayed for activity against Staph�ylococcus aureus. One isolate 18A13O1 from the sponge, Rhabdastrella globostellata, exhibited anti�bacterial activity on primary screening compared to the other samples and was chosen for further study. Visualization using SEM showed aerial and substrate mycelia. Through phylogenetic anal�ysis, it was confirmed that isolate 18A13O1 is a Pseudonocardia carboxydivorans. Purification of an EtOAc extract yielded A13B2, which showed a minimum inhibition concentration against S. aureus at 15.6 μg/mL. It can be concluded that this basic information is very important for further studies related to the development of the production of bioactive secondary metabolites through the solid state fermentation process.