Marine fungi, one of the major decomposers of marine environment, is found to produce potential enzymes and novel biomolecules. The present study explored bioprospecting potentials such as antimicrobial, anticancer and enzymatic activities of marine sediment-derived fungi isolated from continental slope of Eastern Arabian Sea. Morphology and ITS sequencing identified the fungus as Penicillium sp. ArCSPf. The fungal strain exhibited amylase, gelatinase, phytase, lipase and pectinase activity. The active fraction obtained from the ethyl acetate extract column fractionation (F2) of fungus showed antibacterial activity against both methicillin-resistant Staphylococcus aureus (MRSA) and Bacillus cereus. Minimum inhibitory concentrations of F2 were 125 μg/mL for MRSA and 62.5 μg/mL for B. cereus. The active fraction showed a significant anticancer activity (IC₅₀ = 22.79 µg/mL) against MCF-7 breast cancer cells. The secondary metabolite (Z)-Octadec-9-enamide (oleamide, m/z 282.27 (M + H⁺)] was identified in the LC-MS/MS analysis of active fraction F2 in positive ionisation mode. To the best of our knowledge, this is the first report on exploring the bioprospecting potential of a sediment-derived fungus from continental slope of eastern Arabian Sea for the production of therapeutically active compounds.

A marine bacterial isolate, Bacillus vietnamensis sp. MSB17 from the sediments collected from the continental slope of the eastern Arabian Sea exhibited good Malachite Green (MG) decolorization ability in mineral medium supplemented with glucose and yeast extract under static conditions. The complete decolorization of dye (50 mg/L) was attained within 4 h of incubation. The activities of enzymes such as tyrosinase (0.62 IU/ml), laccase (12.02 U/ml), and manganese peroxidase (6.23 U/ml) were observed during dye degradation. UV-VIS, FT-IR, and GC-MS analysis of dye samples extracted with ethyl acetate confirmed the biodegradation of MG into methanone, [4-(dimethylamino) phenyl] phenyl- and 2, 6-bis (1, 1-dimethylethyl) phenol. The metabolites obtained from B. vietnamensis sp. MSB17 mediated MG degradation did not exhibit any microbial toxicity and phytotoxicity. The present study indicated the efficiency of Bacillus vietnamensis sp. MSB17 to effectively degrade MG, revealing its potential to be further utilized for bioremediation purposes.

Antimicrobial resistance (AMR) is a serious global threat driven by the overuse of drugs in humans, animals, as well as the contamination of natural environments with antimicrobial residues. In recent years, the rise of community-acquired infections resistant to antibiotics has drawn renewed attention to the environmental compartment, in particular for pathogens found in aquaculture systems. We quantified the prevalence of antibiotic resistance in Vibrios isolated from the Cochin Estuary as well as the adjoining shrimp farms, and seafood from markets. A total of 280 Vibrio strains were subjected to antimicrobial susceptibility testing and screened for the presence of bla _TEM , bla _CTX-M , and bla _NDM-1 genes. All strains identified were resistant to at least three antimicrobials, and the percentage of drugs resistant per strain ranged from 16% up to 60%. All the strains from the estuary were resistant to amoxicillin, ampicillin, cephalothin, and colistin. Similarly, strains isolated from seafood were resistant to enrofloxacin, furazolidone, and trimethoprim, and all strains from shrimp farms were resistant to colistin. Plasmid-mediated antibiotic resistance was observed in 21% of the strains. In addition, the presence of bla _NDM-1 gene was confirmed in 22.85% of the strains. The presence of multiple resistant phenotypes in vibrios, including resistance to last-resort compounds in domestic food sources, raises serious concerns for public health in the Cochin Estuary. Although localized in nature, our findings also have vital implications for the spread of AMR internationally, given the prominence of South India for seafood exports.