Isolation and Characterization of Boudabousia marimammalium from Mangrove Habitat: Discovery of Dual-Function Antimicrobial and Anticancer Peptides

Yalpi Karthik¹Srinivasa Krishnappa²Manjula Ishwara Kalyani¹Ramakrishna D³Prabhudev S H²Kumar K M⁴Sanchit Thakur⁵Laila A Al Shuraym⁶Lamya Ahmed Alkeridis⁶Ohud Muslat Aharthy⁷Seham Sater Alhelaify⁷Muntazir Mushtaq^5*

• ¹Department of Studies and Research in Microbiology, Mangalore University, Jnana Kaveri, Chikka Aluvara, Kodagu-571232, Karnataka, India, Kodagu, India
• ²Department of Studies and Research in Biochemistry, Jnana Kaveri Campus, Manglore University, Karnataka, 571232, India, Manglore, India
• ³Dayananda Sagar College of Engineering, Bangalore, Karnataka, India
• ⁴Department of Bioinformatics, Pondicherry University, Pondicherry, Puducherry, India
• ⁵MS Swaminathan School of Agriculture, Shoolini University, Solan, Himachal Pradesh, India
• ⁶Princess Nourah bint Abdulrahman University, Riyadh, Saudi Arabia
• ⁷Taif University, Ta'if, Saudi Arabia

Mangrove ecosystems represent a rich and underexplored source of microbial diversity, particularly for actinomycetes, which are known for their metabolic versatility and ecological adaptability. In this study, Actinomycetes were isolated from mangrove soil samples and cultured on starch casein nitrate (SCN) medium for optimal growth. Molecular identification using 16S rRNA gene sequencing and phylogenetic analysis via MEGA X confirmed the isolate as Boudabousia marimammalium. Microscopic characterization revealed filamentous mycelia with spirally coiled spore chains bearing cylindrical, hairy spores with curved edges, cont6sistent with the morphological features of the genus. Crude protein was extracted and partially purified, yielding an 11.52-fold purification with a final protein concentration of 0.195 mg/mL and an 8.48% recovery rate. The protein extract demonstrated notable antimicrobial activity against multiple pathogens, including Proteus vulgaris (22 ± 0.6 mm), Salmonella typhimurium (15 ± 0.6 mm), Bacillus cereus (13 ± 0.6 mm), Pseudomonas aeruginosa (14 ± 0.6 mm), and Staphylococcus aureus (10 ± 0.6 mm). Additionally, anti-cancer activity was observed, with the crude protein causing 37.43% growth inhibition of PC3 prostate cancer cells at a concentration of 200 µg. LC-MS analysis identified a dipeptide with a molecular weight of 351.45 Da, corresponding to Tryprostatin B, a known bioactive compound. These findings suggest that B. marimammalium produces dual-function bioactive peptides with both antimicrobial and anticancer properties.Further investigations into the pharmacokinetics, pharmacodynamics, and mechanistic pathways of these peptides are warranted to evaluate their potential for therapeutic applications.