Abstract
Background:
Marine mollusks serve as hosts for symbiotic bacteria capable of producing secondary metabolites with significant biotechnological potential, including those used in the cosmetic industry. The rich aquatic biodiversity of Ambon, located within the Wallacea region, presents a unique opportunity to explore marine microbes with distinctive metabolite profiles. However, research exploring mollusk symbiont bacteria from Ambon for cosmetic-related bioactive metabolites remains scarce. The valuable metabolite-producing potential of these compounds highlights the importance of further investigating their biological activities and metabolite profiles for prospective cosmetic applications.

Aim:
This study aimed to evaluate the mollusk-associated bacteria for antibacterial and enzymatic activities, identify the bacterial strains, and analyze their secondary metabolites using GC-MS to support the development of active cosmetic ingredients.

Methods:
As many as 6 mollusks were selectively collected from Sopapey waters, Ambon region, and bacterial isolates were obtained using standard culturing techniques. Antibacterial activity was evaluated against Cutibacterium acnes and Staphylococcus epidermidis, enzymatic activities were tested using 1% skim milk on agar medium, and molecular identification was conducted using 16S rRNA sequencing. GC-MS analysis was employed to profile secondary metabolites from selected isolates. Statistical analysis was performed using one-way analysis of variance in RStudio to determine significant differences among the isolates and controls.

Results:
Three isolates exhibited inhibitory activity, with SPG241 showing the strongest inhibition zone, 4.80 ± 0.57 mm (24 hours) and 2.75 ± 0.49 mm (48 hours) against C. acnes and 8.43 ± 1.26 mm (24 hours) and 7.04 ± 0.97 mm (48 hours) against S. epidermidis. Protease assays demonstrated that eight isolates possessed proteolytic activity, with hydrolysis zones of 11.65–13.85 mm in 48 hours. Molecular identification revealed that the potential isolates belonged to Pseudoalteromonas citrea, Pseudoalteromonas peptidolytica, Vibrio xuii, and Vibrio tubiashii. These symbionts produced bioactive metabolites, including esters (e.g., methyl palmitate and trans-13-octadecenoic acid) and functional molecules, such as 2,3-butanediol and 2-piperidinone. Isolates with the highest enzymatic activity exhibited promising cosmetic properties, including emollient, humectant, antioxidant, anti-inflammatory, and antibacterial effects.

Conclusion:
The findings confirm that mollusk symbiont bacteria from Sopapey water, particularly within the Wallacea region, are a promising source of secondary metabolites for natural-based cosmetic products, reinforcing the region’s importance as a promising frontier for the discovery of innovative marine bioactive compounds.

Key words: Cosmetics; GC-MS; Mollusks; Secondary metabolites; Symbiont bacteria; Wallacea.