The Coral Triangle is the global epicenter of marine biodiversity, where soft corals act as vital reef architects driving ecological stability. To survive extreme osmotic and radiation stress in these environments, coral hosts rely on microbial symbionts that produce ectoine—a high-value chemical chaperone, osmoprotectant, and stabilizer. Beyond applications in cosmetics and therapeutics, ectoine serves as a premium industrial biomarker. High-grade reference standards command a market price of $300 per 25 mg, actively utilized by roughly 70 domestic industries in Indonesia that currently depend on imports. However, traditional industrial production via “bacterial milking” requires high-salinity media that corrodes equipment and inflates downstream purification costs. To tap into this high-margin biomarker market sustainably, this study utilizes genome mining to identify Virgibacillus salarius, a bacterial symbiont isolated from an Indonesian soft coral reef architect, as an alternative producer. Genomic characterization of its ectoine gene clusters enabled significant yield optimization. By heterologously expressing these clusters in Escherichia coli BL21(DE3), purified ectoine production escalated from 0.68 mg/L to approximately 400 mg/L via IPTG induction, ultimately reaching a peak of 1.256 g/L with lactose induction while enhancing product purity. This salt-free approach eliminates the need for high-salinity media, making the process highly economical, eco-friendly, and viable for industrial scale-up. Furthermore, establishing domestic manufacturing for these high-value import substitutes strengthens Indonesia’s national health and industrial security, successfully transforming local marine biodiversity into a sustainable engine for economic growth without exploiting wild coral populations.

Keywords. Coral Triangle, Ectoine, soft-coral, industrial biomarker, Virgibacillus salarius