ISOLATION, MOLECULAR CHARACTERIZATION OF BIOSURFACTANT-PRODUCING BACTERIA FROM PETROLEUM-CONTAMINATED SITES AND THEIR APPLICATION IN MESOCARBON-AMALGAMATED OIL ABSORPTION SYSTEMS

Petroleum hydrocarbon contamination poses a persistent environmental threat, necessitating sustainable and efficient remediation strategies. The present study investigated the isolation and molecular characterization of biosurfactant-producing bacteria from petroleum-contaminated soil and water collected from Ennore, Chennai, and Ranimookanur, Thiruvallur, and explored their application in mesocarbon-based oil-absorbing materials. Bacterial isolates were obtained by serial dilution and purification on nutrient agar and subsequently screened for biosurfactant production using oil spreading, emulsification index (E24), and foam-forming assays. Growth was evaluated in mineral salt medium supplemented with different hydrocarbon sources, including coconut, castor, palm, diesel, and engine oils. Among the tested substrates, engine oil supported the highest growth and biosurfactant activity. The most efficient isolate was molecularly identified as Stenotrophomonas maltophilia and deposited in GenBank under accession number PX624000. The crude biosurfactant was incorporated with KOH-activated mesocarbon to fabricate flexible sheets using agar-PVA and spherical beads using sodium alginate-calcium chloride ionic gelation. Both materials exhibited porous structures and effective oil uptake, with the sheet showing comparatively higher absorption performance than the beads.