title: An efficient biosurfactant-producing bacterium Selenomonas ruminantium CT2, isolated from mangrove sediment in south of Thailand.
abstract: Biosurfactant-producing bacteria, isolate CT2, was isolated from mangrove sediment in the south of Thailand. The sequence of the 16S rRNA gene from isolate CT2 showed 100 % similarity with Selenomonas ruminantium. The highest biosurfactant production (5.02 g/l) was obtained when the cells were grown on minimal salt medium containing 15 g/l molasses and 1 g/l commercial monosodium glutamate supplemented with 1 g/l NaCl, 0.1 g/l leucine, 5 % (v/v) inoculum size at 30 °C and 150 rpm after 54 h of cultivation. The biosurfactant obtained by extraction with ethyl acetate showed high surface tension reduction (25.5 mN/m), a small CMC value (8 mg/l), thermal and pH stability with respect to surface tension reduction and emulsification activity and a high level of salt tolerance. The biosurfactant obtained was confirmed as a lipopeptide by using a biochemical test, FT-IR, MNR and mass spectrometry. The crude biosurfactant showed a broad spectrum of antimicrobial activity and also had the ability to emulsify oil and enhance PAHs solubility.
authors.affiliation: Faculty of Agricultural Technology, Phuket Rajabhat University, Phuket 83000, Thailand. s4680108@hotmail.com
authors.forename: Atipan
authors.initials: A
authors.lastname: Saimmai
authors.forename: Theerawat
authors.initials: T
authors.lastname: Onlamool
authors.forename: Vorasan
authors.initials: V
authors.lastname: Sobhon
authors.forename: Suppasil
authors.initials: S
authors.lastname: Maneerat
mesh_terms: D000596:Amino Acids / Q000378:metabolism; D003470:Culture Media / Q000378:metabolism; D004655:Emulsions / Q000737:chemistry; D019015:Geologic Sediments / Q000382:microbiology*; D006863:Hydrogen-Ion Concentration; D008823:Micelles; D009821:Oils; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D020357:Selenomonas / Q000235:genetics / Q000302:isolation & purification* / Q000378:metabolism*; D012965:Sodium Chloride / Q000378:metabolism; D013500:Surface Tension; D013501:Surface-Active Agents / Q000737:chemistry*; D013696:Temperature; D013785:Thailand
chemical_list: D000596:Amino Acids; D003470:Culture Media; D004655:Emulsions; D008823:Micelles; D009821:Oils; D012336:RNA, Ribosomal, 16S; D013501:Surface-Active Agents; D012965:Sodium Chloride