title: Production and characterization of a group of bioemulsifiers from the marine Bacillus velezensis strain H3.
abstract: Marine microbes are a rich source of bioactive compounds, such as drugs, enzymes, and biosurfactants. To explore the bioactive compounds from our marine natural product library, an oil emulsification assay was applied to discover biosurfactants and bioemulsifiers. A spore-forming bacterial strain from sea mud was found to produce bioemulsifiers with good biosurfactant activity and a broad spectrum of antimicrobial properties. It was identified as Bacillus velezensis H3 using genomic and phenotypic data analysis. This strain was able to produce biosurfactants with an optimum emulsification activity at pH 6.0 and 2% NaCl by using starch as the carbon source and ammonium sulfate as the nitrogen source. The emulsification-guided isolation and purification procedure led to the discovery of the biosurfactant components, which were mainly composed of nC(14)-surfactin and anteisoC(15)-surfactin as determined by NMR and MS spectra. These compounds can reduce the surface tension of phosphate-buffered saline (PBS) from 71.8 to 24.8 mN/m. The critical micelle concentrations (CMCs) of C(14)-surfactin and C(15)-surfactin in 0.1 M PBS (pH 8.0) were determined to be 3.06 x 10(-5) and 2.03 x 10(-5) mol/L, respectively. The surface tension values at CMCs for C(14)-surfactin and C(15)-surfactin were 25.7 and 27.0 mM/m, respectively. In addition, the H3 biosurfactant exhibited antimicrobial activities against Staphyloccocus aureus, Mycobacterium, Klebsiella peneumoniae, Pseudomonas aeruginosa, and Candida albicans. Thus B. velezensis H3 is an alternative surfactin producer with potential application as an industrial strain for the lipopeptide production.
authors.affiliation: Institute of Microbiology, Chinese Academy of Sciences, Beijing 100190, China.
authors.forename: Xiangyang
authors.initials: X
authors.lastname: Liu
authors.forename: Biao
authors.initials: B
authors.lastname: Ren
authors.forename: Ming
authors.initials: M
authors.lastname: Chen
authors.forename: Haibin
authors.initials: H
authors.lastname: Wang
authors.forename: Chandrakant R
authors.initials: CR
authors.lastname: Kokare
authors.forename: Xianlong
authors.initials: X
authors.lastname: Zhou
authors.forename: Jidong
authors.initials: J
authors.lastname: Wang
authors.forename: Huanqin
authors.initials: H
authors.lastname: Dai
authors.forename: Fuhang
authors.initials: F
authors.lastname: Song
authors.forename: Mei
authors.initials: M
authors.lastname: Liu
authors.forename: Jian
authors.initials: J
authors.lastname: Wang
authors.forename: Shujin
authors.initials: S
authors.lastname: Wang
authors.forename: Lixin
authors.initials: L
authors.lastname: Zhang
mesh_terms: D000645:Ammonium Sulfate / Q000378:metabolism; D000890:Anti-Infective Agents / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism; D001407:Bacillus / Q000145:classification / Q000302:isolation & purification / Q000378:metabolism*; D016000:Cluster Analysis; D003470:Culture Media / Q000737:chemistry; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D004275:DNA, Ribosomal / Q000737:chemistry / Q000235:genetics; D045703:Emulsifying Agents / Q000737:chemistry / Q000302:isolation & purification* / Q000378:metabolism*; D019015:Geologic Sediments / Q000382:microbiology*; D009682:Magnetic Resonance Spectroscopy; D013058:Mass Spectrometry; D008969:Molecular Sequence Data; D015394:Molecular Structure; D010802:Phylogeny; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D017422:Sequence Analysis, DNA; D013213:Starch / Q000378:metabolism; D013500:Surface Tension / Q000187:drug effects; D013501:Surface-Active Agents / Q000737:chemistry / Q000302:isolation & purification* / Q000378:metabolism*
chemical_list: D000890:Anti-Infective Agents; D003470:Culture Media; D004269:DNA, Bacterial; D004275:DNA, Ribosomal; D045703:Emulsifying Agents; D012336:RNA, Ribosomal, 16S; D013501:Surface-Active Agents; D013213:Starch; D000645:Ammonium Sulfate