Microbial Surfactants

Rosenberg, Eugene; Mitchell, Ralph

doi:10.3109/07388558509150781

Cited by 152 publications

(86 citation statements)

References 141 publications

(9 reference statements)

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“…Surfactants of microbial origin are considered superior to synthetic surfactants because of their biodegradable and potentially less toxic properties and have been examined for their usefulness in human daily life and in industrial applications (4,23). However, we are interested in such surfaceactive products from the viewpoint of basic bacteriology.…”

Section: Discussionmentioning

confidence: 99%

A novel extracellular cyclic lipopeptide which promotes flagellum-dependent and -independent spreading growth of Serratia marcescens

et al. 1992

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Serrawettin W2, a surface-active exolipid produced by nonpigmented Serratia marcescens NS 25, was examined for its chemical structure and physiological functions. The chemical structure was determined by degradation analyses, infrared spectroscopy, mass spectrometry, and proton magnetic resonance spectroscopy.Serrawettin W2 was shown to be a novel cyclodepsipeptide containing a fatty acid (3-hydroxydecanoic acid) and five amino acids. The peptide was proposed to be D-leucine (N-bonded to the carboxylate of the fatty acid)-L-serine-L-threonine-D-phenylalanine-L-isoleucine (bonded to the 3-hydroxyl group). By examining the effects of isolated serrawettin W2 on serrawettinless mutants, this lipopeptide was shown to be active in the promotion of flagellum-independent spreading growth of the bacteria on a hard agar surface. The parent strain NS 25 formed a giant colony with a self-similar characteristic after incubation for a relatively long time (1 to 2 weeks), similar to other fractal colony-producing strains of S. marcescens (producers of the different serrawettins Wl and W3). On a semisolid medium that permitted flagellum-dependent spreading growth, an external supply of serrawettin W2 accelerated surface translocation of a serrawettinless mutant during a short period (12 h) of observation. In contrast, bacterial translocation in the subsurface space of the semisolid agar was not enhanced by serrawettins. Thus, the extracellular lipids seem to contribute specifically to the surface translocation of the bacteria by exhibiting surfactant activity.Previously, we reported that Serratia marcescens and Serratia rubidaea demonstrate wetting activity on various hydrophilic and hydrophobic surfaces (1,12,13,17). The extracellular products responsible for such activity were isolated and named serrawettins (lipopeptides produced by S. marcescens) (15, 16) and rubiwettins [,-D-glucopyranosyl 3-(3'-hydroxytetradecanoyloxy)decanoate and its glucosefree relatives produced by S. rubidaea] (13). Serrawettin Wi, produced by many pigmented S. marcescens strains, is a surface-active cyclodepsipeptide identical to serratamolide, which was discovered by Wasserman as an antibiotic (25, 26). Serrawettins W2 and W3 are also surface-active exolipids of nonpigmented strains of S. marcescens (W2 from strain NS 25 and W3 from strains NS 45 and NS 50). Although serrawettins W2 and W3 were identified as novel types of ninhydrin-negative lipopeptides giving protonated molecular ions at 732 and 684 mlz, respectively, in positive secondary ion mass spectra, the precise chemical structures remained unsolved. In contrast to serrawettin Wl, which has a symmetric dilactone structure composed of 2 mol of serine and 2 mol of 3-hydroxydecanoic acids (12, 26), W2 and W3 were shown to have asymmetric cyclic structures composed of several amino acids and fatty acids (14). In the present study, the chemical structure of serrawettin W2 was determined by a combination of conventional degradation analyses and nondegradation analyses such as two-dimensional nuc...

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Section: Discussionmentioning

confidence: 99%

A novel extracellular cyclic lipopeptide which promotes flagellum-dependent and -independent spreading growth of Serratia marcescens

et al. 1992

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“…In addition, micro-organisms are able to produce a great variety of other interfacial-active molecules, among them lipids, biosurfactants and polymeric emulsifiers (Haferburg et al, 1986;Rosenberg, 1986). However, the literature contains only a few reports of emulsionstabilizing polysaccharides (Cirigliano & Carman, 1985 ;Cooper et al, 1980;Fattom & Shilo, 1985;Floodgate, 1978;Kappeli & Fiechter, 1977;Kaplan & Rosenberg, 1982;Kaplan et al, 1985;Zajic et al, 1974Zajic et al, , 1977aZuckerberg et al, 1979).…”

Section: Introductionmentioning

confidence: 99%

Structural studies of an emulsion-stabilizing exopolysaccharide produced by an adhesive, hydrophobic Rhodococcus strain

Neu¹,

Dengler²,

Jann³

et al. 1992

Journal of General Microbiology

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The primary structure of an emulsion-stabilizing exopolysaccharide from the adhesive, hydrophobic Rhodococcus strain No. 33 was elucidated by NMR spectroscopy, methylation analyses, periodate oxidation and oligosaccharide analyses. The polysaccharide PS-33 consisted of rhamnose, galactose, glucose and glucuronic acid in molar ratios of 2: 1:l:l. The main chain contained 3-substituted &-D-g~UCUrOniC acid linked to the 3-position at a-L-rhamnose, in addition to 3-substituted residues of P-D-galactose and a-D-glucose. The a-L-rhamnose of the side chain was linked to position 4 of the galactose. In addition, the polysaccharide was 0-acetylated, corresponding to one acetyl group per repeating unit. From the results two structural possibilities could be suggested. As the polysaccharide carries hydrophobic groups (methyl of rhamnosel0-acetyl), it is very likely that these are of general significance for the emulsifying activity of polysaccharides. It also seems to be possible that this polysaccharide is at least partially responsible for the hydrophobic cell surface properties of the Rhodococcus strain No. 33 and it may be involved in hydrophobic interactions when adhering to hydrophobic interfaces.

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“…Microorganisms that can secrete biosurfactants and other extracellular surface active agents can enhance mass transfer rates either by micellar solubilization or by emulsification of a NAPL phase (Thomas et al, 1986;Stucki et al, 1987;Rosenberg et al, 1988;Koch et al, 1991). A direct uptake mechanism has also been suggested for PAHs (Wodzinski and Larocca, 1977;Efroymson and Alexander, 1991;Guerin and Boyd, 1992;OrtegaCalvo and Alexander, 1994;Crocker et al, 1995).…”

Section: Introductionmentioning

confidence: 99%

Mass transfer effects on microbial uptake of naphthalene from complex NAPLs

Mukherji

Weber

2001

Biotech & Bioengineering

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Abstract:The bioavailability of naphthalene present as a component of a complex nonaqueous phase liquid (NAPL) comprised by nine aromatic compounds was investigated. Specifically, the effects of naphthalene mass transfer from the NAPL to the aqueous phase on rates of its microbial degradation were examined. The investigations were conducted using a pure culture, ATCC 17484, and a mixed culture of naphthalene-degrading bacteria, the former having been implicated previously in the direct uptake of sorbed naphthalene. The studies were conducted in mass-transfer-limited, segregated-phase reactors (SPRs) in which both the NAPL and aqueous phases were internally well-mixed. A 30-day active biodegradation period was preceded and followed by a 5-7-day period devoid of bioactivity, during which time the rates and extents of mass transfer of components from the NAPL to the aqueous phase were quantified. The NAPLphase naphthalene mass depletion profiles during biodegradation were compared to those predicted by assuming maximum mass depletion under mass-transferlimited conditions using both pre-and post-biodegradation dissolution rate and equilibrium parameters. The observed mass depletion rates were high during the initial stages of biodegradation but decreased significantly in later stages. Throughout biodegradation, even in the initial rapid stage, mass depletion rates never exceeded maximum predicted rates based on pre-biodegradation mass transfer parameters. Reduced depletion rates in the later stages appear to relate to mass transfer hindrance caused by formation of biofilms at the NAPL-water interface.

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Microbial Surfactants

Cited by 152 publications

References 141 publications

A novel extracellular cyclic lipopeptide which promotes flagellum-dependent and -independent spreading growth of Serratia marcescens

A novel extracellular cyclic lipopeptide which promotes flagellum-dependent and -independent spreading growth of Serratia marcescens

Structural studies of an emulsion-stabilizing exopolysaccharide produced by an adhesive, hydrophobic Rhodococcus strain

Mass transfer effects on microbial uptake of naphthalene from complex NAPLs

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