Marine Biosurfactants, I. Screening for Biosurfactants among Crude Oil Degrading Marine Microorganisms from the North Sea

Abstract

Three bacterial strains of marine origin were isolated during a screening for biosurfactants among n-alkane degrading microorganisms. One strain - identified as Alcaligenes sp. MM 1 - produced a novel glucose lipid. In the case of Arthrobacter sp. EK 1 the well-known trehalose tetraester was found as major component. From another pure culture classified as Arthrobacter sp. SI 1, extracellular emulsifying agents with properties indicating high molecular weight substances were detected. Furthermore trehalose corynomycolates were found at up to 2 g/1. The isolated biosurfactants showed good interfacial and emulsifying properties.

Study Onmicrobial Diversity of Biosurfactant Producing Bacteria From Contaminated Enviromental Samples.

“…Emulsification test:-Emulsification capacity of the biosurfactant towards hydrocarbons (diesel, petrol, vegetable oil, kerosene, crude oil) was carried out using a mixture of 2 ml oil added to the same amount of cell free supernatant obtained after vortexing sample culture grown on nutrient broth, at high speed for 2 min and left to stand for 24 h. The emulsification index (E 24 ) was calculated as the percentage of height of the emulsified layer (mm) divided by total height of the liquid/aqueous column (mm) (Yuste et al,2000;Schulz et al, 1991). …”

Screening Concepts for the Isolation of Biosurfactant Producing Microorganisms

“…9 Marine environments have also been reported as successful sampling sites. 6,[16][17][18][19] However, Bodour and Miller-Maier 15 showed that contaminated soils are more yielding than uncontaminated soils. One exceptional example is the discovery of biosurfactant producing strains which were originally isolated when investigating the food hygiene of meat.…”

“…For the screening of biosurfactant producing microbes, enrichment cultures utilizing hydrophobic compounds as the sole carbon source are applied. 3,[5][6][7]11,12,22 This is an indirect screening method as the growth on hydrophobic compounds indicates the production of biosurfactants, but not always correlates with this trait. 3,5 Moreover, the applied screening medium and conditions will influence whether or not surfactants are produced.…”

Isolation of biosurfactant producing microorganisms and lipases from wastewaters from slaughterhouses and soils contaminated with hydrocarbons

“…Si los microorganismos secretan tensioactivos aniónicos, se forma un complejo insoluble, de color azul oscuro, observándose colonias rodeadas de un halo color azul oscuro (Tuleva et al, 2002). Según Mulligan et al (1984), la selección de bacterias productoras de biosurfactantes mediante agar sangre es un método útil para la selección preliminar de estos microorganismos (Mulligan et al, 1984;Schulz et al, 1991;Plaza et al, 2006;Youssef et al, 2004); más no se considera un método definitivo debido a las limitaciones que tiene (Jain et al, 1991) Este método no es específico, ya que algunas enzimas líticas también pueden provocar halos de hidrolisis, además no se pueden utilizar sustratos hidrofóbicos como única fuente de carbono; de tal manera que induzcan la producción de biosurfactantes. Por tanto, este método es recomendable para detección preliminar que debe ser apoyado por otras técnicas basadas en mediciones de la actividad superficial (Mulligan et al, 1984).…”