Degradation of selected (bio-)surfactants by bacterial cultures monitored by calorimetric methods

Abstract

The subjects of the article are investigations concerning the ability of both Rhodococcus opacus 1CP and mixed bacterial cultures to use selected surfactants as sole carbon and energy source. In a comparative manner the biosurfactants rhamnolipid, sophorolipid and trehalose tetraester, and the synthetic surfactant Tween 80 were examined. Particular emphasis was put on a combinatorial approach to determine quantitatively the degree of surfactant degradation by applying calorimetry, thermodynamic calculations and mass spectrometry, HPLC as well as determination of biomass. The pure bacterial strain R. opacus was only able to metabolize a part of the synthetic surfactant Tween 80, whereas the mixed bacterial cultures degraded all of the applied surfactants. Exclusive for the biosurfactant rhamnolipid a complete microbial degradation could be demonstrated. In the case of the other surfactants only primary degradation was observed.

Effects of sophorolipids on fungal and oomycete pathogens in relation to pH solubility

“…Schippers et al () found that sophorolipids enhanced the ability of Sphingomonas yanoikuyae to degrade phenanthrene and did not affect cell growth of the bacterium. Frank et al () reported sophorolipids can be degraded by micro‐organisms. Therefore, it has the potential to be used as a sustainable and environmental friendly alternative for synthesized chemical surfactants (Chuo et al ).…”

Evaluation of biodegradability and biotoxicity of surfactants in soil

“…It has been reported that octadecenoic acid can be degraded by bacteria which have been isolated from soil. 32 As Fig. 7 shows, aer the rst 25 days, most of the aliphatic acid ester and alcohol had decreased, which means that a large proportion of Tween-80 was reduced during this period.…”

“…Because the rhamnolipid can be consumed by microorganisms except for its producing bacterium Pseudomonas aeruginosa, 31 the compounds can be utilized by bacteria in soil. 32 During the rst degradation process, most of the rhamnolipid structures were transformed into alkyl acid and a few alkanes with different carbon chains. Tetracosanoic acid, octadecanoic acid (Z)-9-octadecenamide can be also attained.…”

The biosurfactant viscosin transiently stimulates n-hexadecane mineralization by a bacterial consortium

“…It is often highlighted that biosurfactants are biodegraded easier than chemical surfactants (Mulligan 2005 ), but fast biodegradation of an exogenously added biosurfactant may not only be advantageous, as fast degradation may limit its potential for usage in bioremediation. However, the stability of biosurfactants is rarely investigated in alkane biodegradation studies (Frank et al 2010 ).…”