Publication Date:
2022-06-08
Description:
During the last decade several surface active substances produced by microorganisms (biogenic surfactants, biosurfactants) have been described. Most of them are glycolipids composed of a hydrophilic sugar and one ore more lipophilic corynomycolic acids. A better biodegradability and lower toxicity of biosurfactants should be expected, because of their biogenic origin. However, data in this regard are missing. This paper presents results of toxicity testing series, in which four synthetic surfactants, two commercial oil dispersants, and six biosurfactants have been examinated. The test systems were 1. bacterial growth inhibition. 2. microalgae growth inhibition. 3. microflagellate growth inhibition. 4. biodegradation rate, and 5. bioluminescence inhibition (Microtox test). The multiplication of bacteria was stimulated by surfactants, whilst that of microflagellates and microalgae was inhibited. This may be due to the metabolic usage of surfactants, especially biosurfactants, by the bacteria. The bioluminescence was very sensitive to surfactants. No toxicity could be detected with the glucoselipid GL, produced by the marine bacterium Alcaligenes sp. MMl. Most biosurfactants were degraded faster and possess higher EC50-values than synthetic dispersants.
Type:
Article
,
NonPeerReviewed
Format:
text
