Branched chain surfactants were some of the first used and manufactured. They were chosen over their linear counterparts due to increased solubility. However, the very slow biodegradation of branched chain surfactants lead to their ultimate replacement with the linear counterparts. The branched species are still used in some Latin American countries however, due to its low cost. While human toxicity of branched dodecylbenzene sulfonate (BCDS) is not significant, its environmental buildup does pose a serious problem.
The mechanism for degradation of BCDS is not well documented or investigated. The degradation was studied using a Pseudomonas aeruginosa strain and found to begin with the desulfonation of the surfactant. The process is then believed to undergo side-chain oxidation and leads eventually to the product 3,4-dihydroxybenzoic acid (Campos-Garcia et al., 1999). The steps surrounding the side-chain oxidation have not yet been elucidated.
The following is a text-format branched-chain dodecylbenzene sulfonate pathway map. An organism which can initiate the pathway is given, but other organisms may also carry out later steps. Follow the links for more information on compounds or reactions. This map is also available in graphic (9kb) format.
Branched-Chain Dodecylbenzene Sulfonate
Pseudomonas aeruginosa W51D | | | BCDS monooxygenase | | v +-----Branched Dodecylphenol-----+ | | | | v A v B | | | | v v 3-(4-Hydroxyphenyl)- 2-(4-Hydroxyphenyl)- propionate propionate | | | | v C v D | | | | +------->4-Hydroxybenzoate<------+ | | | | | v to the Vanillin Pathway
Page Author(s): Tyler D. Hall
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