SDS-degrading bacteria attach to riverine sediment in response to the surfactant or its primary biodegradation product dodecan-1-ol

Abstract

A laboratory-scale river microcosm was used to investigate the effect of the anionic surfactant sodium dodecyl sulphate (SDS) on the attachment of five Pseudomonas strains to natural river-sediment surfaces. Three of the Pseudomonas strains were chosen for their known ability to express alkylsulphatase enzymes capable of hydrolysing SDS, and the other two for their lack of such enzymes. One strain from each category was isolated from the indigenous bacterial population present in the river sediment used; other isolates were from soil or sewage. The alkylsulphatase phenotypes were confirmed by gel zymography of cell extracts. Addition of SDS to mixed suspensions of river sediment with any one of the biodegradation-competent strains stimulated the attachment of bacteria to the sediment particles. In contrast, the attachment of biodegradation-incompetent strains was weak and, moreover, was unaffected by SDS. The SDS-stimulated attachment for competent organisms coincided with rapid biodegradation of the surfactant. The primary intermediate of SDS biodegradation, dodecan-1-01, accumulated transiently, and the numbers of attached bacteria correlated closely with the amount of dodecan-1-01 present. Direct addition of dodecan-1-01 also stimulated attachment but the effect was more immediate compared with SDS, when there was a lag period of approximately 2 h. To account for these observations, a model is proposed in which SDS stimulates the attachment of biodegradation-competent bacteria through its conversion to dodecan-1-01, and it is hypothesized that the observed reversibility of the attachment is due to the subsequent removal of dodecan-1-01 by further bacterial metabolism.

Bioremediation of naphthalene in water by Sphingomonas paucimobilis using new biodegradable surfactants based on poly (ɛ-caprolactone)

“…5b). Similar inhibition was observed at higher concentrations of SDS but under higher biomass levels (Abboud et al, 2007) and explained by the increase in permeability (Lamaza et al, 1991) and alteration of the hydrophobicity (Marchesi et al, 1994) of the membrane cell that induce anionic surfactants at higher concentration. These changes seem to correlate with their biodegradation capacity.…”

Cell aggregation of Pseudomonas aeruginosa strain PAO1 as an energy-dependent stress response during growth with sodium dodecyl sulfate

“…Sulfate ester detergents like sodium dodecyl sulfate (SDS) are considered as readily biodegradable (Scott and Jones 2000). Several publications have described SDS degradation by pure cultures of Pseudomonas strains (Payne and Feisal 1963;Stavskaia et al 1989;Marchesi et al 1994;Ellis et al 2002). Degradation is started by an alkyl sulfatase which hydrolyses SDS to sulfate and 1-dodecanol.…”

Sediment Flux and Its Environmental Implications

“…Sediment acts as a carrier for microbial adhesion and metabolic activity, thus encouraging rapid proliferation of microorganisms. Moreover, sediment also transports pollutants and provides direct contact conditions beneficial to microorganisms and organic matter (Marchesi et al, 1994).…”

“…Sediment acts as a carrier for microbial adhesion and metabolic activity, thus encouraging rapid proliferation of microorganisms. Moreover, sediment also transports pollutants and provides direct contact conditions beneficial to microorganisms and organic matter (Marchesi et al, 1994).Although the degradation of organic matter has been a focus for interaction between water, sediment and pollutants in terms of its impact on water quality and pollutant migration and transformation, such degradation does not necessarily mean complete detoxication and mineralization. For example, organic pollutants such as steroids are by no means completely removed in the degradation process.…”