Purification and properties of the S1 secondary alkylsulphohydrolase of the detergent-degrading micro-organism, Pseudomonas C12B

Abstract

The SI secondary alkylsulphohydrolase of the detergent-degrading micro-organism, Pseudomonas C12B, was separated from other alkylsulphohydrolases and purified to homogeneity. Under the experimental conditions used the enzyme completely hydrolysed D-octan-2-yl sulphate (D-1-methylheptyl sulphate), but showed no activity towards the corresponding L-isomer. Additional evidence has been obtained to indicate that it is probably optically stereospecific for D-secondary alkyl sulphate esters with the ester sulphate group at C-2 and with a chain length of at least seven carbon atoms. Enzyme activity towards racemic samples of heptan-2-yl sulphate (1-methylhexyl sulphate), octan-2-yl sulphate and decan-2-yl sulphate (1-methylnonyl sulphate) increased with increasing chain length. L-Octan-2-yl sulphate is a competitive inhibitor of the enzyme, as are certain primary alkyl sulphates and primary alkanesulphonates. Inhibition by each of the last two types of compounds is characteristic of the behaviour of an homologous series. Inhibition increases with increasing chain length and plots of log K1 values against the number of carbon atoms in each alkyl chain show the expected linear relationship. A crude preparation of the S2 secondary alkylsulphohydrolase was used to show that this particular enzyme hydrolyses L-octan-2-yl sulphate, but is probably inactive towards the corresponding D-isomer. The similarity of the SI and S2 enzymes to the CS2 and CS1 enzymes respectively of Comamonas terrigena was established, and some comments have been made on the possible roles of these and other alkylsulphohydrolases in the biodegradation of detergents.

Purification and Characterization of an Inverting Stereo- and Enantioselective sec -Alkylsulfatase from the Gram-Positive Bacterium Rhodococcus ruber DSM 44541

“…4) suggests that the enzyme is nonglobular and thus indicates that the protein is monomeric. However, this enzyme appears to be much smaller than the previously described alkylsulfatases S1 from Pseudomonas strain C12B and CS2 from C. terrigena, which have molecular masses of approximately 250 kDa (2,21), and it seems to be more closely related to the inducible enzyme S3 from Pseudomonas strain C12B (molecular mass, 40 to 46 kDa) (26).…”

“…It was shown that under appropriate culture conditions Pseudomonas sp. strain C12B produced up to five different alkylsulfatases (three secondary and two primary alkylsulfatases, which are specific for the hydrolysis of sec-and prim-alkyl sulfates, respectively) (2,6,11). In contrast, C. terrigena produced only two secondary alkylsulfatases irrespective of the culture conditions employed (1,14).…”

“…In contrast, C. terrigena produced only two secondary alkylsulfatases irrespective of the culture conditions employed (1,14). Some of these enzymes have been purified to homogeneity (2,21).…”

Rapid screening for bacterial phenotypes capable of biodegrading anionic surfactants: development and validation of a microtitre plate method

“…Thus, sulphate esters were generally the most readily degradable and had the highest fraction of Biolog-positive isolates, while the sulphonates were more recalcitrant and had the lowest fraction of Biolog-positive results. The SDS-degrading isolate, Pseudomonas C12B, gave positive results for all the classes of sulphated surfactants, a versatility which matches the known battery of sulphatase activity in this organism (Bartholomew et al, 1978;Cloves et al, 1980;Shaw etal., 1980;Bateman etal., 1986;Hales etal., 1986). The LABS-degrading consortium appears to be metabolically diverse and is capable of biodegrading all the sulphated and sulphonated surfactants used during this study.…”

Comparison of pathways for biodegradation of monomethyl sulphate in Agrobacterium and Hyphomicrobium species

“…Longchain esters undergo hydrolysis catalysed by alkyl sulphatases in Pseudumonas sp. (Bartholomew et al, 1978;Bateman et al, 1986;Cloves et al, 1980;Dodgson & White, 1983;Dodgson et al, 1982;Matcham et al, 1977a, b ;Shaw et al, 1980;White & Russell, 1993) but these enzymes cease to function when the alkyl chain 0001-8396 0 1993 SGM length falls below C,. A coryneform species has been shown recently to produce an alkyl sulphatase restricted to primary esters in the C3-C7 chain length range (White & Matts, 1992).…”