Pseudomonas C12B, an SDS degrading strain, harbours a plasmid coding for degradation of medium chain length n-alkanes

Pseudomonas C12B is able to degrade alkyl sulfates, alkylbenzene sulfonates , and linear alkanes and alkenes. Mitomycin C curing experiments and conjug ation experiments demonstrated that the ability to utilize n-alkanes (C-9-C -12) and n-alkenes (C-10 and C-12) of medium chain length was plasmid-encod ed. The plasmid was designated pDEC. Its size was estimated at several hund reds kb according to mobility in agarose gels. The plasmid did not confer r esistance to the antibiotics tested. Analysis of alkylsulfatases P1 and P2 in original and cured strains confirmed that both enzymes are encoded by th e chromosome. The ability of Pseudomonas C12B to utilize alkylbenzene sulfo nates also appears to be encoded by the chromosome, pDEC could be transferr ed only to cured derivatives of Pseudomonas C12B. but not to strains of P. aeruginosa, P. putida, or Acinetobacter sp. Cured derivatives of Pseudomona s C12B could not serve as hosts for the broad host range plasmid CAM-OCT. T he enzyme system encoded by the putative dec genes present on plasmid pDEC differs from the system coded by the alk genes of plasmid OCT in the size r ange of hydrocarbons preferentially used. (C) 1999 Elsevier Science Ltd. Al l rights reserved.