초록
Microorganisms capale of utilizing linear alkylbenzene sulfonates(LAS) as sole carbon source were isolated from industrial effluent by using LAS agar plates. The isolated strains were identified as Salmonella sp(BC-2) and Escherichia sp.(BC-3) from the results of morphological, cultural and biochemical tests. The optimal condition for the growth and biodegradation of LAS was the initial pH 7.0 and LAS concentration 0.1%. The isolated BC-2 and BC-3 strains harbored plasmid and LAS-degrading activity was lost when the plasmids were cured by mitomycin C. The plasmids were transformed into E. coli and transformants have the LAS-degrading activity. Isolated strains were examined for primary biodegradation rate of LAS in the medium by methylene blueactive substance(MBAS) method. Of these isolates, BC-2 and BC-3 strains degradated LAS upto 60% and high resistant to CdCl$_{2}$ and HgCl$_{2}$. Isolated strains were sensitive to chloramphenicol, kanamycin, rifampicin, streptomycin and tetracycline but resistant to ampicillin and lincomycin.] Its minimal inhibitory concentration(MIC) for ampicillin was more than 1500 $\mu $g/ml.