[2-Naphthalene-sulphonic acid degrading microorganisms]

Derivatives of anionic surfactants, specially naphthalene sulphonates, when discharged into natural waters are accumulated in waters and sediments because of their poor biodegradability. A four-membered bacterial community, able to degrade the sodium salt of 2-naphthalene-sulphonic acid (2NS), was isolated from Río Reconquista. All the isolated strains consisted of gram-negative, strictly aerobic rods, with a strong proteolytic activity and resistance to high levels of cations like Cr (III), Hg (II), Cd (II) and Pb (II). Some of them were resistant to gentamicin, amikacin and chloramphenicol. These strains appeared to be related to the genera Pseudomonas and Alcaligenes. When isolated, if growing on 2NS, a brown-dark pigment is formed by three of them, resulting in an inhibition of growth. The presence of a Pseudomonas aeruginosa strain avoided the production of pigment and resulting in a complete consume of 2NS.