[2-Naphthalene-sulphonic acid degrading microorganisms]

Area of Science:

• Environmental microbiology
• Bioremediation of pollutants
• Wastewater treatment

Background:

• Anionic surfactants, like naphthalene sulfonates, persist in aquatic environments due to poor biodegradability.
• Accumulation of these compounds in water and sediments poses environmental risks.

Purpose of the Study:

• To isolate and characterize bacterial communities capable of degrading 2-naphthalene-sulfonic acid (2NS).
• To investigate factors influencing the biodegradation of 2NS in a natural water system.

Main Methods:

• Isolation of a four-membered bacterial community from Río Reconquista.
• Characterization of bacterial strains based on Gram staining, aerobic respiration, proteolytic activity, and heavy metal/antibiotic resistance.
• Assessment of pigment production and its impact on 2NS degradation.
• Evaluation of the effect of *Pseudomonas aeruginosa* on the bacterial community's degradation efficiency.

Main Results:

• A bacterial consortium degrading 2NS was successfully isolated.
• Isolated strains were Gram-negative, aerobic rods with high tolerance to heavy metals (Cr, Hg, Cd, Pb) and some antibiotics.
• Three strains produced an inhibitory brown-dark pigment when growing on 2NS, hindering growth.
• Co-culturing with *Pseudomonas aeruginosa* prevented pigment formation and led to complete 2NS consumption.

Conclusions:

• The isolated bacterial community demonstrates potential for bioremediating 2NS pollution.
• *Pseudomonas aeruginosa* plays a crucial role in enhancing 2NS degradation by mitigating growth-inhibiting pigment production.