Enrichment, isolation and characterization of dialkyl sulfosuccinate degrading bacteria Comamonas terrigena N3H and Comamonas terrigena N1C

Microorganisms derived from soil, sludge, sewage or river water contaminated by detergents or mineral oils were enriched and tested for the capability of primary biodegradation of dialkyl sulfosuccinates (DASS). Adapted mixed cultures, containing predominantly Gram-negative bacteria, degraded di-n-hexyl sulfosuccinate (DHSS) more readily than di-n-octyl sulfosuccinate (DOSS). Bacterial isolates obtained from enriched mixed cultures that show the highest rates of primary biodegradation and assimilation of DASS belong to the genus Comamonas. Under nongrowth conditions, the DHSS primary biodegradation by these strains follows the Ist order reaction kinetics. The rate constants of primary degradation of DHSS by resting cells of C. terrigena N3H were found to be 30 times higher than when catalyzed by C. terrigena N1C. The capacity for accelerated removal of surface-active properties of DHSS by C. terrigena N3H was retained within the range of pH 4-10 and at temperatures up to 55 degrees C, while DHSS degradation by C. terrigena N1C was completely inhibited above 48 degrees C. Temperature and pH limits for DHSS primary degradation by both strains were to a great extent wider than those for the viability of the cultures. Biodegradation capacity and metabolic stability of C, terrigena N3H make this strain interesting from both scientific and technological point of view.