EFFECT OF DIALKYL SULPHOSUCCINATES ON RESPIRATION ACTIVITY OF DEGRADATIVE AND NONDEGRADATIVE BACTERIA

Dialkyl sulphosuccinates (DASS) exert both stimulatory and inhibitory effects on respiration of bacterial strains depending on concentration and chemical structure of the surfactant. The relative respiration ra te of Comamonas terrigena N3H increased proportionally to the amount o f di-1-hexyl- (DHSS), di-1-octyl- (DOSS) and di-2-ethyl-hexyl- (DEHSS) sulphosuccinates at concentrations less than or equal to 1 mM. With i ncreasing concentrations, an inhibitory effect of DHSS became prevalen t with ID50 = 4.5 mM and ID100 = 10 mM. DOSS and DEHSS did not inhibit respiration of C. terrigena N3H at 0-20 mM. Twelve selected bacterial strains showed rather weak and very different DASS sensitivities. DAS S degradative bacteria were found to be as resistant to metabolic inhi bition by DASS as DASS nondegradative bacteria. No correlation was obs erved between respiration rates in the presence of DHSS and DHSS biode gradation in the series of tested bacteria.