| Abstract |
Like water, linear-alkylbenzene-sulfonate is indispensable for human development. Therefore, this study tests, for the first time, in one experimental setup, the interactions between a wide range of linear-alkylbenzene-sulfonate concentrations and Aspergillus niger growth on a daily basis. The tested conditions are linear-alkylbenzene-sulfonate concentrations, 0.15-1,000 mg/L, starving and fresh Aspergillus niger, presence and absence of an external carbon source, and during a 7 d period. The results show the interactions between linear-alkylbenzene-sulfonate concentrations and the Aspergillus niger growth fluctuate between; no-observed-effect-concentration, inhibition, growth and no-growth. Astonishingly, any of these interactions, even under the same experimental conditions, occurred at more than one linear-alkylbenzene-sulfonate concentration value, and more than one interaction is observed for a single LAS concentration. Therefore, this study recognizes linear-alkylbenzene-sulfonate "interaction" by pattern, rather than by a single concentration value. Linear-alkylbenzene-sulfonate patterns of interaction with Aspergillus niger forms increasing-decreasing trends with peak values, which are influenced by test conditions. Actually, the increasing-decreasing growth patterns are a response to multi-interrelated-mutual-and-reciprocal factors that shape the interactions of linear-alkylbenzene-sulfonate with their environment components over time. Thus, increasing decreasing-growth patterns show the combined effect of linear-alkylbenzene-sulfonate toxicity and biodegradability. |