Changes in Ibuprofen Toxicity and Degradation in Response to Immobilization of Bacillus thuringiensis B1(2015b)

Ibuprofen is one of the most commonly used anti-inflammatory drugs by humans, resulting in its appearance in the environment, which can negatively affect organisms living in it. The studies undertaken have shown that the immobilized Bacillus thuringiensis B1(2015b) strain can decompose this drug at a rate of q = 0.36 mg/L*h, with a K constant of 0.95 mg/L for this process. An analysis of the effect of ibuprofen on the metabolic profile of the immobilized strain B1(2015b) showed an increase in the consumption of carbon, nitrogen, phosphorus, and sulfur compounds by this strain compared to the free strain. Studies on the toxicity of ibuprofen against the B1(2015b) strain indicated a small protective effect of the carrier, manifested by a slightly higher EC₅₀ value = 1190 mg/L (for the free strain EC₅₀ = 1175 mg/L). A toxicity analysis of intermedia formed during ibuprofen degradation indicated that the increase in toxicity is positively correlated with the degree of hydroxylation of ibuprofen metabolites. A toxicity analysis of the post-culture fluid obtained after ibuprofen degradation by the immobilized and free strain indicated that the products formed due to this process are completely safe.