Biodegradation and metabolic pathway of sulfamethoxazole by Sphingobacterium mizutaii

Abstract

Sulfamethoxazole (SMX) is the most commonly used antibiotic in worldwide for inhibiting aquatic animal diseases. However, the residues of SMX are difficult to eliminate and may enter the food chain, leading to considerable threats on human health. The bacterial strain Sphingobacterium mizutaii LLE5 was isolated from activated sludge. This strain could utilize SMX as its sole carbon source and degrade it efficiently. Under optimal degradation conditions (30.8 °C, pH 7.2, and inoculum amount of 3.5 × 107 cfu/mL), S. mizutaii LLE5 could degrade 93.87% of 50 mg/L SMX within 7 days. Four intermediate products from the degradation of SMX were identified and a possible degradation pathway based on these findings was proposed. Furthermore, S. mizutaii LLE5 could also degrade other sulfonamides. This study is the first report on (1) degradation of SMX and other sulfonamides by S. mizutaii, (2) optimization of biodegradation conditions via response surface methodology, and (3) identification of sulfanilamide, 4-aminothiophenol, 5-amino-3-methylisoxazole, and aniline as metabolites in the degradation pathway of SMX in a microorganism. This strain might be useful for the bioremediation of SMX-contaminated environment.

Zirconium ferrite incorporated zeolitic imidazolate framework-8: a suitable photocatalyst for degradation of dopamine and sulfamethoxazole in aqueous solution

“…Permanganate combined with bisulfite has been shown to have a rapid removal capacity for SMX; 59 however, ZrFe 2 O 4 @ZIF-8 exhibited a complete removal of SMX. Sphingobacterium mizutaii LLE5 has demonstrated capacity for removing SMX under optimal degradation conditions with a capacity of 93.87%, 60 which is lower than the efficiency (100%) demonstrated by ZrFe 2 O 4 @ZIF-8. A recent study reported bowl-like FeCuS@Cu 2 S@Fe 0 with excellent complete removal of SMX within 5 min of operation.…”

Enhanced Degradation of Sulfamethoxazole Using Immobilized Biomass Reactor

“…S1 first transformed SMX through hydrogenation and then degraded via desulfurization. This pathway was observed during substrate degradation by Pseudomonas psychrophila HA-4 [14] and Sphingobacterium mizutaii [31]. Acinetobacter sp.…”

“…Some bacterial strains, such as Pseudomonas psychrophila HA-4 [14], Acinetobacter sp. [17], and Sphingobacterium mizutaii LLE5 [31], which utilized SMX as the sole carbon source, have been reported. Achromobacter sp.…”

Comparison of sulfamethoxazole (SMX) degradation effect under different experimental conditions

“…One of the most widely used antibiotics for human usage, animal production, and aquaculture is sulfamethoxazole (SMX) [5,6], which is also regularly found in aquatic environments [7,8]. SMX residues, on the other hand, are difficult to be removed and may enter the food chain, posing substantial dangers to human health [9].…”

“…One of the most widely used antibiotics for human usage, animal production, and aquaculture is sulfamethoxazole (SMX) [5,6], which is also regularly found in aquatic environments [7,8]. SMX residues, on the other hand, are difficult to be removed and may enter the food chain, posing substantial dangers to human health [9].Given the current problem, sulfamethoxazole discharged into the aqueous environment is challenging to be treated. The risk to water ecology and the environment is rising along with the cumulative environmental concentration.…”