Potential of the strain Raoultella sp. KDF8 for removal of analgesics

Abstract

The bacterial strain KDF8 capable of growth in the presence of diclofenac and codeine analgesics was obtained after chemical mutagenesis of nature isolates from polluted soils. The strain KDF8 was identified as Raoultella sp. based on its morphology, biochemical properties, and 16S rRNA gene sequence. It was deposited in the Czech Collection of Microorganisms under the number CCM 8678. A growing culture efficiently removed diclofenac (92% removal) and partially also codeine (about 30% degradation) from culture supernatants within 72 h at 28 °C. The degradation of six analgesics by the whole cell catalyst was investigated in detail. The maximum degradation of diclofenac (91%) by the catalyst was achieved at pH of 7 (1 g/L diclofenac). The specific removal rate at high concentrations of diclofenac and codeine increased up to 16.5 mg/g per h and 5.1 mg/g per h, respectively. HPLC analysis identified 4'-hydroxydiclofenac as a major metabolite of diclofenac transformation and 14-hydroxycodeinone as codeine transformation product. The analgesics ibuprofen and ketoprofen were also removed, albeit to a lower extent of 3.2 and 2.0 mg/g per h, respectively. Naproxen and mefenamic acid were not degraded.

Biological Removal and Fate Assessment of Diclofenac Using Bacillus subtilis and Brevibacillus laterosporus Strains and Ecotoxicological Effects of Diclofenac and 4′-Hydroxy-diclofenac

“…On Figure 1(a), DCF degradation (biotic + abiotic) can firstly be observed to nondetectable levels after 3 days of incubation with either the strain DCF1 (A) or DCF2 (B), while DIU2 (C) strain leads to the lowest percentage of degradation with around 55% of total degradation after 3 days. Palyzová et al [28] observed 92% of biotransformation of DCF at 1.0 g•L −1 after 72 h at 28°C with a strain isolated from polluted soils, Raoultella sp. KDF8.…”

“…Besides, 4′-OH-DCF was also identified as a major metabolite after biodegradation by Raoultella sp. KDF8 [28] and L. portucalensis [30].…”

Diclofenac Degradation—Enzymes, Genetic Background and Cellular Alterations Triggered in Diclofenac-Metabolizing Strain Pseudomonas moorei KB4

“…After Glc addition, degraded dose increased up to approximately 82%. The significantly higher degradation rate was shown by Palyzová et al [ 36 ] for Raoultella sp. KDF8 strain after chemical mutagenesis which metabolized nearly 1.0 g L −1 of DCF.…”

“…A similar trend was observed for all established cultures, but with a varied dynamic. It is widely known that Glc assimilation lowers the pH, mainly due to acetoin and organic acids formation [ 36 , 37 ], thus, the strongest decrease in the pH was observed for control with Glc. In the mono-substrate culture, the pH slightly decreases to almost neutral (7.05 ± 0.01).…”

Biodegradation Potential and Diversity of Diclofenac-degrading Microbiota in an Immobilized Cell Biofilter

“…To the best of our knowledge, the endophyte Microbacterium sp. MG7 [48], a few soil bacterial strains belonging to Raoultella-Klebsiella group [49,50] and Brevibacterium sp. D4 [25] isolated from activated sludge are the only bacteria that have been found to be capable of degrading diclofenac.…”