Decomposition of non-steroidal anti-inflammatory drugs by activated sludge supported by biopreparation in sequencing batch reactor

The presence of non-steroidal anti-inflammatory drugs in wastewater from sewage treatment plants indicates that they are not completely biodegradable. The designed biopreparation based on immobilized bacteria enables the degradation of paracetamol, ibuprofen, naproxen and diclofenac at a rate of 0.50 mg/L*day, 0.14 mg/L*day, 0.16 mg/L*day and 0.04 mg/L*day, respectively. Lower degradation of drugs in the mixture than in monosubstrate systems indicates their additive, antagonistic effect, limiting the degradative capacity of microorganisms. The biopreparation is stable for at least 6 weeks in bioreactor conditions. Biochemical parameters of activated sludge functioning showed increased oxygen demand, which was related to increased ammonia concentration caused by long-term exposure of activated sludge to drugs. Reduced metabolic activity was also observed. The preparation enables decomposing drugs and their metabolites, restoring the activated sludge's functionality. The tested biopreparation can support activated sludge in sewage treatment plants in degrading non-steroidal anti-inflammatory drugs and phenolic compounds.

Use of xanthan gum for whole cell immobilization and its impact in bioremediation - a review

Xanthan gum is one of the exo-polysaccharides produced by bacteria and is characterized by unique non-Newtonian properties. Its structure and conformation strongly depend on the fermentation conditions and such factors as temperature and ions concentration. The properties of the xanthan gum were appreciated in the controlled drug delivery but in the crosslinked form. Due to its ability to enhance the survival rate of immobilized bacteria, the potential of a crosslinked form is promising. Unfortunately, xanthan gum crosslinking procedures often require toxic substances or harsh environmental conditions, which cannot be used in the entrapment of living cells. In this study, we summarised a crosslinking method that could potentially be modified to reduce its toxicity to living cells. Moreover, this review also includes using xanthan gum in bioremediation studies and possible utilization methods to avoid carrier accumulation in the environment.

Xanthan gum as a carrier for bacterial cell entrapment: Developing a novel immobilised biocatalyst

Xanthan gum (XAN) is a widely used polysaccharide in various industries. Because of its unique properties, in this study, an attempt was made to adopt the procedure of xanthan gum cross-linking for the entrapment of bacterial cells that are able to biodegrade naproxen. The developed procedure proved to be completely neutral for Bacillus thuringiensis B1(2015b) cells, which demonstrated a survival rate of 99%. A negative impact of entrapment was noted for strain Planococcus sp. S5, which showed a survival rate in the 93-51% range. To achieve good mechanical properties of the composites, they were additionally hardened using polydopamine (PDA). XAN/PDA composites revealed a high stability in a wide range of pH, and their sorption capacity included both cationic and anionic molecules. Analysis of the survival rate during storage at 4 °C in 0.9% NaCl showed that, after 35 days, 98-99% of B1(2015b) and 47% of S5 cells entrapped in XAN/PDA remained alive. This study also presents the results of naproxen biodegradation conducted using XAN/PDA/B1(2015b) in a trickling filter with autochthonous microflora. Hence, owing to the significant acceleration of drug biodegradation (1 mg/L in 14 days) and the chemical oxygen demand removal, the entrapped B1(2015b) cells in XAN/PDA composites showed a promising potential in bioremediation studies and industrial applications.

BDCA-2, a novel plasmacytoid dendritic cell-specific type II C-type lectin, mediates antigen capture and is a potent inhibitor of interferon alpha/beta induction

Plasmacytoid dendritic cells are present in lymphoid and nonlymphoid tissue and contribute substantially to both innate and adaptive immunity. Recently, we have described several monoclonal antibodies that recognize a plasmacytoid dendritic cell-specific antigen, which we have termed BDCA-2. Molecular cloning of BDCA-2 revealed that BDCA-2 is a novel type II C-type lectin, which shows 50.7% sequence identity at the amino acid level to its putative murine ortholog, the murine dendritic cell-associated C-type lectin 2. Anti-BDCA-2 monoclonal antibodies are rapidly internalized and efficiently presented to T cells, indicating that BDCA-2 could play a role in ligand internalization and presentation. Furthermore, ligation of BDCA-2 potently suppresses induction of interferon alpha/beta production in plasmacytoid dendritic cells, presumably by a mechanism dependent on calcium mobilization and protein-tyrosine phosphorylation by src-family protein-tyrosine kinases. Inasmuch as production of interferon alpha/beta by plasmacytoid dendritic cells is considered to be a major pathophysiological factor in systemic lupus erythematosus, triggering of BDCA-2 should be evaluated as therapeutic strategy for blocking production of interferon alpha/beta in systemic lupus erythematosus patients.

BDCA-2, BDCA-3, and BDCA-4: three markers for distinct subsets of dendritic cells in human peripheral blood

We have generated a panel of mAbs that identify three presumably novel human dendritic cell Ags: BDCA-2, BDCA-3, and BDCA-4. In blood, BDCA-2 and BDCA-4 are expressed on CD11c(-) CD123(bright) plasmacytoid dendritic cells, whereas BDCA-3 is expressed on small population of CD11c(+) CD123(-) dendritic cells. All three Ags are not detectable on a third blood dendritic cell population, which is CD1c(+) CD11c(bright) CD123(dim), or on any other cells in blood. BDCA-4 is also expressed on monocyte-derived and CD34(+) cell-derived dendritic cells. Expression of all three Ags dramatically changes once blood dendritic cells undergo in vitro maturation. BDCA-2 is completely down-regulated on plasmacytoid CD11c(-) CD123(bright) dendritic cells, expression of BDCA-3 is up-regulated on both plasmacytoid CD11c(-) CD123(bright) dendritic cells and CD1c(+) CD11c(bright) CD123(dim) dendritic cells, and expression of BDCA-4 is up-regulated on CD1c(+) CD11c(bright) CD123(dim) dendritic cells. BDCA-2 is rapidly internalized at 37 degrees C after mAb labeling. The three presumably novel Ags serve as specific markers for the respective subpopulations of blood dendritic cells in fresh blood and will be of great value for their further analysis and to evaluate their therapeutic potential.