Decolorization of an industrial effluent by free and immobilized cells of Stenotrophomonas maltophilia AAP56. Implementation of efficient down flow column reactor

Abstract

A bacterial strain AAP56, isolated from a polluted soil (from Kelibia city) and identified as Stentrophomonas maltophilia, was particularly interesting for its ability to decolorize recalcitrant dyes of an industrial effluent: SITEX Black. The final percentage decolorization 60% was shown by bacterial culture after incubation in LB medium at 30°C under shaking conditions. The decolorization was closely correlated with the metabolic bacterial growth. The replacement of yeast extract in LB medium composition by soya flour was clearly efficient to enhance the percentage decolorization by 20% and also to reduce the growth medium cost 60-fold. The bacteria were able to reduce 23% from the initial COD and 28% from the initial BOD 5 of the effluent. The immobilization of bacterial cells in calcium alginate beads improved by 25% the effectiveness of the biotransformation within 24 h in batch conditions. The potential of a downflow fixed column reactor (DFCR) to decolorize SITEX Black was evaluated under dilution rate. The best decolorization percentage (82%) was recorded at 0.3 h -1 . This bioprocess seems to be a potentially useful method to remediate the colored textile wastewater.

Molecular cloning of a copper-dependent laccase from the dye-decolorizing strain Stenotrophomonas maltophilia AAP56

“…Stenotrophomonas maltophilia AAP56 was isolated and described as a bacterial strain with interesting decolorization capacities that showed laccase activity (Galai et al. 2009, 2010).…”

“…In conclusion, the results presented in this study reveal that the copper‐dependent laccase activity previously detected in cultures of Sten. maltophilia AAP56 (Galai et al. 2009, 2010) is because of the product of the copA gene.…”

“…In conclusion, the results presented in this study reveal that the copper-dependent laccase activity previously detected in cultures of Sten. maltophilia AAP56 (Galai et al 2009(Galai et al , 2010 is because of the product of the copA gene. CopA is able to carry out the in vitro decolorization of RB5 only in the presence of mediators.…”

“…Stenotrophomonas maltophilia AAP56 was isolated and described as a bacterial strain with interesting decolorization capacities that showed laccase activity (Galai et al 2009(Galai et al , 2010. To determine whether these characteristics are shared by two different Sten.…”

Biological Treatment of Textile Dyes by Agar‐Agar Immobilized Consortium in a Packed Bed Reactor

“…Various natural or synthetic porous polymeric materials like alginate, agar, polyacrylamide, carrageenan, cellulose acetate and poly-vinyl alcohol (PVA) have been extensively used for the entrapment of microbial cells (Charumathi and Das, 2010;Saratale et al, 2011). Many reports revealed an efficiency of the bioreactors containing immobilized bacteria for the treatment of real as well as synthetic dye containing wastewaters (Wu et al, 2005;Tony et al, 2009;Galai et al, 2010).…”