Degradation characteristics of a novel aniline blue-discoloring bacterial strain MP-13

Abstract:

[Background] The wide use of aniline blue, a common refractory organic pollutants, harms and threatens the ecological environments. Hence, it is important to develop an eco-friendly and cost-effective technology to treat the dye contaminated wastewater. Biological method is environmentally friendly and applied to deal with dye contaminated wastewater. [Objective] Our study was to provide a core theory and supporting technology to isolate and characterize a novel bacterial strain, Trabulsiella odontotermitis MP13, for its potential decolorization of dye wastewater. [Methods] Some aniline blue-decoloring bacteria were first isolated from the gut of a termite species, Microtermes pakistanicus, and then identified by 16S rRNA gene sequence analysis for their phylogeny property and other relevant biological properties. Further, with a variety of evaluation methods, such as FTIR and GC/MS, the degradation characteristics of aniline blue by strain MP13 were analyzed. [Results] A novel bacterial strain MP-13 was identified as Trabulsiella odontotermitis that could tolerate and effectively degrade aniline blue up to a high concentration of 1 500 mg/L. The optimal temperature, pH and rotation speed for dye decolorization were 30 °C, 8.0, and 180 r/min, respectively. The decolorization efficiency was up to 97.3%, when aniline blue concentration was at 200 mg/L. Further, the FTIR and GC/MS analysis showed that aniline blue was biotransformed into low molecular weight aromatic compounds. [Conclusion] Trabulsiella odontotermitis MP-13 exhibited a remarkable decolorization ability for aniline blue, suggesting its potential for industrial dye waste water treatment.