Chemo-metrically formulated consortium with selectively screened bacterial strains for ameliorated biotransformation and detoxification of 1,4-dioxane

Abstract

The biotransformation of 1,4-dioxane, a endrocrine disrupting chemical was achieved using different bacterial strains and their consortia. Three different bacterial isolates were screened on their ability to grow with 50 mg/L 1,4-dioxane in the basal mineral medium. Then the isolates were tested for its efficiency to biotransform 1000 mg/L 1,4-dioxane at varying period of time; 24–120 h. The isolates were distinguished by their morphological features and 16 S rRNA gene sequencing was done to evaluate the phylogenetic relationships. The isolates were identified as Bacillus marisflavi strain MGA, Aeromonas hydrophila strain AG and Shewanella putrefaciens strain AG. The degree of biotransformation was escalated by constructing a bacterial consortium using statistical tool; response-mixture matrix under the design of experiments. The fully grown bacterial strains were used as ingredients in different proportions to formulate the consortium. The biotransformation was analyzed for functional attenuation using spectroscopic techniques and reduction in 1,4-dioxane level was confirmed using mass spectrometry. The precise quantification of biotransformation using mass spectral profile revealed that the consortium removed 31%, 61% and 85% of 1000 mg/L 1,4-dioxane within 96, 120 and 144 h respectively. The activities of inducible laccase were elucidated during biotransformation of 1,4-dioxane. Bio-toxicity of treated and untreated 1,4-dioxane on brine shrimp; Artemia salina showed that the biotransformed products were less toxic. Therefore, this report would be first of its kind to report the biotransformation and detoxification of 1,4-dioxane by a statistically designed bacterial consortium.