Indian Journal of Scientific Research
Year : 2014, Volume : 5, Issue : 1
First page : ( 139) Last page : ( 152)
Print ISSN : 0976-2876. Online ISSN : 2250-0138.

Biodegradation study of reactive blue 172 by Shewanella haliotis DW01 isolated from lake sediment

Birmole Radhika, Patade Swamini, Sirwaiya Vishwas, Bargir Firdaus, Aruna K¹

Department of Microbiology, Wilson College, Mumbai, India

¹Corresponding author

Online published on 8 April, 2015.

Abstract

Reactive Blue 172 (RB-172) dyeis a reactive sulphonateddiazo dye commercially used in the textile industry. Anovel bacterialstrain which degrades RB-172 was isolated from lake watersediment and identified as Shewanella haliotis DW01 based on physiological and biochemical tests together with 16S rRN Agene sequence analysis. The 93% dye decolorizing activity of 50 ppm RB-172 by Shewanella haliotis DW01 was obtained with an inoculum size of 0.8 O.D_530nm inoptimized Luria Bertani medium (Tryptone 0.5%, yeast extract 0.5%, NaCl 1%) pH9.5 at 357°C kept under static condition for 12h with high COD reduction. The isolate demonstrated significant decolorization over a wide range of NaCl concentration (1–7%). The addition of inorganic nitrogenous compounds to the medium significantly decreased the decolorization process. Lactate and pyruvate were supporting RB-172 decolorization. Maximum dye concentration decolorized by the isolate after 12h was 550ppm. An improved decolorization performance was obtained in the presence of higher biomass concentration. Decolorization assay using pre-grown cell mass of Shewanella haliotis DW01 exhibited 87% decolorization after 6h. The bacterium was immobilized and the decolorization process was monitored using UV-Vis Spectrophotometry. The degradation of dye was confirmed by HPTL Cand HPL Canalysis. Toxicity results suggested that degradation products of RB-172 werenontoxic to the common crop such as Phaseolus mungo and Triticum aestivum. It also showed ability to decolorize seven different dyes and mixtures of few dyes.

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Keywords

Shewanella haliotis DW01, Reactive Blue 172 (RB-172), decolorization, biodegradation.

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