Isolation of a malachite green-degrading Pseudomonas sp. MDB-1 strain and cloning of the tmr2 gene

Abstract

The release of malachite green, a commonly used triphenylmethane dye, into the environment is causing increasing concern due to its toxicity, mutagenicity, and carcinogenicity. A bacterial strain that could degrade malachite green was isolated from the water of an aquatic hatchery. It was identified as a Pseudomonas sp. based on the morphological, physiological, and biochemical characteristics, as well as the analysis of 16S rRNA gene sequence and designated as MDB-1. This strain was capable of degrading both malachite green and leucomalachite green, as well as other triphenylmethane dyes including Crystal Violet and Basic Fuchsin. The gene tmr2, encoding the triphenylmethane reductase from MDB-1, was cloned, sequenced and effectively expressed in E. coli. These results highlight the potential of this bacterium for the bioremediation of aquatic environments contaminated by malachite green.

Biodegradation of azo dye Direct Orange 16 by Micrococcus luteus strain SSN2

“…Bioremediation or biological methods have attracted considerable attention as they are eco-friendly, efficient and low cost characteristics (Deng et al 2008). Different groups of microorganisms, including bacteria, yeasts, filamentous fungi and microalgae, have been reported to decolorize various kinds of dyes (Daneshwar et al 2007;Jadhav and Govindwar, 2006;Jasinska et al 2012;Li et al 2009). Although bacterial decolorization of dyes has been extensively studied (Pandey et al 2007;Hong et al 2007;Kudlich et al 1997), focus has always been on the isolation of new especially indigenous bacteria capable of degrading wide range of dyes.…”

NovelCastellaniella denitrificansSA13P as a Potent Malachite Green Decolorizing Strain

“…Several microorganisms capable of degrading malachite green including Chlorella sp., Shewanella sp., and Pseudomonas sp. have been extensively reported [19][20][21][22]. Apparently there is a need to expand novel biological decolorization processes leading to the more efficient clean-up of Malachite Green using a single microorganism.…”

Lipoproteins Binding Malachite Green to Slow the Decolorization of Malachite Green in Pseudomonas sp. JT-1

“…Studies on the biodegradation of MG have focused primarily on decolorization via reduction reactions (2,14,16,17,20). In recent years, different bacteria capable of the decolorization of MG have been reported (7,8,10,13,19). Cultures of Clostridium perfringens, Aeromonas hydrophila DN322, Citrobacter sp.…”

“…KCTC 18061P, Pseudomonas sp. MDB-1, and Lactobacillus acidophilus have been shown to convert MG to leucomalachite green (LMG) (7,8,13,19), which is less toxic to both mammalian and bacterial cells due to its insolubility in water (1). The biochemical mechanism underlying the decolorization has been elucidated in some bacteria.…”

“…The tmr gene has also been cloned from Aeromonas hydrophila DN322, Pseudomonas sp. MDB-1 and an IncP-1β plasmid pGNB1 from the bacterial community of an activated sludge compartment (13,19,21).…”