Biodegradation of Malachite Green Dye by Novel Isolated Bacillus Species AAV from Garden Soil

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ABSTRACT

Malachite green (MG) dye commonly use in textile and paper printing industry to a great extent. Textile effluent released from industries including dyes must be treated before release into the environment due to its toxic nature. In present study, newly isolated bacterial species was able to decolorize MG dye (100%) in 1 h at shaking condition and 94% at static condition. 16S rRNA analysis revealed an isolate as Bacillus sp. AAV. Lignin peroxidase, laccase and tyrosinase enzymes from Bacillus sp. AAV showed significant increased activity during decolourisation. There was 138, 369 and 164% trek in activity of LiP, laccase and tyrosinase after MG decolourization, respectively. Bacillus sp. AAV could decolourise MG efficiently at alkaline pH (8-10) and at 40°C temperature. Biodegradation was monitored by UV-VIS spectrophotometer. Gas chromatography-Mass spectroscopy data was used to propose the degradation pathway of MG dye. The newly isolated Bacillus sp. AAV was able to decolourise ten various types of dyes and textile dye effluent. Phytotoxicity test by using seeds of wheat and sorghum was also carried out to check toxicity of MG dye metabolites. The study reveals that there was no toxicity with respect to tested seeds. This study suggests that Bacillus sp. AAV could be a useful microorganism or its enzyme system for textile dyes and effluent treatment.

Significance of the study:

This study highlights the potential of a newly isolated Bacillus species AAV in the biodegradation of malachite green dye, a toxic pollutant from textile industries. By demonstrating the strain’s efficiency and enzyme activity in dye decolorization, the research underscores its application in environmental remediation. The findings suggest an effective, eco-friendly solution for treating dye-laden industrial effluents.

Summary of the study:

This research identifies a novel Bacillus species AAV from garden soil, capable of completely decolorizing malachite green dye within an hour under shaking conditions. The study shows enhanced activity of lignin peroxidase, laccase, and tyrosinase enzymes during the decolorization process. Bacillus sp. AAV efficiently degrades MG dye at alkaline pH and 40°C, proposing its use in treating various textile dyes and effluents without phytotoxic effects.