Biodegradation of Crystal Violet dye by bacteria isolated from textile industry effluents

Abstract

Industrial effluent containing textile dyes is regarded as a major environmental concern in the present world. Crystal Violet is one of the vital textile dyes of the triphenylmethane group; it is widely used in textile industry and known for its mutagenic and mitotic poisoning nature. Bioremediation, especially through bacteria, is becoming an emerging and important sector in effluent treatment. This study aimed to isolate and identify Crystal Violet degrading bacteria from industrial effluents with potential use in bioremediation. The decolorizing activity of the bacteria was measured using a photo electric colorimeter after aerobic incubation in different time intervals of the isolates. Environmental parameters such as pH, temperature, initial dye concentration and inoculum size were optimized using mineral salt medium containing different concentration of Crystal Violet dye. Complete decolorizing efficiency was observed in a mineral salt medium containing up to 150 mg/l of Crystal Violet dye by 10% (v/v) inoculums of Enterobacter sp. CV–S1 tested under 72 h of shaking incubation at temperature 35 °C and pH 6.5. Newly identified bacteria Enterobacter sp. CV–S1, confirmed by 16S ribosomal RNA sequencing, was found as a potential bioremediation biocatalyst in the aerobic degradation/de-colorization of Crystal Violet dye. The efficiency of degrading triphenylmethane dye by this isolate, minus the supply of extra carbon or nitrogen sources in the media, highlights the significance of larger-scale treatment of textile effluent.

Isolation and characterization of two bacterial strains from textile effluents having Malachite Green dye degradation ability

“…CV-S1 was isolated for Cristal Violet dye degradation as described in the previously published article (Roy e t a l . , 2 0 1 8 ) [7]. CV-S1 was further tested against MG dye.…”

“…Initial OD -Final OD × 100 Initial OD Various parameters like inoculum size, pH, temperature, and initial dye concentration were optimized as previously described by Roy et al (2018) [7]. Briefly, a volume of 10ml solution containing MS medium enriched with trace element solution and MG dye was placed in 50ml test tube.…”

“…The newly constituted branch confirms that the identified strain CV-S1 is a new strain of the genus Enterobacter. [7]…”

“…Hence, there is an urgency of an ecofriendly, cost-effective and efficient approach of degrading textile dyes. Several microorganisms including bacteria, fungi and algae can be a potential alternative of removing polluting dyes [7]. Bioremediation of textile dyes by different microbial species have received much attention due to its cost-effectiveness, eco-friendly nature and public acceptability [8].…”

Characterization of a reactive yellow-2 decolorizing zinc tolerant bacterial strain Pseudomonassp. LT10 isolated from textile industry wastewater

“…As few fungal species have also been found in dye removal process (Hussain et al, 2017) but the bacterial strains are given priority because of their shorter life span and rapid degradation process (Verma and Madamwar, 2003;Elisangela et al, 2009;Imran et al, 2015). Previous scientist have isolated a number of bacteria belonged to different genera and studied their potential for decolorization of various azo dyes e.g., Enterobacter (Roy et al, 2018), Acinetobacter (Meerbergen et al, 2018), Arthrospira maxima (Afreen et al, 2016), Staphylococcus aureus (Ayed et al, 2017), Shewanella (Imran et al, 2014) and Serratia (Najme et al, 2015). Moreover the existence of metal ions including zinc, cadmium, chromium, copper, nickel etc.…”