Textile azo dye decolorization and detoxification using bacteria isolated from textile effluents

Abstract

Azo dyes, which are highly toxic, carcinogenic, and mutagenic for living organisms, are used as coloring chemicals in textile industries. Physicochemical methods used for removing azo dyes are expensive, can generate secondary waste, and are not very efficient. In this study, we used a biological approach to reduce the toxicity of three azo dyes, i.e., congo red, methyl orange, and reactive red 198, from textile effluents. Six dye-decolorizing bacteria were screened from waste water obtained from the textile industry (in the dyeing process) at a concentration 100 mg/l for each azo dye. Using a 16S rRNA approach, the bacteria were identified and assigned as Enterococcus faecalis VTK04, Staphylococcus aureus VTK013, Pseudomonas aeruginosa VTK018, Proteus mirabilis VTK024, Bacillus cereus VTK035, and Enterococcus faecium VTK054. These bacteria were tested for their ability to produce biofilms on the abiotic surface. The adherence assay showed that VTK013, VTK054, and VTK024 had a potential to form stable biofilms on abiotic surfaces (OD570 = 1.37). Moreover, the dye decolorization potential was spectrophotometrically measured after seven days with and without a carbon substrate. The results demonstrated that the absence of the carbon source had a negative impact on decolorization, whereas a carbon-supplemented medium showed a considerable increase in the decolorization of congo red (80% and 96% by VTK013 and VTK018, respectively), methyl orange (100% and 75% by VTK054 and VTK035, respectively), and reactive red 198 (90% and 86% by VTK04 and VTK024, respectively). The phytotoxicity study of the treated dye solutions showed lesser toxicity compared to the untreated dye solution. These results support the possibility of using bacterial isolates for the biodegradation of azo dye effluents.

Isolation and Molecular Identification of Direct Red 80 Synthetic Dye Degradation Bacteria from Palembang Indonesia Jumputan Cloth Industrial Waste

“…has also been reported to have the ability to remove 90% of Novacron Brilliant Blue color (Karim et al, 2018) . In addition, previous research showed that Pseudomonas aeruginosa and Staphylococcus aureus could decolorize congo red by 80% and 96%, respectively (Karnwal, 2019) Comamonas aquatica and Ralstonia mannitolilytica can also reduce methylene blue by 67.9% and 60.3%, respectively Siregar et al (2020) and Bacillus subtilis WG13 has also been reported to be able to remove 70% of direct red 23 colors (Thiruppathi et al, 2021) .…”

“…However, Bacillus cereus in this same group has been tested for its ability to degrade synthetic dye. It can also decolorize synthetic dye, namely methyl orange by 75% with a concentration of 100 mg/L, at pH 7.2 and temperature 37°C, respectively, for 144 hours (Karnwal, 2019) . Bacillus subtilis can remove Direct violet color by 68.57% with a concentration of 20 mg/L at pH 7 and 28°C for 72 hours.…”

“…However, it was less effective in degrading red dye, especially Red Synozol (Fouda et al, 2016) . Pseudomonas aeruginosa was reported to have the ability to decolorize reactive red 198 with a concentration of 100 mg/L up by 96% at pH 7.2 and a temperature of 37°C for 144 hours (Karnwal, 2019) .…”

Optimization of culture conditions for improved green biodecolourization of methylene blue by Rhodococcus pyridinivorans strain UCC 0003

“…Many studies have reported the remarkable roles of bacteria such as Staphylococcus hominus , Vibrio sp., Proteus vulgaris , Dietzia sp., Pseudomonas aeruginosa , Bacillus subtilis , Stenotrophomonas sp., and Halomonas sp. in efficient decolorization of dyes, and there are many other bacterial species that have developed their enzyme systems for degrading dye compounds (Mansur et al, 2017 ; Roy et al, 2018 ; Karnwal, 2019 ; Mandic et al, 2019 ). Bacteria possess multiple mechanisms to remove dyes, and because they are easy to use, they have advantages in terms of commercial value (Sarim et al, 2019 ).…”

Bioremediation of melanoidin contamination in distillery effluent using Aspergillus brasiliensis

“…The decolorization of melanoidin compounds through microbial degradation has the potential to become an ecofriendly and cost-efficient alternative to the current methods of remediation of spent wash (Kumar et al, 1998;Moosvi et al, 2005;Naik et al, 2010). This is a good alternative to chemical treatment as an effective removal of melanoidin can be achieved using microorganisms (Karnwal, 2019). In the past decade, melanoidin degradation by bacteria and actinobacteria has received significant attention (Mohana et al, 2007).…”