Synergistic degradation of diazo dye Direct Red 5B by Portulaca grandiflora and Pseudomonas putida

Abstract

Plants and bacterial consortium of Portulaca grandiflora and Pseudomonas putida showed complete decolorization of a sulfonated diazo dye Direct Red 5B within 72 h, while in vitro cultures of P. grandiflora and P. putida independently showed 92 and 81 % decolorization within 96 h, respectively. A significant induction in the activities of lignin peroxidase, tyrosinase, 2,6-dichlorophenol indophenol reductase and riboflavin reductase was observed in the roots of P. grandiflora during dye decolorization; whereas, the activities of laccase, veratryl alcohol oxidase and 2,6-dichlorophenol indophenol reductase were induced in the cells of P. putida. Plant and bacterial enzymes in the consortium gave an enhanced decolorization of Direct Red 5B synergistically. The metabolites formed after dye degradation analyzed by UV-Vis spectroscopy, Fourier transformed infrared spectroscopy and high performance liquid chromatography confirmed the biotransformation of Direct Red 5B. Differential fate of metabolism of Direct Red 5B by P. grandiflora, P. putida and their consortium were proposed with the help of gas chromatography-mass spectroscopy analysis. P. grandiflora metabolized the dye to give 1-(4-diazenylphenyl)-2-phenyldiazene, 7-(benzylamino) naphthalene-2-sulfonic acid, 7-aminonaphthalene-2-sulfonic acid and methylbenzene. P. putida gave 4-hydroxybenzenesulfonic acid and 4-hydroxynaphthalene-2-sulfonic acid and benzamide. Consortium showed the formation of benzenesulfonic acid, 4-diazenylphenol, 6-aminonaphthalen-1-ol, methylbenzene and naphthalen-1-ol. Consortium achieved an enhanced and efficient degradation of Direct Red 5B. Phytotoxicity study revealed the nontoxic nature of metabolites formed after parent dye degradation. Use of such combinatorial systems of plant and bacteria could prove to be an effective and efficient strategy for the removal of textile dyes from soil and waterways.

Bioaugmentation of floating treatment wetlands for the remediation of textile effluent

“…It might be because of the simultaneous enzymatic activities of both plants and bacteria to transform dyestuff into simpler metabolites and/or intermediates. Numerous studies have reported that plant‐bacterial synergism significantly enhances the removal of dyes from effluents by employing an entirely different sets of enzymatic machinery that allows plants and bacteria to work collaboratively for one task (Khandare et al ; Kabra et al ; Watharkar et al ). Collectively, these results indicate that plant‐bacteria synergism is an economically feasible and promising approach for the remediation of textile wastewater.…”

Textile dye wastewater characteristics and constituents of synthetic effluents: a critical review

“…These characteristics showed differences among the values from one reference to another. As noted by Khandare et al (2013), typical textile wastewater is difficult to define, because the textile application methods, even in the same process, are different from one industry to another. Table 1 Typical characteristics of textile effluents COD chemical oxygen demand, BOD 5-day biochemical oxygen demand, TOC total organic carbon, EC electrical conductivity, TS total solids, TSS total suspended solids, TDS total dissolved solids, TVS total volatile solids, TA total alkalinity, TH total hardness, TKN total kjeldahl nitrogen, TN total nitrogen, NO 3 -N nitrate-nitrogen, Na 2 CO 3 sodium carbonate, NaOH sodium hydroxide and NaCl sodium chloride a Tsypical cotton dye industry effluent < 10 3-6 < 10…”

Evaluation of bacteria isolated from textile wastewater and rhizosphere to simultaneously degrade azo dyes and promote plant growth

“…As hypothesized, the bacterial isolates, when inoculated on plants, had positive effects on growth parameters such as plant biomass, root and shoot length, compared with those of non‐inoculated plants, suggesting that either individual bacterial isolates or a consortium can assist plant growth under dye‐induced toxicity and stress conditions. This result was very interesting, because azo compounds have been reported to be accumulated in roots and when that happened, it might impair plant growth to a substantial degree . This potential useful trait of the dye‐degrading bacteria can be achieved by way of IAA production and P‐solubilization, both of which are common strategies of so‐called plant growth‐promoting bacteria and evidently helpful for plants to overcome dye‐associated stresses.…”