Niraj R. Rane

Bacterial assisted phytoremediation for enhanced degradation of highly sulfonated diazo reactive dye

PurposePhytoremediation is the exploitation of plants and their rhizospheric microorganisms for pollutants treatment like textile dyes, which are toxic, carcinogenic and mutagenic from the effluent. The purpose of this work was to explore a naturally found plant and bacterial synergism to achieve an enhanced degradation of Remazol Black B dye (RBB).MethodsIn vitro cultures of Zinnia angustifolia were obtained by seed culture method. Enzymatic analysis of the plant roots and Exiguobacterium aestuarii strain ZaK cells was performed before and after decolorization of RBB. Metabolites of RBB formed after its degradation were analyzed using UV–Vis spectroscopy, high-performance liquid chromatography (HPLC), Fourier transform infrared (FTIR) and gas chromatography–mass spectrometry (GC-MS). Phytotoxicity studies were performed.ResultsThe consortium ZE was found to be more efficient than individual plant and bacteria. Z. angustifolia roots showed significant induction in the activities of lignin peroxidase, laccase, DCIP reductase and tyrosinase during dye decolorization. E. aestuarii showed significant induction in the activities of veratryl alcohol oxidase, azo reductase and DCIP reductase. Analysis of metabolites revealed differential metabolism of RBB by plant, bacteria and consortium ZE. E. aestuarii and Z. angustifolia led to the formation of 3,6-diamino-4-hydroxynaphthalene-2-sulfonic acid, (ethylsulfonyl)benzene, and 3,4,6-trihydroxynaphthalene-2-sulfonic acid and propane-1-sulfonic acid, respectively, whereas consortium ZE produced 4-hydroxynaphthalene-2-sulfonic acid, naphthalene-2-sulfonic acid and 4-(methylsulfonyl)phenol. The phytotoxicity study revealed the nontoxic nature of the metabolites formed after dye degradation.ConclusionConsortium ZE was found to be more efficient and faster in the degradation of RBB when compared to degradation by Z. angustifoila and E. aestuarii individually.

Green remediation of textile dyes containing wastewater by Ipomoea hederifolia L.

Wild plant and tissue cultures of Ipomoea hederifolia decolorize Scarlet RR (SRR) dye at a concentration of 50 mg L−1 up to 96% and 90% within 60 and 96 h, respectively. Significant induction in the enzyme activities of Lignin peroxidase, laccase, 2,6-dichlorophenol indophenol reductase, superoxide dismutase, catalase and tyrosinase was found in the plant roots and shoots during decolorization. I. hederifolia was also able to treat a dye mixture and a real textile effluent efficiently with a reduction in the American Dye Manufacturers Institute (ADMI) value (color removal) up to 85% and 88%, BOD up to 65% and 63% and COD up to 62% and 68%, respectively. Detailed anatomical studies of the stem and root cells of I. hederifolia during uptake and degradation were carried out, showing a stepwise and mechanistic degradation of the model dye SRR. Products formed after dye degradation were analyzed by UV-Vis spectroscopy, FTIR, HPLC and HPTLC, which confirmed the phytotransformation of SRR, dye mixture and textile effluent. A possible pathway for the phytotransformation of SRR was proposed based on GC-MS analysis, which confirmed the formation of different metabolites with lower molecular weights. The phytotoxicity study revealed the non-toxic nature of the formed products.

Enhanced phytotransformation of Navy Blue RX dye by Petunia grandiflora Juss. with augmentation of rhizospheric Bacillus pumilus strain PgJ and subsequent toxicity analysis.

This study reveals the beneficial synergistic phytoremediation potential of Petunia grandiflora Juss. with its rhizospheric bacterial isolate Bacillus pumilus strain PgJ to decolorize reactive Navy Blue RX (NBRX) dye by their active enzymatic machinery. In vitro cultures of P. grandiflora and B. pumilus gave 80.01% and 76.80% while their consortium decolorized NBRX up to 96.86% within 36 h. Significant induction in the enzyme activities of lignin peroxidase (207%), tyrosinase (133%), laccase (161%), riboflavin reductase (78%) were seen in the roots of tissue cultured plants while enzymes tyrosinase (660%), laccase (689%), riboflavin reductase (528%) were induced significantly in the B. pumilus cells. Metabolites of treated NBRX were analyzed using UV-vis spectroscopy, gas chromatography and biotransformation was visualized using high performance thin layer chromatography profile. Metabolites of the dye exhibited reduced phytotoxicity Sorghum vulgare and Phaeseolus mungo and significant reduction in cytogenotoxicity on Allium cepa roots when compared to NBRX.

Efficient decolorization and detoxification of textile industry effluent by Salvinia molesta in lagoon treatment

Salvinia molesta, an aquatic fern was observed to have a potential of degrading azo dye Rubine GFL up to 97% at a concentration of 100mg/L within 72h using 60±2g of root biomass. Both root as well as stem tissues showed induction in activities of the enzymes such as lignin peroxidase, veratryl alcohol oxidase, laccase, tyrosinase, catalase, DCIP reductase and superoxide dismutase during decolorization of Rubine GFL. FTIR, GC-MS, HPLC and UV-visible spectrophotometric analysis confirmed phytotransformation of the model dye into smaller molecules. Analysis of metabolites revealed breakdown of an azo bond of Rubine GFL by the action of lignin peroxidase and laccase and formation of 2-methyl-4-nitroaniline and N-methylbenzene-1, 4-diamine. Anatomical tracing of dye in the stem of S. molesta confirmed the presence of dye in tissues and subsequent removal after 48h of treatment. The concentration of chlorophyll pigments like chlorophyll a, chlorophyll b and carotenoid was observed during the treatment. Toxicity analysis on seeds of Triticum aestivum and Phaseolus mungo revealed the decreased toxicity of dye metabolites. In situ treatment of a real textile effluent was further monitored in a constructed lagoon of the dimensions of 7m×5m×2m (total surface area 35m(2)) using S. molesta for 192h. This large scale treatment was found to significantly reduce the values of COD, BOD5 and ADMI by 76%, 82% and 81% considering initial values 1185, 1440mg/L and 950 units, respectively.

Bioreactor with Ipomoea hederifolia adventitious roots and its endophyte Cladosporium cladosporioides for textile dye degradation.

In vitro grown untransformed adventitious roots (AR) culture of Ipomoea hederifolia and its endophytic fungus (EF) Cladosporium cladosporioides decolorized Navy Blue HE2R (NB-HE2R) at a concentration of 20 ppm up to 83.3 and 65%, respectively within 96h. Whereas the AR-EF consortium decolorized the dye more efficiently and gave 97% removal within 36h. Significant inductions in the enzyme activities of lignin peroxidase, tyrosinase and laccase were observed in roots, while enzymes like tyrosinase, laccase and riboflavin reductase activities were induced in EF. Metabolites of dye were analyzed using UV-vis spectroscopy, FTIR and gas chromatography-mass spectrometry. Possible metabolic pathways of NB-HE2R were proposed with AR, EF and AR-EF systems independently. Looking at the superior efficacy of AR-EF system, a rhizoreactor was developed for the treatment of NB-HE2R at a concentration of 1000 ppm. Control reactor systems with independently grown AR and EF gave 94 and 85% NB-HE2R removal, respectively within 36h. The AR-EF rhizoreactor, however, gave 97% decolorization. The endophyte colonization additionally increased root and shoot lengths of candidate plants through mutualism. Combined bioreactor strategies can be effectively used for future eco-friendly remediation purposes.

Co-plantation of aquatic macrophytes Typha angustifolia and Paspalum scrobiculatum for effective treatment of textile industry effluent

Field treatment of textile industry effluent was carried out in constructed drenches (91.4m×1.2m×0.6m; 65.8m3) planted independently with Typha angustifolia, Paspalum scrobiculatum and their co-plantation (consortium-TP). The in situ treatment of effluent by T. angustifolia, P. scrobiculatum and consortium-TP was found to decrease ADMI color value by 62, 59 and 76%, COD by 65, 63 and 70%, BOD by 68, 63 and 75%, TDS by 45, 39 and 57%, and TSS by 35, 31 and 47%, respectively within 96h. Heavy metals such as arsenic, cadmium, chromium and lead were also removed up to 28-77% after phytoremediation. T. angustifolia and P. scrobiculatum showed removal of Congo Red (100mg/L) up to 80 and 73%, respectively within 48h while consortium-TP achieved 94% decolorization. Root tissues of T. angustifolia and P. scrobiculatum revealed inductions in the activities of oxido-reductive enzymes such as lignin peroxidase (193 and 32%), veratryl alcohol oxidase (823 and 460%), laccase (492 and 182%) and azo reductase (248 and 83%), respectively during decolorization of Congo Red. Anatomical studies of roots, FTIR, HPLC, UV-vis Spectroscopy and GC-MS analysis verified the phytotransformation. Phytotoxicity studies confirmed reduced toxicity of the metabolites of Congo Red.

Herbal augmentation enhances malachite green bio degradation efficacy of Saccharomyces cerevisiae

Abstract Saccharomyces cerevisiae was able to degrade a highly toxic textile dye malachite green (MG) at 100 mg/L concentration. Although 99% decolourization was observed, a tremendous metabolic and oxidative stress was exerted on the cells. Ethanolic extracts of Terminalia chebula, Clitoria ternatea and Boerhaavia diffusa at a concentration of 1 mg/mL were independently supplied to S. cerevisiae cells to counter the stress. T. chebula, C. ternatea and B. diffusa extracts reduced the activities of glutathione peroxidase (67, 8 and 71%), superoxide dismutase (2, 7 and 16%) and catalase (16, 52 and 57%), respectively. Inductions in the activities of laccase (66, 82 and 50%), lignin peroxidase (35, 75 and 10%), NADH-DCIP reductase (43, 52 and 91%) and MG reductase (66, 126 and 117%) were observed respectively. Presence of dye (MG) extended the lag phase of the growth cycle of S. cerevisiae up to 36 h, which was observed to be restored to normal (4 h) after phytoextract supplementation. Scanning electron microscope imaging revealed the restored cell morphology upon exposure to plant extracts. The accumulation of reactive oxygen species (ROS) was observed to be 355% greater in cells exposed to MG, which was significantly reduced after phytoextracts augmentation when compared to control cells. Phytoextracts proved to be beneficial in increasing the viability of S. cerevisiae cells and reduced the intracellular ROS and nuclear damage. Inclusion of plant extracts during decolourization proved to be beneficial and protected the cells so that 20 treatment cycles could be run achieving significant removal of MG.

Decolorization and detoxification of dye mixture and textile effluent by lichen Dermatocarpon vellereceum in fixed bed upflow bioreactor with subsequent oxidative stress study

Navy Blue HE22 (NBHE22), dye mixture and real textile effluent were decolorized and degraded by lichen Dermatocarpon vellereceum. Up-flow bioreactor showed about 80%, 70%, 80% and 65% removal of American dye manufacturer index (ADMI), biological oxygen demand (BOD), total suspended solids (TSS) and total dissolved solids (TDS), respectively of dye mixture at flow rate of 25mlh-1. The removal of ADMI, BOD, TSS and TDS of real textile effluent were 75%, 65%, 82% and 70%, respectively at flow rate of 30mlh-1. Significant induction of extracellular enzymes such as manganese peroxidase and lignin peroxidase was observed up to 46% and 36% during decolorization of dye mixture, while 43% and 24% during effluent treatment, respectively. Exponential enhancement in the activities of stress enzymes such as catalase (CAT) and guaiacol peroxidase (GPX) was observed after exposure to NBHE22 (116% and 125%, respectively), dye mixture (150% and 300%, respectively) and effluent (400% and 350%, respectively) endorsing the stress tolerance ability of model lichen. Phytotoxicity and genotoxicity studies demonstrated less toxic nature of metabolites resulted from biodegradation.