Phytoremediation is an effective technology for in-situ remediation of high level polluted soils. Phytoremediation is a plant-mediated approach, which involves the use of plants to absorb and remove elemental pollutants or lower their concentration or bioavailability to soil. Plants have efficacy to absorb compounds in the soil even at low concentration through their root system. Plant root system has geotropism which helps them to extend into the soil matrix and hyper accumulate heavy metals to increase their bioavailability considerably and thereby the polluted soil is domesticated and the soil fertility is enhanced. The heavy-metal-resistant endophytes give the promising effect on plant growth, by decreasing metal phytotoxicity and affecting metal translocation and accumulation in plants. It is an eye opening for researches to implement the phytoremediation of organic contaminants through endophytes that produce various enzymes to metabolize organic contaminants and reduce both the phytotoxicity and evapotranspiration of volatile contaminants. Here, we focus on the most widely used phytoremediation strategies, phytostabilization, phytoextraction, phytovolatilization, and phytofiltration in the remediation of heavy metal-polluted soil.

The major intend of this study was to elucidate the laccase production by Trametes versicolor under submerged fermentation using fruit waste peel as substrate. The textile dye was decolorized by the procured crude enzymatic extract using the response surface methodology. The submerged media with organic fruit peel waste extract (jackfruit, pineapple & kaffir) supplemented with gypsum, calcium carbonate, and nutrient broth were considered superior for laccase production. The produced laccase enzyme was used in dye decolorization at the optimum conditions using the Box-Behnken design. Subsequently, the experiment was designed with four variables (dye concentration, pH, temperature & time) with three factors to achieve the maximum direct blue dye decolorization. The highest laccase activity level was obtained from jackfruit peel extract with 3.86U/ml on 15th day at 25oC with pH 5.0 when compared to the other two extracts. The maximum laccase activity with guaiacol was obtained at optimum pH 4 and 40oC. The predicted value was experimentally validated by attaining 81.25% of dye color removal. From the result, the optimum conditions for direct blue color removal were: dye concentration 40ppm, pH 4.0, temperature 40oC at 24 hours. From the results of this study, it was concluded that the jack fruit peel was a more suitable substrate for laccase production. The dye decolorization results were recommended that Box-Behnken design for parameters optimization. The T. versicolor laccase was more proficient for textile dye decolorization. The opportunity was created by using the laccase enzyme for the biological treatment of textile dyeing effluent before discharging into the environment.

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