Mycological assisted phytoremediation enhancement of bioenergy crops <i>Zea mays</i> and <i>Helianthus annuus</i> in heavy metal contaminated lithospheric zone

Abstract

Current investigation has for the first time utilized Trichocomaceae fungi i.e. Aspergillus niger, Aspergillus terreus, Aspergillus flavus and Pencillium i.e. Penicillium chrysogenum for augmenting the phytoremediation potential of bioenergy crops wheat (Zea mays) and ‎ sunflower (Helianthus annuus). Phytoremediation was done for mitigation of heavy metals i.e. Chromium (Cr), Copper (Cu), Lead (Pb) and Cadmium (Cd) from contaminated soils of agricultural significance. Phytoremediant crops were inoculated with fungal cultures by three methods i.e. mixing method, seed inoculation method and layering spreading method. Maize and sunflower plants after fungal inoculation were harvested after 60 days of germination. The estimation of % biomass and bioenergy of maize and sunflower plants was done. Results were indicative of the good phytoremediation potential of roots and shoots for uptake of heavy metals i.e. Cr<Cu<Pb<Cd in the presence of Aspergillus niger, Aspergillus terreus and Aspergillus flavus by fungal inoculation methods. Sunflower and fungal inoculum of Aspergillus flavus and Penicillium chrysogenum extracted significant quantity of metals from the soil. By three fungal inoculation methods, range of % production of biomass was 84−87% and sunflower plants dry biomass 9.6 g yielded 0.16% of oil. Obtained results are have favored the use of fungal inoculation as an effective mode for phytoremediation augmentation of maize and sunflower. Furthermore, current work also signifies the sustainable conversion of bioenergy crops to biofuel production in a cost effective mode.