The role of fungi in the treatment of wastewater has been extensively researched. Many genera of fungi have been employed for the dye decolourization either in living or dead form. In this study, the removal of an acidic dye, Indigo Carmine (IC), from an aqueous solution by biosorption on dead fungus, Pleurotusostreatus, was investigated. The effects of contact time, initial dye concentration, amount of dead biomass, agitation rate and initial pH on dye removal have been determined. Experimental results show that an increase in the amount of dead biomass positively affected the dye removal. The highest removal was obtained at 150-200 rpm. Slightly lower removing activities were found at lower agitation rates. The dye adsorption effi ciency was not affected by pH except minor variation in the pH of 2-8. Color removal was observed to occur rapidly within 60 minutes. The removal of dye by dead biomass of P. ostreatus was clearly dependent on the initial dye concentration of the solution. Dye removal was reduced from 93% to 64% as concentration was increased from 50 to 500 mg/L Indigo Carmine. This study showed that it was possible to remove textile dyes by dead biomass of P. ostreatus.
The arbuscules of mycorrhizae develop within apoplastic compartments of the host plant, as they are separated from the cell protoplast by an interfacial matrix continuous with the plant cell wall. Expansins are proteins that allow cell wall loosening and extension. Using fluorescence and electron microscopy we located the NtEXPA5 epitopes recognized by polyclonal antibody anti-NtEXPA5 in mycorrhizal tobacco roots. The expansin protein was localized mainly within the interfacial matrix of intracellular hyphae, arbuscule trunk and main branches. NtEXPA5 proteins were detected neither within the interface of collapsing arbuscule branches nor in non-colonized cortex cells. In plant cell walls, expansin protein was detected only at the penetration point and in the parts of cell walls that adhered firmly to fungal hyphae growing intracellularly. For the first time, NtEXPA5 protein was localized ultrastructurally in hyphae growing intracellularly at the interface of the hypha tip and sites of bending. The novel localization of NtEXPA5 protein suggests that this protein may be involved in the process of arbuscule formation: that is, in promoting apical hyphal growth and arbuscule ramification, as well as in controlling the dynamic of arbuscule mycorrhiza development.