Comparative evaluation of suspended and chitosan-encapsulated WRF consortium for decolorization of anthraquinone dye mixture

Abstract

Mycoremediation is utilized for the breakdown of a mixture of anthraquinone dyes (MAQD). Due to co-metabolism, the White Rot Fungal Consortium (WRFC) is preferable to pure isolates. The suspended and chitosan-encapsulated WRFC5 (Trametes cubensis WF2, Polyporus umbellatus VS12, Pleurotus pulmonarius MTCC 1805 and Leiotrametes flavida MTCC 12927) were able to decolorize MAQD: Acid blue 129, Alizarin cyanin green, and Remazol brilliant blue R (200 ppm) by 44.53% and 97.35% respectively in 8 h with optimized inoculum size (6%), pH (7), temperature (30°C), glucose (1.25%), potassium nitrate (0.06%) and shaking speed (80 rpm). The reusability of immobilized WRFC5 in chitosan beads was possible up to 20 cycles, yielding a decolorization percentage of 78.85% for the 20th cycle in 8 h. TDS, BOD, and COD of MAQD were reduced by 92.94%, 70%, and 81.25% respectively using suspended WRFC5 and 97.57%, 98.75%, and 99.2% respectively using immobilized WRFC5 in 8 h. Suspended WRFC5 could also reduce color, chloride, nitrate, and lead by 44.53%, 42.66%, 94.33%, and 57.14% respectively, whereas immobilized WRFC5 could reduce by 97.35%, 84%, 99.99%, and 77.85% respectively in 8 h. MnP activity might be the reason for efficient decolorization and degradation by suspended and immobilized WRFC5. The highest MnP activity by suspended and immobilized WRFC5 was found to be 2089.93 and 61.89 U/mL respectively. The above study concluded that the developed chitosan-encapsulated WRFC5 could possibly be used as an excellent natural biomaterial for the simultaneous elimination of color, chloride, nitrate, and lead from MAQD-containing wastewater in a very short span of time and reused for around 20 cycles.