Immobilization and characterization of the Lactarius deliciosus mycelia-embedded polylysine-alginate beads and their decolorization performance

Liquid fermented fungal mycelia with decolorization capability have potential applications in scale-up. In this work, the Lactarius deliciosus mycelia were immobilized on ε -polylysine-alginate beads, and the decolorization effects of ε -polylysine-alginate beads were demonstrated along with Coomassie brilliant blue G-250 as a model dye. Morphology observation confirmed the beads had an exterior film and interior capsule with honeycomb microstructures suitable for mycelia growth. It was manifested that the maximum decolorization efficiency for mycelia was 98.5% at a removal rate of 0.68 mg·L −1 ·h after 3 days. In comparison, the decolorization efficiency of the immobilized mycelia reached the maximum value of 97.3% at a removal rate of 6.1 mg·L −1 ·h after 8 h. The enzyme activities of lignin peroxidase and laccase tested in the immobilized mycelia were significantly higher than in that of the free ones, such as the lignin peroxidase had the highest enzyme activity of 77.6 ± 7.4 U·L −1 in the former, while of 27.4 ± 8.7 U·L −1 in the latter. The immobilization of L. deliciosus mycelia could improve the decolorization of Coomassie brilliant blue G-250 efficiently. The prepared ε -polylysine-alginate beads embedded with L. deliciosus mycelia have very good reusability and a great potential in decolorizing analog dyes.