Decolourization of a textile-reactive dye with Phanerochaete chrysosporium incubated in different ways under non-sterile conditions

Most studies on decolourization of reactive dye with Phanerochaete chrysosporium have been performed under sterile conditions. In this paper, Phanerochaete chrysosporium, suspended in liquid medium, immobilized on nylon nets, and immobilized on polyurethane foams were studied to decolorize a textile-reactive dye in agitated liquid incubation under non-sterile conditions. The results showed that the decolourization against reactive brilliant red K-2BP by mycelia pellets in suspended cultures, the fungi immobilized on nylon nets and immobilized on polyurethane foams were 0%, 52% and 95%, respectively. The suspended incubation system and the system with nylon nets were contaminated with yeasts, which deteriorated the decolourization effects. The three-dimensional reticular structure of polyurethane foam was benefit to Phanerochaete chrysosporium growth in spreading mycelia taking nutrients and oxygen effectively. The foam could quickly absorb liquid medium into its holes, leaving much less nutrients to support the growth of single cell micro-organisms such as yeast in liquid. The micro-environment existed in polyurethane foam was close to the wild growth conditions of white rot fungus in nature. In conclusion, immobilized culture with polyurethane foam carriers is advantaged to reduce the colonization of other micro-organisms, and makes Phanerochaete chrysosporium possess higher decolorizing ability under non-sterile conditions.