Novel method for cell immobilization and its application for production of organic acid

AIMS: The aim was to develop a novel and simple technique for the entrapment of fungal hyphae. METHODS AND RESULTS: A novel immobilization technique was developed by using a structural fibrous network (SFN) of papaya wood as an immobilizing matrix. The technique is simple and a stable entrapment was achieved simply by inoculating the Aspergillus terreus hyphae within culture medium containing SFN pieces for 3 days, without any prior chemical treatment. Results show that SFN has no detrimental effect both on growth and bioactivity of fungi. A 23.5% increase in the itaconic acid production by SFN-immobilized A. terreus was noted when compared with free biomass. SFN-immobilized fungal biomass retained 95% itaconic acid productivity for five repeated batch cycles, 7 days each, without any disintegration/release of hyphae in the production medium. CONCLUSIONS: This is the first report on the use of SFN, a structural material, as an immobilizing matrix for the entrapment of any kind of microbial biomass and its application in organic acid. SIGNIFICANCE AND IMPACT OF THE STUDY: The low cost of SFN and simplicity of the technique applied for immobilization of fungal hyphae within/onto SFN make its use ideal for the immobilization of fungal biomass to produce commercially valuable products.