BACKGROUNDEnhanced fumaric acid production by immobilization of filamentous fungal strains on different solid supports has been reported previously. However, the carbon-rich agro-industrial waste biomass brewery wastewater' as fermentation medium and muslin cloth as immobilizing device for the fungal strain Rhizopus oryzae 1526 have never been investigated before. In the present research work, enhanced production of fumaric acid by an immobilization technique was carried out with a novel combination of fermentation medium, immobilization device and fungal strain. RESULTSMuslin cloth area of 25 cm(2) and 1.5 x 10(6) per mL spore concentration were found optimal for the highest production of fumaric acid. Production level and volumetric productivity of fumaric acid were markedly increased from 30.56 1.40 to 43.67 +/- 0.32 g L-1 and 0.424 to 1.21 g L-1 h for immobilized submerged fermentation compared with free-cell fermentation, respectively. However, the specific fumaric acid production rates for free-cell and 25 cm(2) muslin cloths were found to be comparable (3.39 and 3.49 gg(-1) h(-1), respectively). Scanning electron microscope studies of the immobilized fungus confirmed the good attachment of the fungal hyphae to the muslin cloths. CONCLUSION

Results demonstrated that brewery wastewater and muslin cloth could be used for the enhanced production of fumaric acid through submerged fermentation. (c) 2014 Society of Chemical Industry