Sustainable Bioprocess Evaluation for Xylanase Production by Isolated Aspergillus terreus and Aspergillus fumigatus Under Solid - State Fermentation Using Oil Palm Empty Fruit Bunch Fiber
Xylanase bioprocess by isolated Aspergillus terreus and Aspergillus fumigatus strains under solid-state fermentation using oil palm empty fruit bunch fiber as substrate was investigated. The productions of xylanase enzyme in these fungal strains were influenced by bioprocess parameters. Though enzyme production was noticed in the wide range of pH (3.0 – 8.0), effective xylanase production observed at pH 6.0 and 7.0 by A. terreus and A. fumigatus respectively. Similarly, enzyme titer values improved with increase in moisture content (70%) and inoculum concentration of 2.0 and 1.5 ml (1 x 106 spore solution per ml) for A. terreus and A. fumigatus respectively. Particle size mediated variation also noticed where 2.0 - 0.7 and 2.8- 2.0 mm (15,990 and 14,563 U/g) was effective for xylanase production by A. terreus and A. fumigatus, respectively. Whereas, supplementation of xylose and fructose to A. terreus and A. fumigatus were enhanced the xylanase production to 32,074 and 25,038 U/g, respectively. Furthermore, addition of 0.6 g of sodium nitrate and 0.4 g of ammonium chloride had resulted 39,136 and 35,380 U/g of xylanase titers by using A. terreus and A. fumigatus respectively. Over all xylanase enzyme productivity was improved to the tune of 3.0 and 2.8 folds with A. terreus and A. fumigatus after bioprocess optimization, respectively.