title: Utilization of orange peel, a food industrial waste, in the production of exo-polygalacturonase by pellet forming Aspergillus sojae.
abstract: The production of exo-polygalacturonase (exo-PG) from orange peel (OP), a food industrial waste, using Aspergillus sojae was studied in submerged culture. A simple, low-cost, industrially significant medium formulation, composed of only OP and (NH4)2SO4 (AS) was developed. At an inoculum size of 2.8 × 10(3) spores/mL, growth was in the form of pellets, which provided better mixing of the culture broth and higher exo-PG activity. These pellets were successfully used as an inoculum for bioreactors and 173.0 U/mL exo-PG was produced. Fed-batch cultivation further enhanced the exo-PG activity to 244.0 U/mL in 127.5 h. The final morphology in the form of pellets is significant to industrial fermentation easing the subsequent downstream processing. Furthermore, the low pH trend obtained during this fermentation serves an advantage to fungal fermentations prone to contamination problems. As a result, an economical exo-PG production process was defined utilizing a food industrial by-product and producing high amount of enzyme.
authors.affiliation: Department of Food Engineering, İzmir Institute of Technology, Gulbahce Campus, 35430, Urla, İzmir, Turkey.
authors.forename: Ali Oguz
authors.initials: AO
authors.lastname: Buyukkileci
authors.forename: Marcello Fernandez
authors.initials: MF
authors.lastname: Lahore
authors.forename: Canan
authors.initials: C
authors.lastname: Tari
mesh_terms: D001230:Aspergillus / Q000201:enzymology*; D019149:Bioreactors; D032084:Citrus sinensis; D003470:Culture Media; D005285:Fermentation; D019649:Food Industry; D006863:Hydrogen-Ion Concentration; D007218:Industrial Microbiology; D007220:Industrial Waste; D011096:Polygalacturonase / Q000096:biosynthesis*
chemical_list: D003470:Culture Media; D007220:Industrial Waste; D011096:Polygalacturonase