Control of agitation rate and aeration for enhanced polygalacturonase production in submerged fermentation by Aspergillus sojae using agro-industrial wastes

FRATEBIANCHI, D; TARI, C; CRESPO, J. M; CAVALITTO, S. F

JOURNAL OF CHEMICAL TECHNOLOGY AND BIOTECHNOLOGY

JOHN WILEY & SONS LTD

Lugar: Londres; Año: 2016

0268-2575

BACKGROUND: The koji mold Aspergillus sojae, an industrially importantmicroorganism, can produce high levels of pectinasesutilizing agro-industrial wastes. This study introduces apricot and peach pomace, two agro-industrial wastes barely consideredas raw material for the generation of value-added products, and focuses on its utilization together with orange peel forpolygalacturonase production in submerged cultures using A. sojae.RESULTS: A Doehlert response surface methodology design conducted in shake flasks and applied individually with these threeby-products led to 60?80 U mL−1 polygalacturonase activity. In bioreactor studies performed with a mixture of apricot pomaceand orange peel, by fixing stirrer speed to 600 rpm and cascading airflowto the dissolved oxygen tension up to 1.7 vvm, oxygenlimitation problems were overcome and polygalacturonase activity values of 380 UmL−1 were achieved.CONCLUSION: A simple and efficient strategy to minimize oxygen limitation with the lowest possible shear stress is providedfor stirred-tank bioreactors working with highly viscous broths, so as to ultimately enhancemicrobial enzyme production. Thepolygalacturonase activity yields obtained in our study are among the highest reported in the literature.