Evaluation of agro-industrial wastes, their state and mixing ratio for maximum polygalacturonase and biomass production in submerged fermentation

The potential of important agro-industrial wastes, apple pomace (AP) and orange peel (OP) as C sources, was investigated in the maximization of polygalacturonase (PG), an industrially significant enzyme, using an industrially important microorganism Aspergillus sojae. Factors such as various hydrolysis forms of the C sources (hydrolysed-AP, non-hydrolysed-AP, hydrolysed-AP + OP, non-hydrolysed-AP + OP) and N sources (ammonium sulphate and urea), and incubation time (4, 6, and 8 days) were screened. It was observed that maximum PG activity was achieved at a combination of non-hydrolysed-AP + OP and ammonium sulphate with eight days of incubation. For the pre-optimization study, ammonium sulphate concentration and the mixing ratios of AP + OP at different total C concentrations (9, 15, 21 g l−1) were evaluated. The optimum conditions for the maximum PG production (144.96 U ml−1) was found as 21 g l−1 total carbohydrate concentration totally coming from OP at 15 g l−1 ammonium sulphate concentration. On the other hand, 3:1 mixing ratio of OP + AP at 11.50 g l−1 ammonium sulphate concentration also resulted in a considerable PG activity (115.73 U ml−1). These results demonstrated that AP can be evaluated as an additional C source to OP for PG production, which in turn both can be alternative solutions for the elimination of the waste accumulation in the food industry with economical returns.Fil: Göğüş, Nihan. Izmir Institute of Technology; TurquíaFil: Evcan, Ezgi. Izmir Institute of Technology; TurquíaFil: Tari, Canan. Izmir Institute of Technology; TurquíaFil: Cavalitto, Sebastian Fernando. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - la Plata. Centro de Investigación y Desarrollo En Fermentaciones Industriales. Universidad Nacional de la Plata. Facultad de Cs.exactas. Centro de Investigación y Desarrollo En Fermentaciones Industriales; Argentin

Evaluation of agro-industrial wastes, their state and mixing ratio for maximum polygalacturonase and biomass production in submerged fermentation

The potential of important agro-industrial wastes, apple pomace (AP) and orange peel (OP) as C sources, was investigated in the maximization of polygalacturonase (PG), an industrially significant enzyme, using an industrially important microorganism Aspergillus sojae. Factors such as various hydrolysis forms of the C sources (hydrolysed-AP, non-hydrolysed-AP, hydrolysed-AP + OP, non-hydrolysed-AP + OP) and N sources (ammonium sulphate and urea), and incubation time (4, 6, and 8 days) were screened. It was observed that maximum PG activity was achieved at a combination of non-hydrolysed-AP + OP and ammonium sulphate with eight days of incubation. For the pre-optimization study, ammonium sulphate concentration and the mixing ratios of AP + OP at different total C concentrations (9, 15, 21 g l−1) were evaluated. The optimum conditions for the maximum PG production (144.96 U ml−1) was found as 21 g l−1 total carbohydrate concentration totally coming from OP at 15 g l−1 ammonium sulphate concentration. On the other hand, 3:1 mixing ratio of OP + AP at 11.50 g l−1 ammonium sulphate concentration also resulted in a considerable PG activity (115.73 U ml−1). These results demonstrated that AP can be evaluated as an additional C source to OP for PG production, which in turn both can be alternative solutions for the elimination of the waste accumulation in the food industry with economical returns.Centro de Investigación y Desarrollo en Fermentaciones Industriale

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

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

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

BACKGROUND: The koji mold Aspergillus sojae, an industrially important microorganism, can produce high levels of pectinases utilizing agro-industrial wastes. This study introduces apricot and peach pomace, two agro-industrial wastes barely considered as raw material for the generation of value-added products, and focuses on its utilization together with orange peel for polygalacturonase production in submerged cultures using A. sojae. RESULTS: A Doehlert response surface methodology design conducted in shake flasks and applied individually with these three by-products led to 60–80 U mL−1 polygalacturonase activity. In bioreactor studies performed with a mixture of apricot pomace and orange peel, by fixing stirrer speed to 600 rpm and cascading airflow to the dissolved oxygen tension up to 1.7 vvm, oxygen limitation problems were overcome and polygalacturonase activity values of 380 U mL−1 were achieved. CONCLUSION: A simple and efficient strategy to minimize oxygen limitation with the lowest possible shear stress is provided for stirred-tank bioreactors working with highly viscous broths, so as to ultimately enhance microbial enzyme production. The polygalacturonase activity yields obtained in our study are among the highest reported in the literature.Fil: Fratebianchi de la Parra, Dante. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigación y Desarrollo en Fermentaciones Industriales. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Centro de Investigación y Desarrollo en Fermentaciones Industriales; ArgentinaFil: Crespo, Juan Manuel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigación y Desarrollo en Fermentaciones Industriales. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Centro de Investigación y Desarrollo en Fermentaciones Industriales; ArgentinaFil: Tari, Canan. Izmir Institute of Technology; TurquíaFil: Cavalitto, Sebastian Fernando. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigación y Desarrollo en Fermentaciones Industriales. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Centro de Investigación y Desarrollo en Fermentaciones Industriales; Argentin