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

• Published in: Environmental technology Vol. 36; no. 20; pp. 2657 - 2667
• Main Authors: Göğüş, Nihan, Evcan, Ezgi, Tarı, Canan, Cavalitto, Sebastián F
• Format: Journal Article
• Language: English
• Published: England Taylor & Francis 18.10.2015; Taylor & Francis Ltd
• Subjects: agricultural wastes; agro-industrial waste; Ammonia; Ammonium Sulfate; apple pomace; Aspergillus; Aspergillus sojae; Biomass; biomass production; Citrus sinensis; Economics; environmental technology; Enzymes; Fermentation; Fertilizers; food industry; hydrolysis; Industrial Waste; Industrial wastes; Malus; Maximization; Microorganisms; mixing; Mixing ratios; orange peel; orange peels; polygalacturonase; Polygalacturonase - analysis; Polygalacturonase - metabolism; Polygalacturonases; Reproducibility of Results; submerged fermentation; urea ammonium sulfate; Waste Disposal, Fluid - methods; Wastes; British Isles; agro-industrial waste; apple pomace; orange peel; Aspergillus sojae; polygalacturonase
• ISSN: 1479-487X; 0959-3330; 1479-487X
• DOI: 10.1080/09593330.2015.1042922

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.