Strain selection and medium optimization for glucoamylase production from industrial potato waste by Aspergillus niger

• Published in: Journal of the science of food and agriculture Vol. 96; no. 8; pp. 2788 - 2795
• Main Authors: Izmirlioglu, Gulten, Demirci, Ali
• Format: Journal Article
• Language: English
• Published: Chichester, UK John Wiley & Sons, Ltd 01.06.2016; John Wiley and Sons, Limited
• Subjects: Aspergillus niger; Aspergillus niger - enzymology; Aspergillus niger - metabolism; central composite design; Enzymes; Food Industry; Food science; Glucan 1,4-alpha-Glucosidase - metabolism; Glucoamylase; Glucose; Industrial Waste - analysis; industrial waste potato mash; Malt; Optimization; Plackett-Burman; Potatoes; Solanum tuberosum; Starches; Waste materials; Wastes; central composite design; industrial waste potato mash; Plackett-Burman; Aspergillus niger; glucoamylase
• ISSN: 0022-5142; 1097-0010
• DOI: 10.1002/jsfa.7445

BACKGROUND Glucoamylase is one of the most common enzymes used in the food industry to break down starch into its monomers. Glucoamylase production and its activity are highly dependent on medium composition. Starch is well known as a glucoamylase inducer, and utilization of industrial starchy potato waste is an inexpensive way of improving glucoamylase production. Since glucoamylase production is highly dependent on medium composition, in this study medium optimization for glucoamylase production was considered to enhance glucoamylase activity. RESULTS Among the evaluated microbial species, Aspergillus niger van Tieghem was found to be the best glucoamylase‐producing fungus. The Plackett–Burman design was used to screen various medium ingredients, and malt extract, FeSO4.7H2O and CaCl2·2H2O were found to have significant effects on glucoamylase production. Finally, malt extract, FeSO4.7H2O and CaCl2.2H2O were optimized by using a central composite design of response surface methodology. The results showed that the optimal medium composition for A. niger van Tieghem was 50 g L−1 industrial waste potato mash supplemented with 51.82 g L−1 malt extract, 9.27 g L−1 CaCl2·2H2O and 0.50 g L−1 FeSO4.7H2O. CONCLUSION At the end of optimization, glucoamylase activity and glucose production were improved 126% and 98% compared to only industrial waste potato mash basal medium; 274.4 U mL−1 glucoamylase activity and 41.7 g L−1 glucose levels were achieved, respectively. © 2015 Society of Chemical Industry