THE PRODUCTION OF A NEW FUNGAL α-AMYLASE DEGRADED THE RAW STARCH BY MEANS OF SOLID-STATE FERMENTATION

• Published in: Preparative biochemistry & biotechnology Vol. 40; no. 3; pp. 213 - 228
• Main Authors: Balkan, Bilal, Ertan, Figen
• Format: Journal Article
• Language: English
• Published: England Taylor & Francis Group 14-07-2010
• Subjects: alpha-Amylases - biosynthesis; alpha-Amylases - genetics; alpha-Amylases - metabolism; Chemical Fractionation; Fermentation; Fungi - enzymology; Helianthus; Oryza sativa; Penicillium brevicompactum; purification; raw starch digesting; solid-substrate fermentation; Species Specificity; Starch - metabolism; Triticum aestivum; α-amylase
• ISSN: 1082-6068; 1532-2297
• DOI: 10.1080/10826068.2010.488549

In this study, it was intended to produce a new fungal amylase by solid-state fermentation and purification and also to determine some of its biochemical properties. It was found that Penicillium brevicompactum had the best enzyme activity according to screening methods with amylase degrading raw starch, and P. brevicompactum was selected as the amylase source. Wheat bran, rice husks, and sunflower oil meal were tested to determine the best solid substrate. Wheat bran was determined as the best of these. The fermentation conditions were optimized for the production of amylase. The optimum fermentation conditions were found to be an initial moisture level for the solid substrate of 55%, moistening agent of 0.1 M sodium phosphate buffer (pH 5.0), incubation period of 7 d, inoculum concentration of 2.5 mL, and incubation temperature at 30°C. Penicillium brevicompactum α-amylase was purified 45.98 times by the starch affinity method. The K
m
and V
max
values of α-amylase for soluble starch were 5.71 mg/mL and 666.6 U/mL, respectively. This amylase showed maximum activity at between 30 and 50°C and at pH 5.0. Initial enzyme activity was kept at 100% after incubation at 30°C for 45 min. Enzyme was stable in the pH range of 4.0-5.0. This enzyme was activated by Mn
2+
, Cu
2+
, and Na
+
ions, and was inhibited by Mg
2+
, K
+
, Fe
3+
, and ethylenediamine tetraacetic acid (EDTA). The molecular mass of P. brevicompactum α-amylase was found to be 32.5 kD by sodium dodecyl sulfate (SDS) polyacrylamide gel electrophoresis.