The Effect of Carbon Source of Growth on α-Amylase Production by Aspergillus flavus

Adekunle Odunayo Adejuwon ； Patrick Ojo Olutiola

《Advances in Bioscience and Bioengineering》 3卷1期 (2015/12) Pp. 20-28

並列摘要

Abstract: Background: Aspergillus flavus is known for its capability of production of aflatoxins in food grains in the tropics. It was also recently demonstrated as capable of production of α-amylase in a defined medium with potassium nitrate and some other nitrogen compounds as nitrogen source for fungal growth and development (Adejuwon et al., 2015, Advances in Bioscience and Bioengineering). Materials and methods: In this current investigation a same defined growth medium with potassium nitrate as nitrogen source was inoculated with spore suspensions of approximately 7x10^5 spores per ml of Aspergillus flavus. The carbon source for growth was varied and was independently bread, starch, maltose, sucrose, lactose, glucose and galactose. Incubation was at 30℃. Extracellular proteins produced in medium was monitored daily and analysed for α-amylase activity. Results: The proteins produced by Aspergillus flavus in the inoculated medium exhibited α-amylase activity. All the carbon compounds used in the investigation supported α-amylase expression in the fungus however, starch and maltose were the most supportive with optimum activity expressed as 417 and 364 units/mg protein respectively on the 5th day of incubation. Slight delayed expressions were with bread, starch, maltose, lactose, glucose and galactose. Conclusion: All the carbon compounds used in this investigation will support industrial production of α- amylase by Aspergillus flavus with starch and maltose being most supportive when potassium nitrate is used as a source of nitrogen for growth and development at 30℃. However, Aspergillus flavus poses a danger as a potential biomarker in bioterrorism.

並列關鍵字

Aspergillus flavus ； α-amylase ； growth medium ； nitrogen source ； carbon source