Biotechnology Bulletin ›› 2015, Vol. 31 ›› Issue (7): 188-192.doi: 10.13560/j.cnki.biotech.bull.1985.2015.07.028

• Research report • Previous Articles     Next Articles

Screening of a Strain Producing Acid-stable α-Amylase and Optimization of Its Fermentation Condition

Qu Jianhang1, Yin Yi1, Jiao Guobao2, Ding Changhe1, Zhang Qian1, Qu Lingbo1, Liu Zhongmin2   

  1. (1. College of Biological Engineering,Henan University of Technology,Zhengzhou 450000;2. Henan Yangshao Biochemical Engineering Company,Mianchi 472400)
  • Received:2014-11-25 Online:2015-07-16 Published:2015-07-16

Abstract: A strain SH3 producing acid-stable α-amylase was isolated from the soil nearing a starch factory. It was preliminarily identified as yeast. The pH range of crude enzyme reaction was 3. 8-8. 0 with the optimum of 5. 0, and the activity of the enzyme was still available in the temperature of 80℃ with the optimum of 50℃. The optimization of single-factor fermentation revealed that the optimal condition for the enzyme production was 37℃, pH 5. 0, soluble starch as carbon source, peptone as nitrogen source and 200 mL liquid volume. Orthogonal test showed that the optimal fermentation condition was as soluble starch of 15 g/L, peptone of 30 g/L, 37℃ and pH4. 5, under which the enzyme activity was 96.8 U/mg.

Key words: acid-stable α-amylase, strain screening, fermentation condition, process optimization, yeast