Phytase-active yeasts from grain-based food and beer
Article first published online: 16 MAR 2011
© 2011 The Authors. Journal of Applied Microbiology © 2011 The Society for Applied Microbiology
Journal of Applied Microbiology
Volume 110, Issue 6, pages 1370–1380, June 2011
How to Cite
Nuobariene, L., Hansen, A.S., Jespersen, L. and Arneborg, N. (2011), Phytase-active yeasts from grain-based food and beer. Journal of Applied Microbiology, 110: 1370–1380. doi: 10.1111/j.1365-2672.2011.04988.x
- Issue published online: 12 MAY 2011
- Article first published online: 16 MAR 2011
- Accepted manuscript online: 25 FEB 2011 11:31AM EST
- 2010/2210: received 7 December 2010, revised 15 February 2011 and accepted 20 February 2011
- baking yeast;
- brewer’s yeast;
- Candida krusei;
- phytase activity;
- Saccharomyces cerevisiae;
- Saccharomyces pastorianus
Aims: To screen yeast strains isolated from grain-based food and beer for phytase activity to identify high phytase-active strains.
Methods and Results: The screening of phytase-positive strains was carried out at conditions optimal for leavening of bread dough (pH 5·5 and 30°C), in order to identify strains that could be used for the baking industry. Two growth-based tests were used for the initial testing of phytase-active strains. Tested strains belonged to six species: Saccharomyces cerevisiae, Saccharomyces pastorianus, Saccharomyces bayanus, Kazachstania exigua (former name Saccharomyces exiguus), Candida krusei (teleomorph Issachenkia orientalis) and Arxula adeninivorans. On the basis of initial testing results, 14 strains were selected for the further determination of extracellular and intracellular (cytoplasmic and/or cell-wall bound) phytase activities. The most prominent strains for extracellular phytase production were found to be S. pastorianus KVL008 (a lager beer strain), followed by S. cerevisiae KVL015 (an ale beer strain) and C. krusei P2 (isolated from sorghum beer). Intracellular phytase activities were relatively low in all tested strains.
Conclusions: Herein, for the first time, beer-related strains of S. pastorianus and S. cerevisiae are reported as phytase-positive strains.
Significance and Impact of the Study: The high level of extracellular phytase activity by the strains mentioned previously suggests them to be strains for the production of wholemeal bread with high content of bioavailable minerals.