Optimization of Phytase Production from Escherichia coli by Altering Solid-State Fermentation Conditions

Fermentation

Kyle McKinney²  Justin Combs¹  Patrick Becker¹  Andrea Humphries²  Keith Filer¹  Frank Vriesekoop² 

[1] Alltech Biotechnology, Nicholasville, KY 40536, USA; E-Mails:;Department of Food Science, Harper Adams University, Newport, Shropshire TF10 8NB, UK; E-Mails:

关键词: E. coli;    enzyme;    optimization;    phytase;    solid state fermentation;   

DOI  :  10.3390/fermentation1010013

来源: mdpi

【 摘 要 】

Cultivation of Escherichia coli on wheat-bran substrate under various Solid-State Fermentation (SSF) conditions was evaluated for phytase yield along with the enzyme activity profile as a potential, low-cost alternative to submerged-liquid fermentation. The maximum phytase activity achieved by E. coli was 350 ± 50 SPU of phytase activity per gram of bran, incubated for 96 h with a substrate bed moisture content of 70% (w/v) at 37 °C with a relative air humidity of 90%, and supplemented with 10% (w/w bran) Luria-Bertani broth powder which translates into a 300% increase in phytase activity compared with an un-supplemented culture. The greatest improvements in phytase yield were associated with nutrient supplementation and the optimization of initial substrate moisture content. E. coli production of phytase utilizing solid-state fermentation technology was shown to be feasible utilizing the low-cost agro-residue wheat bran as substrate. Furthermore, the effect of pH and temperature on phytase activity was monitored from pH 2.5 to pH 7.5, and for temperatures ranging from 20 °C to 70 °C. Optimal phytase activity was at pH 5.5 and 50 °C when produced under the SSF optimized conditions.

【 授权许可】

CC BY   
© 2015 by the authors; licensee MDPI, Basel, Switzerland.