This study was carried out to determine the efficiency of various biological wastes, nutrients, some metal ions, temperature, pH on thermostable phytase production. The new isolate Bacillus megaterium EBD 9-1 phytase was used to study the biochemical characteristics. The phytase activity increased markedly at the late stationary and the highest phytase activity after the fourth day of culture. A new growth medium was developed, resulting in a 2.34-fold increase in enzyme production. The crude phytase was optimally active at pH 5.5-7.0 at 37oC and retained its activity at temperatures up to 80oC. The enzyme exhibited thermostability, retaining ~50% activity at 70oC and were fairly stable up to pH 10. KCl was determined as the best metal ion (1437 FTU/mL), but in the studies conducted, enzyme production in 1% Wheat bran and 0.5% Na-Phytate medium was 1615 FTU/mL and 2989 FTU/mL in the presence of KCl and CaCl2, respectively. Large-scale production and lyophilization of the phytase were performed. It remained stable in lyophilized form at +4oC for 1 year. Lyophilized phytase was optimally active. Its effectiveness in the presence of feed additives was also compared with the commercial enzyme at extreme conditions such as high temperature, pH and long incubation time and it was retained its activity and also found to be more efficient than the commercial enzymes. These properties indicated that the B. megaterium EBD 9-1 phytase appeared to be suitable for animal feed additive for poultry to improve the phosphorus bioavailability.
Aybey et al. (Tue,) studied this question.