Department of Biotechnology, Kazimierz Wielki University, ul. K. J. Poniatowskiego 12, 85-671 Bydgoszcz, Poland.
Molecules. 2018 Apr 8;23(4):848. doi: 10.3390/molecules23040848.
One of the key steps in the production of phytases of microbial origin is selection of culture parameters, followed by isolation of the enzyme and evaluation of its catalytic activity. It was found that conditions for yeast culture, strain Finarome, giving the reduction in phytic acid concentration of more than 98% within 24 h of incubation were as follows: pH 5.5, 32 °C, continuous stirring at 80 rpm, the use of mannose as a carbon source and aspartic acid as a source of nitrogen. The highest catalytic activity of the isolated phytase was observed at 37 °C, pH 4.0 and using phytate as substrate at concentration of 5.0 mM. The presence of ethanol in the medium at a concentration of 12% / reduces the catalytic activity to above 60%. Properties of phytase derived from yeast culture, strain Finarome, indicate the possibility of its application in the form of a cell's free crude protein isolate for the hydrolysis of phytic acid to improve the efficiency of alcoholic fermentation processes. Our results also suggest a possibility to use the strain under study to obtain a fusant derived with specialized distillery strains, capable of carrying out a highly efficient fermentation process combined with the utilization of phytates.
微生物来源植酸酶生产的关键步骤之一是选择培养参数，然后分离酶并评估其催化活性。研究发现，酵母培养物菌株 Finarome 的培养条件为：pH5.5、32°C、80rpm 连续搅拌、以甘露糖作为碳源和以天冬氨酸作为氮源，在孵育 24 小时内可将植酸浓度降低 98%以上。分离得到的植酸酶在 37°C、pH4.0 和以植酸钠为底物（浓度为 5.0mM）时表现出最高的催化活性。在浓度为 12%/的培养基中存在乙醇会使催化活性降低至 60%以上。来自酵母培养物菌株 Finarome 的植酸酶的性质表明，它有可能以细胞游离粗蛋白粗提物的形式应用于植酸的水解，以提高酒精发酵过程的效率。我们的研究结果还表明，有可能使用所研究的菌株获得与专用酿酒菌株融合的融合体，该融合体能够进行高效的发酵过程，同时利用植酸盐。
