Study On The Applied Properties Of Plant Phytase

The activity and heat resistance of plant phytase in grain crop seeds were studied in the present experiments. The sprouting, drying, temperature, pH and storing time have diverse effects on the phytase activity. Those were also studied. The in vitro experiment was conducted to determine the hydrolyzing ability of plant phytase to phytate in maize arid soybean meal. The results were as follows:1.The phytase activity in the seeds of oat, barely 2, wheat NEAU 123, wheat NEAU973 821 ,triticale 96026, triticale 92021, triticale 5305, triticale 8809, ShengLi rye and rye 2 was analyzed. These values respectively are: 57.70u/kg.. 143.25u/kg. 1048.06u/kg~ 725.22u/kg~ 1713.46u/kg~ 2201.65u/kg~ 1978.67u/kg~ 1406.49u/kg~53 10.89u/kg~. 3446.53u/kg. It could be concluded that the phytase activity is higher in grain crop seeds, but there are great difference among species and cultivar. Among these grains, the phytase activity in rye is highest, triticale secondary. Wheat also contains higher activity, but barely and oat have little.2.The phytase in grain crop seeds have good heat resistance. When heated at 70C, the phytase activity in these grain seeds nearly had no loss; at 80C or 90C, only had a little; at 100 , the average loss in the 6 cultivar of grain crops was 12%.3.Sprouting could greatly increased the phytase activity in the grain plant seeds(P<0.0 1). The extent of increasing of phytase and the days when the activity was highest varied among grains. At 25 triticale and rye needed I d ,but wheat and barley needed 3d to reach the maximum of phytase activity by sprouting. Contrasted with not sprouting, the phytase activity based on dry matter respectively improved: wheat NEAU 123 2.04 folds, wheat NEAU97382 1 2.55 folds, triticale 96026 1 .32folds, triticale 920211.36 folds, triticale 5305 1.82 folds, rye 2 2.45 folds and barley 4.63 folds.4.Desiccated for 2h at 40扖, then air-dried at room temperature, fresh malt could terminate quickly sprouting. This process had very low destruction.5.For these plant phytase , the optimum temperature is 50C, presenting high activity between 40t and 60扖; the optimum pH lies in the range of 5.5?.0, below 4.0 or above 7.0, almost causing total inactivation. Significant interaction existed between temperature and pH. When pH were 6.0, 5.5 and 5.0, the optimum temperatures respectively are 45 C, 50 , and 55 C. Increasing temperature, the optimum pHdecreased.6.Air-dried malts being stored alone, the phytase activity in them had high stability. Storing for 6 months at room temperature, the activity in the malts retained 84.36O/o~~99.95% except barely malt.7.The degradation experiment in vitro showed that 300u/kg plant phytase liberated71.92% phytate phosphorus from maize and 3 8.94% from soybean meal for Sb at pH5.50,37t. The inorganic phosphorus almost presented linear increase. The rate and extent of degradation of phytate phosphorus were higher in maize than in soybean meal.Master Candidate: Ma XiMajor: Animal Nutrition and Feed ScienceSupervisor: Prof. Shan Anshan...