| The research of phytase has been last for one hundred years. So far, it has beensuccessfully applied in many fields, such as the feedstuff, the grocery and themedicine. The America, Finland, Holland and Germany et al have been recommendedmany phytase preparations. Domestic scholars also have some achievements onphytase. But there are also some problems on the applications. So, it's necessarily toselect new strains which produce phytase, and finally obtain phytase which havepractical value. The main work this study have done as follows:1. Totally, 61 phytase-producing strains have been isolated from 6 soil samplesand 1 distillers'grains sample. Among them, one has the maximum diameter ratio ofits clear zone to its colony. This swain was identified as Tarlaromyces flavus accordingto its morphological properties and the analysis of its 18S rRNA gene sequence. Thesimilarity of its 18S rRNA gene and the standard strain is 100％.2. Studied on the enzyme producing condition and enzymological properties. Theoptimum medium was composed of 6％glucose, 0.2％peptone, 0.5％(NH4)2SO4,0.05％KCl, 0.05％MgSO4·TH2O, 0.004％FeSO4·7H2O, 0.004％MnSO4·H2O. Theoptimum producing condition was: cultivate temperature was 32℃; optimum pH ofthe fermentation medium was 5.5; medium quantity was 50mL(500mL conical flask);inoculation proportion was 2％; rotate speed of the shaker was 80r/min; fermentationtime was 8d. The result of study on enzymological properties was: optimum reactiontemperature was 55℃; optimum reaction pH was 5.5; optimum reaction time was10min; and the final enzyme activity was 294U/ml. |
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