Phytase activity in sourdough lactic acid bacteria:: purification and characterization of a phytase from Lactobacillus sanfranciscensis CB1
Phytase activity in sourdough lactic acid bacteria:: purification and characterization of a phytase from Lactobacillus sanfranciscensis CB1
复制标题
DOI：
10.1016/s0168-1605(03)00072-2
复制
发表时间：
2003-11-01
影响因子：
5.4
通讯作者：
Gobbetti, M
中科院分区：
文献类型：
--
作者：
De Angelis, M;Gallo, G;Gobbetti, M
对12株酸面团乳酸菌的植酸酶活性进行了筛选。它仅存在于细胞内，主要分布在旧金山乳杆菌的菌种和菌株中，具有最高水平的活性。单体CA。50-从L. sanfranciscensisCB 1进行了三步色谱分离。L. sanfranciscensisCB 1在达到生长稳定期后（约1000 μ g/L）表现出最高的植酸钠水解活性。12小时）。在麦芽糖和果糖存在下培养的细胞显示出钙的植酸酶活性的增加。35%，相对于所使用的其他碳源。植酸酶的最适pH为4.0，最适温度为45 ℃。该酶强烈抑制2 mM的苯甲基磺酰氟（PMSF），和2 mM的Hg 2+和Fe 2+。它的pI值为ca。5.0.底物特异性取决于磷酸酯的类型;在α-D-葡萄糖-1-磷酸和D-果糖-6-和1，6-磷酸上检测到非常低的活性，而发现对腺苷-5 '-三-、二-和一-磷酸的水解最高。与这些底物相比，对植酸钠的活性也相关。该酶在70摄氏度下暴露30分钟后具有热稳定性;在80摄氏度下计算的D值约为。如应用于研究pH、温度和NaCl的个体和交互作用的中心复合设计（CCD）所示，酸性条件和升高的温度对于酶适应高NaCl浓度是必不可少的。L. sanfranciscensisCB 1细胞或相应的细胞质提取物用于在37 ℃下发酵酸面团8小时;与未开始的面团相比，发现植酸钠浓度显著降低（64-74%）。酸面团以L开头。sanfranciscensis CB 1细胞多次重复使用，植酸酶活性保持在相当高的水平。(C)2003 Elsevier Science B. V.保留所有权利。
The phytase activity of 12 species of sourdough lactic acid bacteria was screened. It was intracellular only, largely distributed among the species and strains of Lactobacillus sanfranciscensis possessed the highest levels of activity. A monomeric ca. 50-kDa phytase was purified to homogeneity from L. sanfranciscensis CB1 by three chromatographic steps. L. sanfranciscensis CB1 exhibited the highest hydrolysing activity on Na-phytate after reaching the stationary phase of growth (ca. 12 h). Cells cultivated in the presence of maltose and fructose showed an increase of the phytase activity of ca. 35% with respect to the other carbon sources used. The phytase was optimally active at pH 4.0 and 45 degreesC. The enzyme was strongly inhibited by 2 mM of phenylmethylsulfonyl fluoride (PMSF), and 2 mM Hg2+ and Fe2+. It had a pI of ca. 5.0. The substrate specificity was dependent on the type of phosphate ester; a very low activity was detected on alpha-D-glucose-1-phosphate and D-fructose-6- and 1,6-phosphate, while the highest hydrolysis was found towards adenosine-5'-tri-, di- and mono-phosphate. Compared to these substrates, the activity on Na-phytate was also relevant. The enzyme was thermo-stable after exposure to 70 degreesC for 30 min; the D value calculated at 80 degreesC was ca. 10 min. As shown by the Central Composite Design (CCD) applied to study the individual and interactive effects of pH, temperature and NaCl, acidic conditions and elevated temperatures were indispensable for the enzyme adaptation to high NaCl concentrations. L. sanfranciscensis CB1 cells or the correspondent cytoplasmic extract were used to ferment a sourdough for 8 h at 37 degreesC; a marked decreased (64-74%) of the Na-phytate concentration was found compared with the unstarted dough. The sourdough started with L. sanfranciscensis CB1 cells was re-used for several times and the phytase activity was maintained to a considerable level. (C) 2003 Elsevier Science B.V. All rights reserved.