Culture conditions affect the molecular weight properties of hyaluronic acid produced by Streptococcus zooepidemicus
Culture conditions affect the molecular weight properties of hyaluronic acid produced by Streptococcus zooepidemicus
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DOI：
10.1128/aem.63.7.2759-2764.1997
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发表时间：
1997-07-01
影响因子：
4.4
通讯作者：
Johns, MR
中科院分区：
文献类型：
--
作者：
Armstrong, DC;Johns, MR
在含有葡萄糖和酵母膏10g/L的复合培养基中，研究了5种培养条件对动物疫链球菌产生的透明质酸(HA)分子量特性的影响。在37℃厌氧条件下，培养pH(pH 6.3~8.0)和搅拌速度(300~1000rpm)对HA的重均分子量(M-w)没有影响。多分散度(P)在1.8~2.5之间，在较低温度下生长，或在曝气条件下，观察到高相对分子质量的聚合物，产量增加。然而，多分散性保持不受影响，在厌氧条件下，32℃和40℃时的平均M-w(基于葡萄糖耗竭4小时内采集的三个样品)分别为(2.40+/-0.10)×10(6)和(1.90+/-0.05)×10(6)，在1Vol/Vol/min曝气时产生HA，其平均M-w为(2.65+/-0.05)×10(6)，而在同等厌氧条件下为(2.10+/-0.10)×10(6)。初始葡萄糖浓度对聚合物特性的影响最为显著，当初始葡萄糖浓度从20 g/L增加到40 g/L时，在1-Vol/Vol/min曝气量下，平均M-w为(3.1+/-0.1)×10(6)。HA的分子量也具有时间依赖性，在培养早期检测到较小的链(M-w，ca，2.5×10(6))，在指数生长后期达到最大值(M-w，3.2×10(6))，在此条件下的平均多分散性也较大(2.7+/-0.1)，在此条件下进行的重复实验导致最低(40℃，厌氧)和最高(40克葡萄糖/升，1-Vol/Vol/min曝气)-M-w聚合物表现出良好的实验重复性。
The effect of five culture variables on the molecular weight properties of hyaluronic acid (HA) produced by Streptococcus zooepidemicus was studied in batch culture with a complex medium containing glucose and 10 g of yeast extract per liter, Neither the culture pH (pH 6.3 to 8.0) nor the agitation speed (300 to 1,000 rpm) affected the weight-average molecular weight (M-w) of HA under anaerobic conditions at 37 degrees C when 20 g of glucose per liter was used initially, M-w was in the narrow range of 1.5 x 10(6) to 2.3 x 10(6), and polydispersity (P) was between 1.8 and 2.5, When S. zooepidemicus was grown at lower temperatures or,vith aeration, higher-molecular-weight polymer and increased yields were observed. The polydispersity, however, remained unaffected, Anaerobically, the mean M-w (based on three samples taken within 4 h of glucose exhaustion) was (2.40 +/- 0.10) x 10(6) and (1.90 +/- 0.05) x 10(6) at 32 and 40 degrees C respectively, Aeration of the culture at 1 vol/vol/min produced HA with mean M-w of (2.65 +/- 0.05) x 10(6) compared with (2.10 +/- 0.10) x 10(6) under equivalent anaerobic conditions, The initial glucose concentration had the most pronounced effect on polymer characteristics, Increasing this concentration from 20 to 40 g/liter produced HA with mean M-w of (3.1 +/- 0.1) x 10(6) at 1-vol/vol/min aeration. The molecular weight of HA also exhibited time dependency, with smaller chains (M-w, ca, 2.5 x 10(6)) detected early in the culture time course, rising to a maximum (M-w, 3.2 x 10(6)) in the late exponential phase of growth, The mean polydispersity was also greater (2.7 +/- 0.1) under these conditions, Replicate experiments performed under conditions resulting in the lowest (40 degrees C, anaerobic) and highest (40 g of glucose per liter, 1-vol/vol/min aeration)-M-w polymer demonstrated excellent experimental reproducibility.