Structured model-based analysis and control of the hyaluronic acid fermentation by Streptococcus zooepidemicus:: Physiological implications of glucose and complex nitrogen-limited growth
Structured model-based analysis and control of the hyaluronic acid fermentation by Streptococcus zooepidemicus:: Physiological implications of glucose and complex nitrogen-limited growth
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DOI：
10.1021/bp990078n
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发表时间：
1999-09-01
影响因子：
2.9
通讯作者：
Johns, MR
中科院分区：
文献类型：
--
作者：
Cooney, MJ;Goh, LT;Johns, MR
采用结构化二室模型对动物链球菌在葡萄糖复合培养基中厌氧和通气条件下的透明质酸发酵过程进行了描述。两室模型框架被认为是强大的，易于适应，并能够预测瞬时消耗的底物和产品的形成。好氧培养产生了实质上更高浓度的HA比相当的厌氧培养，但生物量特定的生长速率和产量较低，由于过氧化氢的部分抑制。然后利用该模型研究了葡萄糖和复合氮限制生长对透明质酸（HA）厌氧生产的生理影响。葡萄糖限制生长与模型预测一致，尽管HA分子量低于预期，但绝对HA浓度仍不受影响。对于低于0.1 h（-1）的生长速率，也观察到异型发酵生长。尽管比生长速率相对较低，但生物量产量较高;然而，代谢转变并没有显着影响HA生产。对于复杂的氮限制的增长，diauxic增长的复杂的氮（酵母提取物）进行了观察和解释，通过分区的氮组分的阵列成两个不同的，但均匀的池。虽然发现氮限制生长增加HA对生物质的产率，但与在葡萄糖限制生长下观察到的一样，所得HA分子量降低。
The hyaluronic acid (HA) fermentation by Streptococcus zooepidemicus under anaerobic and aerated conditions in glucose-complex media was well described by a structured, two-compartment model. The two-compartment model framework was found to be robust, easily adaptable, and able to predict the transient consumption of substrates and formation of products. Aerobic culture produced a substantially higher concentration of HA than an equivalent anaerobic culture; however biomass-specific growth rate and yield were lower due to partial inhibition by hydrogen peroxide. The model was then used to investigate the physiological implications of glucose and complex-nitrogen-limited growth on the anaerobic production of hyaluronic acid (HA). Glucose-limited growth agreed well with model predictions, although the HA molecular weight was lower than expected even though the absolute HA concentration remained unaffected. Heterofermentative growth was also observed for growth rates below 0.1 h(-1). Despite a comparatively lower specific growth rate, the biomass yield was higher; however the metabolic shift did not significantly affect HA production. For complex-nitrogen-limited growth, diauxic growth on complex-nitrogen (yeast extract) was observed and explained by partitioning the array of nitrogen components into two distinct but homogeneous pools. While nitrogen-limited growth was found to increase the HA to biomass yield, Like that observed under glucose-limited growth, the resulting HA molecular weight was reduced.