期刊
BIOPROCESS AND BIOSYSTEMS ENGINEERING
卷 36, 期 7, 页码 911-925出版社
SPRINGER
DOI: 10.1007/s00449-012-0825-y
关键词
Mechanical stress; Shear stress; Shear rate; Cell damage; Xanthan gum production; Xanthomonas campestris growth; Oxygen transfer rate; Oxygen uptake rate
资金
- MICINN [CTQ2007-60919]
- BSCH-UCM [GR35/10-A (910134)]
The specific growth and the xanthan production rates by the bacterium Xanthomonas campestris under different shear levels in shake flasks and in a stirred and sparged tank bioreactor have been studied. The shake flask has been used as a reference for studying the shear effects. An effectiveness factor expressed by the ratio of the observed growth rate and the growth rate without oxygen limitation or cell damage was calculated in both modes of cultures. It was observed that the effectiveness factor was strongly dependent on the operational conditions. A strong oxygen transfer limitation at low stirring rates, indicated by a 54 % decrease in the effectiveness factor was observed. In contrast, at higher stirrer speed, cell damage was caused by hydrodynamic stress in the turbulent bulk of the broth, yielding again a decrease in the effectiveness factor values for stirrer speeds higher than 500 rpm. Cell morphological changes were also observed depending on the agitation conditions, differences in morphology being evident at high shear stress.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据