Effect of simulated microgravity and shear stress on microcin B17 production by Escherichia coli and on its excretion into the medium
Effect of simulated microgravity and shear stress on microcin B17 production by Escherichia coli and on its excretion into the medium
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DOI：
10.1128/aem.63.10.4090-4092.1997
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发表时间：
1997-10-01
影响因子：
4.4
通讯作者：
Demain, AL
中科院分区：
文献类型：
--
作者：
Fang, A;Pierson, DL;Demain, AL
在模拟微重力条件下，大肠杆菌ZK650产生的抗菌多肽MICB17(MccB17)受到抑制。MccB17的积累位置被发现是不同的，取决于生物体是在摇篮中生长还是在为建立模拟微重力环境而设计的旋转生物反应器中生长。在烧瓶中，积累是细胞的，但在反应器中，几乎所有的微CIN都在介质中，从细胞位置到细胞外位置的变化显然不是重力的函数，因为这些生物反应器中发生了胞外产生，无论它们是在模拟微重力模式下操作还是在正常重力模式下操作，更有可能的是，排泄是由于生物反应器中剪切力的程度要低得多，即使在生物反应器中50毫升的培养体积中添加一个玻璃微珠，就可以产生足够的剪切力，将MccB17的积累位置从培养基转到细胞中。
Production of the antibacterial polypeptide microcin B17 (MccB17) by Escherichia coli ZK650 was inhibited by simulated microgravity. The site of MccB17 accumulation was found to be different, depending on whether the organism was grown in shaking Basks or in rotating bioreactors designed to establish a simulated microgravity environment, In flasks, the accumulation was cellular, but in the reactors, virtually all the microcin was found in the medium, The change from a cellular site to an extracellular one was apparently not a function of gravity, since extracellular production occurred in these bioreactors, irrespective of whether they were operated in the simulated microgravity or normal gravity mode, More probably, excretion is due to the much lower degree of shear stress in the bioreactors, Addition of even a single glass bead to the 50-ml medium volume in the bioreactor created enough shear to change the site of MccB17 accumulation from the medium to the cells.