Guo Xiaofeng, Lidstrom Mary E
Department of Chemical Engineering, University of Washington, Box 352180, Seattle, WA 98195, USA.
Arch Microbiol. 2006 Aug;186(2):139-49. doi: 10.1007/s00203-006-0131-7. Epub 2006 Jul 5.
Chemostat cultures of Methylobacterium extorquens AM1 grown on methanol or succinate at a range of dilution rates were compared to batch cultures in terms of enzyme levels, poly-beta-hydroxybutyrate content, and intracellular concentrations of adenine and pyridine nucleotides. In both chemostat and batch cultures, enzymes specific to C1 metabolism were up-regulated during growth on methanol and down-regulated during growth on succinate, polyhydroxybutyrate levels were higher on succinate, intracellular ATP levels and the energy charge were higher during growth on methanol, while the pools of reducing equivalents were higher during growth on succinate. For most of the tested parameters, little alteration occurred in response to growth rate. Overall, we conclude that the chemostat cultivation conditions developed in this study roughly mimic the growth in batch cultures, but provide a better control over the culturing conditions and a better data reproducibility, which are important for integrative functional studies. This study provides baseline data for future work using chemostat cultures, defining key similarities and differences in the physiology compared to existing batch culture data.
将在一系列稀释率下以甲醇或琥珀酸盐为底物生长的嗜甲基菌AM1的恒化器培养物与分批培养物在酶水平、聚β-羟基丁酸含量以及腺嘌呤和吡啶核苷酸的细胞内浓度方面进行了比较。在恒化器培养和分批培养中，C1代谢特异性酶在以甲醇为底物生长期间上调，而在以琥珀酸盐为底物生长期间下调；聚羟基丁酸水平在以琥珀酸盐为底物时更高；细胞内ATP水平和能荷在以甲醇为底物生长期间更高，而还原当量库在以琥珀酸盐为底物生长期间更高。对于大多数测试参数，响应生长速率几乎没有发生变化。总体而言，我们得出结论，本研究中开发的恒化器培养条件大致模拟了分批培养中的生长，但能更好地控制培养条件并具有更好的数据重现性，这对于综合功能研究很重要。本研究为未来使用恒化器培养的工作提供了基线数据，确定了与现有分批培养数据相比生理学上的关键异同点。
