Department of Food and Fermentation Science, Beppu University, Kitaishigaki 82, Beppu, Oita 874-8501, Japan.
J Biosci Bioeng. 2011 Apr;111(4):414-9. doi: 10.1016/j.jbiosc.2010.12.009. Epub 2011 Jan 13.
Respiration-deficient mutant (RDM) strains of Zymomonas mobilis were isolated from antibiotic-resistant mutants. These RDM strains showed various degrees of respiratory deficiency. All RDM strains exhibited much higher ethanol fermentation capacity than the wild-type strain under aerobic conditions. The strains also gained thermotolerance and exhibited greater ethanol production at high temperature (39°C), under both non-aerobic and aerobic conditions, compared with the wild-type strain. Microarray and subsequent quantitative PCR analyses suggest that enhanced gene expression involved in the metabolism of glucose to ethanol resulted in the high ethanol production of RDM strains under aerobic growth conditions. Reduction of intracellular oxidative stress may also result in improved ethanol fermentation by RDM strains at high temperatures.
呼吸缺陷突变株（RDM）是从抗生素抗性突变株中分离得到的。这些 RDM 菌株表现出不同程度的呼吸缺陷。所有 RDM 菌株在有氧条件下比野生型菌株表现出更高的乙醇发酵能力。与野生型菌株相比，这些菌株在高温（39°C）下，无论是在无氧还是有氧条件下，都表现出更好的耐热性和更高的乙醇产量。微阵列和随后的定量 PCR 分析表明，增强的基因表达涉及葡萄糖到乙醇的代谢，导致 RDM 菌株在有氧生长条件下产生高乙醇。减少细胞内氧化应激也可能导致 RDM 菌株在高温下改善乙醇发酵。
