Expression analysis of a respiration-deficient mutant of Zymomonas mobilis

Investigation of whole-genome gene expression level changes in RDM-4 strain of Zymomonas mobilis respiration-deficient mutant compared to the wild-type strain. The mutant strains were isolated from the antibiotics-resistant mutants of Z. mobilis ZM6. The RDM strains exhibited much higher ethanol fermentation abilities than the wild-type strain under aerobic conditions. The strains also gained thermotolerance and exhibited higher ethanol productivities at high temperature (39 ºC) under both non-aerobic and aerobic conditions compared with the wild-type strain. To evaluate the mechanisms of aerobic fermentation and thermotolerance of the RDM strain, we performed the microarray experiments. A four-chip study using total RNA recovered from the shaking cultures of wt and RDM-4 strains grown at 30ºC, a non-aerobic culture of wt strain grown at 30ºC, and a non-aerobic culture of RDM-4 strain grown at 38ºC. Each chip measures the expression level of 1,998 genes from Z. mobilis.