Overexpression of SMB_G1518-1519 influenced the motilities of <i>C. acetobutylicum</i>.

<p>Overexpression of SMB_G1518-1519 influenced the motilities of <i>C. acetobutylicum</i>.</p

Growth profiles for 1731(pIMP1), 1731(p1518-1519) and DDC14(p1518-1519)

<p>. A) Growth profiles under normal condition. B) Growth profiles under 1% butanol stress.</p

Growth profiles for DSM 1731 and its deletion or disruption mutants.

<p>A) Growth profiles under normal condition. B) Growth profiles under 1% butanol stress.</p

Functional classification of different proteins.

<p>Note: The protein levels in DSM 1731 and 1731(pIMP1) under normal condition were used as the basis for comparison, respectively. The upregulation of fatty acid synthesis enzymes (acyl-ACP (acyl-carrier-protein) thioesterase and 3-oxoacyl-ACP synthase I) is more likely to be an indicator reflecting cell damage from butanol stress. The upregulation of HSPs is regarded as a common response to butanol stress, but not related with the function of SMB_G1518-1519.</p

The analysis of main fermentation products after 50% of growth inhibition degree was achieved.

<p>A) The analysis of main fermentation products after DSM 1731 and its deletion mutant DDC14 were treated by butanol for 6 h. B) The analysis of main fermentation products after the plasmid control strain 1731(pIMP1) and overexpression strain 1731(p1518-1519) were treated by butanol for 18 h.</p

Close-up views of the protein spots with differential expression.

<p>I, DSM 1731; II, DDC14; III, 1731(pIMP1); IV, 1731(p1518-1519). A) The differentially expressed PFOR in DSM1731 and DDC14. B) The differentially expressed PFOR in 731(pIMP1) and 1731(p1518-1519). C) The differentially expressed Hag in DSM1731 and DDC14. D) The differentially expressed Hag in 731(pIMP1) and 1731(p1518-1519).</p

Diagram of growth inhibition.

<p>A), DSM 1731 and its deletion or disruption mutants DDC14, DC93 and DC94. B) 1731(pIMP1) and 1731(p1518-1519). The growth inhibition level was determined by using the following formula: [(<i>A</i>600)+BuOH/<i>A</i>600]×100, <i>A</i>600+BuOH is referred to cell density in the presence of butanol.</p

Bacterial strains, plasmids and primers.

<p><b>Abbreviations</b>: Amp^r, ampicillin resistance; Cm^r, chloramphenicol resistance; Tet^r, tetracycline resistance; <i>Φ3t1</i>, Φ3t1 methyltransferase gene of <i>Bacillus subtilis</i> phage Φ3t1. DSMZ, German Collection of Microorganisms and Cell Cultures, Braunschweig, Germany.</p

The strategy for target gene deletion in clostridial genome.

<p>The strategy for target gene deletion in clostridial genome.</p

Construction of CAC1493-1494 deletion mutants.

<p><b>A</b>. Identification of an insertion mutant by PCR using primers Cac1494B and Pex1494E flanking the target site; <b>B</b>. Identification of the deletion mutants by PCR using primers P1492-5s and Pex1494E; <b>C</b>. Schematic show of operon CAC1493-1494 and the expected deleted operon CAC1493-1494 in the chromosome; <b>D</b>. Southern blot analysis of CAC1493-1494 deletion using CAC34 probe.</p