Increased levels of ATP and NADH are associated with increased solvent production in continuous cultures of Clostridium acetobutylicum

1989 ◽  
Vol 30 (5) ◽  
Author(s):  
CharlesL. Meyer ◽  
EleftheriosT. Papoutsakis
Keyword(s):  
Clostridium Acetobutylicum ◽  
Continuous Cultures ◽  
Solvent Production

scholarly journals SpoIIE Regulates Sporulation but Does Not Directly Affect Solventogenesis in Clostridium acetobutylicum ATCC 824

2005 ◽  
Vol 187 (6) ◽  
pp. 1930-1936 ◽  
Author(s):  
Miles C. Scotcher ◽  
George N. Bennett
Keyword(s):  
Gene Expression ◽  
Antisense Rna ◽  
Clostridium Acetobutylicum ◽  
Promoter Activity ◽  
Normal Growth ◽  
Wild Type ◽  
Solvent Production ◽  
Intact Copy ◽  
Clostridium Acetobutylicum Atcc 824 ◽  
Production Strain

ABSTRACT Using gene expression reporter vectors, we examined the activity of the spoIIE promoter in wild-type and spo0A-deleted strains of Clostridium acetobutylicum ATCC 824. In wild-type cells, the spoIIE promoter is active in a transient manner during late solventogenesis, but in strain SKO1, where the sporulation initiator spo0A is disrupted, no spoIIE promoter activity is detectable at any stage of growth. Strains 824(pMSpo) and 824(pASspo) were created to overexpress spoIIE and to decrease spoIIE expression via antisense RNA targeted against spoIIE, respectively. Some cultures of strains 824(pMSpo) degenerated during fermentations by losing the pSOL1 megaplasmid and hence did not produce the solvents ethanol, acetone, and butanol. The frequent degeneration event was shown to require an intact copy of spoIIE. Nondegenerate cultures of 824(pMSpo) exhibited normal growth and solvent production. Strain 824(pASspo) exhibited prolonged solventogenesis characterized by increased production of ethanol (225%), acetone (43%), and butanol (110%). Sporulation in strains harboring pASspo was significantly delayed, with sporulating cells exhibiting altered morphology. These results suggest that SpoIIE has no direct effect on the control of solventogenesis and that the changes in solvent production in spoIIE-downregulated cells are mediated by effects on the cell during sporulation.

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