Expression of foreign proteins in E. coli is normally inhibited by exogenous production of acetate. To overcomethis problem, various strategies have been proposed and tested to reduce the extent of acetate accumulation.Although these strategies can improve the outcome, the implementation of their proposed techniquesis not practical. Because to achieve optimal results, it requi...

materials and methods: in order to achieve this, recombinant plasmid harboring antisense sequences targeting both of pta and acka was assembled, after transfecting to the cells, its effects on the cell growth and acetate accumulation in the minimal media was assessed and compared with the control, the plasmid without antisense cassette, in presence and absence of iptg in escherichia coli bl21 (...

Clostridium ljungdahlii is a strictly anaerobic acetogene known for its ability to ferment a wide variety of substrates to ethanol and acetate. This bacterium presents a complex anaerobic metabolism including the acetogenic and solventogenic phases. In this study, the effect of various carbon sources on triggering the metabolic shift toward solventogenesis was considered. The bacterium was grow...

chamaemelum nobile (asteraceae) commonly known as 'roman chamomile' is a medicinal plant used for numerous diseases in traditional medicine, although its anticancer activity is unknown. the present study was carried out to investigate the anticancer as well as apoptotic activity of ethyl acetate fraction of c. nobile on different cancerous cell lines. the cells were treated with varyi...

The pathway of propionate conversion in a syntrophic coculture of Smithella propionica and Methanospirillum hungatei JF1 was investigated by (13)C-NMR spectroscopy. Cocultures produced acetate and butyrate from propionate. [3-(13)C]propionate was converted to [2-(13)C]acetate, with no [1-(13)C]acetate formed. Butyrate from [3-(13)C]propionate was labeled at the C2 and C4 positions in a ratio of...

The pathways of short-chain fatty acid (SCFA; acetate, propionate, and butyrate) formation from glucose were determined for the human fecal microbial communities of two subjects. The pathways were identified by radioisotope analysis of the SCFA and CO2 obtained after incubation of fecal suspensions with glucose under 20% CO2 with [1-14C]glucose, [3,4-14C]glucose, or 14CO2. Acetate was chemicall...

Escherichia coli excretes acetate upon growth on fermentable sugars, but the regulation of this production remains elusive. Acetate excretion on excess glucose is thought to be an irreversible process. However, dynamic 13C-metabolic flux analysis revealed a strong bidirectional exchange of acetate between E. coli and its environment. The Pta-AckA pathway was found to be central for both flux di...