CI:Mor interactions in the lysogeny switches of TP901-1 and φ13 bacteriophages.

To structurally characterize in detail the interactions between the phage repressor (CI) and the antirepressor (Mor) in the lysis-lysogeny switches of two Gram-positive bacteriophages, the lactococcal TP901-1 and staphylococcal φ13. We use crystallographic structure determination, computational structural modeling, and analysis, as well as biochemical methods, to elucidate similarities and differences in the CI:Mor interactions for the two genetic switches. By comparing a newly determined and other available crystal structures for the N-terminal domain of CI (CI-NTD), we show that the CI interface involved in Mor binding undergoes structural changes upon binding in TP901-1.

Minimizing acetate formation from overflow metabolism in : comparison of genetic engineering strategies to improve robustness toward sugar gradients in large-scale fermentation processes.

, a well characterized workhorse in biotechnology, has been used to produce many recombinant proteins and metabolites, but have a major drawback in its tendency to revert to overflow metabolism. This phenomenon occurs when excess sugar triggers the production of mainly acetate under aerobic conditions, a detrimental by-product that reduces carbon efficiency, increases cell maintenance, and ultimately inhibits growth. Although this can be prevented by controlled feeding of the sugar carbon source to limit its availability, gradients in commercial-scale bioreactors can still induce it in otherwise carbon-limited cells.

The global transcriptomes of Salmonella enterica serovars Gallinarum, Dublin and Enteritidis in the avian host.

Salmonella enterica serovar Gallinarum causes Fowl Typhoid in poultry, and it is host specific to avian species. The reasons why S. Gallinarum is restricted to avians, and at the same time predominately cause systemic infections in these hosts, are unknown.

Impact of Elevated Levels of Dissolved CO on Performance and Proteome Response of an Industrial 2'-Fucosyllactose Producing Strain.

Large-scale microbial industrial fermentations have significantly higher absolute pressure and dissolved CO concentrations than otherwise comparable laboratory-scale processes. Yet the effect of increased dissolved CO (dCO) levels is rarely addressed in the literature. In the current work, we have investigated the impact of industrial levels of dCO (measured as the partial pressure of CO, pCO) in an -based fed-batch process producing the human milk oligosaccharide 2'-fucosyllactose (2'-FL).