Inhibition of spontaneous induction of lambdoid prophages in Escherichia colicultures: simple procedures with possible biotechnological applications

Abstract

Background: Infections of bacterial cultures by bacteriophages are serious problems in biotechnological laboratories. Apart from such infections, prophage induction in the host cells may also be dangerous. Escherichia coli is a commonly used host in biotechnological production, and many laboratory strains of this bacterium harbour lambdoid prophages. These prophages may be induced under certain conditions leading to phage lytic development. This is fatal for further cultivations as relatively low, though still significant, numbers of phages may be overlooked. Thus, subsequent cultures of non-lysogenic strains may be infected and destroyed by such phage.

Modular, Multi-Input Transcriptional Logic Gating with Orthogonal LacI/GalR Family Chimeras

“… 20 , 23 Similar studies have been used to alter the promoter specificity of T7 RNA polymerase. 5 , 24 − 26 This type of mutation is particularly powerful, as it allows for the coexpression of similar regulatory proteins that target orthogonal pathways. In addition, because the overall function of the transcription factors remains unchanged, they can be easily implemented within large scale circuits with minimal retuning of regulatory strengths.…”

Phage–host interactions during pseudolysogeny

“…Similarly, another advantage of behaving as a pseudolysogen (instead of a real lysogen) might be the ability of the temperate phage to prevent being entirely dependent on the host’s DNA damage response to escape from hibernation. Indeed, although spontaneous induction of prophages does occur in lysogens once every 10 5 –10 8 cells, 19 bacterial numbers are often lower in environmental settings, indicating that spontaneous prophage induction would not always provide an adequate escape route.…”

Impact of Spontaneous Prophage Induction on the Fitness of Bacterial Populations and Host-Microbe Interactions

“…Different parameters were shown to influence the spontaneous induction of phage expression in E. coli, such as overexpression of CI and deletion of recA, thus decreasing the growth rate, or exchanging glucose with glycerol, thus affecting cyclic AMP (cAMP) levels, which have an influence on the SOS response as well (22). In their recent study, Little and Michalowski found that the intrinsic switching rate of E. coli lambda lysogens is almost undetectably low (Ͻ10 Ϫ8 /generation) in a recA mutant background (21).…”