Antibiotic tolerance in environmentally stressed : physical barriers and induction of a viable but nonculturable state.

Bacterial communities exposed to rapid changes in their habitat encounter different forms of stress. Fluctuating conditions of the microenvironment drive microorganisms to develop several stress responses to sustain growth and division, like altering gene expression and changing the cell's physiology. It is commonly known that these protection systems may give rise to differently adapted subpopulations and indirectly impact bacterial susceptibility to antimicrobials.

Cell-to-cell non-conjugative plasmid transfer between Bacillus subtilis and lactic acid bacteria.

Bacillus subtilis is a soil-dwelling bacterium that can interact with a plethora of other microorganisms in its natural habitat. Due to the versatile interactions and its ability to form nanotubes, i.e.

Transcriptome analysis and prediction of the metabolic state of stress-induced viable but non-culturable Bacillus subtilis cells.

Many bacteria adapt their physiology and enter the viable but non-culturable state to survive prolonged exposure to adverse environmental conditions. The VBNC cells maintain active metabolism, membrane integrity and gene transcription. However, they lose the ability to form colonies on a conventional culture media.

Stress-induced activation of the proline biosynthetic pathway in Bacillus subtilis: a population-wide and single-cell study of the osmotically controlled proHJ promoter.

Bacillus subtilis, in its natural habitat, is regularly exposed to rapid changes in the osmolarity of its surrounding. As its primary survival strategy, it accumulates large amounts of the compatible solute proline by activating the de novo proline biosynthesis pathway and exploiting the glutamate pools. This osmotically-induced biosynthesis requires activation of a SigA-type promoter that drives the expression of the proHJ operon.

Diversity of bet-hedging strategies in microbial communities-Recent cases and insights.

Microbial communities are continuously exposed to unpredictable changes in their environment. To thrive in such dynamic habitats, microorganisms have developed the ability to readily switch phenotypes, resulting in a number of differently adapted subpopulations expressing various traits. In evolutionary biology, a particular case of phenotypic heterogeneity that evolved in an unpredictably changing environment has been defined as bet-hedging.

Renaissance of traditional DNA transfer strategies for improvement of industrial lactic acid bacteria.

The ever-expanding genomic insight in natural diversity of lactic acid bacteria (LAB) has revived the industrial interest in traditional and natural genetic mobilization methodologies. Here, we review recent advances in horizontal gene transfer processes in LAB, including natural competence, conjugation, and phage transduction. In addition, we envision the possibilities for industrial strain improvement arising from the recent discoveries of molecular exchanges between bacteria through nanotubes and extracellular vesicles, as well as the constantly expanding genome editing possibilities using the CRISPR-Cas technology.