Niacinamide Antimicrobial Efficacy and Its Mode of Action via Microbial Cell Cycle Arrest.

Niacinamide is a versatile compound widely used in the personal care industry for its ample skin benefits. As a precursor to nicotinamide adenine dinucleotide (NAD+), essential for ATP production and a substrate for poly-ADP-ribose polymerase-1 (PARP-1), studies have highlighted its roles in DNA repair, cellular stress mechanisms, and anti-aging benefits. Niacinamide was also studied for its antimicrobial activity, particularly in the context of host-infection via host immune response, yet its direct antimicrobial activity and the mechanisms of action remain unclear.

Dormant bacterial spores encrypt a long-lasting transcriptional program to be executed during revival.

Sporulating bacteria can retreat into long-lasting dormant spores that preserve the capacity to germinate when propitious. However, how the revival transcriptional program is memorized for years remains elusive. We revealed that in dormant spores, core RNA polymerase (RNAP) resides in a central chromosomal domain, where it remains bound to a subset of intergenic promoter regions.

Glutamate catabolism during sporulation determines the success of the future spore germination.

Bacterial spores can preserve cellular dormancy for years, but still hold the remarkable ability to revive and recommence life. This cellular awakening begins with a rapid and irreversible event termed germination; however, the metabolic determinants required for its success have been hardly explored. Here, we show that at the onset of the process of sporulation, the metabolic enzyme RocG catabolizes glutamate, facilitating ATP production in the spore progenitor cell, and subsequently influencing the eventual spore ATP reservoir.

Reviving the view: evidence that macromolecule synthesis fuels bacterial spore germination.

The Gram positive bacterium and its relatives are capable of forming a durable dormant long-lasting spore. Although spores can remain dormant for years, they possess the remarkable capacity to rapidly resume life and convert into actively growing cells. This cellular transition initiates with a most enigmatic irreversible event, termed germination, lasting only for a few minutes.

Arginine dephosphorylation propels spore germination in bacteria.

Bacterial spores can remain dormant for years but possess the remarkable ability to germinate, within minutes, once nutrients become available. However, it still remains elusive how such instant awakening of cellular machineries is achieved. Utilizing as a model, we show that YwlE arginine (Arg) phosphatase is crucial for spore germination.

Deficiency in Lipoteichoic Acid Synthesis Causes a Failure in Executing the Colony Developmental Program in .

Colonies are an abundant form of bacterial multicellularity; however, relatively little is known about the initial stages of their construction. We have previously described that colony development of the soil bacterium is a highly ordered process, typically initiating with the formation of extending cell chains arranged in a Y shape structure. Furthermore, we demonstrated that Y arm extension is a key for defining the size of the future colony.

Interspecies nutrient extraction and toxin delivery between bacteria.

Bacteria have developed various mechanisms by which they sense, interact, and kill other bacteria, in an attempt to outcompete one another and survive. Here we show that Bacillus subtilis can kill and prey on Bacillus megaterium. We find that Bacillus subtilis rapidly inhibits Bacillus megaterium growth by delivering the tRNase toxin WapA.

The molecular timeline of a reviving bacterial spore.

The bacterial spore can rapidly convert from a dormant to a fully active cell. Here we study this remarkable cellular transition in Bacillus subtilis and reveal the identity of the newly synthesized proteins throughout spore revival. Our analysis uncovers a highly ordered developmental program that correlates with the spore morphological changes and reveals the spatial and temporal molecular events fundamental to reconstruct a cell.

Molecular kinetics of reviving bacterial spores.

Bacterial spores can remain dormant for years, yet they possess a remarkable potential to rapidly resume a vegetative life form. Here, we identified a distinct phase at the onset of spore outgrowth, designated the ripening period. This transition phase is exploited by the germinating spore for molecular reorganization toward elongation and subsequent cell division.

Dynamic expression of the translational machinery during Bacillus subtilis life cycle at a single cell level.

The ability of bacteria to responsively regulate the expression of translation components is crucial for rapid adaptation to fluctuating environments. Utilizing Bacillus subtilis (B. subtilis) as a model organism, we followed the dynamics of the translational machinery at a single cell resolution during growth and differentiation.