Pulcherrimin formation controls growth arrest of theBacillus subtilisbiofilm

Abstract

Significance:Understanding the processes that underpin the mechanism of biofilm formation, dispersal, and inhibition are critical to allow exploitation and to understand how microbes thrive in the environment. Here, we reveal that the formation of an extracellular iron chelate restricts the expansion of a biofilm. The countering benefit to self-restriction of growth is protection of an environmental niche. These findings highlight the complex options and outcomes that bacteria need to balance in order to modulate their local environment to maximise colonisation, and therefore survival.

Machine learning uncovers independently regulated modules in the Bacillus subtilis transcriptome

“…We also see PchR activation in late stage biofilm, glucose exhaustion, and phosphate starvation experiments. These results agree with a recent study that found pulcherrimin to be an important intercellular signal for the stationary phase that also helps exclude competing bacteria from established biofilms 38 . The regulation mechanisms of i-modulons like this one can be the subject of future research.…”

Biofilm formation onto starch fibres by Bacillus subtilis governs its successful adaptation to chickpea milk

“…Intriguingly, the sinI mutant cells refrained from producing the pigment. B. subtilis provides an assorted spectrum of pigments that may or may not be correlated with biofilm formation (Arnaouteli et al ., 2019). Pulcherrimin is one such pigment that B. subtilis produces during biofilm mode of growth (Arnaouteli et al ., 2019).…”

“…B. subtilis provides an assorted spectrum of pigments that may or may not be correlated with biofilm formation (Arnaouteli et al ., 2019). Pulcherrimin is one such pigment that B. subtilis produces during biofilm mode of growth (Arnaouteli et al ., 2019). Pigment production by Bacilli is also recognized as a survival tactics exhibited by the vegetative cells against external stressors.…”

“…Since the biochemical traits of pulcherrimin were close to the observed pigment (Fig. S5), and that the pulcherrimin biosynthesis pathway in B. subtilis was well established (Arnaouteli et al ., 2019), we first checked this pathway using pulcherrimin‐deficient mutants. The mutants lacked the enzymes, YvmC (Cyclo( l ‐leucyl‐ l ‐leucyl) synthase) and CypX (Pulcherriminic acid synthase), that convert two tRNA‐ molecules of leucine to pulcherriminic acid (PA), which in turn binds to iron (Fe 3+ ) to form pulcherrimin.…”

Comment on “Rivalry in Bacillus subtilis colonies: enemy or family?”

“…10 and 11). In particular, in Arnaouteli et al, 2019 13 we demonstrated that proximal sibling colonies can have a marked effect on the growth dynamics of each colony where demarcation or abuttal was determined by nutrient limitation (see e.g. Fig.…”