Biology subjects

Uzi-Gavrilov, S.

Publications and source records attributed to Uzi-Gavrilov, S..

3 recordsLinked to original sources

bioRxiv2026

A phage communication peptide alters Bacillus subtilis colony development and promotes sporulation

Temperate Bacillus phages use arbitrium peptides to coordinate lysis-lysogeny decisions, but whether the mature communication peptide can be sensed directly by Bacillus subtilis and affect its physiology and behavior is unknown. Here we show that the {varphi}3T arbitrium peptide SAIRGA elicits a sequence- and stereochemistry-dependent response in Bacillus subtilis that is strongly expressed in surface-grown colony biofilms but is not accompanied by comparable changes in planktonic growth or static-liquid pellicle morphology. The response persists in the absence of AimR, the canonical arbitrium receptor. Within colonies, SAIRGA alters spatial PtapA activity and increases heat-resistant spore formation without increasing total viable cell yield. Untargeted metabolomics reveals broad dose-dependent remodeling that tracks peptide activity, while program-level proteomics independently converges on late-sporulation and mature-spore-associated states. This study highlights how a phage-derived peptide may act as a signal, enabling the host to pivot toward a survival-focused developmental state.

microbiology↗

bioRxiv2026

Diet-derived peptides mediate the effects of dietary protein source on gastrointestinal health

Plant-based diets support gastrointestinal (GI) health while animal-based diets can disrupt gut homeostasis. Although multiple aspects of these diet types are believed to confer their respective effects, the role of their protein component is less well understood. Here, we conducted a randomized crossover-controlled feeding trial wherein healthy subjects consumed 70% of their daily protein intake in the form of pea protein (PP) or egg white protein (EWP) isolate (NCT05619939). Individuals who consumed EWP reported increased GI symptoms and exhibited elevated intestinal permeability. In contrast, these endpoints did not change following PP consumption. Fecal analysis showed increased diet-derived peptides only following EWP consumption, which was associated with resistance of EWP isolate to degradation by digestive enzymes in vitro. Metagenomic, metaproteomic and metabolomic analyses of stool after the EWP-based diet showed reduced abundance of multiple gut-protective bacterial species and increased bacterial amino acid utilization compared to samples following the PP-based diet. Dietary peptides in the gut luminal content of EWP-fed subjects reduced metabolic function of intestinal epithelial cell in culture. Providing an amino acid-based diet mimicking EWP composition to mice prevented colonic accumulation of diet-derived proteins and GI dysfunction associated with EWP diet consumption. Collectively, these findings demonstrate that dietary protein source is a key mediator of GI function, revealing a modifiable lifestyle factor that impacts human health.

physiology↗

bioRxiv2025

Chemical Crosstalk between the Common Soil Bacteria Pseudomonas chlororaphis and Bacillus subtilis

Chemical conversations between soil inhabitants are of tremendous importance to the health of many ecosystems, and at the same time detailed molecular knowledge underlying these conversations is surprisingly scarce. One of the major bacterial genera inhabiting the rhizosphere is Pseudomonas, of which most species are known to produce phenazines, which carry antibiotic properties. Pseudomonas chlororaphis, a common rhizosphere dwelling species with plant growth-promoting traits, produces phenazine-1-carboxamide (PCN). This study examines how the production of PCN by Pseudomonas affects another common species in soil that it often encounters, namely Bacillus subtilis. When both species were cultured at close distance, distinct and visible changes in colony morphologies were observed with-out changes in growth rates. Interestingly, a clear transformation occurred in the morphology of B. subtilis colonies in the presence of supplemented PCN, indicating the role of phenazines in affecting colony morphology. In addition, untargeted metabolomics analyses showed a decrease in the production of plipastatin and surfactin by B. subtilis in the presence of P. chlororaphis. Our results indicate that PCN induces changes in morphology and signaling of B. subtilis without significantly affecting its growth. We hypothesize that P. chlororaphis and B. subtilis sense one another and act to conserve energy while avoiding competition.

microbiology↗