A rhamnose-rich O-antigen of MP20 is required for symbiosis with .

a β-proteobacterium, forms a nitrogen-fixing symbiosis with many species of the large legume genus as well as with common bean ( L.). are considered to have evolved nodulation independently from the well-studied α-proteobacteria symbionts of legumes.

The multifaceted role of c-di-AMP signaling in the regulation of lipopolysaccharide structure and function.

Background: This study unveils the intricate functional association between cyclic di-3',5'-adenylic acid (c-di-AMP) signaling, cellular bioenergetics, and the regulation of lipopolysaccharide (LPS) profile in , a Gram-negative obligate anaerobe considered as a keystone pathogen involved in the pathogenesis of chronic periodontitis. Previous research has identified variations in LPS profile as a major virulence factor, yet the underlying mechanism of its modulation has remained elusive.

Methods: We employed a comprehensive methodological approach, combining two mutants exhibiting varying levels of c-di-AMP compared to the wild type, alongside an optimized analytical methodology that combines conventional mass spectrometry techniques with a novel approach known as FLAT.

Rhizobial Secretion of Truncated Exopolysaccharides Severely Impairs the Symbiosis.

The symbiosis between R7A and Gifu is an important model system for investigating the role of bacterial exopolysaccharides (EPS) in plant-microbe interactions. Previously, we showed that R7A mutants that are affected at an early stage of EPS synthesis and in lipopolysaccharide (LPS) synthesis induce effective nodules on Gifu after a delay, whereas mutants affected in the biosynthesis of the EPS side chain induce small uninfected nodule primordia and are impaired in infection. The presence of a halo around the mutant when grown on Calcofluor-containing media suggested the mutant secreted a truncated version of R7A EPS.

A phage tail-like bacteriocin suppresses competitors in metapopulations of pathogenic bacteria.

Bacteria can repurpose their own bacteriophage viruses (phage) to kill competing bacteria. Phage-derived elements are frequently strain specific in their killing activity, although there is limited evidence that this specificity drives bacterial population dynamics. Here, we identified intact phage and their derived elements in a metapopulation of wild plant-associated genomes.

Low-level resource partitioning supports coexistence among functionally redundant bacteria during successional dynamics.

Members of microbial communities can substantially overlap in substrate use. However, what enables functionally redundant microorganisms to coassemble or even stably coexist remains poorly understood. Here, we show that during unstable successional dynamics on complex, natural organic matter, functionally redundant bacteria can coexist by partitioning low-concentration substrates even though they compete for one simple, dominant substrate.