Biology subjects

Rajewska, M.

Publications and source records attributed to Rajewska, M..

3 recordsLinked to original sources

bioRxiv2023

Soft rot pathogen Dickeya dadantii 3937 produces tailocins resembling the tails of Enterobacteria bacteriophage P2

Tailocins are nanomolecular machines with bactericidal activity. They are produced by bacteria to contribute to fitness in mixed communities, and hence, they play a critical role in their ecology in a variety of habitats. Here, we characterized the new tailocin produced by Dickeya dadantii strain 3937, a well-characterized member of plant pathogenic Soft Rot Pectobacteriaceae (SRP). Tailocins induced in D. dadantii were ca. 166 nm long tubes surrounded by contractive sheaths with baseplates having tail fibers at one end. A 22-kb genomic cluster involved in their synthesis and having high homology to the cluster coding for the tail of the Enterobacteriophage P2 was identified. The D. dadantii tailocins, termed dickeyocin P2D1 (phage P2-like dickeyocin 1), were resistant to inactivation by pH (3.5 - 12), temperature (4 - 50 {degrees}C), and elevated osmolarity (NaCl concentration: 0.01 - 1 M). P2D1 could kill a variety of different Dickeya spp. but not any strain of Pectobacterium spp. tested and were not toxic to Caenorhabditis elegans. TeaserTailocins are nanomolecular entities similar to syringes that are produced by various bacteria to fight other microorganisms present in the same environment.

microbiology↗

bioRxiv2023

Carbon source and surface type influence the early-stage biofilm formation by rhizosphere bacterium Pseudomonas donghuensis P482.

The competence of bacteria to colonize different environmental niches is often determined by their ability to form biofilms. This depends on both cellular and extracellular factors, such as individual characteristics of a strain, type of colonized surface (abiotic or biotic) or availability and source of nutrients. Pseudomonas donghuensis P482 efficiently colonizes rhizosphere of various plant hosts, but a connection between plant tissue colonization and biofilm formation has not been verified for P482 up to date. Here we demonstrate that the ability of P482 to form biofilm on abiotic surfaces and the structural characteristics of the biofilm are connected to the type of carbon source available to the bacteria, with glycerol promoting formation of developed biofilm at early stages. Also, the type of substratum, polystyrene or glass, significantly influences the ability of P482 to attach to the surface, possibly due to hydrophobic effects. Moreover, mutants in genes associated with motility or chemotaxis, synthesis of polysaccharides, and encoding proteases or regulatory factors, affected in biofilm formation on glass were fully capable of colonizing root tissue of both tomato and maize hosts. This indicates that the ability to form biofilm on distinct abiotic surfaces does not simply correlate with the efficient colonization of rhizosphere and formation of biofilm on plant tissue by P482.

microbiology↗

bioRxiv2023

Being spontaneous has its costs! Characterization of the spontaneous phage ΦD5-resistant mutants of Dickeya solani strain IPO 2222

Lytic bacteriophages able to infect and kill Dickeya spp. can be readily isolated from virtually all Dickeya spp.-containing environments, yet little is known about the selective pressure those viruses exert on their hosts. Here, we identified two spontaneous D. solani IPO 2222 mutants (0.8% of all obtained mutants), DsR34 and DsR207, resistant to infection caused by lytic phage vB_Dsol_D5 ({Phi}D5) that expressed a reduced ability to macerate potato tuber tissues compared to the wild-type, phage-susceptible D. solani IPO 2222 strain. Genome sequencing revealed that genes encoding: secretion protein HlyD (mutant DsR34) and elongation factor Tu (EF-Tu) (mutant DsR207) were altered in these strains. Both mutations impacted the proteomes of cells grown in both rich and minimal media, including the abundance of the cell envelope and transmembrane transport-associated proteins. Furthermore, features essential for the ecological success of these mutants in a plant environment, including their ability to use various carbon and nitrogen sources, produce plant cell wall degrading enzymes, ability to form biofilms, siderophore production, swimming and swarming motility and virulence in planta were assessed. Compared to the wild-type strain, D. solani strain IPO 2222, mutants DsR34 and DsR207 had a reduced ability to macerate chicory leaves and to colonize and cause symptoms in growing potato plants. The implications of the {Phi}D5 resistance on driving traits affecting the ecological performance of D. solani are discussed.

microbiology↗