Rhizobial galactoglucan determines the predatory pattern of Myxococcus xanthus and protects Sinorhizobium meliloti from predation. (28th April 2014)

• Record Type: Journal Article
• Authors: Pérez, Juana; Jiménez‐Zurdo, José I.; Martínez‐Abarca, Francisco; Millán, Vicenta; Shimkets, Lawrence J.; Muñoz‐Dorado, José
• Is Part Of: Environmental microbiology. Volume 16:Number 7(2014:Jul.)
• Page Start: 2341
• Page End: 2350
• Publication Date: 2014-04-28
• Subjects: Microbial ecology -- Periodicals; Environmental Microbiology -- Periodicals; 579.17
• DOI: 10.1111/1462-2920.12477
• Languages: English
• ISSNs: 1462-2912

Abstract

<abstract abstract-type="main"> <title>Summary</title> <p> <italic>M</italic> <italic>yxococcus xanthus</italic> is a social bacterium that preys on prokaryotic and eukaryotic microorganisms. Co‐culture of <italic>M</italic><italic>. xanthus</italic> with reference laboratory strains and field isolates of the legume symbiont <italic>S</italic><italic>inorhizobium meliloti</italic> revealed two different predatory patterns that resemble frontal and wolf‐pack attacks. Use of mutants impaired in the two types of <italic>M</italic><italic>. xanthus</italic> surface motility (A or adventurous and S or social motility) and a <italic>csgA</italic> mutant, which is unable to form macroscopic travelling waves known as ripples, has demonstrated that both motility systems but not rippling are required for efficient predation. To avoid frontal attack and reduce killing rates, rhizobial cells require a functional <italic>expR</italic> gene. ExpR regulates expression of genes involved in a variety of functions. The use of <italic>S</italic><italic>. meliloti</italic> mutants impaired in several of these functions revealed that the exopolysaccharide galactoglucan (EPS II) is the major determinant of the <italic>M</italic><italic>. xanthus</italic> predatory pattern. The data also suggest that this biopolymer confers an ecological advantage to rhizobial survival in soil, which may have broad environmental implications.</p> </abstract>