The role of the capsule encoded by the WCB cluster of Burkholderia cenocepacia H111 and B. seminalis TC3.4.2R3 on the microbial interaction

Abstract

The Burkholderia genus is composed of a broad range of species with phenotypical variations that allow them to occupy different niches, colonizing environments with contrasting characteristics, such as soil, rhizosphere, freshwater, and the inner plant or animal tissues. Burkholderia cepacia complex (Bcc) is a group of species that present a great relevance for medical and agricultural studies since species belonging to this group are associated with biological control of plant disease and inducing inflammatory and pneumonia symptoms in immunocompromised patients. Therefore, the aim of the present study is to understand the molecular and ecological strategy used by these bacteria to interact with plants and animals allowing to development of strategies to control phytopathogens presenting a low risk to animal and human health. The genome of Burkholderia spp. contains a cluster named WCB, which encodes a protein involved in the synthesis of the bacterial capsule and in ecological interactions. Recent studies have shown that this capsule is related to the virulence of Burkholderia spp. and other species, by providing a strategy to evade the host immune system. The ecological interactions of this genus, however, include not only pathogenic ones, but also mutualistic associations with fungi, plants, and animals. The capsule also plays a role in these beneficial interactions, specifically in the colonization of the organisms. Hence, we will generate mutants for genes (glycosyltransferase, transporters, regulators, and lipidic transformation metabolism) belonging to WCB cluster and evaluate the effects of mutations in different mechanisms associated with ecological interactions of Burkholderia cenocepacia H111 and B. seminalis TC3.4.2R3. To generate these mutants, we will use a mutagenesis technique based on the I-Scel nuclease utilization. The present study will provide new insights into the strategies used by these bacteria to colonize different environments and hosts. (AU)