The extracellular proteome of two Bifidobacterium species reveals different adaptation strategies to low iron conditions

作者：Pamela Vazquez-Gutierrez, Marc J. A. Stevens, Peter Gehrig, Simon Barkow‐Oesterreicher, Christophe Lacroix, Christophe Chassard · 发表于：BMC Genomics · 年份：2017 · DOI：10.1186/s12864-016-3472-x · 被引用次数：33 · 研究领域：Bacterial Genetics and Biotechnology、Microbial Fuel Cells and Bioremediation、Iron Metabolism and Disorders

BACKGROUND: Bifidobacteria are among the first anaerobic bacteria colonizing the gut. Bifidobacteria require iron for growth and their iron-sequestration mechanisms are important for their fitness and possibly inhibit enteropathogens. Here we used combined genomic and proteomic analyses to characterize adaptations to low iron conditions of B. kashiwanohense PV20-2 and B. pseudolongum PV8-2, 2 strains isolated from the feces of iron-deficient African infants and selected for their high iron-sequestering ability. RESULTS: Analyses of the genome contents revealed evolutionary adaptation to low iron conditions. A ferric and a ferrous iron operon encoding binding proteins and transporters were found in both strains. Remarkably, the ferric iron operon of B. pseudolongum PV8-2 is not found in other B. pseudolongum strains and likely acquired via horizontal gene transfer. The genome B. kashiwanohense PV20-2 harbors a unique region encoding genes putatively involved in siderophore production. Additionally, the secretomes of the two strains grown under low-iron conditions were analyzed using a combined genomic-proteomic approach. A ferric iron transporter was found in the secretome of B. pseudolongum PV8-2, while ferrous binding proteins were detected in the secretome of B. kashiwanohense PV20-2, suggesting different strategies to take up iron in the strains. In addition, proteins such as elongation factors, a glyceraldehyde-3-phosphate dehydrogenase, and the stress proteins GroEL and ...