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Project

Genetic analysis of spore germination in group II Clostridium botulinum

Clostridium botulinum is an anaerobic sporeforming bacterium that is notorious for producing a potent neurotoxin. Spores of C. botulinum can survive mild food processing treatments and subsequently germinate, multiply, produce toxin and cause botulism. Control of spore germination and outgrowth is therefore essential for the safety of mildly processed foods. However, little is known about the process of spore germination in group II C. botulinum (gIICb), which are a major concern in chilled foods because they are psychrotrophic. In this PhD project, the mechanism of spore germination in gIICb will be investigated using a genetic approach. In a first part, an inventory of putative predicted spore germination genes will be created by bioinformatics analysis of a large number of gIICb genome sequences, including a number of natural nontoxigenic strains recently acquired in our laboratory. This will provide a first view on the diversity of germination mechanisms within gIICb, and the difference with other C. botulinum groups. In a second part, the precise role of some selected predicted germination genes will be experimentally analysed by knock-out mutational analysis. In a third part, two open approaches will be adopted to search for novel germination genes. The first one is the construction and screening of a genome-wide transposon mutant library, the second on is directed evolution. In the latter approach, the mutations underlying interesting germination phenotypes will be identified by whole genome sequencing. From these screenings, one or more candidate novel germination genes will be selected for further analysis.

Date:17 Oct 2017 →  30 Nov 2021
Keywords:Clostridium botulinum, spore germination, Groupe II
Disciplines:Other chemical sciences, Nutrition and dietetics, Agricultural animal production, Food sciences and (bio)technology, Microbiology, Systems biology, Laboratory medicine, Biomaterials engineering, Biological system engineering, Biomechanical engineering, Other (bio)medical engineering, Environmental engineering and biotechnology, Industrial biotechnology, Other biotechnology, bio-engineering and biosystem engineering
Project type:PhD project