Environmental factors affecting bacterial predator-prey interactions in grassland ecosystems

DE Whitworth & CJ Newbold

Myxobacteria are ubiquitous biotechnologically important bacteria, which are particularly abundant in cultivated topsoil. These organisms can be divided into two main classes,  cellulolytic and predatory. Cellulose-degrading saphrophytic myxobacteria are of direct importance in the recycling of nutrients within an ecosystem, while predatory myxobacteria presumably alter nutrient cycling indirectly, by changing the nature of the soil microbial community.  The project will involve isolating myxobacteria from cultivated grasslands, both at the micro (cm) and macro (10m) scale. In addition, culturable non-myxobacterial bacteria (potential prey) will be isolated from the same samples. Microbial diversity will be evaluated in samples (for both myxobacteria and prey) using techniques such as SARST, DGGE and t-RFLP.

The student will learn a large range of standard microbiology techniques (bacterial culture, isolation, physiological assays, etc.), in addition to many common molecular biology techniques (PCR, DNA sequencing, RFLP, etc). They will acquire familiarity with the literatures and how to analyse molecular and sequence data.

The project should generate novel and publishable data regarding the relative distribution of myxobacteria and their food organisms, and how myxobacteria affect microbial diversity. It will also establish general rules regarding nutritional requirements and nutrient availability and will start to characterise the genetics and physiology of phosphate scavenging.