A study of the ecology & diversity of bacteriophages

• Main Author: Bell, Emma Lisa
• Published: University of Strathclyde 2008
• Subjects: 610
• Online Access: http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.501859

Bacteriophages are ubiquitous and abundant in nature, yet our knowledge of their ecology, global impact on the ecosystem, their relationships with one another, and their hosts remains relatively primitive. Their consequence on the resident microbial population greatly depends upon their lifecycle with hosts. Their acquisition or removal of genes between the phages themselves eventually determines their global impact. Therefore by examining their genomes will contribute to our understanding of their importance and potential impact on ecology as a whole. Previous studies have shown that bacteriophages do undergo extensive genetic exchange with one another (Hendrix et al., PNAS, 96,2192-97), however, these have examined bacteriophages from varied locations. Unlike previous studies, this work examines the ecology of phages and their hosts in a single soil source. By concentrating on single environment the dynamics of phages and hosts can be determined by examining their relationships and interactions with one another. Bacteriophages and hosts were isolated from the same soil and placed into distinct groups according to characterisation experiments. The monitoring the phagehost system by soil microcosm experiments allowed the impact of phages upon their host populations to be followed over time. In addition, to our knowledge there are no studies examining the impact of soil phages upon their hosts whilst also examining their genomes. However there is one study examining the genetic relationships of bacteriophages from a single soil sample which found them to be highly related. As a result genomic sequence and hybridisation experiments were applied in order to quantify the degree of relatedness between phages. Genomic sequencing contributed to our understanding of the mechanisms involved in viral evolution within a single soil sample and supported the findings of previous studies.