Exploiting the diverse microbial ecology of marine sponges

Marine sponges (phylum Porifera) are the oldest extant metazoan animals on earth and host large populations of symbiotic microbes: Bacteria, Archaea and unicellular Eukaryota. Those microbes play ecological functions which are essential to the health of the host including carbon, nitrogen and sulfur cycling as well as host defence through the production of bioactive secondary metabolites which protect against infection and predation. The diversity of sponge-associated microbes is remarkable with thousands of OTUs reported from individual sponge species. Amongst those populations are sponge-specific microbes which may be specific to sponges or specific to sponge species. While marine natural product discovery concerns many animal phyla, Porifera account for the largest proportion of novel compounds. Evidence suggests that many of these compounds are the products of symbiotic microbes. Descriptions of sponge-associated microbial community structures have been advanced by the development of next-generation sequencing technologies while the discovery and exploitation of sponge derived bioactive compounds has increased due to developments in sequence-based and function-based metagenomics. Here, we use pyrosequencing to describe the bacterial communities associated with two shallow, temperate water sponges (Raspailia ramosa and Stelligera stuposa) from Irish coastal waters and to describe the bacterial and archaeal communities of a single sponge species (Inflatella pellicula) from two different depths in deep waters in the Atlantic Ocean, including at a depth of 2900m, a depth far greater than that of any previous sequence-based sponge-microbe investigation. We identified diverse microbial communities in all sponges and the presence of sponge-specific taxa recruiting to previously described and novel spongespecific clusters. We also identified archaeal communities which dominated sponge-microbe communities. We demonstrate that sponge-associated microbial communities differ from seawater communities indicating host selection processes. We used sequence-based metagenomic techniques to identify genes of potential industrial and pharmacological interest in the metagenomes of various sponge species and functionbased metagenomic screening in an attempt to identify lipolytic and antibacterial activities from metagenomic clones from the metagenome of the marine sponge Stelletta normani. In addition we have cultured diverse bacterial species from sponge tissues, many of which display antimicrobial activities against clinically relevant bacterial and yeast test strains. Other isolates represent novel species in the genus Maribacter and require emendments to the description of that genus.

Diverse heritage: exploring literary identity in the American Southwest

Since the age of colonisation, the territory of New Mexico has been exposed to a diversity of cultural influence. Throughout recorded history various forces have battled for control of this territory, resulting in a continuous redefinition of its political, geographic and economic boundaries. Early representations of the Southwest have been defined as “strategies of negotiation” between Anglo, Hispanic and Native populations, strategies that are particularly evident in the territory of New Mexico. The contemporary identity of regions like northern New Mexico have destabilised the notion of what constitutes racial purity in regions which are defined by diversity. This thesis aims to evaluate the literary history of northern New Mexico in order to determine how exposure to a diversity of cultural influence has affected the region’s identity. An analysis of Anglo and Native writers from northern New Mexico will illustrate that these racial groups were influenced by the same geographic landscape. As such, their writing displays many characteristics unique to the region. In providing a comparative analysis of Native and Anglo authors from northern New Mexico, this thesis seeks to demonstrate commonalities of theme, structure and content. In doing so this research encourages a new perspective on New Mexico writing one which effectively de-centres contemporary notions of what the American canon should be.