Marine Bacterial Genomics: an ocean of opportunity

For decades, terrestrial microorganisms have been used as sources of countless enzymes and chemical compounds that have been produced by pharmaceutical and biotech companies and used by mankind. There is a need for new chemical compounds, including antibiotics,new enzymatic activities and new microorganisms to be used as cell factories for production.

Therefore exploitation of new microbial niches and use of different strategies is an opportunity to boost discoveries. Even though scientists have started to explore several habitats other than the terrestrial ones, the marine environment stands out as a hitherto under-explored niche. This thesis work uses high-throughput sequencing technologies on a collection of marine bacteria established during the Galathea 3 expedition, with the purpose of unraveling new biodiversity and new bioactivities.

Several tools were used for genomic analysis in order to better understand the potential harbored in marine bacteria. The work presented makes use of whole genome sequencing of marine bacteria to prove that the genetic repertoire for secondary metabolite production harbored in these bacteria is far larger than anticipated; to identify and develop a new phylogenetic marker for the identification of members of the Vibrionaceae family, which led to the identification of two new species using this straightforward pipeline;to discovery of new cytochrome P450 enzymes to be used in biotechnology; and to a thorough study of the marine genus Photobacterium, by means of comparative genomics.

In conclusion, this PhD thesis has contributed to our understanding of the marine microbial environment by studying genomic information of several marine bacteria, expanding the number of marine species taxonomically described, providing identification tools for further marine species documentation and pointing to these organisms as a very promising resource for further bioprospecting.