Deep sea

Overview

Microorganisms that prefer high-pressure conditions are termed piezophiles to describe in one word properties of microbial growth under elevated hydrostatic pressure conditions. In particular, piezotolerant microorganisms are capable of growth at both atmospheric pressure and high pressure. In addition, there are bacteria adapted to a wide range of temperatures called psychrophile. The molecular basis of extremophiles is now being investigated extensively focusing on aspects of gene function and regulation in Antarctic and deep-sea isolates. Little attention has been paid, however, to the potential biotechnological applications of piezophiles and psychrophiles compared with other extremophiles.

Project

Our research group at the CRIBI Biotechnology Centre of the University of Padua has recently completed the genomic sequencing of Photobacterium profundum, a piezophile and psychrotolerant microorganism adapted to life in the ocean depth. We feel that this achievement is particularly relevant as P. profundum is the first piezophilic organism so far investigated at genomic level. Furthermore, it is the first genome entirely sequenced by an Italian group. P. profundum belongs to the Vibrionaceae family. Our study has shown that its genome is 6.2 Mbp long, organised in two main chromosomes of 4.1 and 2.2 million base pairs (Vezzi et al., 2005).

This recent study is the starting point for this new project that is aiming to continue the research on adaptation to high pressure by means of a comparative genomic approach. In this respect we have initiated an active collaboration with the group of Prof. Douglas Bartlett of the Scripps Institution of Oceanography, San Diego, California, on the genomic analysis of four bacteria intersting to understand the adaptation to high pressure. The shotgun phase of the genomic sequencing will be carried out by the J. Craig Venter Institute as a part of an international collaboration supported by the Moore Foundation. The four bacteria that we will study are Photobacterium profundum 3TCK (deep sea piezophile), Shewanella benthica KT99 (deep-sea piezophile heterotroph strictly adapted to high pressure), Psychromonas sp. CNPT3 (deep-sea piezophile heterotroph adapted to high pressure), Moritella sp. PE36 (deep-sea piezophile heterotroph, adapted to high pressure). Our study will be articulated in the following points: 1) contribution to the genomic finishing of the four bacteria mentioned above 2) genome annotation 3) comparative genomic studies for the identification of the peculiarities of these bacteria 4) bioinformatic and functional post-genomic analyses.

Collaborations

Douglas Bartlett (SCRIPPS Institution of Oceanography –San Diego);
Federico Lauro (University of New South Wales, Sydney);