Ecology and Biotechnology of the Genus Shewanella

Abstract

The shewanellae are aquatic microorganisms with worldwide distribution. Their hallmark features include unparalleled respiratory diversity and the capacity to thrive at low temperatures. As a genus the shewanellae are physiologically diverse, and this review provides an overview of the varied roles they serve in the environment and describes what is known about how they might survive in such extreme and harsh environments. In light of their fascinating physiology, these organisms have several biotechnological uses, from bioremediation of chlorinated compounds, radionuclides, and other environmental pollutants to energy-generating biocatalysis. The ecology and biotechnology of these organisms are intertwined, with genomics playing a key role in our understanding of their physiology.

The periplasmic nitrate reductase in Shewanella: the resolution, distribution and functional implications of two NAP isoforms, NapEDABC and NapDAGHB

“…Apart from S. denitrificans, the genomes of all other species of Shewanella examined contain both menaquinone and ubiquinone biosynthetic gene clusters, which suggests that for species which encode both NAP-a and NAP-b the activity of these enzymes may be differentially regulated by the ubiquinone or menaquinone pool, respectively. These notions accord with the renowned environmentally adaptable phenotype of Shewanella (Fredrickson et al, 2008;Hau & Gralnick, 2007).…”

“…Almost all Shewanella species to date have been discovered in extreme aquatic or terrestrial environments, including deep-sea trench sediments, Antarctic ice cores, and sites contaminated with toxic compounds, including arsenic, remnants of military explosives or crude oil (Konstantinidis et al, 2009;Zhao et al, 2005Zhao et al, , 2006. Most Shewanella species are classifiable into one or more selected extremophilic subgroups: halophiles, psychrophiles or barophiles (Fredrickson et al, 2008;Hau & Gralnick, 2007;Pakchung et al, 2006). Most recently, Shewanella vesiculosa sp.…”

Microbial Ecology of the Dark Ocean above, at, and below the Seafloor

“…The deepsea Shewanella species appear to belong to their own clade (275), which has been investigated to study adaptations to high pressure and the evolution of proteins in deep-sea bacteria and to search for useful compounds for biotechnology. Considering the metabolic flexibility of Shewanella (209), this group is a common model in laboratory studies to examine unusual metabolic pathways. For example, Shewanella is often a target for biotechnological applications such as sedimentary biobatteries or microbial fuel cells (412).…”

Phage-induced lysis enhances biofilm formation in Shewanella oneidensis MR-1

“…In addition, a number of radionucleotide oxides can be reduced (Myers and Nealson, 1988;Nealson and Scott, 2003;Icopini et al, 2009). Thus, bacteria such as Shewanella significantly impact biogeochemical cycling processes and are of particular interest with regard to bioremediation processes (Heidelberg et al, 2002;Nealson et al, 2002;Lovley et al, 2004;Ward et al, 2004;Hau and Gralnick, 2007). It has been hypothesized that direct interaction of Shewanella cells with, or close proximity to, an appropriate surface facilitates the deposition of electrons (Das and Caccavo, 2000;Gorby et al, 2006;McLean et al, 2010).…”