The Shewanella Blogger

Shewanella is a very interesting genus to work with.  It is super easy to grow.  Some people call it the E. coli of the environment.  We routinely grow strains on LB agar at 30˚C.  It should only take overnight for colonies to form.  Similarly, LB liquid cultures take overnight to grow and can get up to 5-7 x 10^9 cells/ml.  A second thing I like about Shewanella is that the organism is pretty straightforward to genetically manipulate.  Most tools used in E. coli can also be used with Shewanella.  Electroporation is tough but supposedly not impossible.  We use a conjugation method and a special E. coli donor strain that has a mutation in the dapE gene.  Thus the E. coli needs diaminopimelic acid to grow (part of the cell wall).  Keep DAP around when doing plate conjugation reactions with E. coli to Shewanella and then plate out on antibiotic plates without DAP.  The one bad thing we found with our Shewanella strain species ANA-3 is ampicillin resistance.  This is a pain because we can’t use Amp selection with our strain.  However, it should be easy to knockout the amp gene but we haven’t gotten around to doing this.  That’s it for part I of why I like Shewanella.

Cheers.

Chad

Hello folks,

Here is a very recent review article on Shewanella.  Should be an interesting read.

Towards environmental systems biology of Shewanella by Fredrickson et al.  Nat. Rev. Microbiol

Bacteria of the genus Shewanella are known for their versatile electron-accepting capacities, which allow them to couple the decomposition of organic matter to the reduction of the various terminal electron acceptors that they encounter in their stratified environments. Owing to their diverse metabolic capabilities, shewanellae are important for carbon cycling and have considerable potential for the remediation of contaminated environments and use in microbial fuel cells. Systems-level analysis of the model species Shewanella oneidensis MR-1 and other members of this genus has provided new insights into the signal-transduction proteins, regulators, and metabolic and respiratory subsystems that govern the remarkable versatility of the shewanellae.