What’s new for Shewanella

It’s been a long time since my last post.  A lot has happened since then in the land of Shewanella.  I’ve included a couple of links to recent Shewanella publications.  One in particular is the identification of adenylate cyclases that are involved in anaerobic respiration and showing that cAMP-CRP regulates arsenate respiration pathway.  The work was done in Shewanella sp. ANA-3, which is slightly different than MR-1; ANA-3 can also respire arsenate.  The other paper that might be of interest to Shewanella folks is the use of proteomics to characterize a regulator in MR-1 that might be involved in chromate transformation.

Comparative Temporal Proteomics of a Response Regulator (SO2426)-Deficient Strain and Wild-Type Shewanella oneidensis MR-1 During Chromate Transformation.
Chourey K, Thompson MR, Shah M, Zhang B, Verberkmoes NC, Thompson DK, Hettich RL.
J Proteome Res. 2009 Jan 2;8(1):59-71.
PMID: 19118451 [PubMed - as supplied by publisher]

Functional roles of arcA, etrA, cyclic AMP (cAMP)-cAMP receptor protein, and cya in the arsenate respiration pathway in Shewanella sp. strain ANA-3.
Murphy JN, Durbin KJ, Saltikov CW.
J Bacteriol. 2009 Feb;191(3):1035-43. Epub 2008 Dec 5.
PMID: 19060154 [PubMed - in process]

 

Posting a bit slow

I’ve been a bit busy to post about new developments in the Shewanella world. There are some to report on however, I am too wrapped up with other things. I’ll try to get something up this weekend. I encourage anyone visiting this site to post some news of their own.

Cheers,

Chad

 

Geobacter Genome Browsers up at UC Santa Cruz

We now have several Geobacter genome alignments up on the UCSC genome browser website. One particular Geobacter, G. uraniumreducens has a putative arsenate respiratory reductase gene cluster, which I added a custom track for in the browser (see link). We will be adding Geobacter lovleyi shortly. This should be a great resource for those interested in the genomics of Geobacter and metal reducers in general.

Geobacter genome browser

Geobacter uraniumreducens with custom arr track

[UPDATE 5/31/2008] Gura has a stop codon in the middle of arrB, the iron sulfur subunit gene. I marked this as a custom track in the genome browser. It is interesting because Glov has a fully coded arrB gene, with no stops. Based on this data, I predict that Glov will respire arsenate and that G. uraniireducens (formerly G. uraniumreducens) will not.

Here is the G. lovleyi browser with the custom arr track.

 

New paper on an arsenate respiring bacterium, Alkaliphilus oremlandii

Stolz and colleagues (Duquesne University) published a recent paper on the characterization of an arsenate respiring bacterium isolated from the Ohio River. The microbe, Alkaliphilus oremlandii strain OhILAs, was named in honor of the grandfather of arsenic-respiring bacteria Dr. Ron Oremland. Here is the PubMed link:

Fisher et al. (2008) Transformation of Inorganic and Organic Arsenic by Alkaliphilus oremlandii sp. nov. Strain OhILAs. Ann N Y Acad Sci. 1125:230-41.

The strain is gram positive and appears to tolerate and grow quite well on arsenic. Definitely a paper we should all read.

 

Arsenic can cause ED?

I thought this was an April Fools joke. However, according to a recent article in Environmental Health Perspectives, arsenic exposure in drinking water is a risk factor for erectile dysfunction. Here is the link to the abstract:

Fang et al. “Risk of Erectile Dysfunction Induced by Arsenic Exposure through Well Water Consumption in Taiwan” Environmental Health Perspectives Volume 116, Number 4, April 2008

Linking arsenic to ED seems crazy but in the intro the authors mention that ED is linked to cardiovascular diseases, which is also influenced by arsenic exposure too. If you make the connection between arsenic and cardiovascular disease therefore, ED could be another symptom of arsenic exposure. We’ll see how this plays out in long run.

 

Arsenic Crisis in Bangladesh

Here is an interesting commentary on how the arsenic crisis in Bangladesh came to be. If the sources are true it’s an amazing story with a sad outcome:

http://www.unesco.org/courier/2001_01/uk/planet.htm