New Publication

I'm pleased to report that the final manuscript from my thesis has just been published online in the new "International Society for Microbial Ecology (ISME) Journal". This manuscript is the culmination of my doctoral research and describes how the rhizosphere effect can affect different microbial taxa differently.

The manuscript is now available in print. Enjoy!

Green, S.J., Michel Jr., F.C., Hadar, Y. and D. Minz. [2007]. Contrasting patterns of seed and root colonization by bacteria from the genus Chryseobacterium and from the family Oxalobacteraceae. ISME Journal. 1:291-299.

Kiva.org

I know this is off-topic, but I recently discovered this organization: www.kiva.org. It is an organization which allows you to extent credit via micro loans ($25 or greater) to individuals. It is not a charitable contribution, but rather a zero-interest loan to help people start or expand businesses. It is amazing to see how a little bit of money can go so far. I am not affiliated or paid by Kiva in anyway. I simply think it is a wonderful idea that appears to be implemented in a well-organized manner. Cheers, Stefan

New Position

My friend Dave chided me for not updating my blog frequently enough. I must admit it is true. It is hard to believe that it has already been over 3 months since I last updated it. Anyway, I now have a new position as a research scientist at the SETI Institute. I am still working at the NASA-Ames Research Center, however. I am currently working on a few different projects, including hypersaline microbial mats from Guerrero Negro, Baja, Mexico. The Exobiology Department at NASA-ARC is planning another trip to the salt production facility - Exportadora de Sal S.A. de C.V. - located in Guerrero Negro, Baja, California Sur, Mexico. This trip we're planning to study some of the higher salinity ponds (on the order of 150 ppt salinity) as opposed to the lower, but still hypersaline ponds of about 85 ppt.

I also have an ongoing project with Dr. Jen Blank of the SETI Institute to study the geology, chemistry and biology of ophiolite rocks found in certain locations in Northern California. Ophiolites are pieces of ocean crust that have been lifted up to the surface and exposed. When these rocks undergo weathering, a number of interesting abiotic chemical reactions can occur, and the water chemistry is highly modified. For example, in the system we are studying (see below), the pH of the water in local streams is roughly 9.0, and the water has high levels of carbonate and magnesium. In addition, we are finding unique microbial communities associated with these waters. More on this as the work progresses.
Cheers,
Stefan

Back to California

I have just recently returned to California after a semester as a visiting assistant professor in the Department of Civil Engineering and Geological Sciences at the University of Notre Dame. My wife insisted that among the first things that I do, I should update my blog. I spent the semester teaching Environmental Microbiology and a laboratory class entitled Molecular Tools for Environmental Microbial Ecology. Well, now that the semester is over I can say that I quite enjoyed it, but it was a lot of work. It looks like I will be getting a position at the SETI institute for the time being, and I am looking for a full time faculty position, or more funding to help me remain at SETI/NASA. Anyway, it is good to be back. More soon.
Cheers,
Stefan

Unifrac Update

I received an email from Micah Hamady at the University of Colorado. He informed me that there is now an online version of UniFrac available, and can be found at thefollowing website:

http://bmf.colorado.edu/unifrac/index.psp

In addition, there is a manuscript available:

http://www.biomedcentral.com/1471-2105/7/371

This should be a welcome improvement from having to install and operate Unifrac from Python.

Cheers,

Stefan

FIBR Conference and New Job

I just recently returned from a conference in Bozeman, Montanta. This conference was funded by the NSF Project - Frontiers in Integrative Biological Research, and is part of an ongoing research program at the University of Montana. This research program is involved in investigating microbial communities in hot spring environments in Yellowstone to ask the question - "Do Species Matter in Microbial Communities?"(http://landresources.montana.edu/FIBR/). The conference was excellent, and one of the most intriguing pieces of information I learned was related to the genome sequences of two relatively closely related cyanobacteria of the genus Synechococcus. Two environmental isolates of this genus, recovered from different temperatures along a thermal gradient of a Yellowstone hot springs, had their full genomes sequences. Amazingly, when these genomes were assembled and compared, they were found to have very little synteny (genes or sequences occurring in the same order on chromosomes of different species), despite having ribosomal RNA gene sequences nearly 97% identical. These genomes can be found at The Institute for Genome Research (TIGR) (http://cmr.tigr.org/tigr-scripts/CMR/CmrHomePage.cgi).

Other interesting news. I will be teaching two courses at the University of Notre Dame this fall as a visiting assistant professor in the Civil Engineering and Geological Sciences Department (CEGEOS). The two courses will be Environmental Microbiology, and a laboratory course entitled Molecular Techniques for Microbial Ecology.

Return from ASM

Just got back from the ASM meeting in Orlando, FL. The meeting was good - amazing things being done with full genome comparisons, plus microarray gene expression analyses. Anyway, just a few notes here:

1) A new software package called CLC that is definately worth investigating. [http://www.clcbio.com/]

2) A product called Perfect Match® PCR Enhancer from Statagene. Here is the manual.

See an article by De Milito et al. 1995. I also found this comment in a molecular biology group:

"[Perfect match is] Tetramethyl Ammonium Chloride. It costs about $30 for 500 gms from Fisher, and stinks to high heaven.I titrated it between 10 uM (micromolar) and 1 nanomolar leaving allother conditions the same."

This is not verified information.

Cheers,
Stefan