Science Buddies: "Ask an Expert"

In North of Brazil there is a very vast problem that is the hyper salinization of soil due to irrigation.

This is causing desertification of the soil or infertility implying high costs for it to be recovered. The microbiology of the soil in those regions is affected, since a set of bacterium necessary to help the development of the plant cannot tolerate the level of salinity.
Many Brazilian researches are investigating hyper saline environments to search for bacteria that can tolerate hyper salinity so that they could be tested for bioremediation of the soil.

As I am studying in Israel, I wonder if some of the small variety of bacteria present in the dead sea, that are tolerant to high salinity, could have any effect in bioremediation and therefore, increasing the quality of the soil and/or increase germination rates.

Wow, this is a very interesting idea. I think you could develop an excellent project out of this idea. Do you have an idea of how you would proceed with this?

I found some interesting papers and editorials on this topic.

http://www.karger.com/Article/PDF/88836

http://yosemite.epa.gov/r10/cleanup.nsf ... salts2.pdf

Cheers,
Colin

Hey Colin!
Thank you very much for replying my post.. I'm sorry for the late answer, though...
Well I didn't design the methodology of the experiment yet, but as I study in an international school that is about 1 hour from the Dead Sea, I intend to collect some samples and try to identify the bacteria. I know this first step is already not easy and I would appreciate any sort of suggestion or recommendation...
After identify and culturing the specific bacteria, I would like to test for quality of the soil (I don't know exactly how to measure it, but I'll will focus in level of salinity and pH), and germination rates of seedlings.

So, I want to try in different soil types and compare with a control "standard" one.
But there are still a lot of questions.
I am going to the Dead Sea next week, and I want to start some collections.
Again, thank you for your interest and for the files you sent, they were really helpful. Also, I would appreciate if there is any further appointment or suggestion.
Regards,
Yasmim F.

I posted a link to testing the salinity of soil in the field. You mainly need to dilute your soil samples in water.

http://www.dpi.nsw.gov.au/__data/assets ... linity.pdf

Salinity can have an adverse affect on plant growth, because salt can interfere with water infiltration and air exchange. Moreover, high salinity may induce the plant to produce ethylene, which inhibits root growth. Interetingly, some species of nitrogen fixing bacteria such as Pseudomonas and Rhizobium are halotolerant and can reduce the effects of stress-induced ethylene on plants. Perhaps these bacteria can promote plant growth under high saline conditions. The research article on the nitrogen fixing bacteria is posted below.

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3958208/

Hey! Thank you very much for the files and the directing..
I know that there is a small range of species of bacteria available in the dead sea, but I would like to try there, since it is a hyper saline lake that is in accessible to me as a research source.

Regards,
Yasmim

" I would like to test for quality of the soil (I don't know exactly how to measure it, but I'll will focus in level of salinity and pH), and germination rates of seedlings."

I think this makes sense and sounds reasonable. You need to think about how you are going to collect the samples and use them before you collect them, as you may not be able to store them very long and still have confidence the bacteria will be viable (though they may be very robust, I don't know). Are you going to collect water, or soil from the edge of the dead sea? What are your control samples going to be? I think you need an invariant sample of salty soil to which you can add samples (water? diluted soil?) from different sources, including the dead sea, and one or more control locations, and in which you can try to grow plants. Perhaps commercial soil with salt or sterile saltwater added would be a good idea?

Cheers,
Colin