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Bacteria Growing up to 30,000 ppm conc of Tungsten - (Apr/02/2014 )

Kindly please let me know if it is possible for bacteria to grow at very high tungsten concentrations of 30,000 ppm. Sodium Tungstate was used as the source. The growth was spectrophotometrically measured. 


Appears that you can answer your own question but I suggest you confirm the OD measurement by additional techniques.

-Phil Geis-

Hello Sir, I actually wanted to know if it was possible for bacteria to grow at such high concentrations of tungsten or any other heavy metal for that matter. Should I do MIC to confirm it? Also please let me know if autoclaving any salt of metal destroys it by chance. 




Confirm the change in OD is due to substantial increase in numbers of viable cells.

-Phil Geis-

Ok, I will check that Sir.


Also I was wondering if it is safe to autoclave metals, because I am adding the salt, sodium tungstate to my media, after autoclaving it separately. 


30000ppm is 30 g/L.

Is it 30000ppm of W or 30000 ppm of sodium tungstate?

Keep in mind that it will be a huge increase in the osmolarity as each mmol of sodium tungstate will increase the osmolarity by 3 mOsmol (ionic strength not taken in account).


In general, many salts of heavy metals like chlorides or sulfates in water don't change with autoclaving if they are alone in solution, but you have an metallic oxyanion salt that can behave different. Search for temperature decomposition, autoclaving, stability,... test a small amount or just filter sterilize. It is usually a component of trace metal solutions but they are usually quite diluted in comparison.

-El Crazy Xabi-

Sir it is 30,000 ppm of sodium tungstate. I've read that at higher concentrations the salt starts to form polyoxyanions. I'l search for the temperature stability of the salt...and i'll try filter sterilization the next time.


Thank you Sir! Also sorry for asking the same question twice.