Options for disposing of bacterial strains

Question

Dear Sir, Thanks for your updates on the new Testing Procedure. However, I would like to know about the following :-
( a ) What will be options for disposing the Bacterial strains after completion of the Testing? Is there any chance that cumulative Disposal at same point one after another may eventually lead to further contamination in a concentrated manner?
( b ) Is there any scope that such Bacterial Strain may be used for removal of Arcenic from drinking water> If yes, upto what extent / limit?
Thanks.
Regards.
Nripendra Kumar Sarma 
Guwahati, Assam (India)

Jim Ajioka · Accepted Answer

Bacteria in the soil assist in arsenic decontamination but
 
The bacteria used in current biosensors is Bacillus subtilis, a soil bacteria found virtually everywhere on earth. It is generally considered safe and is used food production in Japan to ferment soy beans to make natto. The strains of B. subtilis used in the biosensors are purposely crippled so they cannot live in the environment and will not compete with wild strains of B. subtilis in the soil. Disposal includes boiling to kill the growing bacteria and incineration could be used as an extra precaution. The biosensors are small and use a relatively low amount of bacteria so the overall environmental impact should be very low.
Bacteria in the soil assist in arsenic decontamination but it is until we know more about the conditions and mechanisms that promote this, using the naturally occurring bacteria in the soil is probably the best solution. Perhaps the most interesting recent developments for arsenic decontamination comes from Prof. Sen Gupta's work on oxygenating water (simple shower head) and circulating it back into the soil (http://www.sciencedirect.com/science/article/pii/S0269749109004643). This changes the state of the arsenic such that it will more easily bind its natural iron constituents in the soil and allow bacterial action to promote this process. The great thing about this method is it essentially reversing the process by which much of the bio-available arsenic is released into the water from the soil in the first place.

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