It has been reported that microorganism can increase fluoride concentration in groundwater through microbial weathering (reference:Article Groundwater fluoride contamination, probable release, and co...
). I have observed few groundwater samples where presence of E.Coli is significant and geological settings of the station indicate that microbial weathering can be a reason of high fluoride concentration. But few studies reported that higher fluoride concentration in groundwater inhibits microbial growth including E.Coli. Therefore, there should not be any E.Coli occurrence in those samples.Can you please help me to justify this scenario.
Fluoride has strong antimicrobial properties (that's why used in toothpaste) and can potentially stop microbial (including E. coli) growth. Fluoride acts more effectively (inhibits enzymes in microbes) at acidic pH. Basically, fluoride acts to reduce the acid tolerance of the bacteria. Escherichia coli gene crcB (there are many homologs of this gene in many eukaryotes) has been shown to play role in fluoride response. Resistance to fluoride in E. coli is efflux mediated. At neutral or higher pH, E. coli can store more fluoride than the concentration that could otherwise stop the bacterial growth. Finding a higher fluoride concentration (you did not mention conc. in your post) and presence of E. coli (there is no mention of what is meant by higher presence either in your post). It could be coincidence but not necessarily a correlation. Also, it is more important to know the geochemical condition, especially pH, water activity in the groundwater matrix, befor making any assumption about these high concentration of fluoride and presence of E. coli. Moreover, E. coli prefers animal gut over being out in the open environment. Also, seepage of sewage contaminating the groundwater could be a reason for the presence of E. coli.
I agree with Professor Jaysankar De. The experimental publications are required.
Dear every one
As Dr. Jaysankar mentioned, Fluoride has anti bacterial effects.
In my point of view as a groundwater hydrologiest,
If E.coli can alterd rocks or soil and then release fluoride, you should have a background concentration of F spices. For this reason you maight be analysis rock formation for found a Fluoride sources. In addition, if you do´nt have any fluoride sources you look cross your water samples it can shows a source for fluoride.
Because E.coli uses substances and it can not realease any fluoride spontiniously.
Gratefully
Dariush
Groundwater has high flouride and therefore the amount of ecoli can be low as pointed out by Prof. De.
- Badges
- Science topic
- Similar topics
- Biological Science
- Microbiology
- Microorganisms