On trying to identify heavy-metal resistant bacteria, i first contaminate a soil with heavy metals and check for the microbial load, i allowed it for 100days of natural attenuation and check the microbial load. Bacteria identified in the first microbial load and identified again in the second load is chosen as the resistant bacteria. Is my procedure scientifically correct???
Well, to some extent your procedure is applicable but then you need to narrow down your method to find out some high heavy metals (HM) resistant bacteria. Preferably, it is important to use soil to isolate bacteria contaminated with HM earlier to be sure that the resistance in bacteria has been developed with time. That will give you a perfect resistant strain with high tolerance capacity. Simply spiking with HM might not be that much useful in soil system. After that, use atlest 2-3 different media like nutrient agar media, PDA media, EMB media, Manitol salt media and so on to make a diverse scope of getting different HM resistant bacteria. Use different concentrations of HM to spike in these media to develop a higher resistant capacity of isolated bacteria. For example, go for 200, 300 up to 1000 ppm of arsenic in these media, or any of your preferred HM according to the concentration present in soil. Then increase these concentrations further more to get only a few HM bacteria with high tolerance capacity. Finally go for the digestion of those bacteria with acid and measure the concentration of HM present in the cell via ICP MS or AAS or atleast in Spectroscopy to determine the HM bioaccumulation capacity of those species. This is how you can isolate different HM bacteria from soil.
Thank you.
I agree with Mr. @Arnab Majumdar. You can prepare media with desired concentration of heavy metals and use it for screening resistance bacteria of different resistance level. You can refer various available literature on isolation of HM resistant bacteria. Further you can study their resistance mechanisms eg. adsorption, precipitation, transformation etc. by standard methodologies.
Good luck!
- Badges
- Science topic
- Similar topics
- Entomology
- Resistance