11th Jul, 2022
University of British Columbia - Vancouver
Question
Asked 11th Jul, 2022
Is it possible to increase the metal tolerance of a ureolytic bacterium by subjecting it to increasing metal concentrations?
I'm using Sporosarcina pasteurii to remove heavy metals from wastewater by producing metal carbonates. The issue I encounter is that high metal concentrations (i.e. Co 2g/L) strongly inhibit bacterial growth and activity.
One of the existing solutions is to isolate another already metal-tolerant strain (such as Lysinibacillus sphaericus). (source :
I have read that it is possible to adapt a bacterial culture to a high concentration of metals by serial acclimatisation, where the bacteria are successively grown in a medium of increasing metal concentration. (source : 10.1016/j.wasman.2018.07.010)
Can this method be adapted to ureolytic bacteria? Are there any examples?
If not, what other methods would you suggest?
Thank you !!
All Answers (3)
Yes, you can try adaptation as a strategy to overcome heavy metals toxicity.
Another method to try is two-step remediation in which you grow your bacteria first and once it has reached the logarithmic phase, then you will add it to your waste sample.
As Cobalt is quite deadly for bacteria, you can use spent culture if nothing else worked (growing bacteria separately, centrifuge, and adding bacterial supernatant containing required metabolites to your waste sample)
Lastly, you can try a mixed bacterial culture to enhance their metabolic activity against heavy metal toxicity.
This is known as "Directed Evolution" and can be used for many adaptations. Keep in mind the result might be "more tolerance" but not more effective in removal...
You can do it by adapting bacterial culture to a high concentration of metals by serial acclimatization. and I can suggest you to induce mutation in your strain, using a UV lamp. this process is called"induced mutagenesis" it's easy and generally used for random selection of mutants. in your case, it's a positive selection of high-concentration heavy metals resistant mutants. good luck.
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