Dear Najam,

I assume you are working with samples of a few grams or mL, right?

In order to have an optimum production of urease from the bacteria you have to find the optimum pH. So, you run production experiments, while varying the pH, correct?

For setting the pH to a certain value you must not use single acids or bases but buffers.

A buffer is a mixture of a weak acid with its corresponding base or a weak base with it corresponding acid. Examples are:

acid: --- base:

acetic acid --- acetate (e.g. NaOAc)

phosphoric acid --- dihydrogenphosphate (e.g. NaH2PO4)

dihydrogenphosphate --- hydrogenphosphate

hydrogenphosphate --- phosphate

ammonia --- ammonium

carbonic acid --- hydrogencarbonate

With these mixtures you can cover a huge range of pH values and importantly, while you run the experiments the pH will not change due to bacterial activity.

Hope this helps

Best wishes

As professor Klein explained, you have to use a buffer system which almost has constant pH. However, I suggest that you better get some help from a chemist, because choosing the amount of the materials required for making a buffer is not easy for you. For each pH your need to have certain concentration of each reagent.

Good luck!

Verdade, concordo com as respostas anteriores.

Axel Klein Thank you for your response, this will surely help.

Mohammad Kooti Thank you for the detailed answer.

Alexsande Oliveira Franco Thankyou

Thank you everyone for your time and effort in responding to the query

Regards

Najam wani

I agree with Axel Klein Sir. because buffers readily absorb excess H+ or OH–, keeping the pH of the body carefully maintained in the aforementioned narrow range.

Neeraj Yadav Thank you fr the response

Hamed Adani

Regards

wani

I agree with the professors. Usually in my daily rotine at the laboratory, I don't work with microrganisms, so I suppose it is quite complicated to control their growth. As it was mentioned, these organisms require lots of care.

Therefore I may help with my chemistry knowlegde. Regarding Green Chemistry I suggest to read this article Article Green and Sustainable Solvents in Chemical Processes

because as you might know, it is a huge area in Chemsitry as well as very important.

I reinforce what professor Mohammad Kooti said that you better get some help from a chemist. The concentration of the buffer should be suitiable for the specific bacteria.

Hope I've could help too.

Paula Chiachia Pasta thank you paula for your response. it surely helped...

regards

wani

Great!

Regards

Hi

pH of soils is related with CEC (cation exchange capacity) of soils. There should be a alternative way to change the pH of soils without adding acid / base / buffer solution. Looking forward to hear more from agri-chemist.

Dear Najam Wani,

many buffer systems for various pH-values could be found in literature. Unfortunatelly many of them involve ions, which might be unwanted for the reaction. Recently I have been looking for a buffer system free of amines and complexing acids. So I decided for an ammoniumacetate buffer, that worked in a range of 5 < pH < 9:

In theory it should be able to calculate the pH-values from the composition, but I found it more convenient to mix the solutions and check by use of an pH-meter the values. My results might give you an indivcation for a starting point to generate your own ammoniumacetate buffer in the preferred pH-range of your bacteria - if your bacteria are ok for ammonium and acetate ions.

Please see a table attached with the compositions I made and the resulting pH-values.

As I have been only looking for pH-values of 5, 6, 7, 8, and 9 for corrosion tests, the resulting solutions have been sufficient for my work. I suggest you play around a little bit with solution No. 1 and clacial acetic acid and ammonia (25 %) solution until you receive the desired pH-value.

Good luck and best regards

Dr. MIchael König

Michael König Dear Dr. Thankyou so much for the refrences and shared material... The explaination was perfect...

Regards

Wani

Adding carbon dioxide gas (CO2) will reduce the pH as it will form carbonic acid in the presence of water. Sparging with air will increase the pH when excess CO2 is present in the system; air will remove CO2.

Dear Dr. Andrea M Dietrich , Thank you for your response.

Changing temperature of water, addition or removal of carbon dioxide.

Danish Ahmed Thankyou for your response sir...It is of sure help...

Introducing Carbon dioxide (CO2) gas into the soil will reduce the pH due to the production of carbonic acid. Making a layer of ground coffee powder under the uppermost layer of the soil will increase the soil pH.

Acids or a bases not only practice to change pH of the system but can act as a catalyst. In presence of base active methylene compds. generate carbanion intermediate where as the presence of acid forms an enol form for further addition reactions..

One word of caution when using ammonium acetate buffers: ammonium acetate itself is not easy to use - it's deliquescent, and also tends to lose ammonia. A better way of making up such a buffer is to use acetic acid and ammonia solutions. Check the densities, especially of the ammonia solution, and from these find the actual concentrations of the reagents, and hence adjust the volumes you use of the liquids so that you get the concentrations you want.

There are various methods/procedures for changing the Ph value of a solution. It depends upon factors such as concentration rate, the impurities etc etc

Dear K. M. N. Saquib Wani I just came across your very interesting technical question. Just in case that this issue is still of interest to you, let me try to give you an answer. As a chemist I can say that a change of the pH value always has to to with addition or removal of acids and bases, no matter what you do. It's just a question if your acids and bases are environmentally friendly or not. Introducing carbon dioxide means that you formally add an acid, namely carbonic acid. Heating or purging with air will remove the CO2; in other words you remove the acid and the pH will increase. Chemically speaking this is absolutely not different from adding HCl or NaOH to change the pH.

For a good overview about the role of soil pH please have a look at the following potentially useful review article:

The Role of Soil pH in Plant Nutrition and Soil Remediation

Article The Role of Soil pH in Plant Nutrition and Soil Remediation

This paper has been posted by the author as public full text on RG, so that you can freely download it as pdf file.

Good luck with your work and best wishes, Frank Edelmann