How to Identify and Estimate the Lactic acid from the Microbial fermented broth other than HPLC using Simple methods?
if possible such as
1. Calorimetric or Spectroscopic methods
and much more
8/27/20
Dear Vignesh,
You could use an enzymatic assay using lactate dehydrogenase and glutamate-pyruvate transaminase. Kits for this are comercially availibile (e.g., Boehringer Mannheim) or you buy the necessary enzymes and co-factors and set-up the assay yourself. Boehringer Mannheim sells kits for detecting both D- and L-lactic acid. See the attached. I hope this information helps you.
Bill Colonna Dept. Food Science & Human Nutrition, Iowa State University, Ames, Iowa, USA [email protected]
Kindly check this https://iopscience.iop.org/article/10.1088/1755-1315/251/1/012054/pdf
Also check https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5627144/
Thank You W.J Colona sir, for taking up a time me to clarify my doubts. Thanks a lot sir and the answer given by you is very useful for me...But then I seek a basic test or test that don't require the Kits since kits are little bit costlier...
Thank You sir...
W.J. Colonna
Thank You Chinaza Godswill Awuchi Sir for your valuable suggestions...Thanks a lot... But then I seek a basic test to identify or estimate the Lactic acid without HPLC
Thank You Chinaza Godswill Awuchi sir
8/31/20
Dear Vignesh,
Another way to quantitate lactic acid in a fermentation is by measuring the amount of NH4OH required to maintain the fermentation at a pre-determined pH value. See the attached document. We did this when we conducted a fermentation workshop several years ago. We fermented glucose w/ Lactobacillus casei (homo-fermentative) and monitored glucose consumption and lactic acid production over time. Lactic acid was determined using an automated enzyme-based method (YSI....very expen$ive instrument!!) and by titrating the culture fluid w/ NH4OH to maintain the pH (either 4.5 or 5.0) to allow the cells to continue growing. We compared moles Lactic Acid (LA) determined enzymatically (YSI) vs. NH4OH titration. The attached graph shows that the correspondence of LA production by the 2 methods was very good. The NH4OH measurement method is not very elegant, but it works. If may work for you assuming that the microbe you are using produces ONLY lactic acid, and not other acids. We could do this w/ L. casei as it produces only LA. It won't work if your microbe is a MIXED ACID fermenter.
I hope this information helps you.
Bill Colonna Dept. Food Science & Human Nutrition, Iowa State University, Ames, Iowa, USA [email protected]
Hi,
There's a traditional method of lactic acid estimation, that is followed in academic labs, for Sauerkraut fermentation. It is a titrimetric analysis. To do this, take 10ml of the clarified fermentation broth and dilute it with 10ml D/W. After having boiled the solution and cooled, titrate it against 0.1 N NaOH, using phenolphthalein indicator.
Percentage of lactic acid in the broth can be estimated by the formula [(9 x 0.1 x B.R)/10]. Lactic acid produced in the process can be calculated by subtracting final - initial value.
Hope this helps you!
Thank You, Dr. W.J. Colonna for your Valuable suggestion. Really It will help me up...thanks a lot and you also have mentioned You have conducted a Fermentation workshop...In the future, If conduct any workshop related to this fermentation and Production...Please let me know sir
Thank You
Thank You Dr. Vijita V. Pillai for your valuable suggestion...It looks worthy...I will work on it...Thanks A lot Dr. Vijita V. Pillai
1) By titration using 0.1 N NaoH , and there is conversion ( i do not have it now but you do searching) to calculate the total volume of NaOh used to lactic acid .
2) Other method by using GC but you have to methylate lactic acid firth to be volatile
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