I am growing lactic acid bacteria in MRS broth and want to estimate lactic acid concentration produced by these bacteria. I am trying to search phototrophic method for that. W
Assuming you need a spectrophotometric method there is a number of enzymatic kits available to estimate concentration of D- and or L- lactic acid. Try with Sigma or R-biopharm. There is also a method based on Cerium but it is not advisable because carbohydrates interfere and usually in MRS there is a high conc. of residual glucose
I have determined lactate from complex media by HPLC... But there are many kits available to determine both L and D lactic acid. There you have the Sigma link.