Dear Chatterjee,

What is the kind of the carbon source that you have added in? is it CO2 or organic compound? And how about the concentration? Each type of bacteria, especially every strain, has a specific nutritional requirement for growing.

Hi Fenny,

I am actually trying to use dextrose as the source of carbon and adding increasing concentrations of it in MRS broth(that has inbuilt 2%dextrose) to see the effect on Lactobacillus growth. I have done this by using 0.1, 1 and 5% dextrose. But i see that above 1% which is 5% the OD value is less as well as no increase in growth.

I have provided the Concentrations of dextrose i added to MRS and the OD values that were obtained

Concentration done OD

5% 0.8

1% 1.05

0.1% 1.1