Why should hcl be used to adjust the ph value in the separation and hydrogenation identification experiment of palmatine in rattan?

Why should hcl be used to adjust the ph value in the separation and hydrogenation identification experiment of palmatine in rattan?

There is no obvious difference between lactic acid bacteria species. For example, the similarity of 16S RNA genes of Lactobacillus plantarum and Lactobacillus curvaturus is above 97%, so we can't draw conclusions casually, only refer to physiological and biochemical indexes.

In addition, the enzyme production analysis of these lactic acid bacteria can also help to determine the source strains of the main flavor substances that have the greatest influence on the tissue state of sour beans.