How do aldehydes kill bacteria?

1 Answer
Sep 10, 2016

Aldehydes kill bacteria mainly by forming protein-protein crosslinks.

Explanation:

The links form between the amine groups of amino acids (mainly lysine) in one chain and the "N"N atoms in the peptide linkages of another chain..

For example, here's how formaldehyde works.

1. Formaldehyde exists in solution as methylene glycol.

"H"_2"C=O" + "H"_2"O" → underbrace("HO-CH"_2"-OH")_color(red)("methylene glycol")

2. The methylene glycol reacts with the amino group of a protein.

"Protein-NH"_2 + "HOCH"_2"OH" → "Protein-NH-CH"_2"-OH" + "H"_2"O"

3. A methylene bridge forms with another protein chain.

"Protein-NH-CH"_2"-OH" + "H-Protein" → "Protein-NH-CH"_2"-Protein" + "H"_2"O"

The protein-protein cross linkages severely disrupt the abilities of the bacteria to propagate and to function.