Answer:
Aldehydes have antibacterial, antifungal, antiviral and sporicidal activity. These are helpful to destroy the spores of Bacillus subtilis and Clostridium sporogenes. Glutaraldehyde and formaldehyde are commonly used aldehydes in disinfectants.
Quaternary ammonium compounds work by denaturing the proteins of the bacterial or fungal cell, affecting the metabolic reactions of the cell and causing vital substances to leak out of the cell, causing death.