Final answer:
The two aldehydes most often used in microbial control are formaldehyde and acetaldehyde, with formaldehyde being a powerful preservative and sterilizing agent and acetaldehyde serving as a starting material in organic synthesis and microbial control.
Step-by-step explanation:
The two aldehydes used most often in microbial control are formaldehyde and acetaldehyde. Formaldehyde, with the chemical formula HCHO, is a colorless gas with a strong, pungent odor and is commonly sold in a solution known as formalin. It has been used extensively for preserving biological specimens and embalming due to its ability to cause coagulation of proteins, thereby killing bacteria and halting decay. However, due to its carcinogenic properties, its usage has decreased in favor of safer alternatives. Acetaldehyde is a volatile, colorless liquid that is a byproduct of the fermentation of sugars and the detoxification of alcohol in the liver. It is used as a starting material in the synthesis of various organic compounds and has microbial control properties as well.