This method of physical microbial control combines the removal of all moisture with extremely low temperatures.

• A. Desiccation.
• B. Lyophilization.
• C. Irradiation.
• D. Pasteurization.

Answer: (B)

Verified step by step guidance

1. Understand the concept of lyophilization: Lyophilization, also known as freeze-drying, is a method used to preserve microorganisms by removing moisture through sublimation at low temperatures.
2. Identify the key components of lyophilization: It involves freezing the microbial sample and then reducing the surrounding pressure to allow the frozen water in the sample to sublimate directly from solid to gas.
3. Compare lyophilization with other methods: Desiccation involves drying out the sample but not necessarily at low temperatures. Irradiation uses radiation to kill microbes, and pasteurization involves heating to kill pathogens.
4. Recognize the advantages of lyophilization: This method preserves the viability and structure of microorganisms, making it ideal for long-term storage and transport.
5. Apply the concept: When asked about a method combining moisture removal and low temperatures, lyophilization is the correct answer due to its unique process of freeze-drying.