The only effective way to store bacterial cultures for short periods of time is to arrest their metabolism by freezing.
True
False
The correct answer and explanation is:
The correct answer is False.
Freezing is one way to preserve bacterial cultures, but it is not the only effective method for short-term storage. While freezing can arrest bacterial metabolism by lowering temperatures to the point where biochemical reactions slow or stop, it is not always the best option for all bacterial species, especially for short-term storage. Freezing often requires the addition of cryoprotectants to prevent ice crystal formation, which can damage the bacterial cells.
For short-term storage, bacterial cultures are often stored in refrigerated conditions rather than freezing. Storing bacteria at temperatures just above freezing, typically between 4°C and 8°C, can effectively slow down metabolism and keep the bacteria viable without the risk of freezing-induced damage. This method is particularly useful for storing cultures for a few days to weeks.
Alternatively, bacterial cultures can be preserved on agar plates or in nutrient broth, which can be stored in a refrigerator. This method maintains the bacteria in a state where they are not growing actively but can be revived quickly when needed.
For longer-term preservation, other methods such as lyophilization (freeze-drying) or the use of glycerol stocks can be employed. These techniques help in maintaining the bacterial cultures over longer periods by preventing metabolic activity while allowing revival when necessary.
In conclusion, while freezing is a useful preservation method, it is not the only effective way to store bacterial cultures for short periods. The method chosen depends on the bacterial species, the intended storage time, and the resources available.