A 20-year study in Lake Mendota shows bacteria evolving seasonally, with genetic variations resetting annually. A 2012 extreme weather event caused lasting gene shifts, highlighting microbial ...

An inoculating loop can be used to transfer bacteria. It is sterilised by heating it to red hot in a Bunsen flame, before and after use. To inoculate the agar, lift the lid of the Petri dish and tilt.