How do I set the default bacterial transformation strain for new circular sequences?
Open Preferences
Click menu SnapGene → Preferences (macOS) or Edit → Preferences (Windows or Linux).
Select "General" in the sidebar an use the drop-down for "Default Transformation Strain" to set the default E. coli strain. The methylation properties of each strain are listed.
Edit the Default Strain List

By default, SnapGene provides a list of 8 commonly used E. coli strains. However, SnapGene includes a database of over 200 E. coli strains. To remove and/or add other strains to the default list, click the drop-down and choose "Edit Strains List...".

In the "Edit Strains List" dialog, use the check boxes to select the strains that will be shown by default in the drop-down menu.
Use the dropdown to set the "Default Transformation Strain" for newly created plasmid sequences.

The default list will be shown in the Info Panel when choosing "Bacterial Transformation Strain".