Hi,
I'm not sure the class can be easily pickled.
However, if you want to solve your loading time problem, the easiest solution is to save the quadstore (which is actually a SQLite3 database) in a local file. Loading a saved quadstore take only a fraction of second, independently of the size of the quadstore.
You can do:
default_world.set_backend(filename = "/path/to/your/file.sqlite3")
to store the quadstore in the given file, and then use default_world.save() to write the file.
More info are available in the doc here:
http://owlready2.readthedocs.io/en/latest/world.html#persistent-world-storing-the-quadstore-in-an-sqlite3-fileThe only limit is that you cannot save each ontology in a separate quadstore: you need to put everything in the same file. But yoy can safely put all ontologies in the same quadstore, unless they are really big.
Jiba