Being so mucoid, it is a bit hard to get a great yield when extracting plasmid DNA from Klebsiella pneumoniae, using a commercial maxiprep kit with collumn. It takes a lot of time for the volumes (cell lysate and wash and elution buffers) to get through the collumn, which I can only assume is due to the mucus that eventually fills the membrane and doesn't allow a good adherence of the DNA to it.
Is there any way to solve this problem?
You can resuspend the pellet in Tris-Cl pH=8, 100 mM (from 10 to 20 ml of o/n culture re-suspended in half of the volume). Boil the suspension during 2 minutes (water bath or thermoblock). Centrifuge at 12 000 g to 15 000g during 5 minutes at +4. Remove the plasmid-containing supernatant as soon as possible and use any protocol for plasmid clean up from commercial kits (example https://www.medicine.wisc.edu/sites/default/files/PlasmidPrep_DNA-Cleanup_QiagenMiniprep.pdf). Hope this help.
The important parameter in plasmid isolation to get good yield is the plasmid copy no and the lysis method used. Low copy no plasmids generally give low yields. So you can start with a higher culture volume. You might wana try beat beating method to lyse your cells.
Try these methods you will get good yield.
You can grow them in broth with shaking and make the extraction in triplicate!
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