A lease is a legal contract. If a property is leased, the owner must fulfill the obligations of the terms of the document. The original owner would have to buy you out of your lease or sell the property with the new owners being aware that it is leased property and that they would become the lessor.
I think they can b/c since it is under new ownership your lease with the old guy is void. I would say you would have to talk to a lawyer about it first before jumping to a conclusion....or you can try and ask the new owner if there is something that you can work out with them. They might want to keep you in there....I would talk to all parties before you start to worry. You do have a lease, so you do have rights. I hope that has helped you.
I don't think so because when you buy a property you would buy the lease as well. But you need to check with the rental association in your area