Ars had its own article on this saying that you do not need enzymes. It's forcing the molecule through a tiny pore and reading the change in an electrical signal. That said, one problem mentioned is that the error rate is quite high.
"Both GridION and MinION operate using the same technology: DNA is added to a solution containing enzymes that bind to the end of each strand. When a current is applied across the solution these enzymes and DNA are drawn to hundreds of wells in a membrane at the bottom of the solution, each just 10 micrometres in diameter."
Perhaps this method use fewer enzymes than the old one.
"Both GridION and MinION operate using the same technology: DNA is added to a solution containing enzymes that bind to the end of each strand. When a current is applied across the solution these enzymes and DNA are drawn to hundreds of wells in a membrane at the bottom of the solution, each just 10 micrometres in diameter."
Perhaps this method use fewer enzymes than the old one.