I'm afraid I giggled, bounced up to my husband, and said "You're a real author now! You got a one-star review!"
After we finally stopped laughing, (ok, at least stopped except when we looked at each other and laughed), that was pretty much it. Okay, there may have been a few dramatic readings of the review in various cartoon voices. Possibly.
But seriously, don't worry. One-stars help customers know if a product is their type of thing just as much as five stars do, and help promote sales. If you get a rash of them, then if you really want, treat them like unhelpful beta readers who gave you almost no feedback - if there's anything that the majority have in common (and it doesn't really work until you have at least ten), then you might tackle trying to improve that in your next book. Sometimes it might be a category or keyword change so they don't feel like they were going to get one type of book and instead got another, or redoing the blurb (no, it's not always the text that needs changed.) Sometimes it might be "Huh. 25 people said the pacing was slow in the first half, and too rushed in the second. Well, maybe I need to check that on my next book."
But "I don't like this genre so I don't like this book" is definitely not your problem, and the rest of your readers are smart enough to treat it like the guy ranting on the corner - roll up your windows and drive on, man.