It's common knowledge that potential employers may check your social media accounts. While you shouldn't post loads of drunken party pics, talking about your interests can make you look better than other candidates.
As finance blog The Simple Dollar points out, when the author was checking into potential candidates, he would gravitate most towards those who discussed their field outside of work:
This indicated that they cared enough about what they were doing that they were engaged in it outside of their nine to five jobs. They sought out situations to discuss aspects of their chosen profession both with other professionals and with their clients.
You have a couple of options if you want to put on a good face. Most simply, you could start showing off your work or talking with others via your existing accounts. If you prefer to keep work and play separate, you can set up secondary accounts that you use for professional correspondence. You can't reasonably assume that no employer will ever find your personal accounts, but at least you can volunteer your professional versions to put your best foot forward.