Remember that scientist whose lab found 637 known species of bacteria in NYC’s subways? Well, that guy, geneticist Chris Mason, will be strolling around the Lower East Side Sunday spouting what will surely be the most fascinating/gag-inducing spiel one is likely to hear on a walking tour. Not into viruses and fungi? That’s okay — “The Artist and the Scientist: Microbial Maps” is just one of more than 200-plus free walking tours hitting the street this weekend as part of Jane’s Walk.

What is Jane’s Walk? It’s actually not just one walk but a series of mini-tours that have been taking place all over the world in honor of Jane Jacobs. She advocated that all people have something to teach others about their own neighborhoods, and in this spirit of community and education germ expert Mason, Mary Miss of City as a Living Lab, and artist William Lamson will stroll down Houston discussing their common interest in bacteria as they walk from the Lafayette subway station to Allen Street Sunday at 12:30 p.m. You’ll know you’re in the right place when you see people holding bright green “City as a Living Lab” signs.

If you have a low ick tolerance and your tastes lean more toward oh, say, local history and pretty buildings, Mark Herdter, a former Metropolitan Museum of Art photographer, has got you covered; he’ll be sharing his masterful knowledge of the Lower East Side’s past, reflected in the neighborhood’s churches, public housing buildings and modern Buddhist temples. His walks start at 3:30 p.m. Friday and 11 a.m. Saturday at the corner of East Broadway and Canal Street.

And lastly, if what you really want is the chance to stuff your face under the guise of educational betterment, Lindsay Realmuto openly admits “my ethnic heritage is Polish and Italian – so this walk is really just a fun excuse for me to eat my favorite childhood food.” She and fellow foodies will eat their way through a tour of six Italian and Polish eateries in North Brooklyn and Greenpoint, starting in American Park. “Kielbasa + Pizza: a Love Story (A Tasty Exploration of Polish and Italian History in Northern Brooklyn)” begins at 11 a.m. and again at 3 p.m. Saturday.