I have recently come across this situation during a site redesign project. There are two primary objectives for the web site property, each with their own distinct and unique persona. What do you do in this situation? I recommend you embrace the bipolar nature of the site, and use a split screen design.
A split screen design, as it suggests, splits the home page in half, each side embracing one of the personas. You can design each side to look very different – color schemes, styles, fonts, etc. Shared elements such as header, footer, navigation, hero images, etc. bridge the gap between the different sides of the site. The hero can rotate between different calls to action, focusing on the personas and themes. And, shared pages such as the home page can be a continuous scroll to allow the large volume of content.
Instead of fighting the nature of the beast to blend the personas, embrace the content divide, emphasize it, and stay focused on your users.
Here are some examples of Split Screen Design I have come across in my research: