From the January 2008 issue of Microbe: “Well more than 99% of microbes from the environent do not thrive in culture and, historically, remain uncharacterized”.
This is an astounding statistic. We only work on what we can propagate, naturally. But many microbes could be adapted to grow in culture, given time and effort. The potential benefits of studying such organisms are huge. But sadly, there is no funding to do this work.