I stand corrected. A quick look shows that in 2013 the was confirmation that bacteria will feed on living algae. I was always under the impression bacteria consumed the nutrients that algae need to grow as well as algae that was dying off.
Scientists offer first definitive proof of bacteria-feeding behavior in green algae
Researchers have captured images of green alga consuming bacteria, offering a glimpse at how early organisms dating back more than 1 billion years may have acquired free-living photosynthetic cells. This acquisition is thought to be a critical first step in the evolution of photosynthetic algae...
www.sciencedaily.com