Dinobryon are a type of Chrysophyceae or golden brown algae that reside in freshwater--specifically temperate lakes. They have two methods of obtaining nutrients. They can ingest bacteria by phagotrophy. They are in turn eaten by copepods and Daphnia (water fleas). By ingesting bacteria, they are able to incorporate the carbon from these bacteria into the food chain of the lake. They can also carry out phototrophy and can use light energy to obtain carbon in the production of sugar. They fill an important role as both consumer and producer in freshwater lakes and are known as a mixotroph.
Termites are consumers of wood. Because wood contains mainly ligno-cellulose fibers, the digestion of this material requires the presence of specific hydrolytic enzymes. Wood cellulose is a polysaccharide--a carbohydrate consisting of long chains of sugar molecules.
Termites can secrete some cellulose enzymes (cellulases) but they also rely on enzymes from the symbiotic microorganisms residing in their gut to assist with the digestion of their food. One method of breaking down the carbohydrates is fermentation by some of the gut microbes. Others produce methane gas as a by-product of the digestion of wood.
There are many different populations of microorganisms that are responsible for the digestion of lignin and cellulose--some are anaerobic and some aerobic. Different environmental conditions are present in the hind and mid-gut and the residents are separated according to whether they are aerobic or anaerobic. The symbionts living in the termite gut include different types of bacteria, archaea and protozoa.
I have included a link with excellent pictures of the residents inside a termite's digestive tract.