What role do microorganisms play in the detritus food chain?

Microorganisms play a vital role in the detritus food chain primarily by breaking down organic matter. This process is essential for the recycling of nutrients back into the ecosystem. When organisms die or produce waste, microorganisms such as bacteria and fungi decompose this material, converting complex organic substances into simpler compounds. This not only helps in the decomposition process but also makes nutrients available for plants and other organisms, thereby supporting the growth of new life.

In contrast, while some microorganisms can produce oxygen through photosynthesis, that function is primarily associated with specific types of bacteria and algae rather than being a general role of all microorganisms in the detritus food chain. Photosynthesis (as included in another choice) is not a function of all microorganisms. Similarly, capturing solar energy is mainly the role of photosynthetic organisms, and not a function directly related to the detritus food chain which relies heavily on decomposers. Therefore, the correct choice emphasizing the breakdown of organic matter clearly illustrates the critical function of microorganisms in nutrient recycling within the ecosystem.