microbivores

Microbivores are organisms that feed primarily on microorganisms, including bacteria, archaea, algae, and other microscopic life. They occupy a key position in many ecosystems by linking microbial production to higher trophic levels and driving nutrient cycling. Microbivory occurs across diverse taxa within the microfauna and meiofauna. Representative microbivores include protists such as ciliates, flagellates, and amoebae; bacterivorous nematodes; rotifers; tardigrades; and some micro-arthropods such as mites and collembolans.

Ecological role: By grazing on microbial biomass, microbivores regulate microbial communities, accelerate organic matter turnover, and promote nutrient mineralization. In soils, their activity supports decomposition and can influence soil structure and carbon storage. In aquatic and sediment systems, they help transfer energy from microbial production up the food web.

Feeding strategies: Bacterivorous protists use phagocytosis or specialized structures to consume bacteria. Nematodes and tardigrades may ingest microbial cells, while rotifers and micro-arthropods often graze on biofilms, detritus with embedded microbes, or microalgae. Some species are selective; others are opportunistic.

Significance and study: Microbivores indicate soil and water ecosystem health and influence nutrient cycling, decomposition, and carbon fluxes. Their abundance responds to moisture, organic matter inputs, and management practices. Researchers identify microbivores by microscopy, DNA barcoding, and stable isotope methods to map trophic links in microbial food webs.