Periphyton and Its Key Role in Paddy Fildes and Environmental Health

Periphyton or periphytic biofilms are microbiomes consisting of a complex matrix including autotrophic and heterotrophic types such as algae, bacteria, fungi, protozoa, metazoa, etc. Periphytic biofilms are commonly found in many aquatic ecosystems such as the sea, lakes, rivers, streams, ponds and paddy fields and play an important role in primary production, food network interactions such as carbon cycle, phosphorus and some other nutrients. Periphytic biofilms respond quickly to environmental changes, especially nutrients and light, and can be used as an indicator of disturbances and adverse conditions in aquatic ecosystems. In recent years, research interests in using periphyton for controljng the non-point source pollution, treating contaminated water, and interferencing nutrient have increased. Although the effects of periphyton on water quality and its relationship to water flows have been investigated by researchers, our understanding of their function in paddy fields and their effect on nutrient cycles is limited. In the present article, an attempt has been made to present a summary of the research done on periphyton and their effect on the nutrient cycle, especially on rice plants' growth in paddy fields.