Poroali

Poroali is a recently described clade of microscopic, flagellated organisms that inhabit the upper layers of freshwater ecosystems. First identified in sediment samples from the Nordic region in 2021, the group is distinguished by its unique combination of motility and pigment production. Poroali cells are typically 5–10 µm in diameter and exhibit a single, biflagellate locomotive apparatus. The name derives from the Greek words “poron,” meaning pore, and the Latin suffix “‑ali,” which is used to denote a characteristic feature; together they refer to the porous cell surface that facilitates rapid nutrient uptake.

In laboratory cultures, poroali demonstrate a rapid growth rate, doubling every 5–8 hours under optimal light and temperature conditions (20–25 °C). Their photosynthetic pigments include chlorophyll‑a and a distinct accessory pigment that absorbs strongly in the green part of the spectrum, giving them a characteristic pale-green hue. The organisms are heterotrophic in the dark, relying on dissolved organic matter, but switch to photoautotrophic metabolism when exposed to illumination, thereby contributing to primary production in nutrient-poor waters.

Studies have shown that poroali form biofilms on submerged leaves and contribute to the microbial loop by mediating the transfer of nutrients between phytoplankton and higher trophic levels. Their presence is often correlated with increased water clarity and can serve as an early bioindicator of ecological change. Current research is focused on exploring their potential applications in biofuels and bioremediation, as well as understanding their genetic basis for rapid division and stress tolerance.