Epipyxis utriculus

Epipyxis utriculus is a species of golden algae (Chrysophyceae) that functions as an epiphyte or a parasite, primarily affecting other microalgae. In the context of industrial algae cultivation and aquatic biology, it is recognized as a significant organism that can compromise the health and yield of target phytoplankton cultures.

The organism is characterized by a single-celled flagellated stage enclosed within a transparent, vase-shaped lorica. Its interaction with host cells is classified as epiphytic overgrowth, which acts as a form of biological stress, causing severe nutrient and light limitation for the host organism.

It predominantly affects various species of microalgae used in aquaculture and biotechnology. When Epipyxis utriculus colonizes a host population, it can cause rapid decline in the culture density, potentially leading to the total collapse of the biomass production system.

Symptoms of infestation include a noticeable reduction in cell division rates, inhibited motility of flagellated species, and general morphological degradation. Microscopic examination typically reveals the distinctive loricae of Epipyxis attached to the surface of the host cells, impeding their normal physiological functions.

To protect cultures from this organism, a combination of rigorous control and management strategies is essential:

• Strict sterilization of growth media and containers.
• Implementation of advanced filtration systems to exclude invasive species.
• Monitoring of water chemical parameters to prevent organic matter accumulation.
• Maintaining optimal light and temperature conditions to favor the target algae.

Environmental conditions that favor the rapid proliferation of Epipyxis utriculus include moderate temperatures and high concentrations of dissolved organic carbon. Prevention relies on maintaining highly controlled axenic or semi-axenic conditions to suppress opportunistic colonization by this golden alga.