Syntrophic acetate oxidation
Clostridium ultunense strain Esp was isolated from sludge from an upflow anaerobic filter treating wastewater from a fishmeal factory. The reactor operated at 37 °C at an organic loading rate of 20–35 g COD day -1 and contained a high ammonium concentration (6 g NH4+- NL -1). Cells are straight or slightly curved rods giving a variable Gram reaction. They appear singly or in chains. Strain Esp produces ellipsoidal endospores occupying a terminal or a subterminal position and possesses a single polar flagellum.