The microbial sensor based on budding cells of the dimorphic yeast Arxula adeninivorans LS3 is one of the best suitable sensors for rapid measurement of biodegradable substances. However, Arxula is able to change its morphology (budding cells mycelia) in response to the cultivation temperature. The suitability of such mycelia was tested as microbial sensor component. The mycelia-based sensor possess a similar linear response, stability, limit of determination and detection compared with the conventional budding cell-based sensor. However, differences exist in the storage capacity and substrate specificity: the mycelia-sensor has with six months a better storage stability as the conventional sensor, achieves a higher sensitivity for specific amino acids or sugars, shows a better correlation between sensorBOD and the BOD 5 -value with yeast extract as model wastewater and is more suitable for measurement of salt water.