Cronobacter spp. are also generally positive for acetoin production (Voges–Proskauer test) and negative for the methyl red test, indicating 2,3-butanediol rather than mixed acid fermentation.
As Cronobacter spp. son xeralmente positivas para a produción de acetoína (proba de Voges–Proskauer) e negativas para a proba do vermello de metilo, que detecta 2,3-butanodiol en vez dunha fermentación ácida mixta.