Isolation, characterization, and application of biogenic amines-degrading strains from fermented food

The aim of the present study was to screen a type of microorganism for degradation of bioamines in fermented food, investigate their characteristics in growth and degrading bioamines, and also assess the effects of inoculating strain starter cultures on biogenic amines (BAs) accumulation in soy sauces. The screening for no-BAs-producing strains was carried out using a double color method and an oxidase test. The degradation rates were determined by high-performance liquid chromatography with fluorescence detection (HPLC-FLD). In this study, strains (J2 and J3) with high ability were isolated from some naturally fermented food samples. They were identified as Wickerhamomyces anomalus and Millerozyma farinosa, respectively, by partial amplification of the 16S rRNA gene. The strains exhibited high multiple BAs degradation activity over a range of pH values (5-8), temperatures (28-35 degrees C), salt (NaCl) concentrations (0-10%), and ethanol concentrations (0-10%). One of the isolated strains, W. anomalus, has the highest biodegradability for putrescine, cadaverine, histamine, and tyramine with degradation rates of 61, 66, 67, and 59% in an experimental model, and 39.3, 33.6, 39.9, and 43.1% in fermented soy sauce containing 10% of NaCl, respectively. Additionally, the study of mechanism demonstrated that the removal ability of BAs was mainly due to biodegradation.