Degradation of undesirable biogenic amines (BAs) in foodstuffs by microorganisms is considered one of the most effective ways of eliminating their toxicity. In this study, we designed two sets of primers for the detection and quantification of the multicopper oxidase gene (MCO), which encodes an enzyme involved in BAs degradation, and endogenous (glyceraldehyde-3-phosphate dehydrogenase) gene (GAPDH) in Lactobacillus casei group by real-time PCR (qPCR). We tested 15 Lactobacillus strains in the screening assays (thus, MCO gene possessing assay (PCR) and monitoring of BAs degradation by HPLC-UV), in which Lactobacillus casei CCDM 198 exhibited the best degradation abilities. For this strain, we monitored the expression of the target gene (MCO) in time (qPCR), the effect of redox treatments (cysteine, ascorbic acid) on the expression of the gene, and the ability to degrade BAs not only in a modified MRS medium (MRS/2) but also in a real food sample (milk). Moreover, decarboxylase activity (ability to form BAs) of this strain was excluded. According to the results, CCDM 198 significantly (P < 0.05) reduced BAs (putrescine, histamine, tyramine, cadaverine), up to 25% decline in 48 h. The highest level of relative expression of MCO (5.21 ± 0.14) was achieved in MRS/2 media with cysteine.

微生物降解食品中不良生物胺的方法被认为是消除其毒性的最有效方法之一。在这项研究中，我们设计了两组引物，用于检测和定量多聚铜氧化酶基因（MCO），该基因编码参与BAs降解的酶和干酪乳杆菌的内源性（甘油醛-3-磷酸脱氢酶）基因（GAPDH）。通过实时PCR（qPCR）进行分组。我们测试了15个乳杆菌中筛选试验菌株（因此，MCO基因具有测定（PCR）和监测由HPLC-UV的BA降解），在该干酪乳杆菌CCDM 198表现出最好的降解能力。对于此菌株，我们及时监测了目标基因（MCO）的表达（qPCR），氧化还原处理（半胱氨酸，抗坏血酸）对该基因表达的影响，以及不仅在修饰的氨基酸中降解BA的能力MRS介质（MRS / 2），也可以在真实食品样本中（牛奶）。此外，排除了该菌株的脱羧酶活性（形成BAs的能力）。根据结果​​，CCDM 198显着（P <0.05）降低了BA（腐胺，组胺，酪胺，尸胺），在48小时内降低了25％。在半胱氨酸的MRS / 2培养基中，MCO的相对表达水平最高（5.21±0.14）。