Department of Food Science, Foggia University, Foggia, Italy.
Lett Appl Microbiol. 2011 Oct;53(4):395-402. doi: 10.1111/j.1472-765X.2011.03120.x. Epub 2011 Aug 1.
Lactobacillus brevis IOEB 9809 is able to produce both tyramine and putrescine via tyrosine decarboxylase and agmatine deiminase enzymes, respectively, when cultured on synthetic media. The aims of this study were to assess the expression of L. brevis IOEB 9809 tdc and aguA1 genes, during wine fermentation and to evaluate the effect of substrate availability and pH on tdc and aguA1 expression, as well as on biogenic amine production and L. brevis viability.
The relative expression of L. brevis IOEB 9809 tdc and aguA1 genes was analysed in wine by quantitative real-time RT-PCR (qRT-PCR) during a period of incubation of 30 days. Cell viability, pH values, putrescine and tyramine concentration were monitored throughout the experiments.
The wine trials indicated that L. brevis IOEB 9809 is able to produce both tyramine and putrescine during wine fermentation. Increased cell viability was also observed in wine supplemented with tyrosine or agmatine. qRT-PCR analysis suggests a strong influence of substrate availability on the expression of genes coding for tyrosine decarboxylase and agmatine deiminase in L. brevis IOEB 9809. Less evident is the relationship between putrescine and tyramine production and tolerance to wine pH.
To our knowledge, this study represents the first assessment of relative expression of L. brevis IOEB 9809 genes involved in biogenic amine production in wine. Furthermore, an effect of biogenic amine production on viability of L. brevis during wine fermentation was established.
短乳杆菌 IOEB 9809 能够分别通过酪氨酸脱羧酶和胍氨酸脱氨酶酶将酪氨酸转化为酪胺和腐胺。本研究的目的是评估 L. brevis IOEB 9809 tdc 和 aguA1 基因在葡萄酒发酵过程中的表达，并评估底物可用性和 pH 值对 tdc 和 aguA1 表达以及生物胺产生和 L. brevis 活力的影响。
通过定量实时 RT-PCR（qRT-PCR）在 30 天的孵育期内分析葡萄酒中 L. brevis IOEB 9809 tdc 和 aguA1 基因的相对表达。在整个实验过程中监测细胞活力、pH 值、腐胺和酪胺浓度。
葡萄酒试验表明，L. brevis IOEB 9809 能够在葡萄酒发酵过程中同时产生酪胺和腐胺。在添加酪氨酸或胍氨酸的葡萄酒中也观察到细胞活力增加。qRT-PCR 分析表明，底物可用性对 L. brevis IOEB 9809 编码酪氨酸脱羧酶和胍氨酸脱氨酶的基因表达有很强的影响。而腐胺和酪胺产生与葡萄酒 pH 值耐受性之间的关系则不那么明显。
据我们所知，这项研究代表了对 L. brevis IOEB 9809 参与葡萄酒中生物胺产生的相对基因表达的首次评估。此外，还确定了生物胺产生对葡萄酒发酵过程中 L. brevis 活力的影响。
