Abstract

Biogenic amines (BAs) are low molecular weight organic bases formed by natural amino acids decarboxylation and trigger an array of toxicological effects in humans and animals. Bacterial amine oxidases enzymes are determined as practical tools to implement the rapid quantification of BAs in foods. Our study set out to obtain a new efficient, amine oxidase enzyme for developing new enzyme-based quantification of histamine. The soils from different sources were screened using histamine as sole carbon and nitrogen sources, and histamine oxidase producing bacteria were selected and identified using specific primers for histamine oxidase (HOD) gene. The HOD gene of six strains, out of 26 isolated histamine-utilizing bacteria, were amplified using our designed primers. The HOD enzyme from Glutamicibacter sp. N1A3101, isolated from nettle soil, was found to be thermostable and showed the highest substrate specificity toward the histamine and with no detected activity in the presence of putrescine, cadaverine, spermine, and spermidine. Its oxidation activity toward tyramine was lower than other HOD reported so far. The isolated enzyme was stable at 60 °C for 30 min and showed pH stability ranging from 6 to 9. Furthermore, we indicated the induction of identified HOD activity in the presence of betahistine as well, with nearly equal efficiency and without the consumption of the substrate.

中文翻译：

---

一种来自谷氨酸杆菌属的新型热稳定碱性组胺氧化酶。N1A3101，由组胺及其类似物β组氨酸诱导

摘要

生物胺（BAs）是由天然氨基酸脱羧形成的低分子量有机碱，可触发一系列对人类和动物的毒理作用。细菌胺氧化酶被确定为对食品中BA进行快速定量的实用工具。我们的研究着手获得一种新的高效胺氧化酶，用于开发基于酶的组胺定量分析。使用组胺作为唯一的碳源和氮源来筛选不同来源的土壤，并使用组胺氧化酶（HOD）基因的特异性引物筛选并鉴定出产生组胺氧化酶的细菌。使用我们设计的引物扩增了26个分离的利用组胺的细菌中的6个菌株的HOD基因。谷氨酸杆菌的HOD酶。从荨麻土壤中分离出来的N1A3101具有热稳定性，并且对组胺表现出最高的底物特异性，在腐胺，尸胺，亚精胺和亚精胺的存在下未检测到活性。迄今为止，其对酪胺的氧化活性低于其他HOD。分离的酶在60°C下稳定30分钟，pH值稳定在6到9之间。此外，我们还表明，在存在倍他司汀的情况下，诱导的已鉴定HOD活性也几乎相同，并且不消耗基质。