Tran Thi Thu Hang, Nguyen Thi Phuong Anh, Pham Thi Diu, Nguyen Thi Hong, Nguyen Thi Lam Doan, Nguyen Thi Thanh Thuy, Tran Thi Lan Huong, Giang Trung Khoa, Bui Thi Thu Hien, Do Bien-Cuong, Nguyen Tien-Thanh, Haltrich Dietmar, Nguyen Hoang Anh
Faculty of Food Science and Technology, Vietnam National University of Agriculture, Hanoi, Viet Nam.
Research Institute for Marine Fisheries, Ministry of Agriculture and Rural Development, Hanoi, Viet Nam.
J Biotechnol. 2023 Mar 20;366:46-53. doi: 10.1016/j.jbiotec.2023.03.002. Epub 2023 Mar 17.
Traditionally produced fish sauce can contain significant amounts of histamine. In some instances, the histamine concentration may be well above the limit recommended by the Codex Alimentarius Commission. The aim of this study was to discover new bacterial strains capable of growing under the stressful environmental conditions of fish sauce fermentation and metabolizing histamine. In this study, 28 bacterial strains were isolated from Vietnamese fish sauce products based on their ability to grow at high salt concentrations (23% NaCl) and tested for their ability to degrade histamine. Strain TT8.5 showed the highest histamine-degradation (45.1 ± 0.2% of initially 5 mM histamine within 7 days) and was identified as Virgibacillus campisalis TT8.5. Its histamine-degrading activity was shown to be localized intracellularly and the enzyme is a putative histamine dehydrogenase. The strain exhibited optimal growth and histamine-degrading activity at 37°C, pH 7%, and 5% NaCl in halophilic archaea (HA) histamine broth. It also showed pronounced histamine-degrading activity in HA histamine broth when cultivated at temperatures of up to 40 °C as well as in the presence of up to 23% NaCl. After treatment with immobilized cells, 17.6-26.9% of the initial histamine in various fish sauce products were reduced within 24 h of incubation, while no significant changes in other parameters of fish sauce quality were observed after this treatment. Our results indicate that V. campisalis TT8.5 is of potential interest to be applied in histamine degradation of traditional fish sauce.
传统生产的鱼露可能含有大量组胺。在某些情况下，组胺浓度可能远高于食品法典委员会推荐的限量。本研究的目的是发现能够在鱼露发酵的应激环境条件下生长并代谢组胺的新细菌菌株。在本研究中，基于它们在高盐浓度（23%氯化钠）下生长的能力，从越南鱼露产品中分离出28株细菌菌株，并测试它们降解组胺的能力。菌株TT8.5表现出最高的组胺降解率（在7天内降解初始5mM组胺的45.1±0.2%），并被鉴定为坎皮斯盐芽孢杆菌TT8.5。其组胺降解活性显示定位于细胞内，该酶是一种推定的组胺脱氢酶。该菌株在嗜盐古菌（HA）组胺肉汤中于37°C、pH 7%和5%氯化钠条件下表现出最佳生长和组胺降解活性。当在高达40°C的温度下以及在高达23%氯化钠存在的情况下培养时，它在HA组胺肉汤中也表现出显著的组胺降解活性。用固定化细胞处理后，在孵育24小时内，各种鱼露产品中初始组胺的17.6 - 26.9%被降解，而在此处理后鱼露质量的其他参数未观察到显著变化。我们的结果表明，坎皮斯盐芽孢杆菌TT8.5在传统鱼露的组胺降解方面具有潜在的应用价值。
