Key Laboratory of Aquatic Product Processing, Ministry of Agriculture and Rural Affairs, National R&D Center for Aquatic Product Processing, South China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangzhou 510300, China; Co-Innovation Center of Jiangsu Marine Bio-industry Technology, Jiangsu Ocean University, Lianyungang 222005, China; Collaborative Innovation Center of Seafood Deep Processing, Dalian Polytechnic University, Dalian 116034, China.
Key Laboratory of Aquatic Product Processing, Ministry of Agriculture and Rural Affairs, National R&D Center for Aquatic Product Processing, South China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangzhou 510300, China.
Food Res Int. 2022 Jun;156:111153. doi: 10.1016/j.foodres.2022.111153. Epub 2022 Mar 17.
Application of low-salt fish sauce is restricted by its easy spoilage and poor flavor formation. In this study, a salt-tolerant strain Tetragenococcus muriaticus with powerful salt tolerance was isolated as starter for the low-salt fish sauce fermentation. The 16S rRNA gene high-throughput sequencing showed that Staphylococcus was the main microbial genus at the beginning of fermentation, reaching 73.75%, followed by Tetragenococcus (16.36%) and Pseudomonas (6.68%), while Tetragenococcus quickly took over the dominant position with the relative abundance over 56.9% after 10 d fermentation and peaked at the end of fermentation. There were a total of 144 volatile compounds identified by HS-SPME-GC-MS, among which aldehydes, esters, alcohols, heterocycles, ketones, and acids were the main volatile flavor compounds and were mainly produced by Tetragenococcus, Synechococcus, Rhodococcus, Stenotrophomonas, Achromobacter, and Brucella based on the correlation network maps constructed by the Pearson's correlation coefficient after O2PLS evaluation. The Sobs, ACE, Chao, and Shannon indexes of microbial community were significantly reduced, while the Simpson index was markedly enhanced in the low-salt fish sauce fermented with T. muriaticus compared with them in the fish sauce without starter addition. The addition of T. muriaticus also obviously improved the types and concentrations of main volatile flavor compounds in the low-salt fish sauce. The correlation network map showed that Tetragenococcus was the only genus that played a crucial role in the spoilage microorganism inhibition and volatile flavor improvement in the fish sauce. T. muriaticus can be developed as a potential microbial starter for the industrial production of low-salt fish sauce.
低盐鱼露的应用受到其易腐坏和风味形成不良的限制。在这项研究中，作为低盐鱼露发酵的起始剂，分离出了一株具有强大耐盐性的耐盐栖海菌（Tetragenococcus muriaticus）。16S rRNA 高通量测序显示，在发酵初期，葡萄球菌是主要的微生物属，达到 73.75%，其次是栖海菌（16.36%）和假单胞菌（6.68%），而栖海菌在 10d 发酵后迅速占据主导地位，相对丰度超过 56.9%，并在发酵结束时达到峰值。通过 HS-SPME-GC-MS 共鉴定出 144 种挥发性化合物，其中醛类、酯类、醇类、杂环类、酮类和酸类是主要的挥发性风味化合物，主要由栖海菌、聚球藻、红球菌、寡养单胞菌、无色杆菌和布鲁氏菌产生，这基于 O2PLS 评价后通过 Pearson 相关系数构建的相关网络图谱。与未添加起始剂的鱼露相比，添加栖海菌的低盐鱼露的微生物群落的 Sobs、ACE、Chao 和 Shannon 指数显著降低，而 Simpson 指数明显提高。栖海菌的添加还明显改善了低盐鱼露中主要挥发性风味化合物的种类和浓度。相关网络图显示，栖海菌是唯一对鱼露中腐败微生物抑制和挥发性风味改善起关键作用的属。栖海菌可作为低盐鱼露工业化生产的潜在微生物起始剂。
