Li Tingting, Yang Bing, Li Xuepeng, Li Jianrong, Zhao Guohua, Kan Jianquan
1College of Food Science, Southwest University, Chongqing, China.
2College of Life Science, Dalian Nationalities University, Dalian, China.
J Food Sci Technol. 2018 Aug;55(8):3016-3025. doi: 10.1007/s13197-018-3222-y. Epub 2018 May 21.
The spoilage of aquatic products is mainly caused by the bacterial growth, and the specific spoilage organism (SSO) plays an important role. Quorum sensing (QS) is a microbial cell-cell communication system which is coordinated with the population density, and is controlled by -acyl-homoserine lactone (AHLs) as the Gram-negative bacteria communication signals. In this study, the SSO was (PF-04), isolated from the turbot () during aerobically refrigerated storage. The supernatant extract of PF-04 tested the AHLs activities utilizing biosensor CV026. AHL production was influenced by the environment temperature, and AHL production reduced obviously at 10 °C compare with 25 °C. In Luria-Bertani (LB) supplemented with 0.5-1.0% NaCl, AHL production reached the maximum. The AHL production was also regulated by pH of culture medium, acidic condition was conducive to persistent existence of the AHL molecules, but the alkaline environment would cause chemically unstable of AHL molecules. QS system in played an imperative role in biofilm formation, protease and siderophore production. AHLs could regulate above three factors in PF-04. In summary, this study showed that (1) the influence of different environmental conditions (temperature, NaCl and pH) on AHL production revealed the correlation of QS in foods and (2) that proved the effect of external AHLs to regulate the biofilm formation, protease and siderophore production in PF-04.
水产品的腐败主要是由细菌生长引起的，特定腐败菌（SSO）起着重要作用。群体感应（QS）是一种微生物细胞间通讯系统，与种群密度相协调，由革兰氏阴性菌的通讯信号N-酰基高丝氨酸内酯（AHLs）控制。在本研究中，从有氧冷藏储存的大菱鲆（Scophthalmus maximus）中分离出特定腐败菌PF-04。PF-04的上清液提取物利用生物传感器CV026检测AHLs活性。AHLs的产生受环境温度影响，与25℃相比，在10℃时AHLs的产生明显减少。在添加0.5-1.0% NaCl的Luria-Bertani（LB）培养基中，AHLs的产生达到最大值。AHLs的产生也受培养基pH值的调节，酸性条件有利于AHL分子的持续存在，但碱性环境会导致AHL分子化学不稳定。大菱鲆中的QS系统在生物膜形成、蛋白酶和铁载体产生中起着至关重要的作用。AHLs可以调节PF-04中的上述三个因素。总之，本研究表明：（1）不同环境条件（温度、NaCl和pH）对AHLs产生的影响揭示了食品中QS的相关性；（2）证明了外源AHLs对调节PF-04中生物膜形成、蛋白酶和铁载体产生的作用。
