The exploitation of natural antimicrobial compounds that can be used in food preservation has been fast tracked by the development of antimicrobial resistance to existing antimicrobials and the increasing consumer demand for natural food preservatives. 2-hydroxyisocaproic acid (HICA) is a natural compound produced through the leucine degradation pathway and is produced in humans and by certain microorganisms such as lactic acid bacteria and Clostridium species. The present study investigated the antibacterial efficacy of HICA against some important bacteria associated with food quality and safety and provided some insights into its possible antimicrobial mechanisms against bacteria. The results revealed that HICA was effective in inhibiting the growth of tested Gram-positive and Gram-negative bacteria including a multi-drug resistant P. aeruginosa strain in this study. The underlying mechanism was investigated by measuring the cell membrane integrity, membrane permeability, membrane depolarisation, and morphological and ultrastructural changes after HICA treatment in bacterial cells. The evidence supports that HICA exerts its activity via penetration of the bacterial cell membranes, thereby causing depolarisation, rupture of membranes, subsequent leakage of cellular contents and cell death. The current study suggests that HICA has potential to be used as an antibacterial agent against food spoilage and food-borne pathogenic bacteria, targeting the bacterial cell envelope.

中文翻译：

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2-羟基异己酸（HICA）的抗菌功效和可能的作用机制。

随着对现有抗微生物剂的抗微生物药物耐药性的发展以及消费者对天然食品防腐剂的需求不断增加，可用于食品保鲜的天然抗微生物化合物的开发得到了快速发展。2-羟基异己酸 (HICA) 是一种通过亮氨酸降解途径产生的天然化合物，由人类和某些微生物（如乳酸菌和梭菌属）产生。本研究调查了 HICA 对与食品质量和安全相关的一些重要细菌的抗菌功效，并对其可能的抗菌机制提供了一些见解。结果表明，HICA 可有效抑制测试的革兰氏阳性和革兰氏阴性细菌的生长，包括多重耐药的 P. 本研究中的绿脓杆菌菌株。通过测量细菌细胞中 HICA 处理后的细胞膜完整性、膜通透性、膜去极化以及形态和超微结构变化来研究潜在机制。证据支持 HICA 通过穿透细菌细胞膜发挥其活性，从而导致去极化、膜破裂、随后的细胞内容物泄漏和细胞死亡。目前的研究表明，HICA 有可能用作针对细菌细胞包膜的抗菌剂，以对抗食物腐败和食源性致病菌。HICA处理细菌细胞后的形态和超微结构变化。证据支持 HICA 通过穿透细菌细胞膜发挥其活性，从而导致去极化、膜破裂、随后的细胞内容物泄漏和细胞死亡。目前的研究表明，HICA 有可能用作针对细菌细胞包膜的抗菌剂，以对抗食物腐败和食源性致病菌。HICA处理细菌细胞后的形态和超微结构变化。证据支持 HICA 通过穿透细菌细胞膜发挥其活性，从而导致去极化、膜破裂、随后的细胞内容物泄漏和细胞死亡。目前的研究表明，HICA 有可能用作针对细菌细胞包膜的抗菌剂，以对抗食物腐败和食源性致病菌。