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Specific sterilization of psychrotrophs in foods by inactivation of alanine racemase

通过灭活丙氨酸消旋酶对食品中的耐冷菌进行特异性灭菌

基本信息

批准号：
12480026
负责人：
YOKOIGAWA Kumio
金额：
$ 6.14万
依托单位：
Nara Women's University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
2000
资助国家：
日本
起止时间：
2000 至 2002
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-12480026/
关键词：
psychrotroph alanine racemase food hygiene 有機酸香辛料

项目摘要

Psychrotrophic bacteria are widely distributed in nature, and often cause deterioration in foods stored at a low temperature. Accordingly, the bacteria have been studied to better understand food preservation, While psychrotrophs are easily sterilized by heat treatment, their extracellular hydrolytic enzymes survive and degrade the quality of foods. Therefore, sterilizing psychrotrophs before their growth in foods is important for food preservation at low temperature. However, there is no effective sterilization method of psychrotrophs in foods other than thermal sterilization, which often changes the original taste.Alanine racemase (EC 5.1.1.1) is a pyridoxal 5'-phosphate-dependent enzyme catalyzing racemization of L- and D-alanine. The enzyme occurs widely in bacteria and is essential in synthesis of peptidoglycan of bacterial cell walls by providing the D-enantiomer. The peptidoglycan biosynthesis is unique to bacteria, and therefore the enzyme has been a target of antibacterial dru … More gs. We examined the sensitivity of psychrotrophs to organic acids and spices in comparison with mesophiles, in order to develop an effective sterilization method of psychrotrophs based upon inactivation of alanine racemase.Fsychrotrophs such as P.fluorescens and B.psychrosaccharolyticus were found to be more sensitive to citrate, acetate, lactate, and succinate at 0.01% concentration than the mesophiles. The organic acid at the concentration also inactivated alanine racemase. Mesophiles were tolerant to the treatment and the intracellular alanine racemase in mesophiles was not inactivated.Also, psychrotrophs were more sensitive to various spices than the mesophiles, although the sensitivity of psychrotrophs to each spice was different depending on the species. When an equal volume of allspice, turmeric, nutmeg, and laurel leaves extracts was mixed and analyzed, the mixed extract completely suppressed the growth of all surveyed psychrotrophs at the concentration of 0.016% for 6 days. When eggplant, cucumber, and cabbage were soaked in the 0.016% mixed extract at 25oC for 10 min and stored at 4oC for 11 days, the growth of psychrotrophs was completely suppressed. The mixed spice extract may be useful for the suppression of psychrotrophs. Less

嗜冷菌广泛分布于自然界中，常引起低温贮藏食品的变质。因此，已经对细菌进行了研究以更好地理解食品保存。虽然耐冷菌很容易通过热处理灭菌，但它们的胞外水解酶存活并降低食品的质量。因此，在嗜冷菌在食品中生长之前对其进行灭菌对于食品的低温保存非常重要。丙氨酸消旋酶（Alanine racemase，EC 5.1.1.1）是一种5 ′-磷酸吡哆醛依赖性酶，催化L-和D-丙氨酸的消旋化反应。该酶广泛存在于细菌中，并且通过提供D-对映体在细菌细胞壁的肽聚糖合成中是必需的。肽聚糖的生物合成是细菌所特有的，因此肽聚糖酶已成为抗菌药物的作用靶点。 ...更多信息 GS.为了探索一种基于丙氨酸消旋酶失活的耐冷菌杀菌方法，我们研究了耐冷菌对有机酸和香料的敏感性，发现荧光假单胞菌和解冷糖B菌对0.01%浓度的柠檬酸、乙酸、乳酸和琥珀酸的敏感性高于中温菌。该浓度的有机酸也使丙氨酸消旋酶失活。嗜冷菌对处理具有耐受性，中温菌胞内丙氨酸消旋酶未被灭活，嗜冷菌对各种香料的敏感性高于中温菌，但不同种类的嗜冷菌对各种香料的敏感性不同。当等体积的多香果、姜黄、肉豆蔻和月桂叶提取物混合并分析时，混合的提取物在0.016%的浓度下6天完全抑制所有调查的耐冷菌的生长。茄子、黄瓜和甘蓝在25 ℃下浸泡10 min，在4 ℃下贮藏11 d后，耐冷菌的生长完全被抑制。混合香料提取物可用于抑制嗜冷菌。少