Department of Food Science, University of Otago, Dunedin, New Zealand.
Compr Rev Food Sci Food Saf. 2021 Jan;20(1):369-400. doi: 10.1111/1541-4337.12676. Epub 2020 Nov 23.
Proteins displayed on the cell surface of lactic acid bacteria (LAB) perform diverse and important biochemical roles. Among these, the cell-envelope proteinases (CEPs) are one of the most widely studied and most exploited for biotechnological applications. CEPs are important players in the proteolytic system of LAB, because they are required by LAB to degrade proteins in the growth media into peptides and/or amino acids required for the nitrogen nutrition of LAB. The most important area of application of CEPs is therefore in protein hydrolysis, especially in dairy products. Also, the physical location of CEPs (i.e., being cell-envelope anchored) allows for relatively easy downstream processing (e.g., extraction) of CEPs. This review describes the biochemical features and organization of CEPs and how this fits them for the purpose of protein hydrolysis. It begins with a focus on the genetic organization and expression of CEPs. The catalytic behavior and cleavage specificities of CEPs from various LAB are also discussed. Following this, the extraction and purification of most CEPs reported to date is described. The industrial applications of CEPs in food technology, health promotion, as well as in the growing area of water purification are discussed. Techniques for improving the production and catalytic efficiency of CEPs are also given an important place in this review.
细菌表面蛋白（Bacterial surface proteins）在乳酸菌（LAB）中发挥着多样化且重要的生化作用。其中，细胞包膜蛋白酶（CEP）是研究和利用最多的一种，可用于生物技术应用。CEP 是 LAB 蛋白水解系统中的重要参与者，因为它们需要 LAB 将生长培养基中的蛋白质降解为 LAB 氮营养所需的肽和/或氨基酸。因此，CEP 的最重要应用领域是蛋白质水解，尤其是在乳制品中。此外，CEP 的物理位置（即细胞包膜锚定）允许相对容易地进行 CEP 的下游处理（例如提取）。本综述描述了 CEP 的生化特征和组织，以及这如何使它们适合蛋白质水解的目的。首先重点介绍 CEP 的遗传组织和表达。还讨论了来自不同 LAB 的 CEP 的催化行为和切割特异性。接下来，描述了迄今为止报道的大多数 CEP 的提取和纯化。讨论了 CEP 在食品技术、促进健康以及日益增长的水净化领域的工业应用。还在本综述中重要位置介绍了提高 CEP 生产和催化效率的技术。
