Chr. Hansen A/S, Discovery, R&D, 2970 Hoersholm, Denmark.
FEMS Microbiol Rev. 2021 Nov 23;45(6). doi: 10.1093/femsre/fuab028.
Manganese (Mn2+) is an essential trace element within organisms spanning the entire tree of life. In this review, we provide an overview of Mn2+ transport and the regulation of its homeostasis in bacteria, with a focus on its functions beyond being a cofactor for enzymes. Crucial differences in Mn2+ homeostasis exist between bacterial species that can be characterized to have an iron- or manganese-centric metabolism. Highly iron-centric species require minimal Mn2+ and mostly use it as a mechanism to cope with oxidative stress. As a consequence, tight regulation of Mn2+ uptake is required, while organisms that use both Fe2+ and Mn2+ need other layers of regulation for maintaining homeostasis. We will focus in detail on manganese-centric bacterial species, in particular lactobacilli, that require little to no Fe2+ and use Mn2+ for a wider variety of functions. These organisms can accumulate extraordinarily high amounts of Mn2+ intracellularly, enabling the nonenzymatic use of Mn2+ for decomposition of reactive oxygen species while simultaneously functioning as a mechanism of competitive exclusion. We further discuss how Mn2+ accumulation can provide both beneficial and pathogenic bacteria with advantages in thriving in their niches.
锰（Mn2+）是一种在跨越整个生命之树的生物体中必不可少的微量元素。在这篇综述中，我们提供了一个关于 Mn2+ 转运及其在细菌中内稳态调节的概述，重点介绍了它作为酶辅助因子以外的功能。具有铁或锰中心代谢的细菌物种之间存在关键的 Mn2+内稳态差异，可以对其进行特征描述。高度铁中心代谢的物种需要最少的 Mn2+，并且主要将其用作应对氧化应激的机制。因此，需要严格调节 Mn2+的摄取，而同时使用 Fe2+和 Mn2+的生物体则需要其他调节层来维持内稳态。我们将详细介绍以锰为中心的细菌物种，特别是乳酸菌，这些细菌几乎不需要 Fe2+，并将 Mn2+用于更广泛的各种功能。这些生物体可以在细胞内积累非常高数量的 Mn2+，从而能够使 Mn2+在非酶促条件下用于分解活性氧，同时作为一种竞争排斥的机制。我们还进一步讨论了 Mn2+积累如何为有益和致病性细菌在其小生境中茁壮成长提供优势。
