SUMMARY Bacteria have long been known to secrete enzymes that degrade cellulose and chitin. The degradation of these two polymers predominantly involves two enzyme families that work synergistically with one another: glycoside hydrolases (GHs) and polysaccharide monooxygenases (PMOs). Although bacterial PMOs are a relatively recent addition to the known biopolymer degradation machinery, there is an extensive amount of literature implicating PMO in numerous physiological roles. This review focuses on these diverse and physiological aspects of bacterial PMOs, including facilitating endosymbiosis, conferring a nutritional advantage, and enhancing virulence in pathogenic organisms. We also discuss the correlation between the presence of PMOs and bacterial lifestyle and speculate on the advantages conferred by PMOs under these conditions. In addition, the molecular aspects of bacterial PMOs, as well as the mechanisms regulating PMO expression and the function of additional domains associated with PMOs, are described. We anticipate that increasing research efforts in this field will continue to expand our understanding of the molecular and physiological roles of bacterial PMOs.

概括长期以来，细菌会分泌降解纤维素和几丁质的酶。这两种聚合物的降解主要涉及两个相互协同作用的酶：糖苷水解酶（GHs）和多糖单加氧酶（PMO）。尽管细菌PMO是已知生物聚合物降解机制的相对较新的功能，但是有大量文献将PMO包含在许多生理作用中。这篇评论集中在细菌PMO的这些多样和生理方面，包括促进共生，赋予营养优势和增强病原生物的毒力。我们还讨论了PMO的存在与细菌生活方式之间的相关性，并推测了在这些条件下PMO所赋予的优势。此外，描述了细菌PMO的分子方面，以及调节PMO表达的机制以及与PMO相关的其他域的功能。我们预计，在该领域中不断增加的研究努力将继续扩大我们对细菌PMO的分子和生理作用的理解。