Genetic engineering of cyanophages for harmful cyanobacterial bloom treatment-A mini review

Harmful cyanobacterial blooms (HCBs) are a prominent worldwide environmental concern. Proliferation of HCBs outpaces the development of mitigation and management technologies. Recently, cyanophages began to emerge as a potential abundant resource that can be harnessed for target-specific HCB treatment. However, there exist two major technical barriers in applying cyanophage-based treatment to HCB mitigation: host specificity and lysogenic life cycle. This minireview attempts to parse documented studies that developed or applied genetic engineering approaches or technologies to tackle the barriers through expanding host range and bypassing or abolishing the lysogenic life stage. We summarized representative technical approaches that may be extrapolated from bacteriophage to cyanophage, discussed genes and pathways that regulate host binding and infection or determine the switch between lytic and lysogenic lifecycles, identified existing knowledge and technological gaps and challenges, and proposed some attainable solutions and future perspectives for this fast-growing field of engineered cyanophage-mediated HCB remediation.