Molecular Pathogens 2024, Vol.15, No.2, 50-60 http://microbescipublisher.com/index.php/mp 51 develop innovative strategies for controlling diseases, thereby contributing to the advancement of sustainable and effective disease management practices. 2 Types of Microbial Predators Microbial predators play a crucial role in regulating microbial communities and maintaining ecological balance. They can be broadly categorized into bacterial predators, fungal predators, and protist predators. Each group exhibits unique predatory mechanisms and ecological impacts. 2.1 Bacterial predators Bacterial predators are a diverse group of microorganisms that prey on other bacteria. Among the most well-studied bacterial predators are the myxobacteria, such as Myxococcus xanthus, which utilize a broad range of prey through the secretion of antibiotic metabolites and hydrolytic enzymes (Morgan et al., 2010). Another notable group is the Bdellovibrio and like organisms (BALOs), which are obligate predators that invade and consume Gram-negative bacteria. Recent studies have also identified novel bacterial predators like Bradymonabacteria, which exhibit versatile survival strategies and a preference for Bacteroidetes (Mu et al., 2020). These bacterial predators can significantly influence microbial community structure and dynamics by reducing bacterial biomass and altering prey populations (Johnke et al., 2014). 2.2 Fungal predators Fungal predators, though less studied than bacterial predators, play a significant role in microbial predation. They often target other fungi and bacteria, employing various mechanisms such as the production of lytic enzymes and secondary metabolites. For instance, the exposure of the non-pathogenic yeast Sporobolomyces primogenomicus to predation by the amoeba Acanthamoeba castellanii led to the emergence of resistant strains with altered morphology, suggesting that fungal predators can exert selective pressures on their prey (Idnurm, 2023). This interaction highlights the potential of fungal predators to influence microbial community composition and drive evolutionary changes in their prey. 2.3 Protist predators Protist predators are key players in microbial ecosystems, primarily preying on bacteria and fungi. They are integral components of the soil microbiome and can significantly impact microbial community structure and function. For example, the introduction of beneficial bacteria like Bacillus can alter protist community structures, indicating that protist predators respond dynamically to changes in their environment (Xiong et al., 2019). Protists such as Cercozoa and Ciliophora have been shown to increase in abundance in response to pathogen invasion, suggesting their role in top-down regulation of microbial communities under pathogenic stress (Gao et al., 2023). Additionally, protists are sensitive to environmental changes, such as antibiotic exposure, which can alter their community composition and ecological functions (Nguyen et al., 2020). In summary, microbial predators, including bacterial, fungal, and protist predators, are essential for maintaining microbial diversity and ecosystem stability. Their predatory activities shape microbial community structures and drive evolutionary adaptations in their prey, highlighting their importance in disease management and ecological research. 3 Mechanisms of Predation Microbial predators employ a variety of mechanisms to attack, kill, and consume their prey. These mechanisms can be broadly categorized into attachment and invasion, secretion of lytic enzymes, and consumption and digestion. Understanding these processes is crucial for leveraging microbial predators in disease management. 3.1 Attachment and invasion Attachment and invasion are the initial steps in microbial predation. Predatory bacteria such as Myxococcus xanthus and Bdellovibrio bacteriovorus exhibit sophisticated mechanisms to attach to and invade their prey. M. xanthus uses a type IV filament-like machinery known as Kil, which promotes motility arrest and prey cell plasmolysis, facilitating tight contact with prey cells for their intoxication (Seef et al., 2021). This
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