Impact of external forces on cyanophage–host interactions in aquatic ecosystems

Abstract

Cyanobacterial (algal) blooms have by convention been attributed to the excessive level of nutrients from pollution and runoff, which promotes the rapid growth and multiplication of cyanobacteria or algae. The cyanophage (virus) is the natural predator of cyanobacteria (the host). The aim of this review is to unveil certain pressures that disrupt cyanophage-host interactions and the formation of cyanobacterial blooms. This review focuses principally on the impact of greenhouse gases, ozone depletion, solar ultraviolet radiation (SUR) and the role of recently discovered virophages, which coexist with and in turn are the natural predator of phages. The key findings are that the increase in SUR, the mutation of cyanophages and cyanobacteria, along with changing nutrient levels, have combined with virophages to impede cyanophage-host interactions and the resultant viral infection and killing of the cyanobacterial cell, which is a necessary step in controlling cyanobacterial blooms. Consider this a 'call to action' for researchers interested in corrective action aimed at evolving aquatic ecosystems.

Cyanophages Infection of Microcystis Bloom in Lowland Dam Reservoir of Sulejów, Poland

“…Additionally, phages are thought to be essential for gene transfer and the nutrient cycle [16,17]. Cyanophages are a type of planktonic viruses that infect cyanobacteria and thus play important roles in modulating cyanobacterial populations (Bclonal^diversity, composition, and evolution) and preserving water quality [12][13][14][15][16][18][19][20]. Since the 1980s, research on cyanophages has focused on viruses specific to saltwater cyanobacteria [21][22][23][24][25].…”

Natural solution to antibiotic resistance: bacteriophages ‘The Living Drugs’

“…The whole cycle can be completed in 30–40 min. The phage is a parasite that depends on the host for its propagation, which is influenced by a variety of factors such as temperature, nutrients, light and other environmental forces (Jassim and Limoges 2013). It subverts the host’s biological function and utilizes the host machinery for reproduction.…”

“…They become a part of the host cell and replicate along with the host chromosome for many generations, coexisting as opposed to lysing the host cell (Jassim and Limoges 2013). This phenomenon is called ‘lysogeny’, which also provides immunity against infection by further phage particles of the same type, ensuring that there is only one copy of phage per bacterial cell.…”

“…Veterinary therapy/biocontrol applications require the appropriate administration targeting specific bacteria, with a strategy that includes a comprehensive methodology, detailing the phage-host interactions, dose optimization and accounting for all chemical and physical factors (Jassim and Limoges 2013). In general, a deep understanding of intrinsic phage properties is critical to designing therapeutic interventions.…”

“…The recently discovered, Sputnik virophage is a satellite virus that inhibits replication of its target phage and thus acts as a parasite of that virus in aquatic environments (Jassim and Limoges 2013). These virophages may also coexist as the natural predator of the phages that target foodborne pathogens, perhaps transmitted from their aquatic environments by fish and seafood.…”