doi:10.1038/nindia.2018.8 Published online 24 January 2018
Researchers have isolated from ocean waters a novel family of bacteria-eating viruses (phages) that plays a major role in killing marine bacteria and maintaining the ocean's ecology1.
The phages were isolated by researchers from Massachusetts Institute of Technology (MIT) and the Albert Einstein College of Medicine, including Radhey Sharma, a visiting MIT researcher now at the University of Delhi.
Marine phages influence biogeochemical cycles globally, provide and regulate microbial biodiversity, cycle carbon through marine food webs, and are essential in preventing bacterial population explosions. The newly identified group of viruses had eluded detection in ocean waters till now because of their special characteristics.
Appropriately named "autolykiviridae" – after a character in Greek mythology notable for being difficult to catch – these new found viruses lack the ‘tail’ found on typical bacterial viruses. Genomic studies revealed they have small genomes – about 10,000 bases, compared to 40,000-50,000 for tailed viruses. Unlike tailed virus, the autolykiviridae prey on unusually large number of marine bacteria underscoring their relevance in influencing oceanic ecosystems.
According to the researchers their discovery of this new group of phages stresses the importance of investigations into "the types and distribution of viruses that exist throughout the world's oceans to understand their roles in the ocean." These viruses may even be prevalent in the human biome, their report points out.
1. Kauffman, K. M. et al. A major lineage of non-tailed dsDNA viruses as unrecognized killers of marine bacteria. Nature 554 (2018) doi: 10.1038/nature25474