Cultivation and characterization of the MaMV-DC cyanophage that infects bloom-forming cyanobacterium Microcystis aeruginosa

Abstract

The MaMV-DC cyanophage, which infects the bloom-forming cyanobacterium Microcystis aeruginosa, was isolated from Lake Dianchi, Kunming, China. Twenty-one cyanobacterial strains were used to detect the host range of MaMV-DC. Microcystic aeruginosa FACHB-524 and plaque purification were used to isolate individual cyanophages, and culturing MaMV-DC with cyanobacteria allowed us to prepare purified cyanophages for further analysis. Electron microscopy demonstrated that the negatively stained viral particles are tadpole-shaped with an icosahedral head approximately 70 nm in diameter and a contractile tail approximately 160 nm in length. Using one-step growth experiments, the latent period and burst size of MaMV-DC were estimated to be 24-48 hours and approximately 80 infectious units per cell, respectively. Restriction endonuclease digestion and agarose gel electrophoresis were performed using purified MaMV-DC genomic DNA, and the genome size was estimated to be approximately 160 kb. Sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) analysis revealed four major structural proteins. These results support the growing interest in using freshwater cyanophages to control bloom-forming cyanobacterium.

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

“…The 95 % homology between the g91 fragment (127 bp) sequences isolated in the present study and the viral sheath protein-encoding gene of the previously isolated Myoviridae strains was shown (Ma-LMM01-type phages from Japan and MaMV-DC phage from China) [18,19,26,27,44] (Fig. 2).…”

“…This virus was first isolated from Lake Mikata (Japan) and its infectious ability was tested against a single toxic strain of Microcystis aeruginosa, i.e., NIES-298, under laboratory conditions [44]. The cyanophage strain MaMV-DC, which also belongs to the family Myoviridae, was isolated for the first time from Lake Dianchi (Kunming, China) from a cyanobacterial bloom of M. aeruginosa [27]. Ou et al [27] verified its infectious ability only against the non-toxic M. aeruginosa FACHB-524 strain (out of 21 strains tested) under laboratory conditions.…”

“…Since the 1980s, research on cyanophages has focused on viruses specific to saltwater cyanobacteria [21][22][23][24][25]. In the last decade, studies have examined the diversity of freshwater cyanophages belonging to Myoviridae, Podoviridae, or Siphoviridae and their impact on their hosts, among others: Synechococcus, Microcystis, Aphanizomenon, Planktothrix, or/and Phormidium genera [11,18,19,[26][27][28][29][30][31][32].…”

“…Studies have led to the discovery of many phages, including strains Ma-LBP and ΦMHI42 from the family Podoviridae; strains Ma-LMM01, Ma-LMM02, Ma-LMM03, Ma-HPM05, and MaMV-DC from the family Myoviridae; and strain MaCV-L, which represents corticovirus-like particles [11,18,19,[26][27][28][29].…”

Unraveling the genome structure of cyanobacterial podovirus A-4L with long direct terminal repeats

“…Cyanobacterial viruses, termed "cyanophages," are also abundant in both marine and freshwater ecosystems and play an important role in regulating the cyanobacteria biomass and community structure, controlling the cyanobacteria bloom, mediating the horizontal gene transfer between cyanobacterial hosts and maintaining the extensive diversity of microbial communities (Lindell et al, 2004;Sullivan et al, 2005;Yoshida et al, 2008;Gao et al, 2009;Zhang and Gui, 2012;Li et al, 2013;Ou et al, 2013;Zhang, 2014). As a preface to gain insight into the biological properties of cyanophages and their interactions with cyanobacterial hosts at the molecular level, it is necessary to obtain their complete genome sequences.…”