Biological Characteristics,genomics And Proteomic Analysis Of Novel Cyanophages

At present,the phenomenon of cyanobacteria bloom is serious in China.The cyanophage control is one of the biological methods to control cyanobacteria bloom.A novel Microcystis cyanophage MJing1 and a novel Nostoc cyanophage NMeng1 were isolated in this study.MJing1 has a broad spectrum of cracking activity.It has cracking effect on 9 strains of cyanobacteria,among which 7 strains belong to Microcystis,1 strain belongs to Aphanizomenon,and 1 strain belongs to Anabaena.The genome of MJing1 was double-stranded DNA,with a total length of 42070 bp.The results of transmission electron microscopy showed that MJing1 had a regular icosahedral head,the diameter of the head was about 59 nm,and the tail was about 12 nm,suggesting that it belonged to the short-tailed cyanophage.NMeng1 can efficiently lysate the host.The results of one-step growth curve showed that the incubation period of NMeng1 was about 24 h,then it entered the cracking stage,and it entered the plateau stage at about 48 h.The burst size of NMeng1 about 67 PFU/cell.The NMeng1 genome is also doublestranded DNA,with a total length of 44509 bp.The results of transmission electron microscopy showed that the head of NMeng1 was icosahedral symmetry with a diameter of about 83 nm.The genome annotation showed that Nmeng1 encoded tail protein-related genes,but no subterminal tail fibers were observed under transmission electron microscopy,suggesting that Nmeng1 belonged to Podoviruses.The broad-spectrum cyanophage MJing1 was used as the research object to study the mechanism of its cracking host.The protein changes of cyanobacteria FACHB-915 before and after infection with MJing1 were determined by non-standard quantitative method.A total of 805 proteins were found to be significantly differentially expressed.GO classification and KEGG pathway showed that after MJing1 infected FACHB-915,the respiration,photosynthesis and self-defense functions of the host are weakened at the protein level,and the binding catalysis of host RNA and the up-regulation of functional proteins related to metal cluster binding promote host death,which is conducive to the transcription of cyanophage related proteins,and promote their synthesis,assembly and release.