Genomic Analysis Of Low Temperature Phage MYBP41-22 And Preliminary Of The Functional Genes

Bacillus cereus is widely distributed and it is also a typical opportunistic pathogen,researches on B.cereus has always obtained attention and the same situation with its phage.People can have a comprehensive understanding of phage from genomic level with the development of modern molecular biology.Phages from extreme environment,because of its small genome and simple structure,it is helpful for studying the origin,evolution and environmental adaptation mechanism of phage.In this study,genomic analysis and features validation of low temperature B.cereus phage MYBP41-22 isolated from Mingyong glacier was done to expose the genomic information of phage and the interaction mechanism between phage and its host.The whole genome of MYBP41-22 was sequenced through Illumina method and analyzed by softwares or biologic analysis websites such as Lasergene,FAStRNA,PALINDROME,Softberry,EMBL-EBI,Codon Usage Database and so on.Analysis results as follow:Length of MYBP41-22 genome was 18,609 bp,GC content was 36.36%,22 possible ORFs were predicted that mainly involved in coding for the structural protein of phage,metabolism-related proteins and the phage proliferation-associated protein,no sequence that codes for tRNA was found and there were seven inverted repeat sequences on the genome.Different from eukaryotes,non-coding region was only 7.90%of the whole phage genome and it probably involves in regulation of gene replication,transformation and translation.The number of predicted promoter sequences was three times as much as the number of genes,it indicated that MYBP41-22 was an active life.By analyzing the codon usage of the same proteins from phage and its host showed condon usage difference of different proteins,even showed condon usage difference of same protein,it proved it is not a long time since MYBP41-22 and its host co-evolution.To explore environmental adaptation of host cell and the possible inhibition mechanism of quorum sensing,thewnprB,papR,plcR genes which code for the central quorum sensing proteins were also detected,the result showed the loss of plcR gene.In this study the gene codes for endolysin was cloned and expressed in E.coli,endolysin showed high specificity to its host but no activity toward all other Bacillus strains in this experiment was detected,endolysin only showed the activity on its original host strain,and showed activity even at 4℃.This study is the first time to resolve genome sequence and to verify function of phage isolated from extremely low temperature.It can not only supply the theoretical support for exposing the deep interaction mechanism and exploring its low temperature adaptation mechanism,but also found the basis for cognizing the feature of glacier microbes and the co-evolution of glacier microbes.