Isolation And Characteration Of Cold Active Bacteriophage From Mingyong Glacier

Phages play important roles in the regulation of microbial population, community structure, nutrient cycling, etc. This is more significant in cold environment with less biodiversity and truncated food chain. Researches on cold active phages can not only renew current knowledge about life forms, but also help developing artificial vectors in building low-temperature expression system, and discovering cold-adapted enzymes applicable in molecular biology and industrial practice. Cold active phages can also be used as a model system for study of microbial in cold environments. However, their application is hindered by the limited cold active phage resources. It is still highly desirable to discover new cold active phages.In this study, we isolated two Pseudomonas fluorescens phages in soil samples from Yunnan Mingyong glacier region. They were named as pfvl and pfv2, respectively.1 We characterized the host bacteria by morphology analysis,16S rRNA gene analysis, and growth temperature range experiments. Host bacteria are cryotolerant and aerobic, grow between 4-28oC. Based on the 16S rDNA sequences, the host strain was identified as Pseudomonas fluorescens.2 Phage pfvl belongs to the Tectivirida family and is a virnlent phage. Phage pfv2 belongs to Podovirida.3 The optimal MOI for phage pfvl invaded host bacteria PF1 is about 1.4 One step growth curve of phage pfvl showed that latent period is about 1h, the burst size is about 10 pfu/cell.5 SDS-PAGE profiles indicate that phage pfvl contains 9 capsid proteins, and molecular weights are estimated at 14 Kda,20 Kda,24 Kda,27 Kda,29 Kda,36 Kda, 38 Kda,45Kda,48 Kda,65 Kda,80 Kda.