Isolation and characterization of the first phage infecting ecologically important marine bacteria Erythrobacter

Abstract

Background Erythrobacter comprises a widespread and ecologically significant genus of marine bacteria. However, no phage infecting Erythrobacter spp. has been reported to date. This study describes the isolation and characterization of phage vB_EliS-R6L from Erythrobacter.MethodsStandard virus enrichment and double-layer agar methods were used to isolate and characterize the phage. Morphology was observed by transmission electron microscopy, and a one-step growth curve assay was performed. The phage genome was sequenced using the Illumina Miseq platform and annotated using standard bioinformatics tools. Phylogenetic analyses were performed based on the deduced amino acid sequences of terminase, endolysin, portal protein, and major capsid protein, and genome recruitment analysis was conducted using Jiulong River Estuary Virome, Pacific Ocean Virome and Global Ocean Survey databases.ResultsA novel phage, vB_EliS-R6L, from coastal waters of Xiamen, China, was isolated and found to infect the marine bacterium Erythrobacter litoralis DSM 8509. Morphological observation and genome analysis revealed that phage vB_EliS-R6L is a siphovirus with a 65.7-kb genome that encodes 108 putative gene products. The phage exhibits growth at a wide range of temperature and pH conditions. Genes encoding five methylase-related proteins were found in the genome, and recognition site predictions suggested its resistance to restriction-modification host systems. Genomic comparisons and phylogenetic analyses indicate that phage vB_EliS-R6L is distinct from other known phages. Metagenomic recruitment analysis revealed that vB_EliS-R6L-like phages are widespread in marine environments, with likely distribution in coastal waters.ConclusionsIsolation of the first Erythrobacter phage (vB_EliS-R6L) will contribute to our understanding of host-phage interactions, the ecology of marine Erythrobacter and viral metagenome annotation efforts.

Characterization of vB_StuS_MMDA13, a Newly Discovered Bacteriophage Infecting the Agar-Degrading Species Sphingomonas turrisvirgatae

“…The one-step growth curve of vB_StuS_MMDA13 on S. turrisvirgatae MCT13 T ( Figure 2) showed a long latency period of 210 min, followed by a rise period of about 200 min. These unexpectedly long latency and rise periods, previously observed also for other Siphoviridae infecting Alphaproteobacteria [22,24,60], could be related to the slow growth of the host bacteria in liquid media (estimated generation time of ≈2 h). The computed average burst size was about 30 PFU per infected cell.…”

“…These metabolic activities have been exploited either in several types of bioreactors or in in situ bioremediation experiments [17][18][19][20][21]. However, studies on phages targeting members of the Sphingomonadaceae family, and on the evaluation of their impact in bioreactors or environments bioaugmented with these species, are limited [22][23][24][25]. In particular, only three phages, i.e., a lysogenic Siphoviridae active against Erythrobacter sp.…”

“…In particular, only three phages, i.e., a lysogenic Siphoviridae active against Erythrobacter sp. [22], a lytic Siphoviridae infecting Sphingobium sp. IP1 [24] and a Microviridae specific to Citromicrobium spp.…”

Isolation and characterization of bacteriophages against virulent Aeromonas hydrophila

“…However, this is not always definitive and further genomebased characterizations of the phages are needed to verify this. Additionally, our phages, being more resistant to alkali than acid condition, showed a broad pH tolerance compared to most isolated phages [38,[45][46][47]. Besides, the phages were found to be relatively stable up to 40 °C.…”

A Virus Infecting Marine Photoheterotrophic Alphaproteobacteria (Citromicrobium spp.) Defines a New Lineage of ssDNA Viruses

“…Aerobic anoxygenic photoheterotrophs, as an important functional group, comprise up to 20% of total bacterioplankton in the coastal oceans, and play significant roles in marine carbon and energy cycling ( Jiao et al, 2010 ; Koblížek, 2015 ). However, only limited number of phages infecting AAPs have been isolated to date, and they are all tailed phages mainly infecting members of genera Roseobacter , Dinoroseobacter , and Erythrobacter ( Zhang and Jiao, 2009 ; Ji et al, 2015 ; Lu et al, 2017 ). In addition, an inducible sipho-like bacteriophage was isolated from Citromicrobium sp.…”