Characterization of Marine Temperate Phage-Host Systems Isolated from Mamala Bay, Oahu, Hawaii

Abstract

To understand the ecological and genetic role of viruses in the marine environment, it is critical to know the infectivity of viruses and the types of interactions that occur between marine viruses and their hosts. We isolated four marine phages from turbid plaques by using four indigenous bacterial hosts obtained from concentrated water samples from Mamala Bay, Oahu, Hawaii. Two of the rod-shaped bacterial hosts were identified as Sphingomonas paucimobilis andFlavobacterium sp. All of the phage isolates were tailed phages and contained double-stranded DNA. Two of the phage isolates had morphologies typical of the family Siphoviridae, while the other two belonged to the families Myoviridae andPodoviridae. The head diameters of these viruses ranged from 47 to 70.7 nm, and the tail lengths ranged from 12 to 146 nm. The burst sizes ranged from 7.8 to 240 phage/bacterial cell, and the genome sizes, as determined by restriction digestion, ranged from 36 to 112 kb. The members of the Siphoviridae, T-φHSIC, and T-φD0, and the member of the Myoviridae, T-φD1B, were found to form lysogenic associations with their bacterial hosts, which were isolated from the same water samples. Hybridization of phage T-φHSIC probe with lysogenic host genomic DNA was observed in dot blot hybridization experiments, indicating that prophage T-φHSIC was integrated within the host genome. These phage-host systems are available for use in studies of marine lysogeny and transduction.

Characterization of temperate cyanophages active against freshwater phycocyanin‐rich Synechococcus species

“…These features are typical of the family Siphoviridae (Ackermann, 1998) and members of this family are notorious for forming lysogenic associations with their hosts (Lederberg & Lederberg, 1952;Canchaya et al, 2002). The capsid diameters were within the range of 30-60 nm normally recorded for phages (Weinbauer, 2004), and the tail lengths were within the range of 88-211 nm previously recorded for siphoviruses (Jiang et al, 1998;Chen et al, 2006). There are currently no literature data to compare burst sizes of cyanosiphoviruses from Synechococcus but the burst sizes obtained here (3.5-23.7 phages per cell) are at the lower end of the overall range of 1.5 (McDaniel, delaRosa & Paul, 2006) to 70 phages per cell (Franche, 1987) recorded for other families of temperate cyanophages.…”

The ecology of Cytophaga–Flavobacteria in aquatic environments

“…Generally, grazing accounts for most of bacterial mortality [60], but the impact of grazing and viral lysis on individual bacterial groups is largely unknown. Phages of Cytophaga^Flavobacteria have been examined in laboratory experiments [61,62], but nothing is known about the impact of viral lysis on natural communities of Cytophaga^Flavobacteria. Turning the tables, Cytophaga-like bacteria are known to lyse cyanobacteria [63], but the signi¢cance of this process in nature is unclear.…”

Isolation and characterization of novel soilborne lytic bacteriophages infecting Dickeya spp. biovar 3 (‘D. solani’)

“…Bacterial viable counts were determined both before the bacteria were mixed with phage and at the end of the Plant Pathology (2014) 63, 758-772 experiment. Burst size was estimated from three independent experiments (six independent measurements) by using the following equation: burst size = ΔV/ΔB, where ΔV represents changes in the number of phage particles and ΔB represents the changes in the bacterial number during the experiment as described earlier (Jiang et al, 1998).…”