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Appl Environ Microbiol, February 1998, p. 535-542, Vol. 64, No. 2
Department of Marine Science, University of
South Florida, St. Petersburg, Florida 33701
Received 24 April 1997/Accepted 14 November 1997
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 and
Flavobacterium 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 and
Podoviridae. 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- Direct viral enumeration techniques
have revealed high levels of viral particles in many regions and many
habitats of the marine environment (3, 10, 28-30).
Moreover, viruses have been found to contribute significantly to the
mortality of bacterioplankton and phytoplankton, indicating that they
are important in microbial ecosystems (10). However, direct
observations of viruses yield little information concerning the
infectivity of the viruses, their genetic diversity, or their ability
to enter into lysogenic interactions with their hosts. It is the last
issue that we have become interested in over the past several years.
There is recent evidence that lysogeny is a common occurrence in the
marine environment. When a series of diverse marine environments were
examined for prophage induction by using mitomycin C and UV radiation,
up to 38% of the bacterial population contained inducible prophage
(17). Examination of 88 random marine bacterial isolates
indicated that more than 40% of these isolates contained inducible
prophage or defective phagelike particles (16). Of nearly
300 marine phage isolates tested, 29 were identified as temperate phage
isolates by Moebus (22). Hidaka and Shirahama (13) have also described isolation of a temperate phage from marine mud in Kagoshima Bay, Japan.
We were interested in isolating marine temperate phage-host systems to
study lysogeny in the marine environment, as well as the potential for
phage-mediated gene transfer (transduction) in the marine environment.
The interactions between marine viruses and their hosts may
significantly influence the genetic diversity and composition of marine
microbial communities. We attempted to isolate several temperate
phage-host systems from water samples from Mamala Bay, Oahu, Hawaii;
our goal was to establish transduction systems with indigenous marine
bacterial hosts and bacteriophages. The characteristics of these
phage-host systems are described here.
Isolation of bacterial hosts and phages.
Twenty-liter water
samples were collected from surface and subsurface waters of Ke'ehi
Lagoon and Sand Island sewage outfall offshore in Mamala Bay, Hawaii,
on 14 to 17 February 1994 by pumping water into acid-washed carboys on
a small boat. The water samples were concentrated by vortex flow
filtration (15) from 20 liters to approximately 50 ml within
3 h of collection. Bacteria were isolated from the concentrated
samples on artificial seawater agar plates containing (per liter)
5 g of peptone and 1 g of yeast extract (ASWJP+PY)
(23). Each of the colonies was reisolated three times to
ensure the purity of the bacterial isolates. Each bacterial isolate was
then used as a host for isolation of temperate phages from the same
concentrated sample or samples from nearby locations.
0099-2240/98/$04.00+0
Copyright © 1998, American Society for Microbiology. All rights reserved.
Characterization of Marine Temperate Phage-Host
Systems Isolated from Mamala Bay, Oahu, Hawaii
ABSTRACT
Top
Abstract
Introduction
Materials & Methods
Results
Discussion
References
HSIC, and
T-D0, and the member of the Myoviridae, T-D1B, were
found to form lysogenic associations with their bacterial hosts, which
were isolated from the same water samples. Hybridization of phage
T-HSIC probe with lysogenic host genomic DNA was observed in dot
blot hybridization experiments, indicating that prophage T-HSIC was
integrated within the host genome. These phage-host systems are
available for use in studies of marine lysogeny and transduction.
INTRODUCTION
Top
Abstract
Introduction
Materials & Methods
Results
Discussion
References
MATERIALS AND METHODS
Top
Abstract
Introduction
Materials & Methods
Results
Discussion
References
Characterization of marine bacterial isolates. Gram staining was performed with each bacterial host by using a Fisher Diagnostics Gram Stain Set (Fisher Scientific, Pittsburgh, Pa.) and the manufacturer's recommended procedures. Bacterial morphologies were examined with a transmission electron microscope (TEM) at magnifications of ×9,000 to ×15,000. Gram-negative rod-shaped bacteria were further tested by using an API-NFT bacterial identification kit (BioMerieux Viteck, Inc., Hazelwood, Mo.) and the manufacturer's recommended procedures.
TEM examination of phage morphology. One drop of a freshly prepared phage lysate was spotted onto a Formvar-carbon-coated 200-mesh TEM grid (Electron Microscopy Sciences, Fort Washington, Pa.). The edge of the grid was touched with a piece of Whatman filter paper to drain away the excess fluid. The grid was then stained with a 2% uranyl sulfate solution for 30 s, washed with 1 drop of deionized water for 10 s, and dried in air before examination with a Hitachi model 500 TEM. The microscope magnification was calibrated by using 50-nm polystyrene beads (nanosphere; Electron Microscope Sciences) as size standards. Photomicrographs of phages were taken at magnifications of ×48,000 to ×100,000. Morphological characteristics of phages were compiled from multiple photomicrographs of phage particles in order to minimize size or shape anomalies.
Determination of phage genome size by restriction enzyme digestion. Phage DNAs were extracted from 10- to 30-ml portions of phage lysates by using a Wizard Lambda Preps DNA purification system (Promega, Madison, Wis.) and the manufacturer's recommended procedures. Briefly, freshly prepared phage lysates were digested with RNase A and DNase I at 37°C for 15 min and precipitated with polyethylene glycol 8000 on ice for 30 min. The precipitates were resuspended in 500 µl of phage buffer containing 150 mM NaCl, 40 mM Tris-HCl (pH 7.4), and 10 mM MgSO4. Phage DNA was purified by using a mini Purification Resin column (Promega) and was eluted from the column with 80°C deionized water. The purified phage DNA was stored at 4°C until restriction enzyme digestion.
For restriction enzyme digestion, approximately 1 µg of each phage DNA was digested in a total volume of 40 µl. Both uncut DNA and restriction enzyme-cut DNA were visualized on agarose gel electrophoresis gels (0.4, 1, and 1.5% agarose) stained with ethidium bromide (26). The molecular weight of each phage DNA was then estimated by using the sizes of large fragments determined from 0.4% gels, the sizes of medium fragments determined from 1% gels, and the sizes of small fragments determined from 1.5% gels. A 1-kb DNA ladder (12.2 to 0.5 kb; Gibco BRL, Gaithersburg, Md.), HindIII-digested
DNA fragments (23 to 0.56 kb;
Promega), and a high-molecular-weight DNA marker (48.5 to 8.3 kb; Gibco BRL) were used as molecular weight markers to calculate the sizes of
the phage DNA fragments by using linear regression and inverse prediction.
One-step growth experiments.
The burst sizes and one-step
growth curves were determined as described by Weiss et al.
(31), with minor modifications. One milliliter of each
overnight culture was transferred to 20 ml of fresh ASWJP+PY and
incubated with shaking for about 2 h, until the
A600 was ~0.6 and the viable cell counts were
around 108 cells/ml. One-milliliter portions of each
bacterial culture were then transferred to fresh tubes and mixed with
phage at a multiplicity of infection of 1. Each mixture was incubated
at room temperature for 20 min to allow phage adsorption. After this
adsorption period, the cells were pelleted to wash away the unattached
phage. Infected cells were diluted to 10
5 in 10 ml of
artificial seawater and incubated at 28°C with shaking. Samples were
withdrawn over time for use in an infectious center assay in which the
soft agar overlay method was used. Bacterial viable counts were
determined before the bacteria were mixed with phage and at the end of
the experiment. Burst size was estimated from triplicate experiments by
using the following equation:
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V represents
changes in the viral number, B represents changes in the
bacterial number, Ve is the viral number at the
end of the experiment, V0 is the viral number at
the beginning of the experiment, Be is the
bacterial number at the end of the experiment, and
B0 is the bacterial number at the beginning of
the experiment.
Purification of plasmid DNA and chromosomal DNA. Plasmid DNA and chromosomal DNA were purified from bacterial cells by using a Wizard Plasmid DNA Preps kit and a Wizard Genomic DNA Preps kit (Promega), respectively, and the manufacturer's recommended procedures. Special precautions were taken to extract DNA from potential lysogens; these precautions included washing potential lysogenic cells three times before DNA extraction to avoid contaminating DNA preparations with free phage DNA. The purity of the chromosomal DNA in these preparations was similar to the purity of chromosomal DNA purified with a cesium chloride gradient. When chromosomal DNA purified with the Prep kits was added to cesium gradients, only a single sharp band was observed in each sample after centrifugation. Concentrations of DNA were measured fluorometrically by using Hoechst 33258 dye as described previously (24).
Probe labeling and dot blot hybridization.
A 100-bp
AccI digestion fragment of temperate phage T-HSIC DNA was
randomly cloned into Riboprobe vector pGEM4Z (Promega) by using the
cloning protocol recommended by the manufacturer. A 35S-RNA
probe was prepared by transcription of the fragment with T7 RNA
polymerase by using 35S-UTP (9).
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RESULTS |
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Abstract
Introduction
Materials & Methods
Results
Discussion
References
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Isolation of bacterial hosts and phages from marine
environments.
Table 1 shows the
results of isolation of bacterial hosts and phages from marine
environments. Four bacterial isolates were found to be able to serve as
hosts for isolation of turbid plaques. Each bacterium was named after
the sampling station. Bacteriophage isolates were also named by using a
similar system, except that the prefix T- (representing temperate
phage) was used. Although one of the phage isolates was later shown to
be lytic, the name of the phage was not changed. In most cases the
phage was isolated from the same sample as that from which the host
bacterium was isolated. One bacterium, designated D1B, was also a host
for a phage isolate (T-D0-3) from a sample obtained from a nearby
environment (Ke'ehi Lagoon). T-D0-3 had the same plaque morphology
as T-D1B and was later shown to produce the same restriction enzyme
band patterns. The phage isolates were host specific, and none of the viruses cross-infected other hosts tested.
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D0 particles in that the heads were smaller (average size,
39 ± 1.15 nm [n = 4], compared to 54.3 ± 3.7 nm [n = 4]); their tails were about the same
length as T-D0 tails (average length, 86.5 ± 6.24 nm) but
appeared to be wider than T-D0 tails (Fig.
2D).
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D0 formed plaques with completely turbid
centers and poorly defined edges. Phage T-HSIC plaques had small
clear centers and wide halos of bacterial growth, and the edge of each
plaque was defined by a sharp, narrow ring. Small-plaque mutants and
large clear-plaque mutants were often seen in the phage preparations,
and the number of plaque mutants increased with prolonged storage of
the phage lysates in a refrigerator. Phage T-D0-3 formed very turbid
plaques which occasionally had tiny clear centers. Phage T-D2S
plaques had relatively large clear centers and halos wider than that of
T-D0-3; unlike the T-HSIC plaques, there was not a clear ring
around each halo. The temperate nature of T-D2S is questionable (see
Discussion).
Figure 2 shows electron photomicrographs of the temperate phages, and
phage sizes are given in Table 2. The
phage head sizes ranged from 47 to 70.7 nm, while the tail sizes ranged
from 12 to 146 nm. Each T-HSIC phage had a long flexible tail, which appeared to be noncontractile (Fig. 2E). Each T-D0-3 phage
apparently had a contractile tail (Fig. 2A and F) and was similar in
morphology to T-D1B (Fig. 2C); both of these phages belong to the
family Myoviridae. Each T-D0 phage had a very thin
flexible tail with no observable collar structure (Fig. 2D). Both
T-D0 and T-HSIC belong to the family Siphoviridae.
Each T-D2S phage (Fig. 2B) had a very short tail, which is
typical of members of the family Podoviridae.
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Genome sizes and types of phage isolates.
All of the phage
isolates were double-stranded DNA viruses, as indicated by restriction
enzyme digestion results (Fig. 3). At
least seven restriction enzymes were used for each purified phage DNA
(Table 3). Interestingly, none of the phage DNAs could be digested by
restriction endonuclease BamHI, but the reason for this
resistance was not determined. T-D0 and T-D2S DNAs were resistant
to EcoRI and BglII, respectively. T-HSIC DNA
was found to be resistant to restriction digestion by XbaI,
KpnI, SalI, PstI, SacI, and
SmaI (data not shown). Some restriction enzymes digested
phage DNA into more than 30 fragments which appeared as a DNA smear on
the agarose gel, while other enzymes digested phage DNA into many
fragments of similar size, resulting in smearing in a region of the
gel. Only clear restriction patterns were used to determine molecular
weight. Phage genome sizes were determined by adding the sizes of the
restriction fragments from each enzyme digestion. Table
3 shows the estimated phage genome sizes
as determined by restriction digestion. The genome size of T-HSIC was about 36 kb, as determined with BglII- and
EcoRI-digested fragments; HpaI digestion of
T-HSIC DNA gave a slightly lower value (33 kb). Some of the
HpaI-digested fragments were more intense than the other
fragments on the gel (Fig. 3), possibly because of multiple bands at
the same molecular weight. Such similar bands may have also occurred in
HpaI-digested T-D0 and T-D2S DNAs. The size of the
T-D0 genome was about 71 kb, as determined by BglII,
EcoRV, and AccI digestion. T-D1B DNA had the
same restriction pattern as phage T-D0-3 DNA (data not shown),
suggesting these phages were the same phage or closely related phages
isolated from different locations. The T-D1B genome size averaged
112 kb, as determined by restriction digestion with HpaI,
BglII, and EcoRV, while the genome size of
T-D2S was 65 kb (Table 3).
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Phage one-step growth curves.
Figure
4 shows the one-step growth curves for
the phage isolates. T-D0 had the smallest burst size of the four
phages examined (ca. 7.8), while T-D2S had the largest burst size
(240). The burst sizes for T-HSIC and T-D1B were ca. 47 and 176, respectively. The latent period of these phages ranged from 90 to 180 min (Fig. 4).
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Lysogenic characteristics.
Bacteria isolated from the turbid
plaque centers or halo areas were resistant to phage infection,
suggesting that the bacterial hosts might be lysogenized with the
phages. Among the four phage-host systems, only the relationship
between temperate phage T-HSIC plaques, and its host, HSIC, was
characterized in detail. Bacteria picked from the halo areas of
T-HSIC plaques, designated L-HSIC, were isolated by preparing at
least three consecutive streaks on fresh agar plates to ensure the
purity of the isolate. L-HSIC had a different colony morphology than
wild-type HSIC. HSIC colonies had smooth surfaces and were rounded and
opaque. L-HSIC colonies were more transparent, had uneven edges, and
appeared wrinkly after incubation for 48 h. L-HSIC cell cultures
inoculated from a single colony shed viruses into the medium which were
infectious to wild-type HSIC.
HSIC DNA was inside the L-HSIC cells, a dot
blot of DNA from T-HSIC, plasmid preparations of HSIC and L-HSIC,
and chromosomal preparations of HSIC and L-HSIC were probed with
35S-labeled phage T-HSIC probe (Fig.
5). Strong hybridization of the probe
with phage DNA was found, as expected. Hybridization of the probe with
L-HSIC plasmid DNA and weak hybridization with L-HSIC chromosomal DNA
were also observed. The weak hybridization of L-HSIC chromosomal DNA
was not a result of contamination of plasmid DNA in the preparation
because chromosomal DNA preparations produced only a single band on a
cesium chloride gradient when an attempt was made to repurify the DNA
(data not shown). The hybridization of the probe with L-HSIC plasmid
DNA was also not a result of contamination of chromosomal DNA, because
the concentration of plasmid DNA dotted was one-fourth the
concentration used in the chromosomal dot, yet resulted in a higher
degree of hybridization. No hybridization was detected with HSIC
plasmid and chromosomal DNA.
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DISCUSSION |
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Abstract
Introduction
Materials & Methods
Results
Discussion
References
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Incorporation of viruses into the budget of microbial C transfer by using the lytic phage-host interaction model resulted in an imbalance in the carbon budget (5). Therefore, the dynamics of temperate phage-host relationships in the marine environment should be considered. Previously, we have shown that lysogenic bacteria were abundant among marine bacterial isolates (16), suggesting that many marine bacteriophages may be temperate in nature. However, isolation of temperate phages from marine environments was rare. Moebus tested nearly 300 marine phage isolates and found that only 29 were temperate (22). However, his phage collections were obtained by using a liquid nutrient enrichment isolation method (21) which favors isolation of lytic phages (8, 14). Kokjohn et al. (18) suggested that high numbers of lytic phages found in the aquatic environment were an artifact of nutrient enrichment isolation methods.
We isolated four different types of turbid plaques on native marine
bacterial hosts from concentrated seawater samples obtained from Mamala
Bay. Two of the turbid plaques resembled the classical turbid plaques
of temperate phages (8). T-HSIC plaque morphology is
similar to the plaque morphology of a Bacillus subtilis
phage described by Romig and Brodesky (25). However, these
authors did not determine if phage DNA was integrated into the host
genome. In this study, using dot blot hybridization and probing, we
detected T-HSIC DNA inside the host cell, suggesting that this phage
isolate is a temperate phage. Plaques of T-D2S are similar to the
plaques of Rhizobium leguminosarum phage 3H (27),
the plaques of the Klebsiella pneumoniae capsule
bacteriophage XIV (20), and the plaques of the M-1 phage of
Rhizobium japonicum (7). Lindberg (20)
described bacteriophages isolated from capsulated species of bacteria
with plaque morphology consisting of a large clear center surrounded by
a crater-like depression or halo in the bacterial lawn. This halo
comprised an area in which the bacterial capsular material was
destroyed by the phage-induced polysaccharide depolymerase but
bacterial viability was not affected (2, 7). A similar phenomenon was observed with the D2S phage-host system, since bacterial
strain D2S was encapsulated. The turbid halos around T-D2S plaques
may have been the result of bacteria with damaged capsular material
rather than lysogeny. Thus, T-D2S may be lytic.
As determined by the API-NFT test, bacterial host D0 was identified as S. paucimobilis (previously known as Pseudomonas paucimobilis). Pseudomonas phages have been routinely isolated from the marine environment (12). Bacterium D1B was identified as a Flavobacterium sp. strain. There are two prior reports of isolation of Flavobacterium marine phages, both from Kagoshima Bay, Japan (11, 12).
It is not surprising that all of our phage isolates are tailed phages. According to a literature review by Børsheim (4), most marine phages in culture have tails. However, the head sizes of our phage isolates were smaller than the head sizes of most of the known marine bacteriophages. Børsheim's review indicated that the sizes of the majority of cultured marine phages range from 60 to 100 nm. Børsheim suggested that most of the marine phages in seawater belong to groups that are not cultivable, because the viruses from seawater samples were dominated by 30- to 60-nm particles. Most of our phage isolates fell into the 30- to 60-nm range and appeared to be representatives of Børsheim's suggested noncultivable group.
A survey of 52 cultured marine phages by Børsheim suggested that there is great variation in burst size; the average marine phage burst size is 185, and burst sizes range from 5 to 610. The burst sizes of our phage isolates fell within this range.
The latent periods of phages nt-1 and nt-6, which were isolated from a salt marsh, are 50 and 60 min, respectively, under optimal conditions (32). However, the latent periods increased to 170 and 120 min, respectively, when the temperate was 10°C below the optimal temperature (33). A phage infecting Vibrio fischeri MJ-1 had a latent period of 25 min (19), while the latent periods for two bacteriophages isolated from the North Sea were 150 and 180 min (6). The latent periods of our phage isolates are comparable to these previously determined latent periods.
It is difficult to compare the genome sizes of our phage isolates with the genome sizes of previously isolated marine phages, because most reports of marine viruses have not characterized the phage nucleic acids. Ackermann and DuBow (1) suggested that nucleic acid type and gross morphology are the most important properties for phage description and classification and that less emphasis should be placed on molecular weight and restriction endonuclease patterns.
The results of dot blot hybridization suggest that the viral DNA was maintained as a prophage inside lysogenized cells. We interpret the hybridization signal of the phage gene probe with the lysogenized host chromosomal DNA as an indication that phage DNA is integrated within the host genome. The hybridization signal was weak compared with the hybridization signal of phage DNA, suggesting that only one copy or a few copies of phage DNA were integrated in the chromosome. Because the size of our probe is only 100 bp, it can hybridize with only a small region of the phage DNA.
Lysogen L-HSIC was spontaneously induced to lytic replication at a high frequency, and more than 106 free phage particles per ml were found in the supernatant of an overnight culture. The hybridization observed in the plasmid DNA fraction may have been present because the phage DNA was maintained as an autonomous plasmid or may have been the result of phage DNA that was injected into the cell but was unable to replicate because of the presence of a vegetative replication repressor produced by the prophage. Lysogens are immune to lytic infection by viruses that are closely related to the prophage but are not resistant to phage DNA injection. The presence of free phage in the culture medium may have created a positive pressure for the maintenance of the lysogens. Wild-type strain HSIC contained a plasmid upon isolation (detected by plasmid prep and gel electrophoresis) (data not shown). The lysogen L-HSIC plasmid DNA preparation may have contained both original plasmid DNA and phage DNA that was in the cell but not in the chromosome. The copy number of phage DNA in the plasmid preparation was apparently higher than the copy number of chromosomal DNA but lower than the copy number of pure phage DNA on a per-weight basis. This explains the greater hybridization observed in the plasmid preparation than in the chromosomal DNA preparation.
The results of this study suggest that temperate phages can be easily found as members of the microbial community. We are currently collecting samples from the Gulf of Mexico for isolation of temperate phage-host systems. Phage isolates from Mamala Bay share many similar properties with other marine phage isolates, while also remaining unique. The interaction of temperate phages and the microbial population in the marine environment may contribute significantly to microbial genetic diversity and composition by conversion and transduction. The indigenous phage-host systems isolated in this study have been used to study marine phage gene transduction (17a).
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ACKNOWLEDGMENTS |
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This research was supported by grants OCE 9502775, OCE 95P00774, and OCE 9115942 from the National Science Foundation. Funds were also provided by the Mamala Bay Study Commission and by a Knight Fellowship and a Gulf Charitable Trust Fellowship to S.C.J.
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FOOTNOTES |
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* Corresponding author. Mailing address: Department of Marine Science, University of South Florida, 140 7th Avenue South, St. Petersburg, FL 33701. Phone: (813) 553-1130. Fax: (813) 553-1189. E-mail: jpaul{at}seas.marine.usf.edu.
Present address: The Center of Marine Biotechnology, University of
Maryland Biotechnology Institute, Baltimore, MD 21202.
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REFERENCES |
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Top
Abstract
Introduction
Materials & Methods
Results
Discussion
References
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| 1. | Ackermann, H. W., and M. S. DuBow. 1987. . Viruses of prokaryotes, vol. 1. General properties of bacteriophages. CRC Press, Boca Raton, Fla. |
| 2. | Barnet, Y. M., and B. Humphrey. 1975. Exopolysaccharide depolymerase induced by Rhizobium bacteriophage. Can. J. Microbiol. 21:1647-1650[Medline]. |
| 3. | Bergh, Ø., K. Y. Børsheim, G. Bratbak, and M. Helda. 1989. High abundance of viruses found in aquatic environments. Nature 340:467-468[Medline]. |
| 4. | Børsheim, K. Y. 1993. Native marine bacteriophages. FEMS Microbiol. Ecol. 102:141-159. |
| 5. | Bratbak, G., M. Heldal, T. F. Thingstad, B. Riemann, and O. H. Haslund. 1992. Incorporation of viruses into the budget of microbial C-transfer. A first approach. Mar. Ecol. Prog. Ser. 83:273-280. |
| 6. |
Chen, P. K.,
R. V. Citarella,
O. Salazar, and R. R. Colwell.
1966.
Properties of two marine bacteriophages.
J. Bacteriol.
91:1136-1139 |
| 7. | Dandekar, A. M., and V. V. Modi. 1987. Interaction between Rhizobium japonicum phage M-1 and its receptor. Can. J. Microbiol. 24:685-688. |
| 8. | Freifelder, D. 1987. . Molecular biology. Jones and Bartlett, Inc., Boston, Mass. |
| 9. |
Frischer, M. E.,
J. M. Thrumond, and J. H. Paul.
1990.
Natural plasmid transformation in a high-frequency-of-transformation marine Vibrio strain.
Appl. Environ. Microbiol.
56:3439-3444 |
| 10. | Fuhrman, J. A., and C. A. Suttle. 1993. Viruses in marine planktonic systems. Oceanography 6:57-63. |
| 11. | Hidaka, T. 1971. Isolation of marine bacteriophages from sea water. Bull. Jpn. Soc. Sci. Fish. 37:1199-1206. |
| 12. | Hidaka, T. 1993. Characterization of marine bacteriophages newly isolated. Mem. Fac. Fish. Kagoshima Univ. 22:47-61. |
| 13. | Hidaka, T., and T. Shirahama. 1974. Preliminary characterization of a temperate phage system isolated from marine mud. Mem. Fac. Fish. Kagoshima Univ. 23:137-148. |
| 14. | Jacob, F., and E. L. Wollman. 1953. Induction of phage development in lysogenic bacteria. Cold Spring Harbor Symp. Quant. Biol. 18:101-121. |
| 15. | Jiang, S. C., J. M. Thurmond, S. L. Pichard, and J. H. Paul. 1992. Concentration of microbial populations from aquatic environments by vortex flow filtration. Mar. Ecol. Prog. Ser. 80:101-107. |
| 16. | Jiang, S. C., and J. H. Paul. 1994. Seasonal and diel abundance of viruses and occurrence of lysogeny/bacteriocinogeny in the marine environment. Mar. Ecol. Prog. Ser. 104:163-172. |
| 17. | Jiang, S. C., and J. H. Paul. 1996. Occurrence of lysogenic bacteria in marine microbial communities as determined by prophage induction. Mar. Ecol. Prog. Ser. 142:27-38. |
| 17a. | Jiang, S., and J. H. Paul. Unpublished data. |
| 18. | Kokjohn, T. A., G. S. Sayler, and R. V. Miller. 1991. Attachment and replication of Pseudomonas aeruginosa bacteriophages under conditions simulating aquatic environments. J. Gen. Microbiol. 137:661-666. |
| 19. | Levisohn, R., J. Moreland, and L. H. Nelson. 1987. Isolation and characterization of a generalized transducing phage for the marine luminous bacterium Vibrio fischeri MJ-1. J. Gen. Microbiol. 133:1577-1582. |
| 20. | Lindberg, A. A. 1977. Bacterial surface carbohydrates and bacteriophage adsorption, p. 289-356. In I. E. Sutherland (ed.), Surface carbohydrates of the prokaryotic cells. Academic Press, London, United Kingdom. |
| 21. | Moebus, K. 1980. A method for the detection of bacteriophages from ocean water. Helgol. Meeresunters. 34:375-391. |
| 22. | Moebus, K. 1983. Lytic and inhibition responses to bacteriophages among marine bacteria, with special reference to the origin of phage-host systems. Helgol. Meeresunters. 36:375-391. |
| 23. |
Paul, J. H.
1982.
The use of Hoechst dyes 33258 and 33342 for enumeration of attached and pelagic bacteria.
Appl. Environ. Microbiol.
43:939-949 |
| 24. |
Paul, J. H., and B. Meyers.
1982.
Fluorometric determination of DNA in aquatic microorganisms by use of Hoechst 33258.
Appl. Environ. Microbiol.
43:1393-1399 |
| 25. |
Romig, W. R., and A. M. Brodesky.
1961.
Isolation and preliminary characterization of bacteriophages for Bacillus subtilis.
J. Bacteriol.
82:135-141 |
| 26. | Sambrook, J., E. F. Fritsch, and T. Maniatis. 1989. . Molecular cloning: a laboratory manual, 2nd ed. Cold Spring Harbor Laboratory Press, Cold Spring Harbor, N.Y. |
| 27. | Staniewski, R. 1987. Morphology and general characteristics of phage active against Rhizobium. J. Basic Microbiol. 27:155-165. |
| 28. | Steward, G. F., D. C. Smith, and F. Azam. 1996. Abundance and production of bacteria and viruses in the Bering and Chukchi seas. Mar. Ecol. Prog. Ser. 131:287-300. |
| 29. |
Torrella, F., and R. Y. Morita.
1979.
Evidence by electron micrographs for a high incidence of bacteriophage particles in the waters of Yaquina Bay, Oregon: ecological and taxonomical implications.
Appl. Environ. Microbiol.
37:774-778 |
| 30. | Weinbauer, M. G., D. Fuks, S. Puskaric, and P. Peduzzi. 1995. Diel, seasonal and depth-related variability of viruses and dissolved DNA in the northern Adriatic Sea. Microb. Ecol. 30:25-41. |
| 31. |
Weiss, B. D.,
M. A. Capage,
M. Kessel, and S. A. Benson.
1994.
Isolation and characterization of a generalized transducing phage for Xanthomonas campestris pv. campestris.
J. Bacteriol.
176:3354-3359 |
| 32. |
Zachary, A.
1976.
Physiology and ecology of bacteriophages of the marine bacterium Beneckea nariegens: salinity.
Appl. Environ. Microbiol.
31:415-422 |
| 33. | Zachary, A. 1978. An ecological study of bacteriophages of Vibrio natriegens. Can. J. Microbiol. 24:321-324[Medline]. |
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