Abstract
The potential effect that induction of lysogenic bacteria has on bacteriophage production and bacterial mortality in coastal waters was investigated, and we present estimates for the percentage of lysogenic cells in a natural aquatic bacterial community. Various concentrations of mitomycin C and exposure times to UV C radiation (UV-C) (wavelength of 254 nm) were used to induce the lytic cycle in lysogenic cells of natural communities of marine bacteria. UV-C treatment occasionally resulted in phage production, but phage production induced by UV-C was always less than that caused by the addition of mitomycin C. There was no evidence that high growth rates of bacteria resulted in lysogenic phage production. The burst size of cells induced by mitomycin C was determined by transmission electron microscopy and ranged from 11 to 45. Dividing the induced phage production by the burst size provided an estimate of the number of lysogenic bacterial cells, which ranged from 0.07 to 4.4% (average, 1.5%) of the total bacterial population. The percentages of lysogenic bacteria that were induced by mitomycin C were similar for samples collected nearshore from the pier of the Marine Science Institute (chlorophyll a, 1.6 to 2.9 (mu)g liter(sup-1)) and in relatively oligotrophic water (chlorophyll a, 0.2 to 0.9 (mu)g liter(sup-1)) collected 25 to 100 km offshore. By using a steady-state model, if all lysogenic bacteria were induced simultaneously, 0.14 to 8.8% (average, 3.0%) of the total bacterial mortality would result from induction of lysogenic cells. If mitomycin C induces all or the majority of lysogenized cells, our results imply that lysogenic phage production is generally not an important source of phage production or bacterial mortality in the coastal waters of the western Gulf of Mexico.
Full Text
The Full Text of this article is available as a PDF (211.0 KB).
Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- Bergh O., Børsheim K. Y., Bratbak G., Heldal M. High abundance of viruses found in aquatic environments. Nature. 1989 Aug 10;340(6233):467–468. doi: 10.1038/340467a0. [DOI] [PubMed] [Google Scholar]
- Bratbak G., Heldal M., Norland S., Thingstad T. F. Viruses as partners in spring bloom microbial trophodynamics. Appl Environ Microbiol. 1990 May;56(5):1400–1405. doi: 10.1128/aem.56.5.1400-1405.1990. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Calendar R. The regulation of phage development. Annu Rev Microbiol. 1970;24:241–296. doi: 10.1146/annurev.mi.24.100170.001325. [DOI] [PubMed] [Google Scholar]
- Peak M. J., Peak J. G., Moehring M. P., Webb R. B. Ultraviolet action spectra for DNA dimer induction, lethality, and mutagenesis in Escherichia coli with emphasis on the UVB region. Photochem Photobiol. 1984 Nov;40(5):613–620. doi: 10.1111/j.1751-1097.1984.tb05349.x. [DOI] [PubMed] [Google Scholar]
- SPENCER R. A marine bacteriophage. Nature. 1955 Apr 16;175(4459):690–691. doi: 10.1038/175690a0. [DOI] [PubMed] [Google Scholar]
- Stewart F. M., Levin B. R. The population biology of bacterial viruses: why be temperate. Theor Popul Biol. 1984 Aug;26(1):93–117. doi: 10.1016/0040-5809(84)90026-1. [DOI] [PubMed] [Google Scholar]
- Suttle C. A., Chan A. M., Cottrell M. T. Use of ultrafiltration to isolate viruses from seawater which are pathogens of marine phytoplankton. Appl Environ Microbiol. 1991 Mar;57(3):721–726. doi: 10.1128/aem.57.3.721-726.1991. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Torrella F., Morita R. Y. 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. 1979 Apr;37(4):774–778. doi: 10.1128/aem.37.4.774-778.1979. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Wiggins B. A., Alexander M. Minimum bacterial density for bacteriophage replication: implications for significance of bacteriophages in natural ecosystems. Appl Environ Microbiol. 1985 Jan;49(1):19–23. doi: 10.1128/aem.49.1.19-23.1985. [DOI] [PMC free article] [PubMed] [Google Scholar]