Article

Matching phylogeny and metabolism in the uncultured marine bacteria, one cell at a time.

Bigelow Laboratory for Ocean Sciences, P.O. Box 475, West Boothbay Harbor, ME 04575-0475, USA.
Proceedings of the National Academy of Sciences (Impact Factor: 9.81). 05/2007; 104(21):9052-7. DOI: 10.1073/pnas.0700496104
Source: PubMed

ABSTRACT The identification of predominant microbial taxa with specific metabolic capabilities remains one the biggest challenges in environmental microbiology, because of the limits of current metagenomic and cell culturing methods. We report results from the direct analysis of multiple genes in individual marine bacteria cells, demonstrating the potential for high-throughput metabolic assignment of yet-uncultured taxa. The protocol uses high-speed fluorescence-activated cell sorting, whole-genome multiple displacement amplification (MDA), and subsequent PCR screening. A pilot library of 11 single amplified genomes (SAGs) was constructed from Gulf of Maine bacterioplankton as proof of concept. The library consisted of five flavobacteria, one sphingobacterium, four alphaproteobacteria, and one gammaproteobacterium. Most of the SAGs, apart from alphaproteobacteria, were phylogenetically distant from existing isolates, with 88-97% identity in the 16S rRNA gene sequence. Thus, single-cell MDA provided access to the genomic material of numerically dominant but yet-uncultured taxonomic groups. Two of five flavobacteria in the SAG library contained proteorhodopsin genes, suggesting that flavobacteria are among the major carriers of this photometabolic system. The pufM and nasA genes were detected in some 100-cell MDA products but not in SAGs, demonstrating that organisms containing bacteriochlorophyll and assimilative nitrate reductase constituted <1% of the sampled bacterioplankton. Compared with metagenomics, the power of our approach lies in the ability to detect metabolic genes in uncultured microorganisms directly, even when the metabolic and phylogenetic markers are located far apart on the chromosome.

0 Bookmarks
 · 
139 Views
  • Reviews in Mineralogy and Geochemistry 02/2013; 75(1):547-574. · 3.57 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: The Hawaii Ocean Time-series (HOT) programme has been tracking microbial and biogeochemical processes in the North Pacific Subtropical Gyre since October 1988. The near-monthly time series observations have revealed previously undocumented phenomena within a temporally dynamic ecosystem that is vulnerable to climate change. Novel microorganisms, genes and unexpected metabolic pathways have been discovered and are being integrated into our evolving ecological paradigms. Continued research, including higher-frequency observations and at-sea experimentation, will help to provide a comprehensive scientific understanding of microbial processes in the largest biome on Earth.
    Nature Reviews Microbiology 08/2014; · 23.32 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Viruses modulate microbial communities and alter ecosystem functions. However, due to cultivation bottlenecks specific virus-host interaction dynamics remain cryptic. Here we examined 127 single-cell amplified genomes (SAGs) from uncultivated SUP05 bacteria isolated from a marine oxygen minimum zone (OMZ) to identify 69 viral contigs representing five new genera within dsDNA Caudovirales and ssDNA Microviridae. Infection frequencies suggest that ~1/3 of SUP05 bacteria are viral-infected, with higher infection frequency where oxygen-deficiency was most severe. Observed Microviridae clonality suggests recovery of bloom-terminating viruses, while systematic co-infection between dsDNA and ssDNA viruses posits previously unrecognized cooperation modes. Analyses of 186 microbial and viral metagenomes revealed that SUP05 viruses persisted for years, but remained endemic to the OMZ. Finally, identification of virus-encoded dissimilatory sulfite reductase suggests SUP05 viruses reprogram their host's energy metabolism. Together these results demonstrate closely coupled SUP05 virus-host co-evolutionary dynamics with potential to modulate biogeochemical cycling in climate-critical and expanding OMZs.
    eLife Sciences 08/2014; · 8.52 Impact Factor

Full-text (2 Sources)

Download
27 Downloads
Available from
May 20, 2014