Astrobiology: Life in the Universe

NASA Astrobiology Institute (NAI)


  1. Seminar Detail

    Microbial Diversity in the Deep Sea and the Underexplored Rare Biosphere

    Microbial Diversity in the Deep Sea and the Underexplored Rare Biosphere

    Presenter: Julie Huber ()

    October 16, 2006 11:00 AM Pacific

    The world’s oceans are teeming with microscopic life forms. The staining of cells with DNA-binding dyes (DAPI and acridine orange) coupled with epifluorescence microscopy demonstrated that nominal cell densities exceed 105/ml of sea water. Extrapolations of these numbers predict that the oceans harbor 3.6 x 1029 microbial cells with cellular carbon of ~3 x 1017 grams. Given the enormous populations of microbes with seemingly unlimited metabolic diversity, the accumulation of mutations during the past 3.5 billion years should have led to very high levels of genetic diversity and phenotypic variation. By adopting a massively parallel 454 tag sequencing strategy, we show that bacterial communities of deep water masses of the North Atlantic and diffuse flow hydrothermal vents are one to two orders of magnitude more complex than previously reported for any microbial environment. A relatively small number of different populations dominate all samples, but thousands of low-abundance populations account for most of the observed phylogenetic diversity. This “rare biosphere” is very ancient and may represent a nearly inexhaustible source of genomic innovation. Members of the rare biosphere are highly divergent from each other and at different times in earth’s history may have had a profound impact on shaping planetary processes.

    Participation Instructions

    With a Polycom....RSVP to Marco Boldt (Marco.Boldt@nasa.gov) and connect to WebEx as instructed below. If you need Polycom help during the live event, call the videoconferencing help-desk at (650) 604-6412

    The slides from the seminar can be accessed real-time using WebEx at:

    https://nasa.webex.com

    Enter the meeting number: 921 614 818

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    Enter your name or site name (this is not an assigned log-in name, please use your institution name or your first and last name), email and the password: huber1234* (case sensitive)

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    Without a Polycom...There are two ways to participate:

    1) You can listen to the seminar on the telephone while viewing the slides in WebEx (see WebEx instructions above). The NASA conference phone number will be displayed when joining the WebEx meeting.

    2) You can watch the Realplayer webcast at: http://vanseg-1.arc.nasa.gov/2006/AB061016-01.ram and view the slides in WebEx (see WebEx instructions above) There is a 30 second delay for the webcast, so you will need to control the slides manually using the arrow buttons in WebEx. Questions for the speaker can be posted in the WebEx chat area to be answered at the end of the talk. Do not try to watch the Realplayer webcast at the same time as the Polycom or the phone. Due to the delay in the webcast, it will sound awful, unless you like dissonance.


    Click here to view Podcast

Team Overview Seminars: Each of the NAI teams will be giving one hour overview seminars that describe the work they will be performing as members of the NAI. These seminars, which will be broadcast via videoconference and web, will provide an opportunity to find out more about the science, EPO and other activities being performed by the NAI teams.

The Director’s Seminar series features talks from scientists who are invited by the NAI Director to present their research results to the community. A primary goal of the seminars is to encourage interdisciplinary collaboration across NAI teams and within the astrobiology community at large. These seminars are open to all, including the general public; however, the target audience is researchers and students who are engaged in astrobiology. While the seminars are technical in nature, speakers are encouraged to develop presentations that can be understood by colleagues from a variety of disciplines across the field. The talks are typically 50 minutes long, with time at the end for questions and discussion.

The Forum for Astrobiology Research (FAR) seminar provides an opportunity for graduate students to present their research results, and to meet as a student community for mutual encouragement and support. FAR science presentations are typically 20-30 minutes each, with several students presenting during one virtual event. On occasion, the FAR seminar will be devoted to group discussion and planning activities.

The University of Washington seminar series is hosted by the NAI VPL team from their campus in Seattle. NAI provides technical support for the seminar series and produces podcasts of the presentations. The talks are typically 50 minutes long, with time at the end for questions and discussion.

Other virtual seminars, such as workshops and summer student presentations, are hosted by NAI. These are typically scheduled as needed and vary in length, content, and target audience.