Accession Number : ADA431240


Title :   Diversity and Phylogenetic Structure of Two Complex Marine Microbial Communities


Descriptive Note : Doctoral thesis


Corporate Author : WOODS HOLE OCEANOGRAPHIC INSTITUTION MA


Personal Author(s) : Klepac-Ceraj, Vanja


Full Text : https://apps.dtic.mil/dtic/tr/fulltext/u2/a431240.pdf


Report Date : Sep 2004


Pagination or Media Count : 109


Abstract : Molecular surveys have revealed that microbial communities are extraordinarily diverse. Yet, two important questions remain unanswered: how many bacterial types co-exist, and do such types form phylogenetically discrete units of potential ecological relevance? This thesis explores these questions by investigating bacterial diversity in two complex marine communities (coastal bacterioplankton and sediment sulfate-reducing bacteria) by (i) comprehensive analysis of large 16S rRNA clone libraries, and (ii) refinement and application of parametric diversity estimators. Identification and correction of sequence artifacts demonstrated their potentially significant contribution to diversity estimates. Still, hundreds of unique rRNA sequences (ribotypes) were detected in the corrected libraries, and extrapolation to community diversity with commonly used non-parametric diversity estimators suggested at least thousands of co-existing ribotypes in the two communities. However, close inspection revealed that the non-parametric estimators likely lead to underestimation of ribotype diversity in the clone libraries.


Descriptors :   *MICROBIOLOGY , *ECOLOGY , COASTAL REGIONS , MOLECULES , BACTERIA , THESES , MARINE ATMOSPHERES , SURVEYS , SULFATES , ARTIFACTS , SEDIMENTS , MICROORGANISMS , EXTRAPOLATION , PLANKTON , REDUCTION(CHEMISTRY)


Subject Categories : Biology
      Ecology


Distribution Statement : APPROVED FOR PUBLIC RELEASE