Toggle Main Menu Toggle Search

Open Access padlockePrints

Statistical Approaches for Estimating Actinobacterial Diversity in Marine Sediments

Lookup NU author(s): Dr James StachORCiD, Dr Luis Maldonado, Emeritus Professor Alan Ward, Professor Michael Goodfellow, Professor Alan Bull


Full text for this publication is not currently held within this repository. Alternative links are provided below where available.


Bacterial diversity in a deep-sea sediment was investigated by constructing actinobacterium-specific 16S ribosomal DNA (rDNA) clone libraries from sediment sections taken 5 to 12, 15 to 18, and 43 to 46 cm below the sea floor at a depth of 3,814 m. Clones were placed into operational taxonomic unit (OTU) groups with ≥99% 16S rDNA sequence similarity; the cutoff value for an OTU was derived by comparing 16S rRNA homology with DNA-DNA reassociation values for members of the class Actinobacteria. Diversity statistics were used to determine how the level of dominance, species richness, and genetic diversity varied with sediment depth. The reciprocal of Simpson's index (1/D) indicated that the pattern of diversity shifted toward dominance from uniformity with increasing sediment depth. Nonparametric estimation of the species richness in the 5- to 12-, 15- to 18-, and 43- to 46-cm sediment sections revealed a trend of decreasing species number with depth, 1, 406, 308, and 212 OTUs, respectively. Application of the LIBSHUFF program indicated that the 5- to 12-cm clone library was composed of OTUs significantly (P = 0.001) different from those of the 15- to 18- and 43- to 46-cm libraries. F ST and phylogenetic grouping of taxa (P tests) were both significant (P < 0.00001 and P < 0.001, respectively), indicating that genetic diversity decreased with sediment depth and that each sediment community harbored unique phylogenetic lineages. It was also shown that even nonconservative OTU definitions result in severe underestimation of species richness; unique phylogenetic clades detected in one OTU group suggest that OTUs do not correspond to real ecological groups sensu Palys (T. Palys, L. K. Nakamura, and F. M. Cohan, Int. J. Syst. Bacteriol. 47:1145-1156, 1997). Mechanisms responsible for diversity and their implications are discussed.

Publication metadata

Author(s): Stach JEM, Maldonado LA, Masson DG, Ward AC, Goodfellow M, Bull AT

Publication type: Article

Publication status: Published

Journal: Applied and Environmental Microbiology

Year: 2003

Volume: 69

Issue: 10

Pages: 6189-6200

ISSN (print): 0099-2240

ISSN (electronic): 1098-5336

Publisher: American Society for Microbiology


DOI: 10.1128/AEM.69.10.6189-6200.2003

PubMed id: 14532080


Altmetrics provided by Altmetric