Phylogenetic diversity

Tetrodotoxin (TTX) and saxitoxin (STX) are potent sodium channel blockers that are found in phylogenetically diverse species of marine life. The wide distribution of TTX and STX has resulted in speculation that bacteria are the source of these toxins. Recently, investigators have reported isolation of marine bacteria, including Vibrio Alteromonas, Plesiomonas, and Pseudomonas species, that produce TTX and STX. This chapter details the methods and results of research to define bacterial sources of TTX and STX. 

L. Marilley and M. Aragno, Phylogenetic diversity of bacterial communities differing in degree of proximity of Lolium perenne and Trifolium repens roots. Applied Soil Ecology 73 127 (1999). 

Webster NS, Wilson KJ, Blackall LL, Hill RT (2001) Phylogenetic diversity of bacteria associated with the marine sponge Rhopaloeides odorabile. Appl Environ Microb 67 434 144... 

Reviews on the fate of aromatic hydrocarbons in marine organisms have been published (2,3,4). They indicated that a substantial amount of information exists on the accumulation of these compounds in a variety of phylogenetically diverse organisms. Recently, emphasis has shifted toward studies of bioconversions of these hydrocarbons. Work has been conducted on enzymes mediating the degradation of aromatic hydrocarbons and on the formation and retention of metabolites. Identifications of individual metabolites in tissues and body fluids of several marine organisms exposed to radiolabeled aromatic hydrocarbons have been made however, insufficient information is available to determine the extent of differences in metabolite profiles as evinced from chromatographic data. 

Ample evidence exists to show that aquatic vertebrates are able to metabolize aromatic hydrocarbons to a variety of conjugated and non-conjugated derivatives. It was shown with fish that the metabolite aromatic hydrocarbon ratio tends to increase after hydrocarbon exposure. Under conditions of depuration (clean water environments) either hydrocarbons or metabolites are discharged through gills, bile, urine, skin, and mucus of marine fish. Further work is necessary with phylogenetically diverse species because the above conclusions are based on only a few studies of selected organisms. 

Hiraishi et al. 1998 Rainey et al. 1999 Kelly and Wood 2000a, 2000b Kelly et al. 2000,2001). A corollary of this phylogenetic diversity is the absence of a single common biochemical pathway, as had already been suspected (Schlegel, 1975 Kelly 1982) and was later established beyond doubt (Kelly, 1988,1989,1990 Kelly et al. 1997 Friedrich 1998 Kelly 1999). 

Poitelon JB, Joyeux M, Welte B et al (2009) Assessment of phylogenetic diversity of bacterial microflora in drinking water using serial analysis of ribosomal sequence tags. Water Res 43(17) 4197-4206... 

The microorganisms deserve much attention, representing the bulk of phylogenetic diversity, thus contributing enormously to the biological evolution. The high turnover makes also the microorganism... 

Lafi, F. F., Garson, M. J., and Fuerst, J. A. (2005). Culturable bacterial symbionts isolated from two distinct sponge species (Pseudoceratina clavata and Rhabdastrella globostellata) from the great barrier reef display similar phylogenetic diversity. Microb. Ecol. 50, 213-220. 

Fuhrman, J. A., K. McCallum, and A. A. Davis. 1993. Phylogenetic diversity of subsurface marine microbial communities from the Atlantic and Pacific Oceans. Applied and Environmental Microbiology 59 1294-1302. 

After establishing a phylogenetic tree, further analysis can be pursued to determine patterns in diversity within and across communities. Phylogenetic diversity (PD) can be determined with the aid of programs like DOTUR (84), and DIVERSITY (85). DOTUR calculates the Shannon-Weiner index, a calculation of diversity based on how predictable the community is, and the Simpson diversity index, a calculation based on both the number of different samples in a community and their proportions in addition to several richness estimators. DIVERSITY calculates PD a diversity index that summates... 

Swann EC, Taylor JW Phylogenetic diversity of yeast-producing basidiomycetes. Mycol Res 1995 99 1205-1210. 

Mehta, M. P., Butterfield, D. A., and Baross, J. A. (2003). Phylogenetic diversity of nitrogenase (nifH) genes in deep-sea and hydrothermal vent environments of the Juan de Fuca ridge. Appl. Environ. 

Paerl, R. W., Foster, R. A., Jenkins, B. D., Montoya, J. P., and Zehr, J. P. (in press). Phylogenetic diversity of cyanobacterial narB genes from diverse marine habitats. Enivronmental Microbiology. 

O, Cavanaugh CM. Phylogenetic diversity of bacterial endosym- 68. bionts in the gutless marine oligochete Olavius loisae (Annelida). 

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