INVESTIGADORES
LARA Ruben Jose
artículos
Título:
Selective microbial degradation of mangrove derived pentacyclic triterpenols in surface sediments
Autor/es:
KOCH, BORIS; HARDER, JENS; LARA, RUBÉN JOSÉ; KATTNER, GERHARD
Revista:
ORGANIC GEOCHEMISTRY
Editorial:
Elsevier
Referencias:
Lugar: Amsterdam; Año: 2005 p. 273 - 285
ISSN:
0146-6380
Resumen:
<!--
/* Font Definitions */
@font-face
{font-family:AdvTT5843c571;
panose-1:0 0 0 0 0 0 0 0 0 0;
mso-font-charset:0;
mso-generic-font-family:roman;
mso-font-format:other;
mso-font-pitch:auto;
mso-font-signature:3 0 0 0 1 0;}
/* Style Definitions */
p.MsoNormal, li.MsoNormal, div.MsoNormal
{mso-style-parent:"";
margin:0pt;
margin-bottom:.0001pt;
mso-pagination:widow-orphan;
font-size:12.0pt;
font-family:"Times New Roman";
mso-fareast-font-family:"Times New Roman";}
@page Section1
{size:612.0pt 792.0pt;
margin:72.0pt 90.0pt 72.0pt 90.0pt;
mso-header-margin:36.0pt;
mso-footer-margin:36.0pt;
mso-paper-source:0;}
div.Section1
{page:Section1;}
-->
The effect of sedimentary microbial
communities on the composition of pentacyclic triterpenol markers as well as bsitosterol
was studied in mangrove surface sediments from North
Brazil during a three months degradation experiment. Leaves of Rhizophora
mangle, Avicennia germinans and Laguncularia racemosa were incubated with
surface sediment and analysed using GC/MS for b-sitosterol, taraxerol, b-amyrin,
germanicol, lupeol and betulin. Taraxerol showed the strongest resistance to
microbial degradation and clearly increased up to 68% of the sum of the
selected markers. Betulin was degraded completely after 40 days, most likely
due to its higher polarity. By means of a numerical model the marker
composition in surface sediments was explainable as a combination of the
dominant input from R. mangle leaves and selective microbial degradation.
Calculated marker degradation constants from the model were compared with
measured constants in the experiment. On the basis of calculated constants the
average age of the organic matter in the upper 1.5 m of sediment was
approximately 530 yr.