Accession Number:

ADA279391

Title:

Structural Characterization and Bacterial Degradation of Marine Carbohydrates

Descriptive Note:

Doctoral thesis

Corporate Author:

WOODS HOLE OCEANOGRAPHIC INSTITUTION MA

Personal Author(s):

Report Date:

1993-06-01

Pagination or Media Count:

243.0

Abstract:

An integrated chemical and microbial approach was used to study the effects of chemical structure on rates and patterns of carbohydrate degradation by anaerobic marine bacteria. Nuclear magnetic resonance spectroscopy NMR was used to characterize plankton carbohydrates, and to follow the bacterial hydrolysis of polysaccharides. A carbohydrate produced by Synechococcus WH7335 was identified as a teichoic acid-like polysaccharide, similar in structure to teichoic acids found in cell walls of gram-positive bacteria. This is the first report of teichoic acids in cyanobacteria. Enrichment experiments with bacteria from anoxic marine sediments showed that mixed cultures of marine bacteria distinguish even between small, very closely-related substrates which do not require extracellular hydrolysis prior to uptake. A series of experiments showed that polysaccharides are degraded by bacteria at virtually the same rate as structurally related substrates in the molecular weight range of 300-600 daltons. The time-course of pullulan degradation was examined with gel permeation chromatography and NMR to provide the first molecular-level evidence in marine systems of the bacterial extracellular hydrolysis of high molecular weight organic matter to lower molecular weight organic matter. The experiments demonstrate that enzymatic hydrolysis of macromolecules is not always the slow step in bacterial degradation of organic matter. Carbohydrate, Bacteria, NMR.

Descriptors:

Subject Categories:

  • Biochemistry
  • Biology
  • Microbiology
  • Physical and Dynamic Oceanography

Distribution Statement:

APPROVED FOR PUBLIC RELEASE


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