Analytic procedures have been modified to determine the abundance of muramic acid (a specific component of the peptidoglycan unit of cell walls of most bacterial prokaryotic organisms) in 4 different Holocene sediment samples. <i>N,O</i>-Heptafluorobutyl-<i>n* 1-Bu ester derivatives were prepared from sediment samples for the detection of muramic acid and amino acids including diaminopimelic acid. The derivatives were analyzed by gas chromatography (GC) and GC-mass spectroscopy. Fast-atom-bombardment ionization was used for the muramic acid derivatives to determine its molecular weight and structure. D-and L-amino acids were separated by GC on a capillary chiral column. Using this technique a stable <i>N,O* 1-heptafluorobutyryl-*2n</i>-Bu ester derivative of muramic acid was identified at picogram levels in Holocene sedimentary microbial communities. It has been reported previously that microorganisms in sediments rapidly degrade muramic acid from cell walls of dead prokaryotes. Kinetic experiments revealed that muramic acid was relatively stable in intact cell walls but decomposed rapidly in the free form. These investigations showed that the concentration of muramic acid may be used as an indicator of the presence of the intact cell walls of cyanobacteria and most other bacteria in Holocene microbial communities, and of microbial contamination in samples older than the Holocene. -- AATA