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Spektrometria mas w badaniach skażeń mikrobiologicznych środowiska . Część I. Kwas muraminowy jako biomarker ścian komórkowych bakterii

Mielniczuk Z., Bal K.

Wiadomości Chemiczne

2012

[Z] 66, 5-6

445-460

Microorganisms synthesize several monomeric chemical structures that are not found elsewhere in nature, e.g. muramic acid (an amino sugar) and D-amino acids (D-alanine and D-glutamic acid) are ubiquitous in bacterial peptidoglycan (PG). Specific sugars (e.g. heptoses) and 3-hydroxylated fatty acids are found in the endotoxin (lipopolysaccharide, LPS) of gram-negative bacteria [42]. The best way to protect against environmental contamination is microbial control. Methods in current use for monitoring of microorganisms mainly include culturing and direct microscopy. However, several factors including samples collection, growth conditions, incubation temperature and interaction between different organisms all affect culturing results. Additionally, culturing based methods can detect only viable organisms and they are also time consuming, sometimes taking days or weeks. However, since both living and dead microorganisms express irritating and toxic structures, they should all be taken into consideration [17]. Muramic acid (MuAc), an amino sugar, has been suggested for use as a chemical marker in gas chromatography-mass spectrometry (GC-MS) determination of bacterial peptidoglycan in both clinical and environmental samples. Several derivatives of MuAc have been applied, including the alditol acetate [1, 2], aldononitrile [3], trifluoroacetyl [4] and trimethylsilyl [5], and methyl ester O-methyl acetate [6] derivatives. Both the alditol acetate and TMS derivatives have proven suitable for the use with GC-ion-trap tandem MS [7]. The aim of our proposition is a trial of application of gas chromatography-mass spectrometry (GC-MS) method as an alternative or complement to culturing, microscopy and other assays for detection, characterization and monitoring of microbial contamination of environment (e.g. water, air, air-conditioning systems), contamination of biochemical and food production chain processes, packaging for foodstuffs etc. by direct analysis of bacterial muramic acid as a biochemical marker. A method is described for the quantitation of muramic acid, a marker of bacterial peptidoglycan as trimethylsilyl (TMS ) derivatives using GC/MS method. The described methods are fast and simple, and can be applied for monitoring of microbial contamination directly, without prior culturing, in complex environmental samples. This method can also be applied for testing processes of cleaning and disinfection on packaging materials or on both packaging materials/foodstuffs in order to decrease their microbial load and thus to ensure better shelf-life.

Kwas muraminowy znany i nieznany

Jędrzejczyk T.

Zeszyty Naukowe. Chemia Spożywcza i Biotechnologia / Politechnika Łódzka

2008

Z. 72

105-118

W pracy opisano stan wiedzy na temat specyficznej cząsteczki zwanej kwasem muraminowym, która występuje w polisacharydach ścian komórkowych bakterii i zarodników. W pracy omówiono jego strukturę, występowanie, właściwości fizykochemiczne, funkcje i przemiany, rolę biologiczna i fizjologiczną oraz metody analizy.

The review describes present knowledge about the very specific molecule namely muramic acid which is an important constituent of bacteria cell walls. Details about physical and chemical characterization are presented with its physiological and biological roles, synthesis, bioconversion. Methods of analytical determination are also described.