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Water Sci Technol

Title:		"Volatile organic compound (VOC) analysis and sources of limonene, cyclohexanone and straight chain aldehydes in axenic cultures of Calothrix and Plectonema"
Author(s):		Hockelmann C; Juttner F;
Address:		"Institute of Plant Biology, Limnological Station, Seestr. 187, CH-8802 Kilchberg, Switzerland. hoeckel@limnol.unizh.ch"
Journal Title:		Water Sci Technol
Year:		2004
Volume:		49
Issue:		9
Page Number:		47 - 54
DOI:
ISSN/ISBN:		0273-1223 (Print) 0273-1223 (Linking)
Abstract:		"The volatile organic compounds (VOCs) in four standing cultures of axenic benthic cyanobacteria (Calothrix and Plectonema) were studied by GC/MS analysis. To verify the biogenic origin of the VOCs, 13C-labelling experiments were performed, and the differences in labelling were used to differentiate between biogenic and non-biogenic sources. Strongly labelled biogenic compounds were derived from the shikimate (cresol, skatole), isoprenoid (beta-cyclocitral, beta-ionone, geosmin) and fatty acid pathways (5Z-heptadecene, 3-octanone, 1-hexanol). New odour compounds derived from microorgansims were beta-cyclogeraniol, dihydro-beta-ionone and 2-hydroxy-2,6,6-trimethylcyclohexanone. The latter compound had already been found in lake water, but could not be assigned to a particular organism. Straight chain aldehydes (octanal, nonanal, decanal), cyclohexanone, cyclohexanol and limonene were unlabelled beyond their natural isotope ratio. Therefore, the biogenic origin of these compounds is doubtful despite their occurrence in axenic cultures. The observation that limonene was a racemate supports this view. The precursors and reactions that lead to the formation of these non-biogenic compounds are unknown and it may be that they are formed by the analytical procedures rather than then being present in the culture medium"
Keywords:		Aldehydes/*analysis Carbon Isotopes/analysis Culture Media Cyanobacteria/*chemistry Cyclohexanones/*analysis Cyclohexenes Fermentation Gas Chromatography-Mass Spectrometry Limonene Solvents/*analysis Taste Terpenes/*analysis Volatilization Water Microbiol;
Notes:		"MedlineHockelmann, C Juttner, F eng Research Support, Non-U.S. Gov't England 2004/07/09 Water Sci Technol. 2004; 49(9):47-54"