Rapid identification of microbial VOCs from tobacco molds using closed-loop stripping and gas chromatography/time-of-flight mass spectrometry

Abstract

Several microbial volatile organic compounds (MVOCs) that can serve as potential chemical markers for microbial contamination in tobacco have been identified. Four different fungal species, Aspergillus niger (AN), A. ornatus (AO), Pencillium chrysogenum (PC) and Rhizopus stolonifer (RS), commonly reported in moldy tobacco were cultured and screened for MVOCs. Because the MVOCs emitted by a microbial species are substrate specific, the fungal strains were separately grown on potato dextrose agar (PDA) and tobacco products. MVOCs from the mold cultures grown on PDA and tobacco products were extracted using closed-loop stripping analysis (CLSA) and identified by gas chromatography/time-of-flight mass spectrometry (GC/TOF-MS). Some of the prominent tobacco mold markers identified by this method include: 1-octen-3-ol; 2-octen-1-ol; 2-methyl-1-butanol; 3-methyl-1-butanol; 1-octene and 2-pentanone. In particular, 1-octen-3-ol was detected in all the mold cultures and moldy tobacco samples analyzed. Olfactory evaluation of 1-octen-3-ol indicated a characteristic musty odor and the odor threshold was determined to be approximately 200 ng/ml. The limits of detection for 1-octen-3-ol using GC/TOF-MS and GC/mass selective detector (MSD) in the full-scan mode and selected ion monitoring (SIM) mode were investigated. The CLSA-GC/TOF-MS demonstrates a fast, sensitive and semi-quantitative analytical technique for screening tobacco materials for the presence of mold via chemical markers of microbial contamination.

Analysis of Volatile Organic Compounds Emitted by Plant Growth-Promoting Fungus <i>Phoma</i> sp. GS8-3 for Growth Promotion Effects on Tobacco

“…We opted to analyze all the VOCs extracted at 3 and 5 d of GS8-3 culture for the growth promotion effect, as the rest of the compounds have been found in trace amounts. Aside from these, 2,3-butanediol (32), and 1-octen-3-o1 (20, 30, 36) have also been checked in tobacco as these two metabolites were previously reported to promote growth and to induce a defense response in Arabidopsis . Synthetic VOCs and their mixtures were analyzed at four concentrations.…”

Effects of Growth Parameters on the Analysis of Aspergillus flavus Volatile Metabolites

“…Detection methods include flame ionization detection (FID) [34,37,38] and mass spectrometry (MS) [8,36,[39][40][41][42] for the quantification and qualification of metabolic profiles. Among the MS techniques, single quadrupole mass detection is most widely used; however, more advanced techniques, such as triple quadrupole (MS/MS) [43,44], time of flight (TOF) [45] and ion mobility mass spectrometry (IMS-MS) [46,47], are utilized depending on the purpose of the analysis.…”

Optimization of headspace solid phase microextraction for the analysis of microbial volatile organic compounds emitted by fungi: Application to historical objects

“…Among many of the identified volatiles, some alcohols: 1-octen-3-ol, 3-octanol, ketones: 1-octen-3-one, 3-octanone, and terpenes: limonene, are already reported in the literature as indicators of active growth of molds [9,10,19,33]. They are released in high concentrations and are adequate for the detection of many molds [10,19,28,29,[80][81][82][83][84][85][86]. These compounds are the so-called C 8 -complex MVOCs [10].…”