scholarly journals Yeast Smell Like What They Eat: Analysis of Volatile Organic Compounds of Malassezia furfur in Growth Media Supplemented with Different Lipids

Molecules ◽  
2019 ◽  
Vol 24 (3) ◽  
pp. 419 ◽  
Author(s):  
Mabel Gonzalez ◽  
Adriana Celis ◽  
Marcela Guevara-Suarez ◽  
Jorge Molina ◽  
Chiara Carazzone

Malassezia furfur is part of the human skin microbiota. Its volatile organic compounds (VOCs) possibly contribute to the characteristic odour in humans, as well as to microbiota interaction. The aim of this study was to investigate how the lipid composition of the liquid medium influences the production of VOCs. Growth was performed in four media: (1) mDixon, (2) oleic acid (OA), (3) oleic acid + palmitic acid (OA+PA), and (4) palmitic acid (PA). The profiles of the VOCs were characterized by HS-SPME/GC-MS in the exponential and stationary phases. A total number of 61 VOCs was found in M. furfur, among which alkanes, alcohols, ketones, and furanic compounds were the most abundant. Some compounds previously reported for Malassezia (γ-dodecalactone, 3-methylbutan-1-ol, and hexan-1-ol) were also found. Through our experiments, using univariate and multivariate unsupervised (Hierarchical Cluster Analysis (HCA) and Principal Component Analysis (PCA)) and supervised (Projection to Latent Structures Discriminant Analysis (PLS-DA)) statistical techniques, we have proven that each tested growth medium stimulates the production of a different volatiles profile in M. furfur. Carbon dioxide, hexan-1-ol, pentyl acetate, isomer5 of methyldecane, dimethyl sulphide, undec-5-ene, isomer2 of methylundecane, isomer1 of methyldecane, and 2-methyltetrahydrofuran were established as differentiating compounds among treatments by all the techniques. The significance of our findings deserves future research to investigate if certain volatile profiles could be related to the beneficial or pathogenic role of this yeast.

2019 ◽  
Vol 95 (8) ◽  
Author(s):  
Wietse de Boer ◽  
Xiaogang Li ◽  
Annelein Meisner ◽  
Paolina Garbeva

ABSTRACT There is increasing evidence that microbial volatile organic compounds (mVOCs) play an important role in interactions between microbes in soils. In this minireview, we zoom in on the possible role of mVOCs in the suppression of plant-pathogenic soil fungi. In particular, we have screened the literature to see what the actual evidence is that mVOCs in soil atmospheres can contribute to pathogen suppression. Furthermore, we discuss biotic and abiotic factors that influence the production of suppressive mVOCs in soils. Since microbes producing mVOCs in soils are part of microbial communities, community ecological aspects such as diversity and assembly play an important role in the composition of produced mVOC blends. These aspects have not received much attention so far. In addition, the fluctuating abiotic conditions in soils, such as changing moisture contents, influence mVOC production and activity. The biotic and abiotic complexity of the soil environment hampers the extrapolation of the production and suppressing activity of mVOCs by microbial isolates on artificial growth media. Yet, several pathogen suppressive mVOCs produced by pure cultures do also occur in soil atmospheres. Therefore, an integration of lab and field studies on the production of mVOCs is needed to understand and predict the composition and dynamics of mVOCs in soil atmospheres. This knowledge, together with the knowledge of the chemistry and physical behaviour of mVOCs in soils, forms the basis for the development of sustainable management strategies to enhance the natural control of soil-borne pathogens with mVOCs. Possibilities for the mVOC-based control of soil-borne pathogens are discussed.


HortScience ◽  
2009 ◽  
Vol 44 (2) ◽  
pp. 396-400 ◽  
Author(s):  
Dong Sik Yang ◽  
Ki-Cheol Son ◽  
Stanley J. Kays

A broad cross-section of volatiles emanating from four species of popular indoor ornamental plants (Spathiphyllum wallisii Regel, Sansevieria trifasciata Prain, Ficus benjamina L., and Chrysalidocarpus lutescens Wendl.) was identified and categorized based on source. Volatile organic compounds from individual plants were obtained using a dynamic headspace system and trapped on Tenax TA during the day and again at night. Using short-path thermal desorption and cryofocusing, the volatiles were transferred onto a capillary column and analyzed using gas chromatography–mass spectroscopy. The volatiles originated from the plants, media/micro-organisms, pot, and pesticides. A total of 23, 12, 13, and 16 compounds were identified from S. wallisii, S. trifasciata, F. benjamina, and C. lutescens, respectively. The night emanation rate was substantially reduced (i.e., by 30.1%, 69.5%, 73.7%, and 63.1%, respectively) reflecting in part the regulation of biosynthesis and the greater diffusion resistance when the stomata were closed. S. wallisii had the highest emanation rate, releasing 15 terpenoid compounds [e.g., linaloloxide, linalool, (Z)-β-farnesene, farnesal, (+)-δ-cadinene, (+)-β-costol] into the surrounding air. Alpha-farnesene (90.3%) was quantitatively the dominant volatile present followed by (Z)-β-farnesene (1.4%), (+)-β-costol (1.4%), and farnesal (1.1%). Substantially fewer terpenoids (i.e., two, nine, and eight) emanated from S. trifasciata, F. benjamina, and C. lutescens, which quantitatively emitted fewer volatiles than S. wallisii. Most terpenoids from the four species were sesquiterpenes rather than monoterpenes. Methyl salicylate, a plant-signaling compound, was emitted by all four species. Certain volatiles (e.g., 2-chlorobenzonitrile, 1-ethyl-3,5-dimethylbenzene) were released from growth media and/or micro-organisms therein; other sources included the plastic pot (e.g., 2-ethyl-1-hexanol, octamethyl cyclotetrasiloxane) and pesticide ingredients [e.g., 2-(2-methoxy- ethoxy)ethanol, 2-ethylhexyl salicylate, homosalate].


1997 ◽  
Vol 6 (3) ◽  
pp. 219-227 ◽  
Author(s):  
Saana Lappalainen ◽  
Anna-Liisa Pasanen ◽  
Pentti Pasanen ◽  
Pentti Kalliokoski

The high relative humidity of the air and many potential growth media, such as bedding materials, hay and grains in the horse stable, for example, provide suitable conditions for fungal growth. Metabolic activity of four common agricultural fungi incubated in peat and wood shavings at 25°C and 4°C was characterized in this study using previously specified volatile metabolites of micro-organisms and CO2 production as indicators. The volatile organic compounds were collected into Tenax resin and analysed by gas chromatography. Several microbial volatile organic compounds (MVOCs), e.g. 1-butanol, 2-hexanone, 2-heptanone, 3-octanone, 1-octen-3-ol and 1-octanol were detected in laboratory experiments; however, these accounted for only 0.08-1.5% of total volatile organic compounds (TVOCs). Emission rates of MVOCs were 0,001-0.176 μg/kg of bedding materials per hour. Despite some limitations of the analytical method, certain individual MVOCs, 2-hexanone, 2-heptanone and 3-octanone, were also detected in concentrations of less than 4.6 μg/m3 (0.07-0.31% of TVOC) in a horse stable where peat and shavings were used as bedding materials. MVOC emission rate was estimated to be 0.2-2.0 μg/kg x h-1 from bedding materials in the stable, being about ten times higher than the rates found in the laboratory experiments. Some compounds, e.g. 3-octanone and 1-octen-3-ol, can be assumed to originate mainly from microbial metabolisms.


Holzforschung ◽  
2001 ◽  
Vol 55 (3) ◽  
pp. 233-237 ◽  
Author(s):  
Sonia N. Humphris ◽  
Ron E. Wheatley ◽  
Alan Bruce

Summary Previous work by Srinivasan et al. (1992) and Bruce et al. (1996) has shown that inhibition of wood decay fungi by volatile organic compounds produced by Trichoderma spp. is dependent on the type of growth media and age of the Trichoderma colony. Wheatley et al. (1997) identified five volatile organic compounds produced by Trichoderma spp. that may be inhibitory to wood decay fungi. The effects of four of these compounds (Acetone, 2-methyl-1-butanol, heptanal and octanal) were tested over a range of concentrations against four selected wood decay fungi. Fungi were incubated in malt extract broth under appropriate conditions and growth was estimated by biomass production and respiration rates. Growth of all four fungi was affected by at least one of the compounds, usually by inhibition but occasionally stimulation. All but two of the fungus/chemical combinations showed significant effects on biomass development (P < 0.05) and fifteen of the sixteen combinations produced a significant concentration effect on respiration rates (P < 0.05). The aldehydes, heptanal and octanal, were very effective against all four wood decay fungi. All four fungi were inhibited by more than 80% at 25 μg ml−1 by heptanal and three of the four fungi were totally inhibited at 250 μg ml−1. Acetone did not inhibit the four wood decay fungi and even stimulated fungal growth at some concentrations. 2-methyl-1-butanol was only effective at the highest concentration of 2500 μg ml−1. The implications of these results for the biological control of wood decay fungi and future studies are discussed.


Sign in / Sign up

Export Citation Format

Share Document