Please enable JavaScript.
Coggle requires JavaScript to display documents.
SUMMARY OF FUNGAL VOLATILE COMPOUNDS AND THEIR ROLE IN ECOSYSTEMS (Why…
SUMMARY OF FUNGAL VOLATILE COMPOUNDS AND THEIR ROLE IN ECOSYSTEMS
Why have scientists studied fungal VOCS?
Biofilters and Biodiesel
Biofilters
because fungi are able to metabolize the volatile compounds, they were used as biofilters to degrade the volatile contaminants and they focus on airborne fungi for this study
Biodiesel
used as sources of generating diesel-type compounds (biodiesel/ mycodiesel) because they are able to utilize plant biomass
E.g.
Ascocoryne
generated VOC mixture include alkanes, alkenes, alcohols, esters, ketones, acids, benzene deriavatives and terpenes (some similar to biofuel target molecules)
Disease detection
Grapes
E.g. the powdery mildew fungus
Uncinula necator
that cause a serious vineyard infection. Diseased grapes produce several distinctive odourants like 1-octen-3-one and (Z)-1,5-octadien-3-one and an unidentified fishy odour which can be detected by farmers.
Humans
Aspergillus fumigatus
cause invasive pulmonary aspergilliosis cause high mortality rate to immmunocompromised individuals.
When grown in-vitro this fungi produces famesene. Terpenes volatile used for early detection of invasive aspergilliosis.
Also, 2-pentylfuran (another volatile compound not terpene) can also be detected in breath of patients with
Aspegillus fumigatus
infections
Olfaction and aroma
A desirable flavour properties of certain cheeses, sausages, beverages are contributed by fungal volatiles and to monitor the quality of these fermented foods, oforant analysis have been used.
There are many fungal VOCs that are classified as natural flavoring ingredients, therefore offering a wide variety of possibilities in food industry.
E.g. the production of 6-pentyl-α-pyrone, a lactose with a characteristic coconut odour by certain species of
Trichorderma
Malodors as indicator of spoilage
The off flavours and odds in food stuff can be used as indirect indicators of contamination. E.g. VOCs has been used to detect spoilage in a jam factory and on bakery products
The presence of fungi in stored agricultural products has been monitored by using VOC sampling
VOCs also produced by indoor molds and their detection provides a non-destructive way to find molds inside a buldings which also can be used to prevent bad odours in compost facilities and feed lots
Fingerprinting and chemotaxonomy
characterization of several basidiomycetes by their odors
VOCs could also be used to distinguished members of genus
Penicillium
at species level
By using volatile production,
Chaetomium spp.
And
Epicoccum spp.
can be distinguished from a group of 76 fungal strains
There are different odorant profiles were found for fungi from different functional groups ( ectomychorrizal, pathogenic and saprophytic )
Ecological roles of VOCs and interspecies interaction
Effects on plant
Enhance plant growth
In lettuce, VOCs wmitted from a consortium of
Fusarium oxysporum
and bacteria also promote the growth
Induce systemic resistance in plant
Affect barley root morphology
Inhibit
Arabidopsis
seed germination
Promote starch accumulation in leaves in several plant species.
Effects on fungi
Kill a range of microbial pathogen in process dubbed "mycofumigation"
Virulent strain of
F.oxysporum
inhibit the growth of its nonvirulent form.
Inhibit the growth of several bacteria
Mycofumigation to E.coli exhibit the number of toxigenic properties which are DNA alkylation and also raising possible cues about the safety of mycofumigation process.
Changes in pigmentation of sapstain fungi such ah in
Lactobacillus plantarum
VOCs and indoor quality
More people spend their time indoors and the microflora in the buildings and their content are
important
to human health.
Damp buildings
support complex microbial ecosystems (molds & mildews)
Indoor fungi (from offgassing of industrial solvents, airborne particulates, mycotoxins bioproduction industry and mold VOCs) is related to poorly defined health problem (sick building syndrome or damp-building related disease) with
symptoms
fatigue, respiratory distress, skin problem, eye irritation.
Many biogenic VOC is toxic to mammalian tissues
Drosophila melanogaster (flies) used to study toxigenic potential of fungal VOCs. The
results
was exposure to chemical standards of several 8C fungal VOCs can cause neurotoxic symptoms proved through molecular techniques (GFP-linked markers, confocal microscopy and mutant analysis)
Low concentration of 1-octen-3-ol caused parkinsonian symptoms, reduced dopamine levels cause dopaminergenic neuron degeneration but over expression of vesicular monoamine transporter rescued the dopamine toxicity and neurodegeneration
1-octen-3-ol stimulate no -mediated inflammatory response in nervous and respiratory tissues of flies and this is also toxic to human cell culture produced from embryonic and human plasma membrane dopamine transporter stem lines
Effect on anthropods
use to attract and repel inserts
attractant for midges
serve as aggregation pheromones and oMycofumigation to position stimulants
important in host location and attraction to food resourses
Introduction
Volatile organic compounds (VOCs) are low molecular weight compounds that can vaporize and enter the gas phase at normal atmospheric temperatures and pressure. It has low medium water solubility and distinct odor. The growing fungi produced VOCs as a mixture of compounds with different molecular size which the quantities, the amounts and the types.
Roles of VOCs
VOCs are also conducted for economic reasons for instance, in food and flavor productions
Agriculturalists also used them as indicators that cause mold spoilage in crops.
Building scientist used them as indicators of hidden mold growth in water-damaged buildings
Entomologists study them as chemical cues that attract or repel certain insect species while mycologists have described them as spore inhibitors and as signals for fungal development.
How do we analyze fungal VOCs?
They must be isolated and characterized for their concentration, separation, identification and quantification of gas phase molecules.
They also use a few methods to understand the mushrooms aromas for examples, steam distillation and liquid-liquid extraction, subsequent concentration and then laborious chemical identification of individual concentrated VOCs.
VOCs are collected from a headspace which trapped on absorptive surface and separated by GC. Then the individual VOCs from complex mixtures are identified by comparisons of mass spectra with library spectra, authentic standards, and/or chromatographic retention indices
Coupling a headspace sorptive extraction technique with gas chromatography, time of flight mass spectrometry were able to identify
Penicillium italicum
,
Penicillium camemberti
and
Penicillium roqueforti
based on their volatile metabolite profile.
Next, Solid phase microextraction (SPME). It is a portable method. VOCs are concentrated on a
fiber and later delivered to the input of a detector. SPME is well suited for taking environmental samples that are then transported back to the laboratory. SPME is the relative quantity of a target volatile compound in an exploratory situation or in a repetitive sampling process but is not useful for the identification of novel compounds.