Аннотация:532 The possibilities of using fungal fluorophores to assess responses
of filamentous fungi to external stimuli E.V. Fedoseeva, Pirogov
Russian National Research Medical University / Pediatric faculty; D.
Khundzhua, Lomonosov Moscow State University / Depament of
General Physics; V. Terekhova, Lomonosov Moscow State University /
Lab of Ecotoxicological Soil Analysis; M. Freidkin, Lomonosov
Moscow State University / Department of General Physics; S. Patsaeva,
Lomonosov Moscow State University / Depament of General Physics.
The interest to functional and structural indicators of mycobiota with a
respective to use them in biogiagnostics is currently rising because fungi
represent as essential component among environmental decomposers of
organic material in ecosystems. The complexity of utilization of fungi in
biogiagnostics is explained by the variability of reactions to external
stimuli due to their physiological and biochemical plasticity. In this
regard, it seems very important to find the reactions of fungal cultures
adequately reflecting their response to external stimuli in different
conditions. The essential biogenic fluorophores such as NADH,
tryptophan, melanin, ergosterol, pyridoxine, riboflavin, FAD, and FMN
can be monitored instrumentally by spectroscopic techniques. The aim
of the present study was to investigate the features of fluorescence
spectra of fulamentous fungi cultivated under different concentrations of
source of bioavailable and nor readily bioavailable carbon in the growth
medium. The research objects were strains of Alternaria alternata,
Cladosporium cladosporioides, and Trichoderma harzianum. The
strains were kindly provided by O.E. Marfenina and A.E. Ivaniva, Soil
Science Faculty of MSU. The filamentous fungi were grown on liquid
and agar Czapek medium contained a varying level of sucrose (0.3 and
3%) and humic substances (0.02 and 0.1%). Fluorescence spectra were
measured using a luminescence spectrometer Solar CM2203 at several
wavelengths of the exciting radiation (250, 280, 310, 350, and 450 nm).
Fluorescence excitation spectra were registered for emission at 350, 440,
and 460 nm. Typical fluorescence spectra of fungal samples (spore
suspensions and supernatant liquids) with the UV-excitation consist of
two overlapping bands. The UV-band with maximum at 300-350 nm
under excitation at 280 nm is a protein-like fluorescence, and the band in
the blue region with the maximum at 400-450 nm under excitation at
310-370 nm is emission of fungal chromophores like NADH and or
melanins. We suggest using the intensity of the first fluorescence band
in the fungal samples for rapid evaluation of spore biomass. Measured
fluorescence characteristics were found correlating with saturation of
growth medium by source of bioavailable and not readily bioavailable
carbon. Therefore we consider this research as promising on the way of
using fungal fluorophores to assess responses of filamentous fungi to
external stimuli