Humic Substances Enhance Growth and Respiration in the Basidiomycetes Trametes Maxima Under Carbon Limited Conditionsстатья
Информация о цитировании статьи получена из
Web of Science,
Scopus
Статья опубликована в журнале из списка Web of Science и/или Scopus
Дата последнего поиска статьи во внешних источниках: 3 октября 2014 г.
Аннотация:Abstract Humic substances (HS) represent the major reservoir
of carbon (C) in ecosystems, and their turnover is crucial
for understanding the global C cycle. Although basidiomycetes
clearly have a role in HS degradation, much less is
known about the effect of HS on fungal traits. We studied
the alteration of physiological, biochemical, and morphological
characteristics of Trametes maxima in the presence of HS.
Both complete medium and minimal (C-limited) medium
mimicking natural environmental conditions were used.
Adding HS led to increased biomass yield, but under Climited
conditions the effect was more apparent. This result
indicated that HS were used as an additional substrate and
agreed with data showing a greater penetration of tritiumlabeled
HS into the cell interior under C-limited conditions.
Humic substances induced ultra-structural changes in fungal
cells, especially under C limitation, including reducing the
thicknesses of the hyphal sheath and cell wall. In the minimal
medium, cellular respiration increased nearly three-fold under
HS application, while the corresponding effect in complete
medium was lower. In addition, in the presence of inhibitors,
HS stimulated either the cytochrome or the alternative pathway
of respiration, depending on presence or absence of
glucose in the medium. Our results suggest that, under conditions
mimicking the natural environment, HS may play three
major roles: as a surplus substrate for fungal growth, as a
factor positively affecting cellmorphology, and as an activator
of physiological respiration.