Energetic constraints on fungal growth
File(s)
Published version
Author(s)
Heaton, L
Jones, NS
Fricker, M
Type
Journal Article
Abstract
Saprotrophic fungi are obliged to spend energy on growth, reproduction and substrate digestion.
To understand the trade-offs involved, we developed a model which, for any given growth rate,
identifies the strategy that maximises the fraction of energy that could possibly be spent on reproduction.
Our model's predictions of growth rates and bioconversion effciencies are consistent with
empirical findings, and it predicts the optimal investment in reproduction, resource acquisition and
biomass recycling for a given environment and time scale of reproduction. Thus if the timescale
of reproduction is large compared to the time required for the fungus to double in size, the model
suggests that the total energy available for reproduction is maximal when a very small fraction of the
energy budget is spent on reproduction. The model also suggests that fungi growing on substrates
with a high concentration of low molecular weight compounds will not benefit from recycling: they
should be able to grow more rapidly and allocate more energy to reproduction without recycling. In
contrast, recycling offers considerable benefits to fungi growing on recalcitrant substrates, where the
individual hyphae are not crowded, and the time taken to consume resource is significantly longer
than the fungus doubling time.
To understand the trade-offs involved, we developed a model which, for any given growth rate,
identifies the strategy that maximises the fraction of energy that could possibly be spent on reproduction.
Our model's predictions of growth rates and bioconversion effciencies are consistent with
empirical findings, and it predicts the optimal investment in reproduction, resource acquisition and
biomass recycling for a given environment and time scale of reproduction. Thus if the timescale
of reproduction is large compared to the time required for the fungus to double in size, the model
suggests that the total energy available for reproduction is maximal when a very small fraction of the
energy budget is spent on reproduction. The model also suggests that fungi growing on substrates
with a high concentration of low molecular weight compounds will not benefit from recycling: they
should be able to grow more rapidly and allocate more energy to reproduction without recycling. In
contrast, recycling offers considerable benefits to fungi growing on recalcitrant substrates, where the
individual hyphae are not crowded, and the time taken to consume resource is significantly longer
than the fungus doubling time.
Date Issued
2015-12-08
Date Acceptance
2015-07-23
Citation
American Naturalist, 2015, 187
ISSN
1537-5323
Publisher
University of Chicago Press
Journal / Book Title
American Naturalist
Volume
187
Copyright Statement
© 2015 by The University of Chicago
Subjects
Ecology
06 Biological Sciences
Publication Status
Published
Article Number
2