Chapter Four

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Table 2.3 Principle functions of saprobic fungi in ecosystems (Modified from Tsui,
1999 and Christensen, 1989).
1. Decomposition of organic matter. This involves the volatilization of C, H and O, reduction in
volume, fragmentation, increase in homogenecity, and assimilation by microbes and detritus
feeders.
2. Elemental release. The minaeralization of N, P, K, S and other ions from organic and inorganic
materials commonly accompanies decomposition.
3. Modification of soil permeability and promotion of aggregation.
4. Modification of soil ionic exchange and water holding capacities.
5. Detoxification of soil. This function is a derivatives of chemical or physical alternation e.g.,
degradation, volatilization, or sequestering.
6. Synthesis of humic substances.
7. Participation in saprophytic food chains.
8. Production of environmental biochemicals e.g., antibiotics, immunosuppressants.
9. Cultivation for enzymes or food.
10. Being the bioindicator of air pollution.
2.3 Life Strategies of Saprobes
Substrates for fungal growth may be living or non-living. Fungi can be divided
into three categories according to their nutritional mode; parasitic, endophytic or
saprobic. An important factor affecting the distribution and life-styles of fungi is their
heterotrophy; all growth requires utilization of organic compounds (Cooke and
Rayner, 1984). Different fungi vary widely in their ability to gain access to and utilize
different carbon sources. This variation affects many aspects of their behavior, which
includes their patterns of establishment in natural nutrient sources, their interrelationships
with other organisms, and the types of material which they can occupy
(Cooke and Rayner, 1984; Kendrick, 2000; Dix and Webster, 1995). Parasities are an
organism living on or in, and obtaining its nutrients from, another living organism
(Kirk et al., 2001), This category includes ‘pathogens’ - a parasite living in another