21st Century Guidebook to Fungi, SECOND EDITION, by David Moore, Geoffrey D. Robson and Anthony P. J. Trinci

Table of Contents

1. Chapter 9: Continuing the diversity theme: cell and tissue differentiation
2. Chapter 10: Fungi in ecosystems
   1. Contributions of fungi to ecosystems
   2. Breakdown of polysaccharide: cellulose
   3. Breakdown of polysaccharide: hemicellulose
   4. Breakdown of polysaccharide: pectins
   5. Breakdown of polysaccharide: chitin
   6. Breakdown of polysaccharide: starch and glycogen
   7. Lignin degradation
   8. Digestion of protein
   9. Lipases and esterases
   10. Phosphatases and sulfatases
   11. The flow of nutrients: transport and translocation
   12. Primary (intermediary) metabolism
   13. Secondary metabolism
   14. Chapter 10 References and further reading
   15. Buy a PDF of Chapter 10
3. Chapter 11: Exploiting fungi for food

Chapter 10: Fungi in ecosystems

Fungi make crucial contributions to all ecosystems because of their abilities as decomposers. One of the most important Kingdom-specific characteristic of fungi is that they obtain their nutrients by external digestion of substrates. In the real world, though there is some digestion and chemical modification of inorganic substrates (see Chapter 1, CLICK HERE to view a reminder), the bulk of the substrates that fungi recycle are the remains of animals and, most particularly, plants. In this Chapter we give an account of the ways in which fungal hyphae obtain, absorb, metabolise, reprocess and redistribute nutrients.

In doing this, fungi obviously contribute to recycling and mineralisation of nutrients and in what follows we will describe the enzyme systems that enable this activity. Our description is relatively brief and more details can be found in the premier text on fungal physiology (Jennings, 2008). For clarity we have to describe separately the enzyme systems involved, and in an order that we have chosen for descriptive purposes. This introduction is intended to convey the impression that for most fungi in most circumstances the initial nutritional step is the excretion of enzymes able to convert polymers to the simple sugars, amino acids, carboxylic acids, purines, pyrimidines, etc., that the cell can absorb. Also, in most circumstances most fungal mycelia will be carrying out all of these biochemical changes simultaneously.

In this Chapter we will see how fungi contribute to ecosystems. How they breakdown the polysaccharides cellulose, hemicellulose, pectins, chitin, starch and glycogen. Their (unique) ability to degrade lignin, and the ways they digest protein, lipids, esters, phosphates and sulfates. The flow of nutrients is dealt with in terms of transport and translocation; and in the final two Sections we deal briefly, but comprehensively, with the main pathways of primary (intermediary) metabolism as well as secondary metabolites, including commercial products like statins and strobilurins.

For the price of a Coffee & Butter Croissant ($5) you can buy yourself a PDF file of this chapter from 21st Century Guidebook to Fungi Online. Our PDFs feature an elegantly simple text layout that is easily readable on your mobile or other device, and all hyperlinks are live so you can continue to enjoy the Internet experience. Chapter 10: Fungi in ecosystems, is a 45-page PDF file priced at FIVE US$ ($5) Delivered to you by SendOwl Not convinced yet? Download a FREE sample HERE

Updated July, 2019