General mycology

1. Fungi and Development
Mycologists have over time delivered so much knowledge about fungi (taxonomy, physiology,
genetics, host/substrate relations (including plant pathology and studies of biotrophic
interactions), molecular biology, metabolites, enzymes and protein expression) that biological
products, biological processes, and biological solutions to important problems are already
widespread within many industrial sectors. Today, fungi are providing more of the solutions for
meeting and addressing the various global challenges including health, climate change
sustainable development, environmental pollution, and food security among others. Therefore,
fungi play important roles in economic and social development.
Agriculture
One of the most important roles of mycology in development is in its application to agriculture.
Fungi diseases cause many millions of dollars worth of damage each year to crops. None of our
cultivated plants is without fungus diseases of some kind. Fungi are the principal agents causing
damage to forest trees and shade trees.
Apart from being causative agents of most plant diseases, fungi play a critical role in soil fertility
through the role of mycorrhizal fungi in the soil. Biological control of pests, diseases and weeds
is also an important economic application of fungi in today’s world.
Environmental remediation
Evidence that fungi can "lock" depleted uranium into a mineral form that would be less likely to
find its way into plants, animals, or the water supply is being utilized in remediation of polluted
environments.
Fung also acts as biogeochemical agents. Fungi often dominate the biota in polluted soils, and
play a major role in the establishment and survival of plants through mycorrhiza. Therefore,
marginalized communities such as those living in wastelands can use fungi to rehabilitate their
lands into productive economic entities.
Industrial uses of fungi
Many fungi are useful to humans and have been exploited both industrially and commercially.
Societies have utilized fungi for centuries in a wide variety of ways by capitalizing on the
metabolism and metabolites (chemicals made from metabolism) produced. The oldest and best
known example is the use of yeasts performing fermentation in brewing, wine making and bread
making. Yeasts and other fungi play a critical role in drug production, food processing, bio-
control agents, enzyme biotechnology, as well as research and development.
1. Food industry

2. Yeast (Saccharomyces cerevisae) is used to make alcohol and carbon dioxide. It uses the
fermentation process to break down sugars. Up to 50% of the sugar can be converted to alcohol,
but rarely surpasses 15% because the fungi are sensitive to high concentrations of alcohol.
In the beer making industry, cereal grains are fermented to make the final product. Wine is
composed of fermented grapes while hard cider is essentially fermented apples. Sake is produced
by rice fermentation, using Aspergillus oryzae and then an additional fermentation step utilizing
bacteria and yeasts.
With bread making, fermentation utilizes sugar to produce carbon dioxide and alcohol. The
carbon dioxide produces the bubbles and causes bread to rise, while the alcohol produced
evaporates off while baking.
Fungi are also used in cheese production. Various cheeses are inoculated with Penicillium
roquefortii to impart a strong and pungent flavor in the resultant cheeses.
Most sodas and soft drinks contain citric acid as a main ingredient. Citric acid is also used in
other drinks, many candies, canned goods, baked goods, etc. It is too expensive to isolate the
citric acid from citrus fruits so it is produced in large-scale fermentation by utilizing Aspergillus
niger.
2. Enzymes production
Fungi are able to break down plant cell walls by the production of a wide variety of enzymes.
This capability has been exploited commercially and today, a number of enzymes of industrial
and commercial use have been harvested from fungi. Enzymes are used to treat and modify
fibers, particularly during textile processing and in caring for textiles afterwards. For example,
enzymes called catalases are used to treat cotton fibers and prepare them for the dyeing
processes. By degrading surface fibers, many enzymes, including some cellulases and xylanases,
are used to finish fabrics, help in the tanning of leathers or give jeans a stonewashed effect.
Stonewashed jeans are placed in a large vat containing the fungus Trichoderma, which produces
enzymes (cellulases) that partially digest the cotton fibers of the jeans to add softness and
produce the stonewashed look. The natural enzyme supplement Beano™, contains the enzyme
(α-galacatosidase) from Aspergillus terreus, used for digestive discomfort. The pulp and paper
industry benefits from the enzyme production capabilities of certain fungi to soften wood fibers
and provide alternatives to chemical bleaching. For example, the basidiomycetes Trametes and
Phanerochaete are used for lignin biodegradation and Bjerkandera is used for hardwood
cellulose bio-bleaching by producing the enzymes peroxidase and xylanase. Certain fungi are the
primary source for xylanases, which are used industrially to breakdown xylan, the second most
abundant polysaccharide in nature.
3. Antibiotics production
Fungi make an extraordinarily important contribution to managing disease in humans and other
animals. In 1941, penicillin from the fungus Penicillium chrysogenum was first used successfully
to treat an infection caused by a bacterium. Use of penicilin revolutionised the treatment of
pathogenic disease. Many formally fatal diseases caused by bacteria became treatable, and new
forms of medical intervention were possible. The antibacterial effect of penicillin was

3. discovered by Alexander Fleming in 1929. He noted that a fungal colony had grown as a
contaminant on an agar plate streaked with the bacterium Staphylococcus aureus, and that the
bacterial colonies around the fungus were transparent, because their cells were lysing. Today,
pharmaceutical companies are involved in production of antibiotics at an industrial scale.
Industrial production of penicillin
Penicillin is produced industrially from Penicillium chrysogenum using a fed-batch process.
Batch fermentation is a partially closed system in which nutrients are only added at the start of
the fermentation process and wastes removed at the end. Only pH control solutions and gas
exchange are regulated. This ensures that the cells are constantly subject to stress, a condition
required for the production of secondary metabolites such as penicillin. (NB: the continuous
culture involves feeding the microorganism with fresh nutrients and, at the same time, removing
spent medium from the system)
The first step in industrial production of penicillin is the addition of medium to the fermenter.
The medium comprises of corn steel liqor (a byproduct of starch), yeast extract, lactose, pH
buffers, and minerals. A starter culture of Peniccilium is then added to the batch fermenter and
allowed to grow for 40 hours. Penicillin secretion begins after 40 hours.
The mould mycelium (cell matter) is then filtered from the filtrate through rotating filters. The
harvested filtrate is subjected to a process of purification to obtain the final product. The organic
solvent butylacetate is added to dissolve the penicillin. Potassium salts are added and a penicillin
precipitate is formed, which is then washed and dried.

4. The steps involved in industrial production of penicillin
Why are there so few clinically useful antibiotics?
Several hundreds of compounds with antibiotic activity have been isolated from
microorganisms over the years, but only a few of them are clinically useful. The reason
for this is that only compounds with selective toxicity can be used clinically i.e. they
must be highly effective against a microorganism but have minimal toxicity to humans.
In practice, this is expressed in terms of the therapeutic index - the ratio of the toxic
dose to the therapeutic dose. The larger the index, the better is its therapeutic value.
However, a large number of antibiotics produced from microorganisms have high
toxicity and this prevents them from being used clinically due to the adverse side effects

5. associated with them. The Food and Drug Administration (an American federal agency
involved in regulation of food and drugs safety) provides the recommended therapeutic
indices for drugs prior to approval for distribution to the public.
Role of fungi in sustainable development
Sustainable development is development that meets the needs of the present, without
compromising the ability of future generations to meet their own needs. It is the maintenance of
economic, social and industrial growth while preserving the integrity of the biosphere. Fungi
contribute to sustainable development in several ways:
The mushroom industry: Wastes from agricultural and industrial activities are used to produce
food instead of being dumped in the environment
Enzymes: Enzymes produced by fungi are a sustainable alternative to the use of harsh chemicals
in industry. Because enzymes work under moderate conditions, such as warm temperatures and
neutral pH, they reduce energy consumption by eliminating the need to maintain extreme
environments, as required by many chemically catalyzed reactions. Reducing energy
consumption leads to decreased greenhouse gas emissions.
Mycorrhizal species: They help in enhancing soil fertility while reducing the utilization of
chemical fertilizers, which have negative environmental effects
Fungi in bio-control: Fungi has an important role in the management of agro-ecosystems and in
the reduction of environmental pollution and use of chemical herbicides