Fungus Has Its Influence Upon Human Affairs

Auckland Star, Volume LXXII, Issue 238, 8 October 1941, Page 6

Fungus Has Its Influence Upon Human Affairs

MOST people know the difference between a mushroom and a toadstool—the one accepted as a special food delicacy—the other covering everything in the nature of a sizeable fungus, and collectively .banned as poisonous. The great fungus fraternity, however, enter very largely into our lives, especially the innumerable forms of bacteria which contrive to take vast toll of our food, destroy our dwellings and even endanger our most priceless possession—health.

By A. W. B. Powell

In a recent lecture, delivered at Chelsea, England, Dr. J. Ramsbottom, 0.8. E., of the British Museum of Natural History, gave a most able summary of the profit and loss accounts of fungi in relation to man.

Under the stress of the war, with its inevitable food restrictions, there is an excellent opportunity for breaking down the conservatism and prejudice that envelops many unexploited avenues to new sources of foodstuffs. Dr. Ramsbottom explained that although the English list of toadstools undoubtedly contains a few poisonous species, and one that is really deadly, on the other hand there are at least fifty species that far surpass the common field mushroom in flavour. Toadstools—To Eat! The French with their natural aptitude for culinary experiments have long released the ban from a number of species of toadstools. For 2000 years and more the Chinese have cultivated and eaten a fungus that grows on logs and decayed branches. A similar species which looks like grey, floppy dog's ears is quite common in the New Zealand bush, and for many years local Chinese merchants have purchased this commodity dry, for subsequent sale in China.

As a youngster I well remember that the price per pound offered seemed quite attractive, but the difference between fresh and dry weight soon revealed that the remuneration was anything but generous.

The food value of fungus is not very high judged merely by calories, but there is a B and D vitamin contest plus attractive flavouring to relieve the monotony of the less interesting staples.

It is the minute fungi or bacteria that collectively has the most profound influence on our lives. For centuries men have contended with the wholesale destruction of their foodstuffs by bacterial diseases. Even now, although most of these plant diseases are known, their control in practice has not reached a high degree of efficiency.

The United States, which always does everything in a big way; has some astounding figures to show on the loss side of the ledger. For instance, stem-rust of wheat causes an average annual loss of £10,000,000, and it may rise to six times these figures in a bad year. Similarly maize losses fluctuate between 2 and 50 per cent of the whole crop or an average annual loss of 200,000,000 bushels.

We all know the difficulties in respect to blight that beset the potato grower. The classical example occurred in Europe a century ago, causing widespread famine and devastation which, in the resultant economic and political effects, was responsible for the wrecking of a British Cabinet.

Dry Rot Damage

Other forms of fungi give rise to timber rot, both in respect to living trees and more particularly in that most destructive agent known as dry rot. This latter malady was for long a mystery, but is now attributed primarily to lack of ventilation.

In city buildings in New Zealand dry rot causes great damage to floors that are in close proximity to the ground and inadequately ventilated beneath. In innumerable instances such floors have required replacement every three to five years.

Cool storage and sterilisation of foodstuffs have proved of inestimable value in preserving our food supplies. Although freezing does not ensure the killing of fungi, it certainly prevents their growth. The spores of many common moulds are so indestructible that they can be taken down to the temperature of liquid hydrogen without loss of vitality, and are able to withstand the rarified air, intense cold and blazing sunlight of the stratosphere.

Just as the old saying describes fire as a good friend but a bad master, so with bacterial fungi. During the long centuries man discovered that not all the effects of fungal activity resulted in making wholesome food and drink distasteful or poisonous. Most of these fermentations are brought about by yeasts which act on the sugar present in fruits, cereals, plant juices and the like with the resultant production of alcohol.

With modern control methods it has become possible to regulate some of the fermentations so that the same species is used under the same conditions with a more or less standard result. Hence the more or less stable and individual characteristics of brands of beer and also the epicure's cheeses. Harnessing Fungoid Activity As more and more is learned concerning the properties of fungoid activity, so there is opportunity for harnessing more and more of them to our needs. For instance, that well-known article citric acid was until a few years ago obtained exclusively from lemons, but is now generally produced from a mould known as Aspergillus Niger. • It would seem that we would be much happier without fungoid parasites or at least those which affect us, our animals and the plants we use, but we are forgetting the most important role of fungi —as a method of sanitation. The role of fungi in the forest, for instance, is to remove the dead leaves, branches and fallen trees by slow degrees and, finally, add these derived materials to the soil, thus enriching it and stimulating the growth of young trees ultimately to replace the old. One of the most deadly of the fungoid pests is that known as ergot, notorious for causing disease in rye and other cereals, which when eaten in bread brings about gangrene and convulsions.

There are signs, however, that even ergot will eventually be harnessed and worked as a power for good, so that what was once an unmitigated evil may yet be persuaded to adopt a role beneficial to mankind.