GERMS AND WHAT THEY MEAN TO US.

Hokitika Guardian, 12 June 1926, Page 4

GERMS AND WHAT THEY MEAN TO US.

- HOW YEAST PROLONGED THE WAR. ; [iy J. |{. s. Haldane, Reader in Biochemistry, Cambridge University, in the London “ Daily Mail.”) X<> living tilings are more persistently and unjustly libelled than the microscopic plants and animals which we lump together under the heading ol germs. Many thousands ot' different kinds are known. Thirty or forty have definitely been proved to cause human diseases, as many more are under suspicion, some others are harmful to domestic plants and animals; the vast majority are neutral or friendly, and a few are indispensable. Generally we take their activities lor granted, if we manure a field with sulphate of ammonia we are sure t’llill the soil will contain the two races of bacteria needed to convert it into nitrates which a plant can use. If we give a cow hay we assume that her stomach, unlike our own, will contain he bacteria needed to render it digestible.

Hut for some processes it is necessary to supply the right germ artificially. For untold ages man has possessed a domesticated microbe—namely, yeast —which is closely related to the cause of a serious skin disease, though itself, of course, quite harmless, '[’here are as many races of yeast as of dogs, and bakers’ and brewers’ yeast are as different as a dachshund and a greyhound. The different qualities of beers depend largely on the types of yeast employed, and yeast breeding is a highly skilled trade, though unfortunately this country depends to too large an extent on yeast imported from Holland. I)R WFIZMAXX’S DISCOVERY. Until recently it was believed that yeast confined its activities to turning sugar into alcohol and carbon dioxide, the gas which makes the froth on beer and the bubbles in bread. Unfortunately just before the war Professor Xeuberg. of Merlin, showed that if sodium sulphite was added to fermenting malt the yeast converted the sugar largely into glycerine. This essential raw material for explosives is generally derived from fat as a by-pro-duct in soap-boiling. When our blockade cut off Germany’s supply of fat Coniisteiii and l.udeeko were able to make glycerine from malt by this process, and their invention prolonged the var by several months. At the same time the British munition manufacturers needed acetone to dissolve one of the constituents of cordite, and here, too, a microbe was employed, and. indeed, proved a. more useful ally than some of the minor signatories of the Treaty of Versailles. Dr Weixhaiin. of Liverpool, the Zionist leader, succeeded in isolating a bacillus which makes acetone from starch.

Tf damp starch is left exposed to air it will “ go ■ had ” as the result of attack by a number of moulds, yeasts and bacteria, which produce various dif'fo rent substances from. it. Among others. Dr Wcizniann’s bacillus is often present, and accordingly small qunnti--1 ies of acetone will often appear. His achievement, which forms the basis of a tiatent' recently upheld in the law courts, was to isolate this particular microbe from, the others so as to obtain a large yield of acetone. BACTERIA IX INDUSTRY.

The cultivation of a single race of bacteria without contamination by other kinds is a highly skilled occupation. Any culture containing unwanted. types must lie thrown away. It is ns if a farmer were compelled to burn a field of corn whenever weeds wore found in it. The art of breeding bacteria finds its greatest applications in medicine. .Many tons of typhoid bacilli have been bred in order to produce immunity by the injection of their dead bodies. Some species are easily grown. Others are extremely fastidious with retard to the food. A few can so far he grown only in living men or animals. But every year the skilled grower of bacteria is finding a place in fresh industries. for these tiny creatures can often perform chemical transformations with an ease which is the envy of human chemists.

For exam pip, explosives for use in coal mines must not ignite air containiig firedamp (methane). And it turns out that the cheapest par of making the methane with which to test them is to employ a bacillus. The commercial bacteriologist is now employed in sueli industries as the manufacture of cheese, vinegar and ginger beer, in all of which, bacteria nlay a part. "Rule of thumb methods are successful nine times out of ten in these processes; the bacteriologist can ensure success on the tenth occasion.

We are hegiiiing to study bacteria with a view not merely to identifying them and killing them but to the elucidation of their life-processes. In three neighbouring rooms of a modern bio-chemical laboratory research workers will be collecting and analysing the gases breathed out by a man, a rabbit and a tube full of bacteria ; for many bacteria breathe. And the bacteria will be as carefully fed and warmed as the man and the rabbit. For wo require the very fullest information as io the habits not only of possibly useful microbes but of those which cause dis-

(t is easy enough to kill these latter outside the body but extremely difficult to do so when they have obtained a footing there. By treating them kindly we may discover not only the good points of our friends but the weak points of our foes, and the same research worker may initiate a new industry and cure an old disease.