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Bacteria​—Some Harmful, Many Helpful

MORE than one physician has observed that the regulations for cleanliness found in the law of Moses presuppose knowledge of the harmful effects of bacteria. But it was not until 1676 that proof of their existence was established by the Dutch naturalist Leeuwenhoek. With the use of a primitive microscope, he was the first one to see these tiny “animalcules,” as he called them. Until his day men could only speculate on the existence of such microscopic organisms.

That bacteria were not made visible until the invention of the microscope can be appreciated when we note that bacteria are so small that they need to be magnified one thousand times before they can be clearly seen. In fact, they are so small that in a pinch of earth that you can hold between your thumb and forefinger there may be as many as 200,000,000 of them!

Bacteria are found everywhere, in the air, soil and water. This doubtless is one reason why it took so long to prove the law of biogenesis, namely, that all life comes from precedent life. Before Pasteur’s experiments on this subject it was thought that bacteria generated spontaneously.

Actually bacteria are considered to be plants. They grow and divide at various rates. At the rate of dividing every hour, one bacterium could become 16,000,000 in twenty-four hours! Fortunately conditions often limit their growth. Most of them can survive in temperatures short of boiling or freezing, but they need to have more moderate temperatures to keep growing and dividing. That is why food kept in a refrigerator lasts longer, and keeps indefinitely if kept in the freezer.

Different Classifications

Bacteria may be categorized according to the way the air affects them: the aerobic depend upon air, the anaerobic upon the lack of air or oxygen. By and large, bacteria prefer darkness to light.

Bacteria are also classified according to their basic shapes. There is the spherical kind known as “cocci,” which grow in pairs, clusters, or chains. Then there are the rod-shaped bacteria, and therefore termed “bacilli,” an example of which is the typhoid bacillus. Still another kind is the “spirelli,” the spiral-shaped bacteria, of which the Asiatic cholera germ is an example. And there is a subdivision of the latter, known as the “spirochetes.” The germ that spreads syphilis is one of these.

Smaller than bacteria are rickettsia, named after their discoverer, H. T. Ricketts. And much smaller than even the rickettsia are the viruses, their name coming from a root meaning “poison.”

Potential for Harm

Ever since the time of Pasteur there has been heated debate as to how much harm bacteria can do if the body is truly sound, if it is in optimum health. While Pasteur kept blaming the bacteria, it is reported that on his deathbed he said: “Bernard [one of his leading opponents] was right. The microbe is nothing, the terrain [environment, ‘host,’ the body] is everything.”

Still the fact remains, the possibilities of using bacteria in warfare are so terrible that upward of seventy nations recently renounced their use and pledged themselves “‘to destroy or divert to peaceful purposes, as soon as possible but not later than nine months’ . . . all biological agents.” Yes, bacteriological weapons are considered by some to be even more dangerous than nuclear weapons.​—New York Times, April 11, 1972.

And every once in a while one reads in the press of persons dying from eating canned food spoiled by bacteria, such as botulinus and salmonella. Such spoiled food is so toxic or poisonous that you should not even taste it to see whether it is spoiled. Usually it betrays itself by causing the can to bulge, if not also by the odor and color of the food.

However, most bacteria are helpful. In fact, one American scientist took a count and found, among some thousands of millions of bacteria, a ratio of 30,000 helpful or harmless bacteria to one harmful one.

The Helpful Kind​—in the Soil

Among the greatest ways in which bacteria benefit man is by their activity in the soil. It has well been said that if it were not for bacteria all life on earth would soon be at a standstill. How so?

Well, sooner or later all earth’s living things die​—at least they have until now. Without bacteria to break down the dead bodies of insects, animals and humankind, as well as dead plants, the dead remains would soon so encumber the earth as to make life impossible for either plants or animals.

Certain bacteria also enrich the soil by taking nitrogen from the air and changing it into nitrogen compounds that plants can use​—plants being unable to utilize nitrogen directly from the air. These valuable bacteria are found in small growths, or nodules, on the roots of legumes, a large family of plants that include clover, alfalfa and peas.

Then again, there is iron, indispensable to man, beast and plant life. Certain of the bacteria in the soil are able to take up this iron and make it available for plants. Bacteria also play a vital role in the utilization of phosphorus, another indispensable element of all living things. Bacteria make this nonmetallic element available to plants.

Well has it been observed that bacteria are “responsible for the fertility of our fields.”

Bacteria Aid in Processing Wastes

Bacteria also play a vital role in rendering city sewage harmless. In the so-called secondary or filter treatment sewage is sprinkled onto a bed consisting of broken stones or gravel. This provides surfaces where a film of oxidizing bacteria can live and work on the sewage. Where ponds may be frozen over for six months of the year, anaerobic bacteria, not needing oxygen, do the work.

The heavy remains of sewage are known as sludge. Bacteria also serve to convert this heavy sludge into a relatively stabilized form that is without odor and can be used for fertilizer. In still another method, biologically active sludge, that is, sludge containing much bacteria, together with oxygen, is added to the sewage to make it harmless.

Bacteria in the Body

Bacteria abound in the body, in the mouth and particularly in the intestines. In fact, it is said that in bulk the bacteria in the bowels exceed that of food and wastes to the extent of two to one. While there may be many harmful bacteria in the intestines, so long as they are outnumbered by the beneficial bacteria the body stays well.

In particular does the lactobacillus, or acidophilus bacteria serve the body well. It is used today to remedy minor bowel ills. Also, there are two kinds of antibiotics obtained from bacteria that serve valuable medical purposes.

Important, too, is the role that bacteria play in the digestion of cellulose in the rumen, or the cow’s first stomach. Men cannot digest cellulose, but the bacteria in the cow’s rumen break down the hay and grass the cow eats and produce from this cellulose fatty acids, protein and practically all the vitamins.

Bacteria’s Role in Fermentation

There is still another way in which bacteria are helpful to man and that is in the fermenting process. Do you like yogurt, or sour or clabber milk? You have bacteria to thank. Or do you like rich, flavorful cheeses, such as limburger, blue or Roquefort? Then know that not only are bacteria responsible for these aroma-rich delicacies but when you are eating them you are devouring bacteria by the millions!

Or do you like sauerkraut with your ‘hot dogs’ or cooked with pigs’ knuckles, or in some other tasty ways? Well, here again it is the bacteria plus, of course, a little salt that accounts for this change of sliced cabbage to sauerkraut.

And who does not appreciate that a little wine is good for the digestion, as well as for the heart and nerves? (1 Tim. 5:23) Well, while the fermentation of wine is primarily due to yeasts, bacteria also play a role in wine making.

Ever More Uses

Now researchers are experimenting with training bacteria to digest oil, to clean up oil spills. Bacteria are also used to produce synthetic proteins from petroleum. There is talk, too, of developing a biological cell that will furnish inexpensive light and power, the bacteria being fed on sewage.

It does indeed seem likely that with the passing of time bacteria will prove to be ever less harmful and ever more helpful.