Science: Microbe Zoo

The narrow, three-story brick building at 2112 M Street in Georgetown looks as ordinary as any structure in the District of Columbia. But in the refrigerators that cram its rooms are germs of the world’s most terrible diseases. Close beside them are beneficial bugs that flavor cheeses, and turn grain into beer. Last week this microbe zoo was preparing to add another class of inmate: cultures of cells from higher animals, such as cancer cells.

The American Type Culture Collection —the zoo’s official name—is the world’s biggest bank of microorganisms. Operating under grants from foundations and Government agencies, the zoo is depended upon by scientific and industrial patrons to supply them with bugs that are “standard,” meaning that they will behave as they are supposed to behave. Keeping microorganisms standard is not easy.

When they are permitted to multiply freely, they often mutate, changing their character. The remedy, explains Director William A. Clark, is to put the bugs in a state of suspended animation.

Double Vials. One way to quiet them down is freeze-drying. A culture of bacteria is set to growing in a nutrient broth.

When the crop is big enough, a sample is put into a cotton-stoppered vial inside a bigger vial, and frozen solid. When the air is pumped out of the vial, the frozen water departs as vapor, leaving a dry residue that looks like an aspirin tablet and contains perhaps 1,000,000 deeply sleeping germs. Some germs will live for 20 years in this state, and can be awakened by adding nutrient. Thus encouraged, they multiply—and then can be put back to sleep again for another 20 years.

From all over the U.S. and from many foreign countries come orders for Dr.

Clark’s microscopic sleeping beauties. The ATCC made more than 8,000 shipments in 1959. Disease germs went mostly to medical schools and drug companies (no amateurs need apply for plague or typhoid), but nonharmful cultures went to everybody who asked. High schools got standardized bacteria for biology experiments at the bargain price of $2 per vial.

For Cheese & Hides. Dr. Clark does not ask the reason for industrial requests, but he can guess that an order for Penicillium camemberti or Penicillium roqueforti came from a person with cheese making on his mind. Aspergillus flavus, which pro duces an enzyme that breaks down pro tein, may be intended for use in dehairing hides, or perhaps to remove the protein that makes beer cloudy when chilled.

Chemical companies often call for molds or bacteria to make such things as citric acid for soft drinks. Airplane manufac turers order fungi to test the mildew proofing of their airplanes. Three strains of mutated Staphylococcus aureus, a con tribution from Russia, are used for screen ing anti-cancer drugs.

With new bugs arriving, the ATCC’s little building is bursting at the seams.

But Director Clark is always on the look out for more; the earth swarms with mi-crospecimens that he feels could do service by taking a long, standardizing sleep in his refrigerators and liquid nitrogen tanks.