Edges and boards have light shelfwear and rubbing. DJ protected with mylar. Pages tight and clean. Library discard with usual marks and attachments. Pocket removed. 192 pages. HardCover Binding. Year: 1968. ISBN: 0. Contrary to popular belief, most bacteria and other microorganisms are helpful and friendly to human beings. For thousands of years man has used microorganisms in the preparation of food. He did not realize it, but when he stumbled upon a way to make cheese, leavened bread, beer, wine and sauerkraut, he was making use of microorganisms. The edible mushroom is itself a microorganism-a fungus. Such unexpected and fascinating information enlivens this many-faceted story of the roles microorganisms play in our lives.