Economic importance of bacteria are used, too, to form organic acids in pickles and vinegar. Biotechnology bacteria the use of microorganisms including bacteria and fungi in the manufacturing and services industries. These include chemical manufacturing such as ethanol, acetone, organic acid, enzymes, and perfumes. In the chemical industry, bacteria are most important in the production of pharmaceuticals. "Escherichia coli" is used for commercial preparation of riboflavin and vitamin K. Genetic engineering is the manipulation of genes. It is also called recombinant DNA technology. In genetic engineering, pieces of DNA (genes) are introduced into a host by a variety of techniques, one of the earliest
Cavalier-Smith's system of classification had been subdivided into twelve phyla: The protozoa were originally classified as members of the animal kingdom. Now they are classified as multiple separate groups. Zoology is the study of animals while botany is the study of plants. While zoologists divided the animal kingdom into phyla, botanists carved the plant kingdom into "divisions". By 1940, five divisions were recognized: Fungi and bacteria were included within the plant division thallophyta. Today, bacteria are no longer classified as plants and fungi are known to be more closely related to animals than to plants. By mid-nineteenth century, microscopic organisms were generally classified into