Bacteria are single cellular  microorganisms that lack a nuclear membrane and are dividing by binary fission. The study of bacteria called as bacteriology. Bacteriological study helps in the field of agricultural, or soil, bacteriology; clinical diagnostic bacteriology; industrial bacteriology; marine bacteriology; public-health bacteriology; sanitary, or hygienic, bacteriology; and systematic bacteriology. Major researches in this field help in development of many useful vaccines. The major advantages are the discovery of antibiotics that are helpful in the diagnosis of various types of disease. Recombinant bacteria are useful in bacteriologic research to manufacture biomolecules (e.g. interferon) needed for research and patient care.