Bacteriologists are specialty microbiologists, studying living things that are visible only through the microscope. Bacteriologists focus on bacteria and how they affect other living things. They work for many varied industries, including universities, government, pharmaceutical manufacturing, water treatment and food processing. A bachelor's degree in microbiology qualifies you for entry-level jobs, but many positions require a master's degree or a doctorate.

Complete a Bachelor of Science degree in microbiology, including classes in chemistry, biochemistry, physics, computer science, statistics and English composition. Classes in the major typically include general microbiology, molecular and cellular biology, microbial genetics and microbial physiology. Undergraduate programs also include research and lab sections to help prepare students for jobs.

Complete an internship or get a summer job with a relevant company such as a drug manufacturer, food company or agricultural lab. Employers prefer to hire bacteriologists who have extensive practical experience in the lab. With internship experience plus a bachelor's degree, you'll qualify for entry-level positions such as lab assistant in a pharmaceutical company.

Complete a master's degree in bacteriology or microbiology to qualify for higher positions in labs or as a step toward the Ph.D. A master's degree typically takes one to two years and includes classes such as advanced molecular biology, genetics and advanced biochemistry. Programs geared toward preparing students for jobs require significant lab work and often include internship opportunities. M.S. programs leading to an eventual doctorate emphasize research and require a master's thesis.

Prepare for a career doing independent research or managing a lab by completing a Ph.D. Doctoral programs in microbiology or bacteriology require advanced coursework, a qualifying examination and preparation of a thesis based on independent research. Many Ph.D. graduates also complete postdoctoral appointments as a steppingstone to permanent jobs. Bacteriologists with the Ph.D. typically work for universities, government agencies and clinical and industrial labs.

Complete a medical degree in addition to the Ph.D. if you're interested in doing clinical research such as for infectious diseases. Medical school typically takes four years, including two years of coursework and two years of clinical rotations. As a shortcut, some universities offer a combined M.D. and Ph.D. program targeted at training medical scientists for jobs in academia and biomedical research.