Noel Krieg joined the Biology Department at Virginia Tech in 1960. He served as the major professor for 13 Ph.D. students and 22 M.S. students. In 1978, he received the Carski Distinguished Teaching Award from the American Society for Microbiology. In 1983, Virginia Tech awarded him the position of Alumni Distinguished Professor. In 1987, he was elected to membership in the American Academy of Microbiology.
His research career was devoted to studies of the taxonomy and physiology of microaerophilic bacteria, including azospirilla and campylobacters. In addition to research papers, Dr. Krieg co-authored two textbooks of general microbiology. For 25 years, he was a member of the Bergey's Manual Trust, which publishes the international reference book Bergey's Manual of Systematic Bacteriology. He also co-edited other major reference books such as Manual of Methods for General Bacteriology and Methods for General and Molecular Bacteriology.
Although Dr. Krieg retired in 1999, he still teaches part-time, having initiated a new course called Prokaryotic Diversity.