Bobby G. Young, 51, a professor of microbiology at the University of Maryland and a former researcher at the National Cancer Institute and the National Institutes of Health, died Sunday at Peninsula General Hospital in Salisbury, Md., following a heart attack.

Dr. Young was on a fishing trip when he was stricken. His body was found at a camping ground near Salisbury.

He was born in Cape Girardeau, Mo., served in the Navy after World War II, and graduated from Southeast Missouri State College in 1951. After two more years of naval service during the Korean conflict, he moved to the Washington area and joined the staff of the National Cancer Institute in 1954. He later worked in the division of biologics standards of NIH.

He earned a doctorate at Johns Hopkins University in 1965 and joined the faculty of the University of Maryland as an associate professor in 1969. His particular interest was genetics and vaccines. In 1970, he was named acting chairman of the department of microbiology and then was chairman from 1971 to 1975. He was appointed a full professor at that time.

Dr. Young, who lived in Rockville, was a former chairman of the Faculty Council at the university. He was a member of the American Association for the Advancement of Science, the American Society for Microbiology and the Washington Academy of Sciences. He was the author or coauthor of numerous papers published in professional journals.

Survivors include his wife, Sharon D. Young, two daughters, Theresa and Patricia Young, all of Rockville, and two grandchildren.

The family suggests that expressions of sympathy be in the form of contributions to the University of Maryland Foundation -- Isabel McDonald Memorial Fund, University of Maryland, College Park, Md., 20742.