Rita R. Colwell, an internationally known microbiologist at the University of Maryland's College Park campus, was appointed chief academic officer of Maryland's five-campus system yesterday.

As vice president for academic affairs, Colwell, 48, will be the highest ranking woman in the school's administration and the first to serve permanently in that post. (Ruth Young, dean of social work at Maryland's Baltimore City campus, served as acting vice president from July 1979 to August 1980.)

Colwell replaces David Adamany, who left Maryland last April to become president of Wayne State University in Michigan.

She has been a professor in the microbiology department since 1972 and director of Maryland Sea Grant, a federally funded agency that studies the Chesapeake Bay and other state waterways, since 1977. Colwell has traveled extensively, researching topics such as cholera, water quality, ocean dumping and genetics.

Perhaps the most important of Colwell's new administrative duties, which include testifying for the school before the General Assembly, overseeing all academic programs at Maryland's various campuses and overseeing the Sea Grant Program, will be recommending faculty promotions to University President John Toll.

Last week, about 200 College Park students rallied to protest the emphasis on research in the school's tenure promotion guidelines. The focus of their action was an instructor of radio, television and film, who admittedly had done little research, whose tenure application has not yet been acted on.

Asked about her views on research versus teaching, Colwell said, "I consider research a very important kind of teaching. Teaching is research, and research is teaching."

Colwell's appointment was the second major administrative action by the university in two days. Former National Science Foundation director John B. Slaughter was inaugurated Tuesday as the College Park campus's first black chancellor.

"I think it proves Dr. Toll is seeking the best people he can, and doesn't care about race or sex," Colwell said.

Sam W. Joseph, chairman of the microbiology department, said Colwell "takes a number of tasks and does them well."

Colwell said she will continue as a microbiology professor and will take over as president of the American Society for Microbiology in July.

David Sparks, who was acting vice president for academic affairs for the last year, will return to his post as the university's vice president of graduate studies and research when Colwell takes over in July.

Colwell's most recent travel was to Bangladesh, fron which she returned Sunday after a lecture and research tour to study that nation's public health system.