He notably served as a professor (1932–1947) and rector (1938–1945) of Norges tannlegehøgskole, Norway's ambassador to Sweden (1947–1953), Norwegian Minister of Education and Church Affairs (1953–1960) and chairman of the International Whaling Commission.

He was born in Kvæfjord Municipality as a son of teacher Hans Christian Bergersen (1835–1925) and his wife Ingeborg Kristine Heitmann (1848–1938).

His advisor for the master's degree was Kristine Bonnevie, and his thesis was translated, shortened and issues in the German journal Zeitschrift für Zellforschung und mikroskopische Anatomie in 1926.

Bergersen was a board member of the Norwegian Students' Society, and worked part-time as a curator and assistant at the university and its palaeontological museum.

In December 1953, while still serving as ambassador, he joined the Cabinet of Oscar Torp as Minister of Education and Church Affairs.

[2] Bergersen was also a board member of the Norwegian Maritime Museum from 1928 to 1967, of the Oslo municipal cinema from 1935 to 1940 and Kommunenes Filmcentral.