Gallien received a diploma from Martin Luther University in 1975. Three years later he was given a Doctor of Philosophy degree from the same university.
Gallien began his career as a head of a research laboratory and co-worker of director at the Institute of Vaccines in 1978 and held it for eleven years.
Since 1990 he was a head of molecular genetic engineering department at National Veterinary Reference Laboratory in Dessau.
Nowadays Peter works as a professor of plant protection department at Umweltbundesamt in Berlin.
He is a contributor of articles to professional journals.
On August 12, 1954 Peter Gallien married Annette König. They have 2 children.