noun
microbiologist
A scientist who studies microorganisms such as bacteria, viruses, and fungi.
彼女は微生物学者として研究所で働いている。
She works as a microbiologist at a research institute.
微生物学 is the field of microbiology, while 微生物学者 refers to a person who studies it.
Compound of 微生物 (microorganism) + 学者 (scholar, -ologist).