exotoxin

名词 exotoxin:

1. a toxin that is secreted by microorganisms into the surrounding medium

ex.o.tox.in

n.（名词）
A poisonous substance secreted by a microorganism and released into the medium in which it grows.
外毒素：由微生物分泌并排入其生长的介质中的有毒物质