Space, it turned out to be germ-free (7)
I believe the answer is:
aseptic
'be germ-free' is the definition.
(I've seen this before)
'space it turned out' is the wordplay.
'turned out' is an anagram indicator.
'space'+'it'='spaceit'
'spaceit' is an anagram of 'ASEPTIC'.
'to' is the link.
(Other definitions for aseptic that I've seen before include "Free of bacterial or viral contamination" , "Paciest (anag.)" , "Sterile" , "Free from harmful bacteria" , "ideal conditions for hospital?" .)