Derivatives of intracellular metabolites were analyzed by GC/MS
with a Bruker 450-GC instrument coupled to a Bruker 300-
MS single quadruple mass spectrometer (Bruker Inc., Fremont,
USA). A 1-L sample aliquot was injected onto a VF-5 ms column
(30 m × 250 m internal diameter, 0.25 m film thickness)
in splitless mode. He