( ( During fermentation ) ( oxygen ( ( is ( used up ) ) . ) ) )
(ROOT (S (PP (IN During) (NP (NN fermentation))) (NP (NN oxygen)) (VP (VBZ is) (VP (VBN used) (PRT (RP up)))) (. .)))
During fermentation oxygen is used up.
(ROOT (S (NP (NNP Fermentation)) (VP (VBZ does) (RB not) (VP (VB use) (NP (NN oxygen)))) (. .)))