( ( Facultative anaerobes ) ( ( can ( ( ( ( grow aerobically ) ( if ( oxygen ( is present ) ) ) ) and ) ( ( switch ( to ( ( ( fermentation or ) anaerobic ) respiration ) ) ) ( if ( oxygen ( is absent ) ) ) ) ) ) . ) )
(ROOT (S (NP (JJ Facultative) (NNS anaerobes)) (VP (MD can) (VP (VP (VB grow) (ADVP (RB aerobically)) (SBAR (IN if) (S (NP (NN oxygen)) (VP (VBZ is) (ADJP (JJ present)))))) (CC and) (VP (VB switch) (PP (TO to) (NP (ADJP (JJ fermentation) (CC or) (JJ anaerobic)) (NN respiration))) (SBAR (IN if) (S (NP (NN oxygen)) (VP (VBZ is) (ADJP (JJ absent)))))))) (. .)))
Facultative anaerobes can grow aerobically if oxygen is present and switch to fermentation or anaerobic respiration if oxygen is absent.
(ROOT (S (NP (NNP Fermentation)) (VP (VBZ does) (RB not) (VP (VB use) (NP (NN oxygen)))) (. .)))