( ( others ( -LRB- ( ( anaerobic bacteria ) -RRB- ) ) ) ( ( ( ( ( can not ) ( grow ( in ( ( the presence ) ( of ( free oxygen ) ) ) ) ) ) but ) ( ( obtain oxygen ) ( from compounds ) ) ) . ) )
(ROOT (S (NP (NP (NNS others)) (PRN (-LRB- -LRB-) (NP (JJ anaerobic) (NNS bacteria)) (-RRB- -RRB-))) (VP (VP (MD can) (RB not) (VP (VB grow) (PP (IN in) (NP (NP (DT the) (NN presence)) (PP (IN of) (NP (JJ free) (NN oxygen))))))) (CC but) (VP (VB obtain) (NP (NN oxygen)) (PP (IN from) (NP (NNS compounds))))) (. .)))
others (anaerobic bacteria) cannot grow in the presence of free oxygen but obtain oxygen from compounds.
(ROOT (S (NP (JJ Anaerobic) (NN respiration)) (VP (VBZ occurs) (SBAR (IN if) (S (NP (NN oxygen)) (VP (MD can) (RB not) (VP (VB be) (VP (VBN obtained) (PP (IN at) (NP (DT a) (JJ sufficient) (NN rate))))))))) (. .)))