( ( In ( ( the absence ) ( of oxygen ) ) ) ( , ( ( ( the ( only organisms ) ) ( able ( to grow ) ) ) ( ( are ( those ( able ( to ( ( ( steal ( oxygen ( -LRB- ( reduction -RRB- ) ) ) ) ( from ( the food ) ) ) ( by ( forming ( ( reduced ( organic compounds ) ) ( which ( often ( have ( foul odors ) ) ) ) ) ) ) ) ) ) ) ) . ) ) ) )
(ROOT (S (PP (IN In) (NP (NP (DT the) (NN absence)) (PP (IN of) (NP (NN oxygen))))) (, ,) (NP (NP (DT the) (JJ only) (NNS organisms)) (ADJP (JJ able) (S (VP (TO to) (VP (VB grow)))))) (VP (VBP are) (NP (NP (DT those)) (ADJP (JJ able) (S (VP (TO to) (VP (VB steal) (NP (NP (NN oxygen)) (PRN (-LRB- -LRB-) (NP (NN reduction)) (-RRB- -RRB-))) (PP (IN from) (NP (DT the) (NN food))) (PP (IN by) (S (VP (VBG forming) (NP (NP (VBN reduced) (JJ organic) (NNS compounds)) (SBAR (WHNP (WDT which)) (S (ADVP (RB often)) (VP (VBP have) (NP (JJ foul) (NNS odors))))))))))))))) (. .)))
In the absence of oxygen, the only organisms able to grow are those able to steal oxygen ( reduction ) from the food by forming reduced organic compounds which often have foul odors.
(ROOT (S (NP (NNS Plants)) (VP (CONJP (RB not) (JJ only)) (VP (VBP contribute) (NP (NN food))) (CC but) (VP (VBD oxygen) (PP (IN for) (NP (NNS organisms))))) (. .)))