( ( ( The ( ( most important ) role ) ) ( of ( bacteria ( in ( most ( food webs ) ) ) ) ) ) ( ( is ( to ( ( ( decompose ( -LRB- ( ( break down ) -RRB- ) ) ) ( the bodies ) ) ( of ( dead ( ( plants and ) animals ) ) ) ) ) ) . ) )
(ROOT (S (NP (NP (DT The) (ADJP (RBS most) (JJ important)) (NN role)) (PP (IN of) (NP (NP (NNS bacteria)) (PP (IN in) (NP (JJS most) (NN food) (NNS webs)))))) (VP (VBZ is) (S (VP (TO to) (VP (VB decompose) (PRN (-LRB- -LRB-) (S (VP (VB break) (PRT (RP down)))) (-RRB- -RRB-)) (NP (DT the) (NNS bodies)) (PP (IN of) (NP (JJ dead) (NNS plants) (CC and) (NNS animals))))))) (. .)))
The most important role of bacteria in most food webs is to decompose (break down) the bodies of dead plants and animals.
(ROOT (S (NP (NP (DT A) (NN role)) (PP (IN of) (NP (NP (NNS mushrooms)) (PP (IN in) (NP (NNS ecosystems)))))) (VP (VBZ is) (VP (VBG breaking) (PRT (RP down)) (NP (JJ dead) (NN plant) (NN material)))) (. .)))