( Fermentation ( ( is ( ( the process ) ( ( by which ) ( ( ( an ( organic substance ) ) ( -LRB- ( usually ( ( a sugar ) -RRB- ) ) ) ) ( is ( ( converted ( by ( ( a ( single-celled microorganism ) ) ( such ( as yeast ) ) ) ) ) ( into alcohol ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (NNP Fermentation)) (VP (VBZ is) (NP (NP (DT the) (NN process)) (SBAR (WHPP (IN by) (WHNP (WDT which))) (S (NP (NP (DT an) (JJ organic) (NN substance)) (PRN (-LRB- -LRB-) (ADVP (RB usually)) (NP (DT a) (NN sugar)) (-RRB- -RRB-))) (VP (VBZ is) (VP (VBN converted) (PP (IN by) (NP (NP (DT a) (JJ single-celled) (NN microorganism)) (PP (JJ such) (IN as) (NP (NN yeast))))) (PP (IN into) (NP (NN alcohol))))))))) (. .)))
Fermentation is the process by which an organic substance (usually a sugar) is converted by a single-celled microorganism such as yeast into alcohol.
(ROOT (S (NP (NNP Single-celled)) (VP (VBP are) (ADJP (JJ yeasts))) (. .)))