( This ( ( is ( done ( through ( ( a process ) ( called fermentation ) ) ) ) ) . ) )
(ROOT (S (NP (DT This)) (VP (VBZ is) (VP (VBN done) (PP (IN through) (NP (NP (DT a) (NN process)) (VP (VBN called) (NP (NN fermentation))))))) (. .)))
This is done through a process called fermentation.
(ROOT (S (NP (NNP Fermentation)) (VP (VBZ is) (NP (NP (DT the) (NN process)) (PP (IN of) (S (VP (VBG making) (NP (NN atp)) (PP (IN without) (NP (NN oxygen)))))))) (. .)))