| Abstract |
Several cellulase titers were used to saccharify suspensions of tomato pomace in 300 ml shake-flasks. The sacharification of the substrate produced glucose at different initial rates from 1.8 g of reducing sugar kg(-1) per enzyme unit fat 10 g of tomato pomace kg(-1)) to 36.1 g of reducing sugar kg(-1) per enzyme unit (at 160 g of tomato pomace kg(-1)). Maximum concentrations of reducing sugars were observed in the experiments with 160 g of tomato pomace kg(-1) producing hydrolysates containing 49.7 g of reducing sugars kg(-1) The maximum yield was 31\% (w/w) corresponding to a 76\% (w/w) cellulose conversion. The saccharification of tomato pomace also yielded other monosaccharides with the following distribution: glucose, 76.6\% (w/w), fructose, 11.2\% (w/w); xylose, 7.5\% (w/w) and cellobiose, 3.8\% (w/w). Fungal cultures grown in tomato pomace syrups showed that the initial biomass of 2.02 g kg(-1) increased exponentially after a 4 h lag phase to yield 9.02 g kg(-1) at the end of 48 h. The uptake of glucose occurred at 0.64 g/lh. At the end of the fermentation the fungi had consumed 93.4\% of the total sugar, displaying a biomass yield of 0.53 g/g. The glucose was totally consumed between 12 and 24 h fermentation and the fungal growth observed up to 48 h was due to xylose and fructose, which started to be used after 12 h. (C) 1997 Elsevier Science Ltd. |
