Study on the Suitability of Untreated Corrugated Cardboard for D(-)-lactic Acid Production by SSF Using Lactobacillus coryniformis subsp.torquens

摘要

The specific production of D-lactic acid from untreated residual corrugated cardboard by Simultaneous Sacchari-fication and Fermentation(SSF)has been assessed.In a set of 10 experiments,the effects of the liquor to solid ratio(LSR)and the enzyme to solid ratio(ESR)on the kinetics of the SSF process have been evaluated.Generalized models providing a close reproduction of the experimental results have been developed and employed to assess the selection of optimal operational conditions.Under selected operational conditions(defined by ESR = 19 FPU/g and LSR = 30 g/g)a concentration of 12,1 g D-lactic acid/I was achieved at a volumetric productivity of 0,25 g/l centre dot h,with 44,2% polysaccharide conversion into lactic acid.Further increases in yield or productivity would need additional processing of the corrugated cardboard in order to improve its enzymatic digestibility.