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Journal of Industrial and Environmental Chemistry
|
Volume 2
GREEN CHEMISTRY &
TECHNOLOGY
7
th
International Conference on
J u n e 1 8 - 2 0 , 2 0 1 8 | D u b l i n , I r e l a n d
PREDICTION OF GLUCOSE YIELD AFTER ENZYMATIC
DIGESTIBILITY OF PRETREATED BIOMASS
Michael Ioelovich
Polymate, Israel
T
he aim of this research was to predict the glucose yield after enzymatic hydrolysis of pretreated plant biomass using chemical
composition and the crystallinity degree of cellulose component. Biomass of various origin were used, such as poplar, switchgrass,
bagasse, corn stover, corn cobs, rice and wheat straw. The biomass samples were pretreated using one and two-step pretreatments.
Chemical composition of the biomasses was determined by conventional methods of chemical analysis. The pretreated biomass samples
were hydrolyzed with a mixture of commercial cellulase Accelerase-1500 (DuPont/Genencor) supplemented with β–glycosidase NS-188
(Novozymes A/S). Conditions of the hydrolysis were the following: biomass loading (BL) was 50 g/L; dose of the cellulase 15 FPU/g
sample; temperature 50oC; pH=4.8; duration 24 h. Concentration of glucose (G, g/L) in hydrolyzates was analyzed by HPLC-method. Yield
of glucose was calculated as: Y(%) = 100% G/BL. The results showed that lignin-hemicellulose complex affected negatively on enzymatic
cleavage of cellulose, whereas increased content of cellulose with decreased crystallinity degree promotes enzymatic hydrolysis. The
best correlation (R2 =0.98) was discovered for the dependence of glucose yield (Y) on the combined parameter (P): Y= 0.96 P + 5; where P
= 2C(1-X) – 0.5 LH, X is crystallinity degree of cellulose, C is percentage of cellulose and LH is percentage of ligno-hemicellulose complex
in the pretreated biomass samples. Thus, increased content of cellulose, its reduced crystallinity, as well as decreased content of lignin
and hemicelluloses in the pretreated biomass, promote enzymatic saccharification. The discovered correlation Y=f(P) permits prediction
the saccharification degree of the pretreated biomass, which can be used for choice the best pretreatment method. In particular, a nitric
acid/alkaline pretreatment of herbaceous plants provides the delignified biomass containing the low-crystalline cellulose having an
enhanced enzymatic digestibility and maximum glucose yield.
J Ind Environ Chem 2018, Volume 2 | DOI: 10.4066/2591-7331-C1-003