Effects of grinding processes on enzymatic degradation of wheat straw.
The effectiveness of wheat straw fine to ultra-fine grindings at pilot scale was studied. The produced powders were characterised by their particle-size distribution (laser diffraction), crystallinity (WAXS) and enzymatic degradability (Trichoderma reesei enzymatic cocktail). A large range of wheat-straw powders was produced: from coarse (median particle size ∼800 μm) to fine particles (∼50 μm) using sieve-based grindings, then ultra-fine particles ∼20 μm by jet milling and ∼10 μm by ball milling. The wheat straw degradability was enhanced by the decrease of particle size until a limit: ∼100 μm, up to 36% total carbohydrate and 40% glucose hydrolysis yields. Ball milling samples overcame this limit up to 46% total carbohydrate and 72% glucose yields as a consequence of cellulose crystallinity reduction (from 22% to 13%). Ball milling appeared to be an effective pretreatment with similar glucose yield and superior carbohydrate yield compared to steam explosion pretreatment.
INRA, UMR 1208 IATE Agropolymers Engineering and Emerging Technologies, INRA/CIRAD/UM2/SupAgro, 2 place Pierre Viala, F-34060 Montpellier, France.
Gabriela Ghizzi D
GG
Silva
Marie
M
Couturier
Jean-Guy
JG
Berrin
Alain
A
Buléon
Xavier
X
Rouau
D001709:Biotechnology / Q000379:methods*; D050260:Carbohydrate Metabolism; D002482:Cellulose / Q000737:chemistry; D003460:Crystallization; D043364:Endo-1,4-beta Xylanases / Q000378:metabolism*; D006868:Hydrolysis; D007700:Kinetics; D010316:Particle Size; D013227:Steam; D014242:Trichoderma / Q000201:enzymology*; D014908:Triticum / Q000737:chemistry*; D014866:Waste Products / Q000032:analysis*
D013227:Steam; D014866:Waste Products; D002482:Cellulose; D043364:Endo-1,4-beta Xylanases