Enhanced ethanol production from deacetylated yellow poplar acid hydrolysate by Pichia stipitis.
In this study, alkaline-pretreatment for the extraction of acetic acid from xylan of hemicellulose was introduced prior to concentrated acid hydrolysis of yellow poplar wood meal. Ethanol fermentability in deacetylated yellow poplar hydrolysate (DYPH) by Pichia stipitis was also investigated. The alkali-pretreatment conditions were evaluated in terms of temperature, reaction time, and alkalinity. 94% of the acetyl group in xylan of the yellow poplar hemicellulose fraction was extracted using 0.5% sodium hydroxide solution at 60 degrees C for 60 min. The cell growth and ethanol production of P. stipitis was strongly affected by acetic acid, either in synthetic medium with 7.1g/l of acetic acid added or in yellow poplar hydrolysate (YPH) containing 7.1g/l of acetic acid. On the other hand, ethanol production in DYPH was slightly higher than that of the control although cell growth decreased by 34%. In the case of DYPH, the ethanol yield, volumetric ethanol productivity, and theoretical yield percentage was 0.48 g/g, 0.40 g/lh, and 93.2%, respectively. Thus, the alkaline-pretreatment method greatly enhanced the ethanol fermentability of yellow poplar hydrolysate.
Cho
Dae Haeng
DH
Department of Chemical Engineering, Kwangwoon University, Seoul 139-701, Republic of Korea.
Shin
Soo-Jeong
SJ
Bae
Yangwon
Y
Park
Chulhwan
C
Kim
Yong Hwan
YH
D019342:Acetic Acid / Q000737:chemistry; D001709:Biotechnology / Q000379:methods*; D002241:Carbohydrates / Q000737:chemistry; D000431:Ethanol / Q000737:chemistry*; D005285:Fermentation; D006868:Hydrolysis; D007700:Kinetics; D031567:Liriodendron; D010843:Pichia / Q000378:metabolism*; D011134:Polysaccharides / Q000737:chemistry*; D013997:Time Factors; D014934:Wood
D002241:Carbohydrates; D011134:Polysaccharides; D000431:Ethanol; C007916:hemicellulose; D019342:Acetic Acid