TY - JOUR
T1 - Lactic Acid Production from a Whole Slurry of Acid-Pretreated Spent Coffee Grounds by Engineered Saccharomyces cerevisiae
AU - Kim, Jeong won
AU - Jang, Jeong Hwa
AU - Yeo, Hyeon Jin
AU - Seol, Jeongman
AU - Kim, Soo Rin
AU - Jung, Young Hoon
N1 - Publisher Copyright:
© 2019, Springer Science+Business Media, LLC, part of Springer Nature.
PY - 2019/9/15
Y1 - 2019/9/15
N2 - Spent coffee grounds (SCG) generated after coffee extraction are the main byproduct of the coffee industry. Valorization of the SCG has been increasingly focused following considerable attention in coffee consumption. Lactic acid bacteria fermentation is the primary source of generation of lactic acid, a monomer of polylactic acid that has various industrial applications; however, because of the low tolerance of lactic acid bacteria to toxic compounds, it is necessary to apply Saccharomyces cerevisiae to produce lactic acid whose tolerance to toxic compounds is higher. In this study, we evaluated the feasibility of using SCG as substrate for the production of lactic acid by S. cerevisiae strain expressing heterologous lactate dehydrogenase. The fermentation profiles of the engineered yeast showed that lactic acid production was promoted by xylose addition. From simultaneous saccharification and fermentation (SSF) using a whole slurry of acid-pretreated SCG, containing high amounts of hemicellulose fractions, lactic acid (0.11 g) and ethanol (0.10 g) per g SCG were obtained after 24 h of SSF, of which yields were 413% and 221% higher, respectively, than those of washed pretreated SCG. Thus, fermentation of whole slurry SCG by engineered S. cerevisiae is a suitable way of lactic acid production, selectively.
AB - Spent coffee grounds (SCG) generated after coffee extraction are the main byproduct of the coffee industry. Valorization of the SCG has been increasingly focused following considerable attention in coffee consumption. Lactic acid bacteria fermentation is the primary source of generation of lactic acid, a monomer of polylactic acid that has various industrial applications; however, because of the low tolerance of lactic acid bacteria to toxic compounds, it is necessary to apply Saccharomyces cerevisiae to produce lactic acid whose tolerance to toxic compounds is higher. In this study, we evaluated the feasibility of using SCG as substrate for the production of lactic acid by S. cerevisiae strain expressing heterologous lactate dehydrogenase. The fermentation profiles of the engineered yeast showed that lactic acid production was promoted by xylose addition. From simultaneous saccharification and fermentation (SSF) using a whole slurry of acid-pretreated SCG, containing high amounts of hemicellulose fractions, lactic acid (0.11 g) and ethanol (0.10 g) per g SCG were obtained after 24 h of SSF, of which yields were 413% and 221% higher, respectively, than those of washed pretreated SCG. Thus, fermentation of whole slurry SCG by engineered S. cerevisiae is a suitable way of lactic acid production, selectively.
KW - Biorefinery
KW - Lactic acid
KW - Metabolic engineering
KW - Pretreatment
KW - Saccharomyces cerevisiae
KW - Spent coffee grounds
UR - http://www.scopus.com/inward/record.url?scp=85064230330&partnerID=8YFLogxK
U2 - 10.1007/s12010-019-03000-6
DO - 10.1007/s12010-019-03000-6
M3 - Article
C2 - 30969397
AN - SCOPUS:85064230330
SN - 0273-2289
VL - 189
SP - 206
EP - 216
JO - Applied Biochemistry and Biotechnology
JF - Applied Biochemistry and Biotechnology
IS - 1
ER -