TY - JOUR
T1 - Bioconversion of Agave Bagasse Lignin to Medium-Chain-Length Polyhydroxyalkanoates by Pseudomonas putida
AU - Arreola-Vargas, Jorge
AU - Xu, Bing
AU - Hu, Cheng
AU - Meng, Xianzhi
AU - Wang, Yun Yan
AU - Ragauskas, Arthur J.
AU - Méndez-Acosta, Hugo Oscar
AU - Perez-Pimienta, José Antonio
AU - Dai, Susie Y.
AU - Yuan, Joshua S.
N1 - Publisher Copyright:
© 2022 American Chemical Society.
PY - 2022/12/5
Y1 - 2022/12/5
N2 - Inadequate disposal of Agave tequilana bagasse (ATB) brings environmental and economic issues to tequila producing regions. Recent works have proposed technologies for valorization of the polysaccharide's fractions of ATB. However, lignin bioconversion has not been investigated due to its recalcitrant nature. Herein, a systematic pretreatment is proposed to release the lignocellulosic fractions and produce medium-chain-length polyhydroxyalkanoates (PHA) from the lignin fraction of ATB. Nuclear magnetic resonance (NMR) analyses revealed that ATB lignin contained 63% of β-O-4 interunit linkages, making this lignin more suitable for pretreatment and biodegradation compared to other lignins. Exploratory experiments revealed that two-stage fermentation is suitable for PHA production from ATB lignin using wild type and engineered Pseudomonas putida strains. PHA increased from 0.09 to 0.39 g/L compared to single batch fermentation. Further improvement to 0.76 g/L was possible by using a central composite design to optimize the inoculum, substrate, and nitrogen concentrations. Finally, PHA depolymerase gene phaZ was knocked out from P. putida and tested at optimal conditions, enabling a PHA titer of 0.97 g/L. Analyses by NMR and GC-MS confirmed lignin derivatives consumption and decrease of β-O-4 linkages. This study lays the foundations to enable agave lignin bioprocessing and opens new avenues for ATB biorefineries.
AB - Inadequate disposal of Agave tequilana bagasse (ATB) brings environmental and economic issues to tequila producing regions. Recent works have proposed technologies for valorization of the polysaccharide's fractions of ATB. However, lignin bioconversion has not been investigated due to its recalcitrant nature. Herein, a systematic pretreatment is proposed to release the lignocellulosic fractions and produce medium-chain-length polyhydroxyalkanoates (PHA) from the lignin fraction of ATB. Nuclear magnetic resonance (NMR) analyses revealed that ATB lignin contained 63% of β-O-4 interunit linkages, making this lignin more suitable for pretreatment and biodegradation compared to other lignins. Exploratory experiments revealed that two-stage fermentation is suitable for PHA production from ATB lignin using wild type and engineered Pseudomonas putida strains. PHA increased from 0.09 to 0.39 g/L compared to single batch fermentation. Further improvement to 0.76 g/L was possible by using a central composite design to optimize the inoculum, substrate, and nitrogen concentrations. Finally, PHA depolymerase gene phaZ was knocked out from P. putida and tested at optimal conditions, enabling a PHA titer of 0.97 g/L. Analyses by NMR and GC-MS confirmed lignin derivatives consumption and decrease of β-O-4 linkages. This study lays the foundations to enable agave lignin bioprocessing and opens new avenues for ATB biorefineries.
KW - Bioplastics
KW - PHA
KW - biorefinery
KW - lignocellulosic biomass
KW - β-O-4 linkages
UR - https://www.scopus.com/pages/publications/85142644026
U2 - 10.1021/acssuschemeng.2c03677
DO - 10.1021/acssuschemeng.2c03677
M3 - Article
AN - SCOPUS:85142644026
SN - 2168-0485
VL - 10
SP - 15670
EP - 15679
JO - ACS Sustainable Chemistry and Engineering
JF - ACS Sustainable Chemistry and Engineering
IS - 48
ER -