FRACTIONATION OF LIGNIN DERIVED COMPOUNDS FROM THERMOCHEMICALLY PROCESSED LIGNIN TOWARDS ANTIMICROBIAL PROPERTIES

• Main Author: Dodge, Luke A.
• Format: Others
• Published: UKnowledge 2018
• Subjects: lignin; pyrolysis; hydrogenolysis; liquid-liquid extraction; antimicrobial; Bioresource and Agricultural Engineering
• Online Access: https://uknowledge.uky.edu/bae_etds/54; https://uknowledge.uky.edu/cgi/viewcontent.cgi?article=1056&context=bae_etds

The overuse of antibiotics in agriculture is an emerging concern, due to their potential detrimental impact to the environment. This study focuses on exploring antimicrobial properties of lignin derived compounds. Lignin is of interest as a feedstock to replacing some petroleum-based chemicals and products because it is the most abundant source of renewable aromatic compounds on the planet. Two lignin rich streams, residues from the enzymatic hydrolysis of dilute acid and alkaline pretreated corn stover, were decomposed via pyrolysis and hydrogenolysis, respectively. The resulting liquid oils were subjected to sequential extractions using a series of solvents with different polarities. Chemical compositions of the extracted fractions were characterized through HPLC and GC/MS. These extracted compounds were screened against Saccharomyces cerevisiae (S. cerevisiae), Escherichia coli, and Lactobacillus amylovorus for antimicrobial properties. Six lignin model monomers: guaiacol, vanillin, vanillic acid, syringaldehyde, 2,6-dimethoxyphenol, and syringic acid were compared to the oils and extracted fractions for antimicrobial properties. Development of lignin-derived chemicals with antimicrobial properties could provide a novel use for this underutilized natural resource.