title: Detoxification of biomass hydrolysates with nucleophilic amino acids enhances alcoholic fermentation.
abstract: Carbonyl compounds generated in biomass pretreatment hinder the biochemical conversion of biomass hydrolysates to biofuels. A novel approach of detoxifying hydrolysates with amino acids for ethanol production was developed. Among the 20 amino acids assessed for their detoxification efficiency and nucleophilicity, cysteine was the most effective one. It increased both ethanol productivity and final yield of biomass hydrolysates from 0.18 (untreated) to 1.77 g/L/h and from 0.02 to 0.42 g/g, respectively. Detoxification efficiency was followed by histidine and it increased the final yield to 0.42 g/g, then by lysine, tryptophan and asparagine. It was observed all five effective amino acids contained reactive side-chain functional groups, which played important roles in the amino acid detoxification reaction. The study further showed cysteine and glycine detoxifications were temperature and pH dependent. The mechanistic study using mass spectrometry revealed thiazolidine carboxylic acid, a Schiff base, was formed by condensation of aldehyde and cysteine.
authors: Forest Products Laboratory and Center for Bioenergy and Bioproducts, Auburn University, 520 Devall Drive, Auburn, AL 36849, United States.
authors: Rui
authors: R
authors: Xie
authors: Forest Products Laboratory and Center for Bioenergy and Bioproducts, Auburn University, 520 Devall Drive, Auburn, AL 36849, United States. Electronic address: mtu@auburn.edu.
authors: Maobing
authors: M
authors: Tu
authors: Forest Products Laboratory and Center for Bioenergy and Bioproducts, Auburn University, 520 Devall Drive, Auburn, AL 36849, United States.
authors: Jamarius
authors: J
authors: Carvin
authors: Department of Chemistry and Biochemistry, Auburn University, Auburn, AL 36849, United States.
authors: Yonnie
authors: Y
authors: Wu
mesh_terms: D000596:Amino Acids / Q000378:metabolism*; D056804:Biofuels / Q000382:microbiology; D018533:Biomass; D000431:Ethanol / Q000378:metabolism*; D005285:Fermentation / Q000502:physiology*; D006863:Hydrogen-Ion Concentration; D006868:Hydrolysis; D013696:Temperature
chemical_list: D000596:Amino Acids; D056804:Biofuels; D000431:Ethanol
keywords: Amino acids; Detoxification; Fermentation; Hydrolysates; Saccharomyces cerevisiae