Metabolism of Multiple Aromatic Compounds in Corn Stover Hydrolysate by Rhodopseudomonas palustris
| Autor: | J. Zachary Oshlag, Arne Ulbrich, Weiping Zhang, Joshua J. Coon, David B. Hodge, Yaoping Zhang, Samantha L. Austin, Alan Higbee, Wayne S. Kontur, Daniel R. Noguera, Timothy J. Donohue |
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| Jazyk: | angličtina |
| Rok vydání: | 2015 |
| Předmět: |
Carbohydrates
Lignocellulosic biomass Rhodobacter sphaeroides Hydrocarbons Aromatic Lignin Zea mays Hydrolysate Article Bioenergy Ammonia Environmental Chemistry Food science Anaerobiosis Biomass Biotransformation Waste Products biology Chemistry Hydrolysis food and beverages General Chemistry Benzoic Acid biology.organism_classification Rhodopseudomonas Corn stover Biodegradation Environmental Biochemistry Biofuel Mutation Fermentation Rhodopseudomonas palustris Bacteria |
| Popis: | Lignocellulosic biomass hydrolysates hold great potential as a feedstock for microbial biofuel production, due to their high concentration of fermentable sugars. Present at lower concentrations are a suite of aromatic compounds that can inhibit fermentation by biofuel-producing microbes. We have developed a microbial-mediated strategy for removing these aromatic compounds, using the purple nonsulfur bacterium Rhodopseudomonas palustris. When grown photoheterotrophically in an anaerobic environment, R. palustris removes most of the aromatics from ammonia fiber expansion (AFEX) treated corn stover hydrolysate (ACSH), while leaving the sugars mostly intact. We show that R. palustris can metabolize a host of aromatic substrates in ACSH that have either been previously described as unable to support growth, such as methoxylated aromatics, and those that have not yet been tested, such as aromatic amides. Removing the aromatics from ACSH with R. palustris, allowed growth of a second microbe that could not grow in the untreated ACSH. By using defined mutants, we show that most of these aromatic compounds are metabolized by the benzoyl-CoA pathway. We also show that loss of enzymes in the benzoyl-CoA pathway prevents total degradation of the aromatics in the hydrolysate, and instead allows for biological transformation of this suite of aromatics into selected aromatic compounds potentially recoverable as an additional bioproduct. |
| Databáze: | OpenAIRE |
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