Direct and simultaneous determination of representative byproducts in a lignocellulosic hydrolysate of corn stover via gas chromatography–mass spectrometry with a Deans switch

Zheng, Rongping; Zhang, Hongman; Zhao, Jing; Lei, Mingliu; Huang, He

doi:10.1016/j.chroma.2011.05.099

Cited by 12 publications

(4 citation statements)

References 43 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…D-xylose, L-arabinose), as well as organic acids (e.g. acetate, formate) (Lee, 1997;Zheng et al, 2011). In most cases, these mixtures can only be metabolized partly or sequentially (Dien et al, 1999;Han et al, 2011;Yanase et al, 2012).…”

Section: Introductionmentioning

confidence: 99%

D‐Xylose assimilation via the Weimberg pathway by solvent‐tolerant Pseudomonas taiwanensis VLB120

Köhler

Blank

Frick

et al. 2014

Environmental Microbiology

View full text Add to dashboard Cite

The natural ability of Pseudomonas taiwanensis VLB120 to use xylose as sole carbon and energy source offers a high potential for sustainable industrial biotechnology. In general, three xylose assimilation routes are reported for bacteria. To elaborate the metabolic capacity of P. taiwanensis VLB120 and to identify potential targets for metabolic engineering, an in silico/in vivo experiment was designed, allowing for discrimination between these pathways. Kinetics of glucose and xylose degradation in P. taiwanensis VLB120 was determined and the underlying stoichiometry was investigated by genome-based metabolic modelling and tracer studies using stable isotope labelling. Additionally, reverse transcription quantitative polymerase chain reaction experiments have been performed to link physiology to the genomic inventory. Based on in silico experiments, a labelling strategy was developed, ensuring a measurable and unique (13) C-labelling distribution in proteinogenic amino acids for every possible distribution between the different xylose metabolization routes. A comparison with in vivo results allows the conclusion that xylose is metabolized by P. taiwanensis VLB120 via the Weimberg pathway. Transcriptomic and physiological studies point to the biotransformation of xylose to xylonate by glucose dehydrogenase. The kinetics of this enzyme is also responsible for the preference of glucose as carbon source by cells growing in the presence of glucose and xylose.

show abstract

Section: Introductionmentioning

confidence: 99%

D‐Xylose assimilation via the Weimberg pathway by solvent‐tolerant Pseudomonas taiwanensis VLB120

Köhler

Blank

Frick

et al. 2014

Environmental Microbiology

View full text Add to dashboard Cite

show abstract

“…Different processes including pretreatment with dilute acids, hot water, ammonia fiber explosion and treatment with FeCl 3 have been tested to overcome this challenge [4-7]. The drawbacks of these pretreatments are accumulation of inhibitory compounds, use of harsh chemicals, hence the expense of the equipment, and lack of reaction specificity [8,9]. …”

Section: Introductionmentioning

confidence: 99%

A time course analysis of the extracellular proteome of Aspergillus nidulans growing on sorghum stover

Saykhedkar

Ray

Ayoubi-Canaan

et al. 2012

Biotechnol Biofuels

View full text Add to dashboard Cite

BackgroundFungi are important players in the turnover of plant biomass because they produce a broad range of degradative enzymes. Aspergillus nidulans, a well-studied saprophyte and close homologue to industrially important species such as A. niger and A. oryzae, was selected for this study.ResultsA. nidulans was grown on sorghum stover under solid-state culture conditions for 1, 2, 3, 5, 7 and 14 days. Based on analysis of chitin content, A. nidulans grew to be 4-5% of the total biomass in the culture after 2 days and then maintained a steady state of 4% of the total biomass for the next 12 days. A hyphal mat developed on the surface of the sorghum by day one and as seen by scanning electron microscopy the hyphae enmeshed the sorghum particles by day 5. After 14 days hyphae had penetrated the entire sorghum slurry. Analysis (1-D PAGE LC-MS/MS) of the secretome of A. nidulans, and analysis of the breakdown products from the sorghum stover showed a wide range of enzymes secreted. A total of 294 extracellular proteins were identified with hemicellulases, cellulases, polygalacturonases, chitinases, esterases and lipases predominating the secretome. Time course analysis revealed a total of 196, 166, 172 and 182 proteins on day 1, 3, 7 and 14 respectively. The fungus used 20% of the xylan and cellulose by day 7 and 30% by day 14. Cellobiose dehydrogenase, feruloyl esterases, and CAZy family 61 endoglucanases, all of which are thought to reduce the recalcitrance of biomass to hydrolysis, were found in high abundance.ConclusionsOur results show that A. nidulans secretes a wide array of enzymes to degrade the major polysaccharides and lipids (but probably not lignin) by 1 day of growth on sorghum. The data suggests simultaneous breakdown of hemicellulose, cellulose and pectin. Despite secretion of most of the enzymes on day 1, changes in the relative abundances of enzymes over the time course indicates that the set of enzymes secreted is tailored to the specific substrates available. Our findings reveal that A. nidulans is capable of degrading the major polysaccharides in sorghum without any chemical pre-treatment.

show abstract

“…However, previous studies have suggested that fermentation inhibitor compounds, such as 5-hydroxymethylfurfural, 5methylfurfual, levulinic acid, and formic acid, might come from glucose degradation. 16,30 In spruce, DA pretreatments produced more than twice these inhibitor compounds when compared to those from SPORL pretreatments. 16 These could attribute to the low mass balances of glucan in the DA-pretreated samples (cf.…”

Section: ■ Results and Discussionmentioning

confidence: 99%

“…The furfural contents in the SP hydrolysates were about 3.9–5.4% (Figure B), which were higher than those in the DA hydrolysates (∼2.0%; Figure A). Studies have shown that xylan, in comparison to other polysaccharides, can easily be hydrolyzed under acidic conditions and release xylose into the pretreatment hydrolysates, and these xyloses might continue to be broken down into furfural and other degradation products . Hence, by considering the mass balance of xylan, the lower xylan contents of 8% SP hydrolysates compared to those of 4% SP hydrolysates indicated that further degradation might occur during the pretreatment processes.…”

Section: Resultsmentioning

confidence: 99%

Comparison of Dilute Acid and Sulfite Pretreatments onAcacia confusafor Biofuel Application and the Influence of Its Extractives

Yeh

Chang

2014

J. Agric. Food Chem.

View full text Add to dashboard Cite

Chemical components of lignocellulosic biomass may impede biofuel processing efficiency. To understand whether the heartwood of Acacia confusa is suitable for biofuel application, extractive-free heartwood of A. confusa was subjected to dilute acid (DA) or sulfite pretreatments. Sugar recoveries were used to evaluate the performance of different pretreatments. Cell wall properties, such as 4-O-alkylated lignin structures, S/G ratios, and xylan contents, of the pretreated samples showed significant correlations with the enzymatic saccharification of glucan. The 4% bisulfite-pretreated samples produced higher total sugar recoveries than DA-treated samples. The highest total sugar recoveries from DA and sulfite pretreatment were 52.0% (170 °C for 20 min) and 65.3% (4% NaHSO3 and 1% H2SO4), respectively. The results also demonstrated that the existence of extractives in the heartwood of A. confusa hindered the sugar recoveries from both the pretreatments and enzymatic saccharification. Total sugar recoveries were reduced 11.7-17.7% in heartwood samples with extractives.

show abstract

Direct and simultaneous determination of representative byproducts in a lignocellulosic hydrolysate of corn stover via gas chromatography–mass spectrometry with a Deans switch

Cited by 12 publications

References 43 publications

D‐Xylose assimilation via the Weimberg pathway by solvent‐tolerant Pseudomonas taiwanensis VLB120

D‐Xylose assimilation via the Weimberg pathway by solvent‐tolerant Pseudomonas taiwanensis VLB120

A time course analysis of the extracellular proteome of Aspergillus nidulans growing on sorghum stover

Comparison of Dilute Acid and Sulfite Pretreatments onAcacia confusafor Biofuel Application and the Influence of Its Extractives

Contact Info

Product

Resources

About