From Agricultural Byproducts to Value-Added Materials: Wheat Straw-Based Hydrogels as Soil Conditioners?

Abstract Background Succinic acid has great potential to be a new bio-based building block for deriving a number of value-added chemicals in industry. Bio-based succinic acid production from renewable biomass can provide a feasible approach to partially alleviate the dependence of global manufacturing on petroleum refinery. To improve the economics of biological processes, we attempted to explore possible solutions with a fungal cell platform. In this study, Aspergillus niger, a well-known industrial production organism for bio-based organic acids, was exploited for its potential for succinic acid production. Results With a ribonucleoprotein (RNP)-based CRISPR–Cas9 system, consecutive genetic manipulations were realized in engineering of the citric acid-producing strain A. niger ATCC 1015. Two genes involved in production of two byproducts, gluconic acid and oxalic acid, were disrupted. In addition, an efficient C4-dicarboxylate transporter and a soluble NADH-dependent fumarate reductase were overexpressed. The resulting strain SAP-3 produced 17 g/L succinic acid while there was no succinic acid detected at a measurable level in the wild-type strain using a synthetic substrate. Furthermore, two cultivation parameters, temperature and pH, were investigated for their effects on succinic acid production. The highest amount of succinic acid was obtained at 35 °C after 3 days, and low culture pH had inhibitory effects on succinic acid production. Two types of renewable biomass were explored as substrates for succinic acid production. After 6 days, the SAP-3 strain was capable of producing 23 g/L and 9 g/L succinic acid from sugar beet molasses and wheat straw hydrolysate, respectively. Conclusions In this study, we have successfully applied the RNP-based CRISPR–Cas9 system in genetic engineering of A. niger and significantly improved the succinic acid production in the engineered strain. The studies on cultivation parameters revealed the impacts of pH and temperature on succinic acid production and the future challenges in strain development. The feasibility of using renewable biomass for succinic acid production by A. niger has been demonstrated with molasses and wheat straw hydrolysate.

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Unrevealing model compounds of soil conditioners impacts on the wheat straw autohydrolysis efficiency and enzymatic hydrolysis

10.21203/rs.3.rs-26483/v2 ◽

2020 ◽

Author(s):

Xinxing Wu ◽

Wei Tang ◽

Chen Huang ◽

Caoxing Huang ◽

Chenhuan Lai ◽

...

Keyword(s):

Organic Matter ◽

Enzymatic Hydrolysis ◽

Wheat Straw ◽

Sodium Phosphate ◽

Soluble Salts ◽

Model Compounds ◽

Enzymatic Digestibility ◽

Sodium Humate ◽

Soil Conditioners ◽

Enzymatic Accessibility

Abstract Background: Soil-derived exogenous ash (EA) poses a challenge toward lignocellulosics autohydrolysis due to its buffering capacity. Previous works focusing on this phenomenon have failed to also investigate the role that soluble salts, and organic matter plays in this system. Herein, sodium phosphate and sodium humate were employed as model buffering compounds representing soluble salts and organic matter and dosed into a de-ashed wheat straw (DWS) autohydrolysis process to show the potential impacts of WS attached soil conditioners on the WS autohydrolysis efficiency which would further affect the enzymatic digestibility of autohydrolyzed WS.Results: Results showed that with the increasing loadings of sodium phosphate and sodium humate resulted in elevated pH values (from 4.0 to 5.1 and from 4.1 to 4.7, respectively). Meanwhile, the reductions of xylan removal yields from ~84.3-61.4% to 72.3-53.0% by loading (1~30 g/L) sodium phosphate and sodium humate during WS autohydrolysis lead to a significant decrease of cellulose accessibilities which finally lead to a reduction of the enzymatic digestibility of autohydrolyzed WS from ~75.4-77.2% to 47.3-57.7%.Conclusion: The existence of different types soil conditioner model compounds result in various component fractions from autohydrolyzed WS in the process of autohydrolysis. A lack of sufficient xylan removal was found to drive the significant decrease in enzymatic accessibility. The results demonstrated the various effects of two typical tested soil conditioners on WS autohydrolysis and enzymatic hydrolysis.

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Unrevealing model compounds of soil conditioners impacts on the wheat straw autohydrolysis efficiency and enzymatic hydrolysis

Biotechnology for Biofuels ◽

10.1186/s13068-020-01763-3 ◽

2020 ◽

Vol 13 (1) ◽

Cited By ~ 1

Author(s):

Xinxing Wu ◽

Wei Tang ◽

Chen Huang ◽

Caoxing Huang ◽

Chenhuan Lai ◽

...

Keyword(s):

Enzymatic Hydrolysis ◽

Wheat Straw ◽

Model Compounds ◽

Soil Conditioners

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Maleic acid hydrotropic fractionation of wheat straw to facilitate value‐added multi‐product biorefinery at atmospheric pressure

GCB Bioenergy ◽

10.1111/gcbb.12866 ◽

2021 ◽

Author(s):

Chen Su ◽

Kolby Hirth ◽

Zhulan Liu ◽

Yunfeng Cao ◽

J. Y. Zhu

Keyword(s):

Wheat Straw ◽

Maleic Acid ◽

Atmospheric Pressure ◽

Value Added

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Ethanol Production from Wheat Straw Hydrolysate by Issatchenkia Orientalis Isolated from Waste Cooking Oil

Journal of Fungi ◽

10.3390/jof7020121 ◽

2021 ◽

Vol 7 (2) ◽

pp. 121

Author(s):

Alexander Zwirzitz ◽

Lauren Alteio ◽

Daniel Sulzenbacher ◽

Michael Atanasoff ◽

Manuel Selg

Keyword(s):

Ethanol Production ◽

Wheat Straw ◽

Elevated Temperatures ◽

Value Added ◽

Waste Cooking Oil ◽

Lignocellulosic Materials ◽

Fermentation Inhibitors ◽

Issatchenkia Orientalis ◽

Cooking Oil ◽

Wheat Straw Hydrolysate

The interest in using non-conventional yeasts to produce value-added compounds from low cost substrates, such as lignocellulosic materials, has increased in recent years. Setting out to discover novel microbial strains that can be used in biorefineries, an Issatchenkia orientalis strain was isolated from waste cooking oil (WCO) and its capability to produce ethanol from wheat straw hydrolysate (WSHL) was analyzed. As with previously isolated I. orientalis strains, WCO-isolated I. orientalis KJ27-7 is thermotolerant. It grows well at elevated temperatures up to 42 °C. Furthermore, spot drop tests showed that it is tolerant to various chemical fermentation inhibitors that are derived from the pre-treatment of lignocellulosic materials. I. orientalis KJ27-7 is particularly tolerant to acetic acid (up to 75 mM) and tolerates 10 mM formic acid, 5 mM furfural and 10 mM hydroxymethylfurfural. Important for biotechnological cellulosic ethanol production, I. orientalis KJ27-7 grows well on plates containing up to 10% ethanol and media containing up to 90% WSHL. As observed in shake flask fermentations, the specific ethanol productivity correlates with WSHL concentrations. In 90% WSHL media, I. orientalis KJ27-7 produced 10.3 g L−1 ethanol within 24 h. This corresponds to a product yield of 0.50 g g−1 glucose (97% of the theoretical maximum) and a volumetric productivity of 0.43 g L−1 h−1. Therefore, I. orientalis KJ27-7 is an efficient producer of lignocellulosic ethanol from WSHL.

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Evaluating Lignin-Rich Residues from Biochemical Ethanol Production of Wheat Straw and Olive Tree Pruning by FTIR and 2D-NMR

International Journal of Polymer Science ◽

10.1155/2015/314891 ◽

2015 ◽

Vol 2015 ◽

pp. 1-11 ◽

Cited By ~ 33

Author(s):

José I. Santos ◽

Raquel Martín-Sampedro ◽

Úrsula Fillat ◽

José M. Oliva ◽

María J. Negro ◽

...

Keyword(s):

Ethanol Production ◽

Wheat Straw ◽

Internal Energy ◽

Energy Use ◽

Value Added ◽

Olive Tree ◽

2D Nmr ◽

Cellulosic Biomass ◽

G Ratio ◽

Tree Pruning

Lignin-rich residues from the cellulose-based industry are traditionally incinerated for internal energy use. The future biorefineries that convert cellulosic biomass into biofuels will generate more lignin than necessary for internal energy use, and therefore value-added products from lignin could be produced. In this context, a good understanding of lignin is necessary prior to its valorization. The present study focused on the characterization of lignin-rich residues from biochemical ethanol production, including steam explosion, saccharification, and fermentation, of wheat straw and olive tree pruning. In addition to the composition and purity, the lignin structures (S/G ratio, interunit linkages) were investigated by spectroscopy techniques such as FTIR and 2D-NMR. Together with the high lignin content, both residues contained significant amounts of carbohydrates, mainly glucose and protein. Wheat straw lignin showed a very low S/G ratio associated withp-hydroxycinnamates (p-coumarate and ferulate), whereas a strong predominance of S over G units was observed for olive tree pruning lignin. The main interunit linkages present in both lignins wereβ-O-4′ethers followed by resinols and phenylcoumarans. These structural characteristics determine the use of these lignins in respect to their valorization.

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Subcritical water technology for wheat straw hydrolysis to produce value added products

Journal of Cleaner Production ◽

10.1016/j.jclepro.2014.02.011 ◽

2014 ◽

Vol 70 ◽

pp. 68-77 ◽

Cited By ~ 33

Author(s):

Wael Abdelmoez ◽

Soah M. Nage ◽

Ali Bastawess ◽

Ahmed Ihab ◽

Hiroke Yoshida

Keyword(s):

Wheat Straw ◽

Subcritical Water ◽

Value Added ◽

Value Added Products

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A multi-omics approach to lignocellulolytic enzyme discovery reveals a new ligninase activity from Parascedosporium putredinis NO1

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.2008888118 ◽

2021 ◽

Vol 118 (18) ◽

pp. e2008888118

Author(s):

Nicola C. Oates ◽

Amira Abood ◽

Alexandra M. Schirmacher ◽

Anna M. Alessi ◽

Susannah M. Bird ◽

...

Keyword(s):

Wheat Straw ◽

Structural Component ◽

Oxidase Activity ◽

Plant Cells ◽

Value Added ◽

Carbohydrate Active Enzymes ◽

Lignocellulosic Substrates ◽

Enzyme Discovery ◽

Terrestrial Source ◽

Agricultural Byproduct

Lignocellulose, the structural component of plant cells, is a major agricultural byproduct and the most abundant terrestrial source of biopolymers on Earth. The complex and insoluble nature of lignocellulose limits its conversion into value-added commodities, and currently, efficient transformation requires expensive pretreatments and high loadings of enzymes. Here, we report on a fungus from the Parascedosporium genus, isolated from a wheat-straw composting community, that secretes a large and diverse array of carbohydrate-active enzymes (CAZymes) when grown on lignocellulosic substrates. We describe an oxidase activity that cleaves the major β-ether units in lignin, thereby releasing the flavonoid tricin from monocot lignin and enhancing the digestion of lignocellulose by polysaccharidase mixtures. We show that the enzyme, which holds potential for the biorefining industry, is widely distributed among lignocellulose-degrading fungi from the Sordariomycetes phylum.

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