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At least 559 records · Page 31
All sourcesNASA NTRSDOE OSTI
DOE OSTI2014

Comparison of SHF and SSF of wet exploded corn stover and loblolly pine using in-house enzymes produced from T. reesei RUT C30 and A. saccharolyticus

The aim of the present study was to compare bioethanol production from wet exploded corn stover (WECS) and loblolly pine (WELP) hydrolyzed with in-house and commercial enzymes and fermented separately (SHF) and simultaneously (SSF). In-house enzymes produced from Trichoderma reesei, RUT-C30 and a novel fungal strain, Aspergillus saccharolyticus were loaded as 5 and 15 FPU/g glucan and supplemented with 10 and 30 CBU/g glucan, respectively. For hydrolysis and fermentation, slurries of WECS and WELP at 5 and 10% (w/w) solids loading (SL) were utilized. Saccharomyces cerevisae was used for ethanol fermentation at 33°C. Maximally, 15.6 g/L and 13.4 g/L (corresponding to theoretical ethanol yield of 76% and 67%, respectively) were achieved in SSF process from WECS and WELP, respectively at 5% SL and 15 FPU/g glucan loading of in-house enzymes. Ethanol concentrations in all cases were higher for SSF compared to SHF under same conditions. A cross comparison of SSF with commercial enzymes (Celluclast 1.5 L + Novozym 188) showed highest ethanol concentration of 17.3 g/L and 15.4 g/L (corresponding to theoretical ethanol yield of 84% and 77%, respectively) from WECS and WELP, respectively at 5% SL and 15 FPU/g glucan. These findings demonstrated that in-house enzymes were comparable to commercial enzymes as these fungi produced other lignocellulolytic enzymes beyond cellulase and hence enhanced the overall enzyme activity.

59 BASIC BIOLOGICAL SCIENCES↗
DOE OSTI2019

Metabolic engineering of Escherichia coli for the production of butyric acid at high titer and productivity

Background: Several anaerobic bacteria produce butyric acid, a commodity chemical with use in chemical, pharmaceutical, food and feed industries, using complex media with acetate as a co-product. Butyrate titer of various recombinant Escherichia coli did not exceed 10 g l -1 in batch fermentations in any of the media tested. Results: A recombinant E. coli (strain LW393) that produced butyrate as the major fermentation product was constructed with genes from E. coli, Clostridium acetobutylicum and Treponema denticola. Strain LW393 produced 323±6 mM (28.4±0.4 g l -1 ) butyric acid in batch fermentations in mineral salt medium with glucose as C source at a yield of 0.37±0.01 g (g glucose consumed) -1 . Butyrate accounted for 90% of the total products produced by the culture. Supplementing this medium with yeast extract further increased butyric acid titer to 375±4 mM. Average volumetric productivity of butyrate with xylose as C source was 0.89±0.07 g l -1 h -1 . Conclusions: The butyrate titer reported in this study is about 2.5–3-times higher than the values reported for other recombinant E. coli and this is achieved in mineral salt medium with an expectation of lower purifcation and production cost of butyrate.

09 BIOMASS FUELS↗
DOE OSTI2013

Involvement of a Bacterial Microcompartment in the Metabolism of Fucose and Rhamnose by Clostridium phytofermentans

Clostridium phytofermentans, an anaerobic soil bacterium, can directly convert plant biomass into biofuels. The genome of C. phytofermentans contains three loci with genes encoding shell proteins of bacterial microcompartments (BMC), organelles composed entirely of proteins. One of the BMC loci has homology to a BMC-encoding locus implicated in the conversion of fucose to propanol and propionate in a human gut commensal, Roseburia inulinivorans. We hypothesized that it had a similar role in C. phytofermentans. When C. phytofermentans was grown on fucose, the major products identified were ethanol, propanol and propionate. Transmission electron microscopy of fucose- and rhamnose-grown cultures revealed polyhedral structures, presumably BMCs. Microarray analysis indicated that during growth on fucose, operons coding for the BMC locus, fucose dissimilatory enzymes, and an ATP-binding cassette transporter became the dominant transcripts. These data are consistent with fucose fermentation producing a 1,2-propanediol intermediate that is further metabolized in the microcompartment encoded in the BMC locus. Growth on another deoxyhexose sugar, rhamnose, resulted in the expression of the same BMC locus and similar fermentation products. However, a different set of dissimilatory enzymes and transport system genes were induced. Quite surprisingly, growth on fucose or rhamnose also led to the expression of a diverse array of complex plant polysaccharide-degrading enzymes. Based on physiological, genomic, and microarray analyses, we propose a model for the fermentation of fucose and rhamnose in C. phytofermentans that includes enzymes encoded in the same BMC locus. Comparative genomic analysis suggests that this BMC may be present in other clostridial species.

59 BASIC BIOLOGICAL SCIENCES↗
DOE OSTI2017

Biofuel production from Jerusalem artichoke tuber inulins: a review

Jerusalem artichoke (JA) has a high productivity of tubers that are rich in inulins, a fructan polymer. These inulins can be easily broken down into fructose and glucose for conversion into ethanol by fermentation. This paper discusses tuber and inulin yields, effect of cultivar and environment on tuber productivity, and approaches to fermentation for ethanol production. Consolidated bioprocessing with Kluyveromyces marxianus has been the most popular approach for fermentation into ethanol. Apart from ethanol, fructose can be dehydrated into into 5-hydrolxymethylfurfural followed by catalytic conversion into hydrocarbons. Finally, findings from several studies indicate that this plant from tubers alone can produce ethanol at yields that rival corn and sugarcane ethanol. JA has tremendous potential for use as a bioenergy feedstock.

09 BIOMASS FUELS↗
DOE OSTI2017

Mixed Carboxylic Acid Production by Megasphaera elsdenii from Glucose and Lignocellulosic Hydrolysate

Here, volatile fatty acids (VFAs) can be readily produced from many anaerobic microbes and subsequently utilized as precursors to renewable biofuels and biochemicals. Megasphaera elsdenii represents a promising host for production of VFAs, butyric acid (BA) and hexanoic acid (HA). However, due to the toxicity of these acids, product removal via an extractive fermentation system is required to achieve high titers and productivities. Here, we examine multiple aspects of extractive separations to produce BA and HA from glucose and lignocellulosic hydrolysate with M. elsdenii . A mixture of oleyl alcohol and 10% (v/v) trioctylamine was selected as an extraction solvent due to its insignificant inhibitory effect on the bacteria. Batch extractive fermentations were conducted in the pH range of 5.0 to 6.5 to select the best cell growth rate and extraction efficiency combination. Subsequently, fed-batch pertractive fermentations were run over 230 h, demonstrating high BA and HA concentrations in the extracted fraction (57.2 g/L from ~190 g/L glucose) and productivity (0.26 g/L/h). To our knowledge, these are the highest combined acid titers and productivity values reported for M. elsdenii and bacterial mono-cultures from sugars. Lastly, the production of BA and HA (up to 17 g/L) from lignocellulosic sugars was demonstrated.

09 BIOMASS FUELS↗
DOE OSTI2020

Microbiological, Physicochemical, and Immunological Analysis of a Commercial Cashew Nut-Based Yogurt

Nut-based milks and yogurts are gaining popularity, but may not offer the same benefits as dairy yogurts to consumers. Cashew nuts often cause severe allergic reactions, and cashew nut allergens are stable to several types of processing. To compare its characteristics to dairy yogurt and characterize the effects of fermentation on the Ana o 1–3 cashew nut allergens, a commercial yogurt made from cashew nuts (Cashewgurt) was evaluated for microbiological, physiochemical, and immunological properties. Average counts for lactobacilli and Streptococcus thermophilus were greater than 10 million colony forming units per milliliter, indicating the capacity to provide a health benefit. Cashewgurt pH and viscosity values were comparable to cow milk yogurts, and it was off white in color. SDS-PAGE analysis indicated a clear reduction in Ana o 1 and 2, and immuno-assay with polyclonal anti-cashew IgG antibody and cashew-allergic IgE indicated an overall reduction in allergen content. In contrast, SDS-PAGE, mass spectrometry, immunoblot, and ELISA all revealed that Ana o 3 was relatively unaffected by the fermentation process. In conclusion, Ana o 1 and Ana o 2 are sensitive to degradation, while Ana o 3 survives lactic acid bacterial fermentation during yogurt production. The analysis presented here indicates that cashew nut yogurt is not suitable for those with cashew nut allergy.

59 BASIC BIOLOGICAL SCIENCES↗
DOE OSTI2019

Economic Analysis of Cellulosic Ethanol Production from Sugarcane Bagasse Using a Sequential Deacetylation, Hot Water and Disk-Refining Pretreatment

A new process for conversion of sugarcane bagasse to ethanol was analyzed for production costs and energy consumption using experimental results. The process includes a sequential three-stage deacetylation, hot water, and disk-refining pretreatment and a commercial glucose-xylose fermenting S. cerevisiae strain. The simultaneous saccharification and co-fermentation (SScF) step used was investigated at two solids loadings: 10% and 16% w/w. Additionally, a sensitivity analysis was conducted for the major operating parameters. The minimum ethanol selling price (MESP) varied between $4.91and $4.52/gal ethanol. The higher SScF solids loading (16%) reduced the total operating, utilities, and production costs by 9.5%, 15.6%, and 5.6%, respectively. Other important factors in determining selling price were costs for fermentation medium and enzymes (e.g., cellulases). Hence, these findings support operating at high solids and producing enzymes onsite as strategies to minimize MESP.

42 ENGINEERING↗
DOE OSTI2021

BETO 2021 Peer Review - Catalytic Upgrading of Biochemical Intermediates (CUBI) 2.3.1.101-104

The Catalytic Upgrading of Biochemical Intermediates (CUBI) project is a multi-lab effort within ChemCatBio (CCB) that is focused on improving the catalytic upgrading of intermediates from biochemical deconstruction and/or biological conversion (i.e. fermentation) to fuels and chemical co-products. This is accomplished by developing catalysts with improved performance and durability, mitigating the impact of biogenically-derived inhibitors (including water), and evaluating intensified processes to reduce separations requirements and improve carbon utilization. Specific catalytic upgrading routes being developed are: 1) fermentation-derived 2,3-butanediol (BDO); 2) fermentation-derived carboxylic acids; and 3) lignocellulosic sugar-derived furfurals. These routes represent key technology pathways being investigated within BETO's biochemical conversion portfolio. By utilizing experimental and characterization capabilities and modeling tools across the 4 CUBI labs and collaborations with CCB Enabling Projects, the CUBI project is advancing catalytic upgrading process performance and robustness. Its impact is already well-established by several high-impact journal articles and patent publications, along with industrial engagement in related, competitively-awarded collaborations. The CUBI project will result in >25% MFSP cost reduction in the catalytic upgrading section of integrated biochemical conversion routes, as quantified by ongoing TEA modeling.

29 ENERGY PLANNING, POLICY, AND ECONOMY↗
DOE OSTI2017

Genomic, Transcriptional, and Phenotypic Analysis of the Glucose Derepressed Clostridium beijerinckii Mutant Exhibiting Acid Crash Phenotype

Clostridium beijerinckii is a predominant solventogenic bacterium that is used for the ABE fermentation. Various C. beijerinckii mutants are constructed for desirable phenotypes. The C. beijerinckii mutant BA105 harboring a glucose derepression phenotype was previously isolated and demonstrated the enhanced amylolytic activity in the presence of glucose. Despite its potential use, BA105 is not further characterized and utilized. Therefore, the authors investigate fermentation phenotypes of BA105 in this study. Under the typical batch fermentation conditions, BA105 consistently exhibits acid crash phenotype resulting in limited glucose uptake and cell growth. However, when the culture pH is maintained above 5.5, BA105 exhibits the increased glucose uptake and butanol production than did the wild‐type. To further analyze BA105, the authors perform genome sequencing and RNA sequencing. Genome analysis identifies two SNPs unique to BA105, in the upstream region of AbrB regulator (Cbei_4885) and the ROK family glucokinase (Cbei_4895) which are involved in catabolite repression and regulation of sugar metabolism. Transcriptional analysis of BA105 reveals significant differential expression of the genes associated with the PTS sugar transport system and acid production. This study improves understanding of the acid crash phenomenon and provides the genetic basis underlying the catabolite derepression phenotype of C. beijericnkii .

Seo, Seung‐Oh↗
DOE OSTI2016

Toward high solids loading process for lignocellulosic biofuel production at a low cost: Biofuel Production at High Solids Loading

High solids loadings (>18 wt%) in enzymatic hydrolysis and fermentation are desired for lignocellulosic biofuel production at a high titer and low cost. However, sugar conversion and ethanol yield decrease with increasing solids loading. The factor(s) limiting sugar conversion at high solids loading is not clearly understood. In the present study, we investigated the effect of solids loading on simultaneous saccharification and co-fermentation (SSCF) of AFEX™ (ammonia fiber expansion) pretreated corn stover for ethanol production using a xylose fermenting strain Saccharomyces cerevisiae 424A(LNH-ST). Decreased sugar conversion and ethanol yield with increasing solids loading were also observed. End-product (ethanol) was proven to be the major cause of this issue and increased degradation products with increasing solids loading was also a cause. For the first time, we show that with in situ removal of end-product by performing SSCF aerobically, sugar conversion stopped decreasing with increasing solids loading and monomeric sugar conversion reached as high as 93% at a high solids loading of 24.9 wt%. In this work, techno-economic analysis was employed to explore the economic possibilities of cellulosic ethanol production at high solids loadings. The results suggest that low-cost in situ removal of ethanol during SSCF would significantly improve the economics of high solids loading processes.

09 BIOMASS FUELS↗
DOE OSTI2018

Improving methyl ketone production in Escherichia coli by heterologous expression of NADH‐dependent FabG

Abstract We previously engineered Escherichia coli to overproduce medium‐ to long‐chain saturated and monounsaturated methyl ketones, which could potentially be applied as diesel fuel blending agents or in the flavor and fragrance industry. Recent efforts at strain optimization have focused on cofactor balance, as fatty acid‐derived pathways face the systematic metabolic challenge of net NADPH consumption (in large part, resulting from the key fatty acid biosynthetic enzyme FabG [β‐ketoacyl‐ACP reductase]) and net NADH production. In this study, we attempted to mitigate cofactor imbalance by heterologously expressing NADH‐dependent, rather than NADPH‐dependent, versions of FabG identified in previous studies. Of the four NADH‐dependent versions of FabG tested in our previously best‐reported methyl ketone‐producing strain (EGS1895), the version from Acholeplasma laidlawii (Al_FabG) showed the greatest increase in methyl ketone yield in shake flasks (35–75% higher than for an RFP negative‐control strain, depending on sugar loading). An improved strain (EGS2920) attained methyl ketone titers during fed‐batch fermentation of 5.4 ± 0.5 g/L, which were, on average, ca. 40% greater than those for the base strain (EGS1895) under fermentation conditions optimized in this study. Shotgun proteomic data for strains EGS2920 and EGS1895 during fed‐batch fermentation were consistent with the goal of alleviating NADPH limitation through expression of Al_FabG. For example, relative to strain EGS1895, strain EGS2920 significantly upregulated glucose‐6‐phosphate isomerase (directing flux into glycolysis rather than the NADPH‐producing pentose phosphate pathway) and downregulated MaeB (a NADP + ‐dependent malate dehydrogenase). Overall, the results suggest that heterologous expression of NADH‐dependent FabG in E. coli may improve sustained production of fatty acid‐derived renewable fuels and chemicals.

Goh, Ee‐Been↗
DOE OSTI2021

Hydrolysis of lignocellulose by anaerobic fungi produces free sugars and organic acids for two–stage fine chemical production with Kluyveromyces marxianus

Development of the bioeconomy is driven by our ability to access the energy-rich carbon trapped in recalcitrant plant materials. Current strategies to release this carbon rely on expensive enzyme cocktails and physicochemical pretreatment, producing inhibitory compounds that hinder subsequent microbial bioproduction. Anaerobic fungi are an appealing solution as they hydrolyze crude, untreated biomass at ambient conditions into sugars that can be converted into value-added products by partner organisms. However, some carbon is lost to anaerobic fungal fermentation products. To improve efficiency and recapture this lost carbon, we built a two-stage bioprocessing system pairing the anaerobic fungus Piromyces indianae with the yeast Kluyveromyces marxianus, which grows on a wide range of sugars and fermentation products. In doing so we produce fine and commodity chemicals directly from untreated lignocellulose. P. indianae efficiently hydrolyzed substrates such as corn stover and poplar to generate sugars, fermentation acids, and ethanol, which K. marxianus consumed while producing 2.4 g/L ethyl acetate. An engineered strain of K. marxianus was also able to produce 550 mg/L 2-phenylethanol and 150 mg/L isoamyl alcohol from P. indianae hydrolyzed lignocellulosic biomass. Despite the use of crude untreated plant material, production yields were comparable to optimized rich yeast media due to the use of all available carbon including organic acids, which formed up to 97% of free carbon in the fungal hydrolysate. Furthermore, this work demonstrates that anaerobic fungal pretreatment of lignocellulose can sustain the production of fine chemicals at high efficiency by partnering organisms with broad substrate versatility.

59 BASIC BIOLOGICAL SCIENCES↗
DOE OSTI2014

Hydrogenase Activity of Mineral-Associated and Suspended Populations of Desulfovibrio desulfuricans Essex 6

The interactions between sulfate-reducing microorganisms and iron oxides influence a number of important redox-sensitive biogeochemical processes including the formation of iron sulfides. Enzymes, such as hydrogenase which catalyze the reversible oxidation of molecular hydrogen, are known to mediate electron transfer to metals and may contribute to the formation and speciation of ferrous sulfides formed at the cell–mineral interface. In the present study, we compared the whole cell hydrogenase activity of Desulfovibrio desulfuricans strain Essex 6 growing as biofilms on hematite (hematite-associated) or as suspended populations using different metabolic pathways. Hematite-associated cells exhibited significantly greater hydrogenase activity than suspended populations during sulfate respiration but not during pyruvate fermentation. The enhanced activity of the hematite-associated, sulfate-grown cells appears to be dependent on iron availability rather than a general response to surface attachment since the activity of glass-associated cells did not differ from that of suspended populations. Hydrogenase activity of pyruvate-fermenting cells was stimulated by addition of iron as soluble Fe(II)Cl2 and, in the absence of added iron, both sulfate-reducing and pyruvate-fermenting cells displayed similar rates of hydrogenase activity. These data suggest that iron exerts a stronger influence on whole cell hydrogenase activity than either metabolic pathway or mode of growth. The location of hydrogenase to the cell envelope and the enhanced activity at the hematite surface in sulfate-reducing cells may influence the redox conditions that control the species of iron sulfides on the mineral surface.

58 GEOSCIENCES↗
DOE OSTI2017

Biomanufacturing: history and perspective

Abstract Biomanufacturing is a type of manufacturing that utilizes biological systems (e.g., living microorganisms, resting cells, animal cells, plant cells, tissues, enzymes, or in vitro synthetic (enzymatic) systems) to produce commercially important biomolecules for use in the agricultural, food, material, energy, and pharmaceutical industries. History of biomanufacturing could be classified into the three revolutions in terms of respective product types (mainly), production platforms, and research technologies. Biomanufacturing 1.0 focuses on the production of primary metabolites (e.g., butanol, acetone, ethanol, citric acid) by using mono-culture fermentation; biomanufacturing 2.0 focuses on the production of secondary metabolites (e.g., penicillin, streptomycin) by using a dedicated mutant and aerobic submerged liquid fermentation; and biomanufacturing 3.0 focuses on the production of large-size biomolecules—proteins and enzymes (e.g., erythropoietin, insulin, growth hormone, amylase, DNA polymerase) by using recombinant DNA technology and advanced cell culture. Biomanufacturing 4.0 could focus on new products, for example, human tissues or cells made by regenerative medicine, artificial starch made by in vitro synthetic biosystems, isobutanol fermented by metabolic engineering, and synthetic biology-driven microorganisms, as well as exiting products produced by far better approaches. Biomanufacturing 4.0 would help address some of the most important challenges of humankind, such as food security, energy security and sustainability, water crisis, climate change, health issues, and conflict related to the energy, food, and water nexus.

Zhang, Yi-Heng Percival↗
DOE OSTI2014

The novel zinc cluster regulator Tog1 plays important roles in oleate utilization and oxidative stress response in Saccharomyces cerevisiae

Highlights: • TOG1 deletion results in defective growth on non-fermentable carbon sources. • Removal of TOG1 sensitizes cells to oxidative stress. • Tog1 directly binds and activates expression of oleate utilizing genes. • The Δtog1 cells display reduced peroxisomal content in oleate culture. • S. cerevisiae zinc cluster Tog1 is a novel activator of oleate utilization. - Abstract: Many zinc cluster proteins have been shown to play a role in the transcriptional regulation of glucose-repressible genes during glucose exhaustion and diauxic shift. Here, we studied an additional member of this family called Yer184c (herein called Tog1) for transcriptional regulator of oleate. Our results showed that a Δtog1 strain displays impaired growth with several non-fermentable carbons. Tog1 is also implicated in oxidative stress tolerance. Importantly, during the glucose–oleate shift, combined results from quantitative real time-PCR and chromatin immunoprecipitation (ChIP) experiments showed that Tog1 acts as a direct activator of oleate utilizing genes, encoded key enzymes in β-Oxidation and NADPH regeneration (POX1, FOX2, POT1 and IDP2), the glyoxylate shunt (MLS1 and ICL1), and gluconeogenesis (PCK1 and FBP1). A transmission electron microscopy (TEM) analysis of the Δtog1 strain assayed with oleate also revealed a substantial decrease in peroxisome abundance that is vital for fatty acid oxidation. Overall, our results clearly demonstrated that Tog1 is a newly characterized zinc cluster regulator that functions in the complex network of non-fermentable carbon metabolism in Saccharomycescerevisiae.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2013

Nitrogen and Sulfur Requirements for Clostridium thermocellum and Caldicellulosiruptor bescii on Cellulosic Substrates in Minimal Nutrient Media

Growth media for cellulolytic Clostridium thermocellum and Caldicellulosiruptor bescii bacteria usually contain excess nutrients that would increase costs for consolidated bioprocessing for biofuel production and create a waste stream with nitrogen, sulfur and phosphate. C. thermocellum was grown on crystalline cellulose with varying concentrations of nitrogen and sulfur compounds, and growth rate and alcohol production response curves were determined. Both bacteria assimilated sulfate in the presence of ascorbate reductant, increasing the ratio of oxidized to reduced fermentation products. From these results, a low ionic strength, defined minimal nutrient medium with decreased nitrogen, sulfur, phosphate and vitamin supplements was developed for the fermentation of cellobiose, cellulose and acid-pretreated Populus. Carbon and electron balance calculations indicate the unidentified residual fermentation products must include highly reduced molecules. Both bacterial populations were maintained in co-cultures with substrates containing xylan or hemicellulose in defined medium with sulfate and basal vitamin supplements.

biofuel↗
DOE OSTI2015

The mechanism of neutral red-mediated microbial electrosynthesis in Escherichia coli: menaquinone reduction

The aim of this work was to elucidate the mechanism of mediated microbial electrosynthesis via neutral red from an electrode to fermenting Escherichia coli cultures in a bioelectrochemical system. Chemical reduction of NAD+ by reduced neutral red did not occur as predicted. Instead, neutral red was shown to reduce the menaquinone pool in the inner bacterial membrane. The reduced menaquinone pool altered fermentative metabolite production via the arcB redox-sensing cascade in the absence of terminal electron acceptors. When the acceptors DMSO, fumarate, or nitrate were provided, as many as 19% of the electrons trapped in the reduced acceptors were derived from the electrode. These results demonstrate the mechanism of neutral red-mediated microbial electrosynthesis during fermentation as well as how neutral red enables microbial electrosynthesis of reduced terminal electron acceptors.

Harrington, Timothy D.↗
DOE OSTI2017

Co-production of bio-ethanol, xylonic acid and slow-release nitrogen fertilizer from low-cost straw pulping solid residue

In this paper, a novel bio-refinery sequence yielding varieties of co-products was developed using straw pulping solid residue. This process utilizes neutral sulfite pretreatment which under optimal conditions (160 °C and 3% (w/v) sulfite charge) provides 64.3% delignification while retaining 90% of cellulose and 67.3% of xylan. The pretreated solids exhibited excellent enzymatic digestibility, with saccharification yields of 86.9% and 81.1% for cellulose and xylan, respectively. After pretreatment, the process of semi-simultaneous saccharification and fermentation (S-SSF) and bio-catalysis was investigated. The results revealed that decreased ethanol yields were achieved when solid loading increased from 5% to 30%. An acceptable ethanol yield of 76.8% was obtained at 20% solid loading. After fermentation, bio-catalysis of xylose remaining in fermentation broth resulted in near 100% xylonic acid (XA) yield at varied solid loadings. Finally, to complete the co-product portfolio, oxidation ammoniation of the dissolved lignin successfully transformed it into biodegradable slow-release nitrogen fertilizer with excellent agricultural properties.

09 BIOMASS FUELS↗