Alternative Feedstock Research Articles

Kinetics and Transesterification of the Oil Obtained from Cussonia bateri (Jansa Seed) as a Step in Biodiesel Production Using Natural Heterogeneous Catalyst

The ongoing search for a more sustainable, renewable, and affordable fuel source has necessitated the quest and search for a better diesel. Biodiesel, an environmentally friendly diesel, has been able to solve many of the issues that have arisen as a result of the use of fossil fuels. They are mostly synthesized by transesterification of a FFA with an alcohol employing an appropriate catalyst. This study examines the use of jansa seed oil as a low-cost feedstock for biodiesel production. Transesterification of free fatty acids (FFA) with methanol and ethanol catalyzed by snail shell was used to process the biodiesel. In the biodiesel production, the alcohol to oil molar ratio was 12:1, the catalyst amount was 0.75 g, and the reaction temperature was 65°C. The reversible second-order reaction rate was used to characterize the kinetics of FFA transesterification. Kinetic modeling of the biodiesel production process was also carried out in order to determine the sequence of the reaction and estimate the reaction rate constant. The activation energy of the ethyl ester was higher than that of the methyl ester, implying that the ethyl ester would require more energy (slower reaction rate) to activate a molecule for chemical transformation. The reusability of the catalyst for continuous transesterfication runs was investigated under the same operating conditions, and the conversion of the catalyst declined from 99.6 percent to 86.4 percent after the fifth regeneration cycle. Jansa seed oil has the potential to be a valuable raw source for generating fatty oil for the use as an alternate feedstock in the production of biodiesel.

Waste tire-derived porous nitrogen-doped carbon black as an electrode material for supercapacitors

Given that the disposal of waste tires has become a significant environmental hazard and economic challenge worldwide, establishing practical treatment processes and profitable applications for carbon black derived from waste tires are critical for boosting industrial pyrolysis of waste tires. In this work, nitrogen-functionalized waste tire-derived carbon black (WTCB) is successfully coactivated by melamine (M) and alkali metal-based activation agents, including C4H6K2O7-M, KHCO3-M, and KOH-M. The resultant porous carbon black exhibits excellent electrochemical performance due to the synergistic effect of nitrogen-doping and active-potassium-atom-induced pore creation. The proposed activation process serves to tune multiple physical properties of WTCB, such as the specific surface area, pore structure, wettability, and conductivity, all of which largely increase the electrochemical performance. C4H6K2O7-M, with a specific surface area of 247.5 m2/g and nitrogen doping of pyrrolic-N and pyridinic-N species, reaches the highest electrochemical capacitance. The activated WTCBs not only have porous features resembling activated carbon but exhibit comparable conductivity to commercial carbon black, emerging as a potentially viable alternative feedstock for carbon electrodes used in energy-related applications. Moreover, the proposed regeneration methods can be directly adopted in existing industrial pyrolysis plants, providing a feasible and greener implementation strategy for the industrial processing of waste tires.

Simultaneous Lipid Production and Valorization of Crude Glycerol by Mixotrophic and Heterotrophic Cultivation of <em>Arthrospira platensis

This study investigates the possible use of crude glycerol as external carbon source for mixotrophic and heterotrophic cultivation of Arthrospira platensis for the purpose of producing lipid. Recently, biodiesel has become a remarkable biofuel while cyanobacterial lipid is an alternative feedstock for biodiesel production. In this study effect of carbon source concentration, trophic culture type on production of biomass, chlorophyll, protein, total carbohydrate and lipid were examined. In terms of total lipid content, the highest value was detected as 5.78 ± 0.21 mg/g cell with 10 mM crude glycerol in mixotrophic cultivation on 18th day. Higher specific growth rates were detected in mixotrophic cultures. The fatty acid composition was detected by gas chromatography. The produced lipid had the basic fatty acids for a quality biodiesel production — palmitic, stearic, oleic and linoleic acids. The biodiesel potential of produced lipid was investigated. The indicator of oxidative stability of the fuel, iodine value was in accordance with UNE-EN 14214. Cetane number and oxidative stability are related to productive combustion characteristics of fuel which comply with ASTM 6751 standards. These results show that the fatty acid composition of the produced lipid, from a waste material via economical fermentation, is suitable for a qualitative fuel production.

Biosugar production from marine algae Kappaphycus alvarezii by acid hydrolysis

Marine algae are a promising alternative feedstock for biosugar production since they are rich in carbohydrate content, do not compete with food crops for land, and are fast growing. This study used the marine algae Kappaphycus alvarezii as feedstock to produce biosugar. In order to convert the algal biomass to biosugar, hydrolysis is needed to breakdown the complex structure of the lignocellulosic material in the algal tissues. In this study, the hydrolysis process was performed using different acid concentration (H2SO4 0.1-0.3 M); different concentrations of the alga (0.5%, 1%, 1.5% and 2%); and different reaction times (0-120 min). The results showed that that the highest biosugar yield was obtained at an algal concentration of 0.5% and an acid concentration of 0.1 M, yielding a sugar content of 0.54 g sugar/g dry biomass. These results indicate that acid hydrolysis is a promising method for economic biosugar production from marine algae.

Utilization of Modified Zeolite as Catalyst for Steam Gasification of Palm Kernel Shell

Syngas from biomass gasification is being developed for alternative feedstock in the chemical industry. Palm kernel shell which is generated from palm oil industry can be potentially used as raw material for gasification process. The purpose of this study was to investigate the use of modified natural zeolite catalysts in steam gasification of palm kernel shells. Mordenite type zeolite was modified by acid leaching to be used as a tar cracking catalyst. Steam gasification was conducted at the temperature range of 750–850 °C and the steam to biomass ratio was in the range of 0–2.25. The result showed that steam gasification of palm kernel shell with the addition of zeolite catalyst at 750 °C and steam to biomass ratio 2.25 could reduce tar content up to 98% or became 0.7 g/Nm3. In this study, gasification of palm kernel shells produced syngas with the hydrogen concentration in the range of 52–64% and H2/CO ratio of 2.7–5.7. Copyright © 2021 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0).

The effect of caustic soda treatment to recover rare earth elements from secondary feedstocks with low concentrations

Caustic soda (NaOH) treatment has enhanced rare earth element (REE) extraction from monazite. This study examined the effectiveness of caustic soda for RE-phosphates with lower concentrations for extraction from coal overburden, an alternative feedstock derived from mining waste. Pourbaix (Eh-pH) diagrams were constructed for La, Ce, Nd, Eu, and Y-PO4-H2O systems to understand the thermodynamics of NaOH-facilitated acid leaching for low-concentration RE-phosphates and oxides and to elucidate the difference in recoveries among individual REEs. The Eh-pH diagrams indicated that low crystallinity is beneficial for extraction. Nd was thermodynamically most favorable for the extraction process among the five elements examined, and Y was the least promising. Experiments were conducted using three Pennsylvania coal overburden samples to validate the effect of caustic soda on rare earth leaching. The experimental results showed that for NaOH (6 M), a leaching time of 2 h at 125 °C was sufficient to obtain twice the recovery values compared to those without the NaOH treatment. After implementing the caustic soda treatment, a high total REE recovery (>60%), especially for Nd and Pr, could be achieved with diluted HCl and more environmentally friendlier citric acid. The results were similar for both coarse and fine particles. This novel approach is likely to improve the feasibility of REE extraction from coal-associated feedstock in a more environmentally benign manner.

Sustainable electricity generation from photo-bioelectrochemical cell based on carbon nanotubes and chlorophyll anode

This study developed a photo-bioelectrochemical cell based on CNT-chlorophylls to produce photocurrent by lighting electrodes in water-based solutions. The extracted chlorophyll from Chlorella vulgaris microalgae was used to modify carbon nanotube (CNT) as a photo-biocatalyst offering low cost and abundant resources. Furthermore, it is an excellent choice as an alternative bioenergy feedstock compared to lignocellulosic material. The physical interactions between the hydrophobic chlorophyll tail and the hydrophobic nature of the CNT induce the hydrophobic interaction. Subsequently, the CNT/chlorophyll photo-biocatalyst ink was deposited on the carbon felt and used as a photo-anode in photo-bioelectrochemical cells. With the introduction of light, the CNT/chlorophyll photo-biocatalyst is capable of generating 6 times higher photo-currents than in the dark. Also, the maximum power density produced by this device was about 9.48 mW/m2, which is eleven times greater than the CNT control. Therefore, this analysis is a promising system of generating relatively large amounts of photo-bioelectrochemical current by incorporating biological renewable material of chlorophyll derived from Chlorella vulgaris.

Valorization of an Andean crop (yacon) through the production of a yeast cell-bound phytase

The suitability of the yeast Schwanniomyces (f. Debaryomyces) occidentalis to produce phytase activity on a Smallanthus sonchifolius (yacon) extract-based medium (YSM) was studied. Optimal conditions for phytase production were evaluated in YSM at 28 °C and pH 5.5, with an inoculum of 107 cells/mL, in shaken flasks, using a Box-Benkhen optimization design, and analyzed by response surface methodology. Phytase location was determined by subcellular fractioning and protoplast formation. Maximum phytase titres were obtained with 0.11% w/v yacon reducing sugar, 0.65% w/v (NH4)2SO4 and 16 h of fermentation. The maximum phytase activity attained under these conditions was over 6-fold higher than in non-optimized medium. Scaling-up in a STR-type bioreactor further increased phytase productivity by 1.5-fold. Phytase produced was associated to the cell wall fraction, and presented optimal temperature and pH range values of 75–80 °C and 4.0–5.0, respectively, retaining 80% of its activity at 80 °C for 40 min. Progressively increasing phosphorus concentration in the medium inhibited enzyme production, up to 60% with 0.1% w/v KH2PO4. Yeast biomass, phytase production and production kinetics in YSM were similar to those produced in a cane molasses-based medium. Yacon resulted in a promising alternative feed stock to produce a yeast-bound phytase potentially applicable in the feed industry as a nutritional additive.

Biological upgrading of pyrolysis-derived wastewater: Engineering Pseudomonas putida for alkylphenol, furfural, and acetone catabolism and (methyl)muconic acid production

While biomass-derived carbohydrates have been predominant substrates for biological production of renewable fuels, chemicals, and materials, organic waste streams are growing in prominence as potential alternative feedstocks to improve the sustainability of manufacturing processes. Catalytic fast pyrolysis (CFP) is a promising approach to generate biofuels from lignocellulosic biomass, but it generates a complex, carbon-rich, and toxic wastewater stream that is challenging to process catalytically but could be biologically upgraded to valuable co-products. In this work, we implemented modular, heterologous catabolic pathways in the Pseudomonas putida KT2440-derived EM42 strain along with the overexpression of native toxicity tolerance machinery to enable utilization of 89% (w/w) of carbon in CFP wastewater. The dmp monooxygenase and meta-cleavage pathway from Pseudomonas putida CF600 were constitutively expressed to enable utilization of phenol, cresols, 2- and 3-ethyl phenol, and methyl catechols, and the native chaperones clpB, groES, and groEL were overexpressed to improve toxicity tolerance to diverse aromatic substrates. Next, heterologous furfural and acetone utilization pathways were incorporated, and a native alcohol dehydrogenase was overexpressed to improve methanol utilization, generating reducing equivalents. All pathways (encoded by genes totaling ~30 kilobases of DNA) were combined into a single strain that can catabolize a mock CFP wastewater stream as a sole carbon source. Further engineering enabled conversion of all aromatic compounds in the mock wastewater stream to (methyl)muconates with a ~90% (mol/mol) yield. Biological upgrading of CFP wastewater as outlined in this work provides a roadmap for future applications in valorizing other heterogeneous waste streams.

Metabolic and process engineering for microbial production of protocatechuate with Corynebacterium glutamicum.

3,4-Dihydroxybenzoate (protocatechuate, PCA) is a phenolic compound naturally found in edible vegetables and medicinal herbs. PCA is of high interest in the chemical industry and has wide potential for pharmaceutical applications. We designed and constructed a novel Corynebacterium glutamicum strain to enable the efficient utilization of d-xylose for microbial production of PCA. Shake flask cultivation of the engineered strain showed a maximum PCA titer of 62.1 ± 12.1 mM (9.6 ± 1.9 g L-1 ) from d-xylose as the primary carbon and energy source. The corresponding yield was 0.33 C-mol PCA per C-mol d-xylose, which corresponds to 38% of the maximum theoretical yield. Under growth-decoupled bioreactor conditions, a comparable PCA titer and a total amount of 16.5 ± 1.1 g PCA could be achieved when d-glucose and d-xylose were combined as orthogonal carbon substrates for biocatalyst provision and product synthesis, respectively. Downstream processing of PCA was realized via electrochemically induced crystallization by taking advantage of the pH-dependent properties of PCA. This resulted in a maximum final purity of 95.4%. The established PCA production process represents a highly sustainable approach, which will serve as a blueprint for the bio-based production of other hydroxybenzoic acids from alternative sugar feedstocks.

Properties of Wood-Plastic Composites Manufactured from Two Different Wood Feedstocks: Wood Flour and Wood Pellets.

Driven by the motive of minimizing the transportation costs of raw materials to manufacture wood–plastic composites (WPCs), Part I and the current Part II of this paper series explore the utilization of an alternative wood feedstock, i.e., pellets. Part I of this study reported on the characteristics of wood flour and wood pellets manufactured from secondary processing mill residues. Part II reports on the physical and mechanical properties of polypropylene (PP)-based WPCs made using the two different wood feedstocks, i.e., wood flour and wood pellets. WPCs were made from 40-mesh wood flour and wood pellets from four different wood species (white cedar, white pine, spruce-fir and red maple) in the presence and absence of the coupling agent maleic anhydride polypropylene (MAPP). With MAPP, the weight percentage of wood filler was 20%, PP 78%, MAPP 2% and without MAPP, formulation by weight percentage of wood filler was 20% and PP 80%. Fluorescent images showed wood particles’ distribution in the PP polymer matrix was similar for both wood flour and ground wood pellets. Dispersion of particles was higher with ground wood pellets in the PP matrix. On average, the density of composite products from wood pellets was higher, tensile strength, tensile modulus and impact strength were lower than the composites made from wood flour. Flexural properties of the control composites made with pellets were higher and with MAPP were lower than the composites made from wood flour. However, the overall mechanical property differences were low (0.5–10%) depending on the particular WPC formulations. Statistical analysis also showed there was no significant differences in the material property values of the composites made from wood flour and wood pellets. In some situations, WPC properties were better using wood pellets rather than using wood flour. We expect if the material properties of WPCs from wood flour versus wood pellets are similar and with a greater reduction in transportation costs for wood pellet feedstocks, this would be beneficial to WPC manufacturers and consumers.

Lab-scale production of biodiesel from soybean acid oil using immobilized whole cells as catalyst

The study demonstrates the lab-scale production of biodiesel from soybean acid oil (SAO) in a 5 L lab-scale bioreactor using immobilized whole cells as a catalyst. The maximum lipase activity 2.89 ± 0.6 U/mL of immobilized whole cells was achieved at optimum conditions viz; pH (7.1), temperature (31 °C), peptone (1.2% w/v) and immobilized pieces (10) in 100 mL growth medium. The esterification approach was fit to Michaelis–Menten model, based on concentration-time profile with 75 gL−1 Michaelis constant (K M) and 78 gL−1h−1 maximum velocities (V max) resulting in a maximum yield of up to 95.4% over 24 h of reaction. A 5% decrease in the catalytic potential of immobilized whole cells from 1st to 5th recycle of immobilized support. The fuel properties of resulted biodiesel were noted to meet the specifications of major international biodiesel standards such as ASTM D6751 to a significant extent. The study reveals the potential use of immobilized whole-cell catalyst and acid oil as an alternative, low-cost bearing and quality feedstock for the generation of biodiesel for a diverse variety of industrial/commercial use.

Recent progress and advances in soy sauce production technologies: A review

Soy sauce is a traditional condiment that, because of its documented health benefits, is becoming increasingly ubiquitous. It is produced in a two-stage fermentation process consisting of a solid-state fermentation or koji involving mold, followed by brine fermentation or moromi involving halophilic bacteria and salt-tolerant yeasts. Efforts have been made to tackle the present limitations facing this industry, including the long fermentation time, the high salt concentrations, and the generated by-products with the use of genetic engineering such as genome shuffling, mutagenesis, enzyme alteration, mixed starter cultures, and gamma-aminobutyric acid-generating microorganisms. This analysis offers an overview of the latest technologies employed in the soy sauce industry, explaining the various conventional and alternative feedstocks used, the manufacturing processes, the microbial community, and their main role. The transition of soy sauce from a standard condiment to a potential functional food will also be explored. Novelty impact statement Soy sauce is a traditional food condiment that is currently transitioning into a functional food. With rapid advancements in food science, this review covers recent progress and advances in soy sauce production technologies. In addition, it also reviews strategies to resolve long fermentation time, high salt content, and utilization of soy sauce residues to value-added biodiesel.

Characterization of a microbial consortium with potential for biological degradation of cactus pear biomass for biofuel production

Cactus pear (Opuntia ficus-indica) is a crassulacean acid metabolism (CAM) species that serves as a food, feed, and bioenergy crop. O. ficus-indica is an attractive alternative biofuel feedstock due to its low water demand and high biomass productivity. Current ethanol yields from O. ficus-indica are not commercially viable due to low concentrations of released fermentable carbohydrates. Axenic strains of bacteria and fungi were isolated and characterized from a soil microbial community consortium that effectively degrades cladodes into soluble components. The consortium consisted of species representing 14 genera of eubacteria and four genera of fungi. The digestion efficiency of each axenic isolate was evaluated by measuring the release of soluble material after aerobic digestion of cladodes and direct measurement of cellulase and pectinase activities in the culture supernatants. Pectobacterium cacticida was the most effective eubacterial species identified for degrading cladodes among all isolates evaluated. Thus, P. cacticida holds great promise for increasing the release of fermentable sugars and improving overall ethanol yields.

Sustainable aquaculture and animal feed from microalgae – Nutritive value and techno-functional components

Microalgae are being promoted as a superior alternative feedstock for sustainable biofuel production and recently they are also being increasingly recognized as phytoremediation agents in bioremediation. Other than these, microalgae have been utilized as a sustainable feed in aquaculture for many years. The success of microalgae as a feed is based on the nutritional quality of microalgae, which are rich in protein, carbohydrates, fats, vitamins, minerals, and other beneficial biologically active components such as carotenoids and polyunsaturated fatty acids. Standards for the evaluation of microalgae include the assessment of various qualities such as digestibility, bioavailability, and toxicity analysis. This review provides comprehensive information regarding the current status and desirable characteristics of microalgae as a feed ingredient. Feed quality assessments such as protein quality, toxicological and microbiological analysis for microalgae are discussed. The techno-functional components of microalgae are presented in the feed perspective. The utilization of microalgae in various animal husbandry sectors and aquaculture are summarized. The advantages – disadvantages of microalgae as a feed is also presented, along with future research prospects. In short, this review will provide an overall view of the nutritional quality of microalgae and its beneficial application as a sustainable feed ingredient.

Refining of vegetable waste to renewable sugars for ethanol production: Depolymerization and fermentation optimization

The study evaluates the potential of different vegetable wastes namely, composite vegetable waste (CVW), potato waste (PW), sweet potato waste (SPW) and yam waste (YW) as an alternative feedstock for the production of renewable sugars. Thermal assisted chemical pretreatment followed by enzymatic saccharification yielded maximum sugars (0.515 g/g CVW, 0.56 g/g PW, 0.57 g/g SPW and 0.56 g/g YW) with total carbohydrate depolymerization of 95.01%, 88.30%, 90.32% and 88.59% respectively. Obtained sugars were valorized into bioethanol through fermentation using S. cerevisiae by optimizing the pH and temperature. The highest ethanol yield of 251.85 mg/g was obtained from SPW at 35°C followed by YW (240.98 mg/g), PW (235.4 mg/g) and CVW (125.6 mg/g) at pH 5.0. Utilizing the abundantly available vegetable wastes as a renewable feedstock for reducing sugars and subsequent bioethanol production will influence the economics and sustainability of the process positively in circular biorefinery format.

Facile Synthesis of Carbon Film with High Carrier Concentration Using Coal Tar and the Application in Joule Heating

The excellent electrical, thermal, and mechanical properties of carbon films make them promising for application in functional devices. As the byproduct of the coking industry with low cost and large quantity, coal tar can be an alternative feedstock for preparing high-performance carbon films. This work adopts the negative-pressure chemical vapor deposition (NPCVD) approach to prepare thin films on a glass substrate with tunable electrical properties and thickness using coal tar as carbon source. The sheet resistance of as-prepared carbon films can be adjusted within 3 orders of magnitude due to its high carrier density (up to 2.1 × 1022/cm3). As potential Joule heater, carbon film is characterized by fast heating rate (up to 12.5 °C/s) and high temperature (up to 300 °C at 40 V in 24 s). The thickness and sp2 cluster size affect the carrier density and carrier mobility of carbon film. These results verify the feasibility of using coal tar to synthesis high-performance carbon films suitable for electronic applications.

From unavoidable food waste to advanced biomaterials: microfibrilated lignocellulose production by microwave-assisted hydrothermal treatment of cassava peel and almond hull

Lignocellulose based nanomaterials are emerging green biosolids commonly obtained from wood pulp. Alternative feedstocks, such as as unavoidable food waste, are interesting resources for nano/microfibers. This research reports the production and characterization of microfibrillated lignocellulose (MFLC) from cassava peel (CP) and almond hull (AH) via acid-free microwave-assisted hydrothermal treatment (MHT) at different temperatures (120–220 °C). During processing, the structural changes were tracked by ATR-IR, TGA, XRD, 13C CPMAS NMR, zeta potential, HPLC, elemental analysis (CHN; carbon, hydrogen and nitrogen), TEM and SEM analyses. The microwave processing temperature and nature of feedstock exerted a significant influence on the yields and properties of the MFLCs produced. The MFLC yields from CP and AH shifted by 15–49% and 31–73%, respectively. Increasing the MHT temperature substantially affected the crystallinity index (13–66% for CP and 36–62% for AH) and thermal stability (300–374 °C for CP and 300–364 °C for AH) of the MFLCs produced. This suggested that the MFLC from CP is more fragile and brittle than that produced from AH. These phenomena influenced the gelation capabilities of the fibers. AH MFLC pretreated with ethanol at low temperature gave better film-forming capabilities, while untreated and heptane pretreated materials formed stable hydrogels at solid concentration (2% w/v). At high processing temperatures, the microfibrils were separated into elementary fibers, regardless of pretreatment or feedstock type. Given these data, this work demonstrates that the acid-free MHT processing of CP and AH is a facile method for producing MFLC with potential applications, including adsorption, packaging and the production of nanocomposites and personal care rheology modifiers.Graphic abstract

Lignocellulosic biomass to biobutanol: Toxic effects and response mechanism of the combined stress of lignin-derived phenolic acids and phenolic aldehydes to Clostridium acetobutylicum

Lignocellulosic biomass is the most abundant bioresource to consider as an alternative feedstock to produce environmentally friendlier biobutanol as an advanced biofuel. However, the pretreatment for lignocellulose depolymerization suffers from toxic inhibitors formation and wastewater generation. The phenolic compounds, including phenolic aldehydes (Phe-Ad) and phenolic acids (Phe-Ac), derived from lignin degradation during the acid pretreatment of lignocellulose such as corn stover, are the main inhibitors for butanol fermentation. However, the overall impacts of the co-existence of Phe-Ad and Phe-Ac (Com-Phe) on solventogenic clostridia metabolism were not investigated thus far. Here, toxic effects of Com-Phe on butanol fermentation were firstly evaluated by analyzing apparent kinetics, reducing power, and reactive oxygen species (ROS). The lower intracellular reducing power level and higher ROS result in a 56.3 % decrease of butanol titer after 12 h stress. Subsequently, the response mechanism of Clostridium acetobutylicum to Com-Phe stress was elucidated by RNA-seq focusing on physiological processes with carbon metabolism and product biosynthesis. Some key genes related to heat shock proteins (HSP) and antioxidative activity were up-regulated under Com-Phe stress, which might be an adaptive mechanism of cells to alleviate its toxicity. Phenolics also altered two-component systems, sporulation, and cell division processes. This is the first report on systematic evaluation of the toxicity of Com-Phe on solventogenic clostridia. The proposed response mechanism provides valuable guidance (such as regulation of sugar transport, HSP-related genes, glutathione metabolism, etc.) for developing robust strains and promotes cleaner biobutanol production from lignocellulosic biomass.

Enhancing erythritol production by wheat straw biochar-incorporated solid-state fermentation of agricultural wastes using defatted Schizochytrium sp. biomass as supplementary feedstock

Defatted Schizochytrium residue was used as a supplementary feedstock for efficiency erythritol production in this study. Microalgae are attractive feedstocks for the microbial process. However, proper enzymatic hydrolysis and toxicity alleviation must be considered for efficient fermentation. A strategy was proposed herein for producing erythritol from enzymatic hydrolysate of the defatted Schizochytrium residue (SRH), resorting to the wheat (Triticum aestivum L.) straw biochar-incorporated solid-state fermentation (SSF) of agricultural wastes to relieve the toxicant inhibition. Enhanced erythritol production (190.5 mg/gds) was achieved in batch SSF supplemented with 4% biochar and 20 % concentrated SRH, which was obtained from the cellulose–protease (1:1) system performed under pH 5.0 and 45 °C for 24 h with 0.8 % (m/v) of enzyme addition. Fed- and repeated-batch fermentation demonstrated enduring high cell viability and improved erythritol yield of 223.2 and 205.4 mg/gds, respectively. Cost analysis suggested high availabilities of raw substrates for erythritol cultivation, which was energy conserving and operable. Moreover, SRH was proven to be an economic alternative feedstock for low-cost erythritol production via the biochar-incorporated SSF.