Synergistic impacts of antibiotics and heavy metals on Hermetia illucens: Unveiling dynamics in larval gut bacterial communities and microbial metabolites.

Hermetia illucens larvae showcases remarkable bioremediation capabilities for both antibiotics and heavy metal contaminants. However, the distinctions in larval intestinal microbiota arising from the single and combined effects of antibiotics and heavy metals remain poorly elucidated. In this study, we delved into the details of larval intestinal bacterial communities and microbial metabolites when exposed to single and combined contaminants of oxytetracycline (OTC) and hexavalent chromium (Cr(VI)). After conversion, single contaminant-spiked substrate showed 75.5% of OTC degradation and 95.2% of Cr(VI) reductiuon, while combined contaminant-spiked substrate exhibited 71.3% of OTC degradation and 93.4% of Cr(VI) reductiuon. Single and combined effects led to differences in intestinal bacterial communities, mainly reflected in the genera of Enterococcus, Pseudogracilibacillus, Gracilibacillus, Wohlfahrtiimonas, Sporosarcina, Lysinibacillus, and Myroide. Moreover, these effects also induced differences across various categories of microbial metabolites, which categorized into amino acid and its metabolites, benzene and substituted derivatives, carbohydrates and its metabolites, heterocyclic compounds, hormones and hormone-related compounds, nucleotide and its metabolites, and organic acid and its derivatives. In particular, the differences induced OTC was greater than that of Cr(VI), and combined effects increased the complexity of microbial metabolism compared to that of single contaminant. Correlation analysis indicated that the bacterial genera, Preudogracilibacillus, Enterococcus, Sporosarcina, Lysinibacillus, Wohlfahrtiimonas, Ignatzschineria, and Fusobacterium exhibited significant correlation with significant differential metabolites, these might be used as indicators for the resistance and bioremediation of OTC and Cr(VI) contaminants. These findings are conducive to further understanding that the metabolism of intestinal microbiota determines the resistance of Hermetia illucens to antibiotics and heavy metals.

The enhanced degradation behavior of oxytetracycline by black soldier fly larvae with tetracycline resistance genes in the larval gut: Kinetic process and mechanism.

Black soldier fly larvae (larvae) can digest organic wastes and degrade contaminants such as oxytetracycline (OTC). However, compared to the kinetic processes and enhanced mechanisms used in the traditional microbial degradation of OTC, those employed by larvae are largely uncharacterized. To obtain further details, a combined analysis of larval development, larval nutritional values (crude protein, crude fat and the composition of fatty acids) and the expression of tetracycline resistance genes (TRGs) in the larval gut was performed for the degradation of OTC added to substrates and for oxytetracycline bacterial residue (OBR). When the larvae were exposed to the substrates, the degradation processes were enhanced significantly (P < 0.01), with a 4.74-7.86-fold decrease in the degradation half-life (day-1) and a 3.34-5.74-fold increase in the final degradation efficiencies. This result was attributed to the abundant TRGs (with a detection rate of 35.90%∼52.14%) in the larval gut. The TRGs presented the resistance mechanisms of cellular protection and efflux pumps, which ensured that the larvae could tolerate elevated OTC concentrations. Investigation of the TRGs indicated that enzymatic inactivation enhanced OTC degradation by larvae. These findings demonstrate that the larval degradation of antibiotic contaminants is an efficient method based on abundant TRGs in the larval gut, even though OTC degradation results in OBR. In addition, a more optimized system for higher reductions in antibiotic levels and the expansion of larval bioremediation to other fields is necessary.

Investigations of CO2 Capture from Gas Mixtures Using Porous Liquids.

Porous liquids, a new porous material with fluidity, can be applied in numerous fields, such as gas storage and/or separation. In this work, the separation of binary gas mixtures CO2/N2 and CO2/CH4 with porous liquids was examined by molecular dynamics (MD) simulations. The pure gas adsorption capacity was analyzed with different concentrations of porous liquids. The dependence of the separation effect of a gas mixture on the total pressure and temperature was investigated. Meanwhile, for both CO2/N2 and CO2/CH4 systems, the adsorption and separation effects of porous liquids with a cage:solvent ratio of 1:12 are better than those of 1:91 and 1:170. The results of the spatial distribution function and/or trajectories indicated that porous liquids prefer CO2, leading to the location of CO2 in the channels formed in porous liquids. However, N2 and CH4 are hardly adsorbed into the bulk. The diffusion of gas molecules follows the order of CO2 > N2 (for CO2/N2) and CH4 > CO2 (for CO2/CH4) in the bulk and N2 > CO2 (for CO2/N2) and CH4 > CO2 (for CO2/CH4) at the interface of porous liquids. Upon increasing the concentrations of porous liquids, the working capacities of CO2 show small decreases in CO2/N2 and CO2/CH4 systems, but the sorbent selection parameters are higher in pressure- and temperature-swing adsorption processes. The porous liquid with a cage:solvent ratio of 1:12 is more suitable for the separation of CO2/N2 and CO2/CH4 systems than ratios of 1:91 and 1:170.

Porous Material Screening and Evaluation for Deep Desulfurization of Dry Air.

We employ molecular simulations to screen the best microporous materials for deep desulfurization of dry air. Pressure-swing adsorption and temperature-swing adsorption in desulfurization processes are investigated. The selectivity, working ability, selection parameters, and diffusivity of mixed gases are examined to evaluate those materials. The results show that UiO-66, ZIF-71, ZIF-69, and ZIF-97 exhibit good performance for the separation of H2S from air. The selectivity and adsorption capacity of H2S are larger than 300 and 0.01 mmol/g at room temperature and atmospheric pressure, respectively. UiO-66, ZIF-71, ZIF-69, MIL-100, Zn-DOBDC, ZnBDC, IRMOF-11, and MIL-140B are ideal materials to remove SO2 in air. The selectivity of SO2 is higher than 500 and the adsorption capacity is higher than 0.06 mmol/g. The diffusivity of sulfides is determined by the competition between the sterically hindered effect and the intermolecular synergistic effect. Comprehensive analysis found that zeolitic imidazolate frameworks (ZIFs) are good materials for the removal of sulfides.

Aqueous ethyl acetate as a novel solvent for the degreasing of black soldier fly (Hermetia illucens L.) larvae: degreasing rate, nutritional value evaluation of the degreased meal, and thermal properties.

BACKGROUND: The aim of this study was to select appropriate low-toxicity degreasing solvents to degrease black soldier fly (BSF, Hermetia illucens L.) larvae to prepare high-quality protein. Aqueous ethyl acetate was chosen as the solvent to extract BSF protein, and traditional solvents, such as petroleum ether, n-hexane, and isopropanol, were chosen as controls. RESULTS: The meal degreased by aqueous ethyl acetate (the volume ratio of ethyl acetate to water is 90 to 10, EA + W10) shows a high degreasing rate (29.04%), crude protein content (562.3 g kg-1 ), essential amino acid index (EAAI, 95.57), and digestible indispensable amino acid score (DIAAS, 85). The digestibility of the degreased meal samples in the simulated in vitro intestine can reach 76.52%. Thermodynamic analysis and the apparent morphology of the protein fragments showed that the meal degreased by EA + W10 exhibited thermodynamic stability, which suggests that using aqueous ethyl acetate as the degreasing solvent did not affect the nutritional value of the degreased meal. CONCLUSION: The results suggest that aqueous ethyl acetate (EA + W10) can be used as a novel solvent in the degreasing of BSF larvae meal to prepare high-quality protein with high EAAI and DIAAS and good digestibility. © 2019 Society of Chemical Industry.

The underlying mechanisms of oxytetracycline degradation mediated by gut microbial proteins and metabolites in Hermetia illucens.

Hermetia illucens larvae can enhance the degradation of oxytetracycline (OTC) through its biotransformation. However, the underlying mechanisms mediated by gut metabolites and proteins are unclear. To gain further insights, the kinetics of OTC degradation, the functional structures of gut bacterial communities, proteins, and metabolites were investigated. An availability-adjusted first-order model effectively evaluated OTC degradation kinetics, with degradation half-lives of 4.18 and 21.71 days for OTC degradation with and without larval biotransformation, respectively. Dominant bacteria in the larval guts were Enterococcus, Psychrobacter, Providencia, Myroides, Enterobacteriaceae, and Lactobacillales. OTC exposure led to significant differential expression of proteins, with functional classification revealing involvement in digestion, transformation, and adaptability to environmental stress. Upregulated proteins, such as aromatic ring hydroxylase, acted as oxidoreductases modifying the chemical structure of OTC. Unique metabolites, aclarubicin and sancycline identified were possible OTC metabolic intermediates. Correlation analysis revealed significant interdependence between gut bacteria, metabolites, and proteins. These findings reveal a synergistic mechanism involving gut microbial metabolism and enzyme structure that drives the rapid degradation of OTC and facilitates the engineering applications of bioremediation.

Cyclodextrin-modified PVDF membranes with improved anti-fouling performance.

The design of hydrophilic polyvinylidene fluoride (PVDF) membranes with anti-fouling properties has been explored for decades. Surface modification and blending are typical strategies to tailor the hydrophilicity of PVDF membranes. Herein, cyclodextrin was used to improve the antifouling performance of PVDF membranes. Cyclodextrin-modified PVDF membranes were prepared by coupling PVDF amination (blending with branched polyethyleneimine) and activated cyclodextrin grafting. The blending of PEI in the PVDF casting solution preliminarily aminated the PVDF, resulting in PEI-crosslinked/grafted PVDF membranes after phase inversion. Aldehydes groups on cyclodextrin, introduced by oxidation, endow cyclodextrin to be grafted on the aminated PVDF membrane by the formation of imines. Borch reduction performed on the activated cyclodextrin-grafted PVDF membrane converted the imine bonds to secondary amines, ensuring the membrane stability. The resulting membranes possess excellent antifouling performance, with a lower protein adsorption capacity (5.7 µg/cm2, indicated by Bovine Serum Albumin (BSA)), and a higher water flux recovery rate (FRR = 96%). The proposed method provides a facial strategy to prepare anti-fouling PVDF membranes.

Microbial fermentation and black soldier fly feeding to enhance maize straw degradation.

This study used an innovative synergistic microbial and insect approach to treat maize straw and kitchen waste substrates, including cyclic microbial fermentation and feeding of black soldier fly larvae (BSFL) using the fermented substrate. Increasing cycle numbers led to significantly increased cellulose, hemicellulose, and lignin degradation rates (DR) in the maize straw, which increased by 68.28%, 81.43% and 99.95%, respectively, compared to those in the blank group without frass addition. Moreover, according to the experimental results, it was revealed that the structure of lignocellulose, the composition and structure of the bacterial community in the BSFL gut and frass changed significantly after the addition of the previous cycle of frass treatment. Moreover, the differences in amplicon sequence variants (ASVs) between the gut and frass further increased. The relative abundances of Enterococcus and Actinobacteria in the gut and Gammaproteobacteria_unclassified and Dysgonomonas in the frass increased significantly, which may play a more positive role in lignocellulose degradation. In conclusion, this study showed that frass fermentation + BSFL feeding to degrade straw is a promising method and that frass fermentation is beneficial for the whole cycle. Furthermore, these findings underscore the beneficial impact of frass fermentation on the entire cycle.

Enhanced biodegradation of microplastic and phthalic acid ester plasticizer: The role of gut microorganisms in black soldier fly larvae.

Hermetia illucens larvae are recognized for their ability to mitigate or eliminate contaminants by biodegradation. However, the biodegradation characteristics of microplastics and phthalic acid esters plasticizers, as well as the role of larval gut microorganisms, have remained largely unrevealed. Here, the degradation kinetics of plasticizers, and biodegradation characteristics of microplastics were examined. The role of larval gut microorganisms was investigated. For larval development, microplastics slowed larval growth significantly (P < 0.01), but the effect of plasticizer was not significant. The degradation kinetics of plasticizers were enhanced, resulting in an 8.11 to 20.41-fold decrease in degradation half-life and a 3.34 to 3.82-fold increase in final degradation efficiencies, compared to degradation without larval participation. The depolymerization and biodeterioration of microplastics were conspicuously evident, primarily through a weight loss of 17.63 %-25.52 %, variation of chemical composition and structure, bio-oxidation and bioerosion of microplastic surface. The synergistic effect driven by larval gut microorganisms, each with various functions, facilitated the biodegradation. Specifically, Ignatzschineria, Paenalcaligenes, Moheibacter, Morganella, Dysgonomonas, Stenotrophomonas, Bacteroides, Sphingobacterium, etc., appeared to be the key contributors, owing to their xenobiotic biodegradation and metabolism functions. These findings offered a new perspective on the potential for microplastics and plasticizers biodegradation, assisted by larval gut microbiota.

Combination of microalgae cultivation with membrane processes for the treatment of municipal wastewater.

The treatment of wastewater by microalgae cultivation has attracted more and more attention. However, the way to harvest microalgae cells from the wastewater and the treatment of the large quantity of residual solution have become critical issues. In this work, a new approach for the treatment of municipal wastewater is presented. The combination of flocculation for removing mainly microalgae and thereafter membrane filtration for chemical oxygen demand (COD) and conductivity reduction of the residual solution after flocculation is discussed. The COD concentration of the wastewater decreased from 260 to 84 mg/L after flocculation by chitosan. Five ultrafiltration (UF) membranes and two nanofiltration (NF) membranes were used for filtration to find a suitable membrane for COD and conductivity reduction. Among the five UF membranes, GR82PE showed the best performance, whose permeate flux and COD retention at 4 bar were 189.66 L/(m(2)·h) and 43.03%, respectively. NF membranes showed higher COD and conductivity retentions than UF membranes. The COD retention of Desal5-DK reached 98.3% at 20 bar. Lastly, the flux recovery after the filtration test of each membrane is also discussed.

Tailoring the performance of composite PEI nanofiltration membranes via incorporating activated cyclodextrins.

Cyclodextrins (CDs) with unique cavity structures have been used as materials for nanofiltration membrane fabrications. In the present work, the activated CD (O-CD), oxidated by NaIO4, and polyethyleneimine (PEI) were co-deposited on a hydrolyzed polyacrylonitrile support, post-treated by glycerol protection and heating treatment, to prepare nanofiltration membranes with low molecular weight cut-off (MWCO). As the cavities in CD present and the aldehyde groups introduced after oxidation, the O-CDs were expected to crosslink the PEI layer and provide extra permeating channels. The filtration experiments showed that the incorporation of O-CDs improved the permeances of the O-CD-PEI/HPAN nanofiltration membranes. The performance can be tailored by the control of the loading or the oxidation degree of the O-CD. At optimal conditions, the permeance increment was nearly double (from 9.2 to 21.1 Lm-2·h-1·bar-1). While the selectivity was without significant sacrifice, the rejection of PEG 200 remained around 90%. Meanwhile, the membrane stability was demonstrated by pro-longed filtratiing a PEG 200 aqueous solution. The constant permeance and rejection confirmed the O-CD-PEI/HPAN membranes were stable. The incorporation of activated CD in PEI offers a facile strategy to promote the permeance of PEI-based membranes.

Highly Active and Water-Resistant Cu-Doped OMS-2 Catalysts for CO Oxidation: The Importance of the OMS-2 Synthesis Method and Cu Doping.

Porous cryptomelane-type Mn oxide (OMS-2) has an outstanding redox property, making it a highly desirable substitute for noble metal catalysts for CO oxidation, but its catalytic activity still needs to be improved, especially in the presence of water. Given the strong structure-performance correlation of OMS-2 for oxidation reactions, herein, OMS-2 is synthesized by solid state (OMS-2S), reflux (OMS-2R), and hydrothermal (OMS-2H) methods, aiming to improve its CO oxidation performance through manipulating synthesis parameters to tailor its particle size, morphology, and crystallinity. Characterization shows that OMS-2S has the highest CO oxidation activity in the absence of water due to its low crystallinity, high specific surface area, large oxygen vacancy content, and good redox property, but the presence of water can greatly reduce its CO oxidation activity. Doping Cu into an OMS-2 can not only improve its CO oxidation activity but also greatly improve its water tolerance. The Cu-doped OMS-2S catalyst with ∼4 wt % Cu can achieve a T90 of 49 °C (1% CO/10% O2/N2 and WHSV = 60,000 mL·g-1·h-1), ranking among the lowest reported T90 values for Mn oxide-based CO oxidation catalysts, and it can maintain nearly 100% CO conversion in the presence of 5 vol % water for over 50 h. In situ DRIFTs characterization indicates that the good water resistance of Cu-doped OMS-2S can be attributed to the significantly suppressed surface hydroxyl group generation because of Cu doping. This work demonstrates the importance of the synthesis method and Cu doping in determining the CO oxidation activity and water resistance of OMS-2 and will provide guidance for synthesizing highly active and water-resistant CO oxidation catalysts.

[Separation and purification of total flavonids of Astragalus membranaceus with ethanol/phosphate aqueous two-phase system].

OBJECTIVE: To study separation and purification of flavonids with ethanol/phosphate aqueous two-phase system. METHOD: The diversity of phase separation ability and the distribution of target products in various systems were taken as indicators to analyze aqueous two-phase extraction systems and phase diagrams formed by ethanol and some common salts, screen out EtOH/ K2HPO4 system as the optimla system for extracting total flavonids, and study the impact of proportion of components in EtOH/K2 HPO4 system on the partition coefficient and phase ratio of flavonids. RESULT AND CONCLUSION: The EtOH/K2 HPO4 system with omegaEtOH 36.05% and omegaKHPO4 18.20% has been proved as the optimal conditions for separating and purifying total flavonoids of Astragalus (TFA). Under this optimal condition, the partition coefficient and the extraction yield of TFA reached 10.33 and 96.6%, respectively. After extraction, the contents of A. membranaceus saponins and A. membranaceus polysaccharides in top and bottom phases were determined at the same time, showing that A. membranaceus saponins in the removal rate reached 92.01%, and A. membranaceus polysaccharides were totally concentrated in bottom water phase, indicating a removal rate of 100%. Therefore, this is beneficial to separate and purify total flavonids from A. membranaceus crude extracts.

Black Soldier Fly Larvae Can Effectively Degrade Oxytetracycline Bacterial Residue by Means of the Gut Bacterial Community.

Antibiotic bacterial residue is a unique hazardous waste, and its safe and effective disposal has always been a concern of pharmaceutical enterprises. This report presents the effective treatment of hazardous waste-antibiotic bacterial residue-by black soldier fly larvae (larvae), oxytetracycline bacterial residue (OBR), and soya meal with mass ratios of 0:1 (soya), 1:20 (OBRlow), and 1:2 (OBRhigh), which were used as substrates for larval bioconversion. Degradation of OBR and oxytetracycline, the bacterial community, the incidence of antibiotic resistance genes (ARGs) and the bacterial function in the gut were examined. When the larvae were harvested, 70.8, 59.3, and 54.5% of the substrates had been consumed for soya, OBRlow and OBRhigh; 65.9 and 63.3% of the oxytetracycline was degraded effectively in OBRlow and OBRhigh, respectively. The larval bacterial communities were affected by OBR, abundant and various ARGs were discovered in the gut, and metabolism was the major predicted function of the gut. These findings show that OBR can be digested and converted by larvae with gut bacteria, and the larvae can be used as a bioremediation tool for the treatment of hazardous waste. Finally, the abundant ARGs in the gut deserve further attention and consideration in environmental health risk assessments.

Pretreatment is an important method for increasing the conversion efficiency of rice straw by black soldier fly larvae based on the function of gut microorganisms.

Rice straw is considered as a renewable biomass energy source and its efficient utilization is still a topic worthy of attention. Black soldier fly larvae, Hermetia illucens (L.), (Diptera: Stratiomydiae) is a kind of saprophytic insect, which can effectively digest organic wastes. Here we report that alkaline peroxide-pretreatment improves the digestion of rice straw by these larvae, especially the decomposition of cellulose, which was at 70.9% compared to 58.2% without pretreatment. After conversion, the effective conversion rates of rice straw to larvae were 10.7% and 11.4%, for raw rice straw and rice straw with pretreatment, respectively. With pretreatment the composition of larval gut microorganisms was altered where Actinomyces, Dysgonomonas, Devosia and Pelagibacterium were the dominant flora for digesting rice straw. In addition, metabolism, environmental information processing and genetic information processing were the major gut microbial functions. These findings demonstrate that chemical pretreatment for the removal of lignin and hemicellulose was an effective measure for the digestion and consumption of rice straw by black soldier fly larvae.

Multi-role graphitic carbon nitride-derived highly porous iron/nitrogen co-doped carbon nanosheets for highly efficient oxygen reduction catalyst.

Pyrolyzing precursors containing iron, nitrogen and carbon elements is a commonly used process for synthesizing FeNC catalysts for oxygen reduction reaction (ORR). Generally, aggregation of iron-based species is prone to occur because of a lack of chemical bonds between iron-based species and carbon matrix and synthesizing highly porous FeNC catalysts is difficult because carbon skeleton is prone to collapse during pyrolysis. Herein, highly porous FeNC catalysts with fine iron-based species are synthesized by selecting glucose as carbon source, FeCl3 as iron source, and urea-derived g-C3N4 as nitrogen source, iron anchoring and stabilizing species, and pore-forming template. The multi-role g-C3N4-derived catalyst synthesized at 1100 °C (FeNC1100) has fine iron-based species, large specific surface area (737 m2 g-1), and extremely high pore volume (2.66 cm3 g-1). Accordingly, FeNC1100 shows a larger half-wave potential (E1/2 = 0.894 V), a higher stability (ΔE1/2 = 6 mV) after 10,000 potential cycles in alkaline media, and a higher peak power density (P = 152 mW cm-2) when employed as ORR catalyst of zinc-air battery, which are all superior to those of the commercial Pt/C catalyst (E1/2 = 0.864 V, ΔE1/2 = 30 mV, P = 134 mW cm-2). The present work brings a new method for synthesizing highly porous FeNC catalysts decorated with fine active sites for ORR.

Highly porous Fe/N/C catalyst for oxygen reduction: the importance of pores.

Fe/N/C full of ultrafine Fe-based species and pores is synthesized by pyrolyzing a g-C3N4-coordinated Fe matrix embedded in carbon for oxygen reduction. Enhanced oxygen reduction activity is observed on Fe/N/C with higher pore volume and the Fe/N/C catalyst with the largest pore volume shows the highest half-wave potential of 0.890 V.

Removal of Metal Ions in Phosphoric Acid by Electro-Electrodialysis with Cross-Linked Anion-Exchange Membranes.

There are numerous metallic impurities in wet phosphoric acid, which causes striking negative effects on industrial phosphoric acid production. In this study, the purification behavior of metallic impurities (Fe, Mg, Ca) from a wet phosphoric acid solution employing the electro-electrodialysis (EED) technology was investigated. The cross-linked polysulfone anion-exchange membranes (AEMs) for EED were prepared using N,N,N',N'-tetramethyl-1,6-hexanediamine (TMHDA) to achieve simultaneous cross-linking and quaternization without any cross-linkers or catalysts. The performance of the resulting membranes can be determined using quaternization reagents. When the molar ratio of trimethylamine/TMHDA/chloromethylated polysulfone is 3:1:1, the cross-linked membrane CQAPSU-3-1 exhibits lower water swelling and membrane area resistance than the non-cross-linked membrane. The low membrane area resistance of CQAPSU-3-1 with long alkyl chains is obtained due to the hydrophilic-hydrophobic microphase separation structure formed by TMHDA. EED experiments with different initial phosphoric acid concentrations of 0.52 and 1.07 M were conducted to evaluate the phosphoric acid purification of different AEMs. The results show that the EED experiments were more suitable for the purification of wet phosphoric acid solution at low concentrations. It was found that the phosphoric acid concentration in the anode compartment could be increased from 0.52 to 1.04 M. Through optimization, with an initial acid concentration of 0.52 M, CQAPSU-3-1 exhibits an enhanced metallic impurity removal ratio of higher than 72.0%, the current efficiency of more than 90%, and energy consumption of 0.48 kWh/kg. Therefore, CQAPSU-3-1 exhibits much higher purification efficiency than other membranes at a low initial phosphoric acid concentration, suggesting its potential in phosphoric acid purification application.

Preparation, antioxidant activity evaluation, and identification of antioxidant peptide from black soldier fly (Hermetia illucens L.) larvae.

Black soldier fly larvae protein (BLP) was hydrolyzed using alcalase, neutrase, trypsin, and papain. The BLP hydrolysates (BLPHs) were fractionated by ultrafiltration into three peptide fractions of molecular weight (<3 kDa, 3-10 kDa and >10 kDa). Their antioxidant activities in vitro and the amino acid composition were determined. Results showed that the alcalase was more efficient in hydrolyzing the BLP into oligopeptides. BLPHs-I presented the best scavenging activity to superoxide radicals, hydroxyl radicals, DPPH, and ABTS radicals. The best scavenging activities were found in BLPHs-I containing high levels of aromatic and hydrophobic amino acids. Seventeen novel sequences with typical features of well-known antioxidant proteins were identified by LC-MS/MS. Results demonstrated that BLPHs-I possesses a great capacity as antioxidant peptides applied in functional foods. PRACTICAL APPLICATIONS: Black soldier fly larvae protein (BLP) can also be hydrolyzed to produce antioxidant peptides and their sequences were identified. It can be used in pharmaceutical products and functional foods.

Zinc, sulfur and nitrogen co-doped carbon from sodium chloride/zinc chloride-assisted pyrolysis of thiourea/sucrose for highly efficient oxygen reduction reaction in both acidic and alkaline media.

Zn and N co-doped carbon (Zn-N-C) shows encouraging catalytic stability for oxygen reduction reaction (ORR) because of the fulfilled d orbital of Zn, but its catalytic activity is not satisfactory. Herein, hierarchically porous Zn, S and N co-doped carbon (Zn-S-N-C) with large specific surface area (2433 m2 g-1) and pore volume (3.007 cm3 g-1) is synthesized by using NaCl/ZnCl2-assisted pyrolysis of sucrose and thiourea. The Zn-S-N-C catalyst exhibits superior ORR activity with half-wave potentials (E1/2) up to 0.774 V in 0.1 M HClO4 and 0.894 V in 0.1 M KOH, good ORR stability with 19- and 4-mV loss in E1/2 values after 10,000 potential cycles in 0.1 M HClO4 and 0.1 M KOH, respectively, and excellent methanol tolerance. The good ORR performance of Zn-S-N-C can be attributed to its enhanced intrinsic ORR activity resulting from the formation of S, N doped carbon and ZnS in Zn-S-N-C, its hierarchically porous structure resulting from the pore-forming roles played by ZnCl2, NaCl and thiourea, and its improved graphitization degree resulting from the added ZnCl2 during Zn-S-N-C synthesis. This work will provide a novel strategy for the synthesis of hierarchically porous Zn, S and N co-doped carbon materials for ORR.