Search Results (424)

The high stability of chelated heavy metal complexes like Cu-EDTA renders their effective removal from industrial wastewater a persistent challenge for conventional treatment processes. This study developed a sustainable and high-performance CuO-modified biochar (CuO-BC) from corn straw waste for peroxydisulfate (PDS)-activated degradation of Cu-EDTA. Through systematic optimization, hydrothermal co-precipitation using copper acetate as the precursor followed by secondary pyrolysis at 350 °C was identified as the optimal synthesis strategy, yielding a dandelion-like structure with highly dispersed CuO on the BC surface. It achieved 93.8% decomplexation efficiency and 57.3% TOC removal within 120 min under optimized conditions, with an observed rate constant (K_obs) of 0.0220 min⁻¹—five times higher than BC. Comprehensive characterization revealed that CuO-BC possessed a specific surface area and pore volume of 4.36 and 15.5 times those of BC, along with abundant oxygen-containing functional groups and well-exposed Cu–O active sites. The enhanced performance is attributed to the synergistic effects of hierarchical porosity facilitating mass transfer, uniform dispersion of CuO preventing aggregation, and surface functional groups promoting PDS activation. This work presents a green and scalable approach to transform agricultural waste into an efficient metal oxide-BC composite catalyst, offering dual benefits of environmental remediation and resource valorization. Full article

Soil acidification, primarily driven by intensive agricultural practices and excessive nitrogen fertilization, is a growing concern worldwide, severely affecting soil health and crop growth. To identify effective soil amendments for mitigating acidity, this study systematically evaluated the physicochemical characteristics and acid-neutralization capacity of biochar derived from different biomass and pyrolysis conditions. Maize straw was pyrolyzed at different temperature to determine the optimal preparation temperature, which was then applied to other biomass, including reed straw, soybean straw, and corn cobs, for comparative analysis. The objectives were to compare the structure, surface features, and acid-neutralization capacity of this biochar, specifically targeting the acidic soil in the black soil region of Northeast China, and to determine the optimal biochar for mitigating soil acidification. The results show that biochar from maize straw pyrolyzed at 700 °C (MBC700) exhibited the highest acid-neutralization efficiency, increasing the pH of acidic soil from 5.50 to 6.06 within seven days, with a long-term buffering capacity. In contrast, reed straw biochar (RBC) exhibited a higher intrinsic pH (9.96) and a larger specific surface area (42.3 m²∙g⁻¹), but its weaker structural integrity limited its durability. Gradient addition experiments further demonstrated that MBC700 at a 0.5% dosage achieved superior acid-neutralization efficiency compared with RBC and other types of biochar at the same rate, indicating better reactivity and applicability. The findings suggest that biochar derived from crop residues can effectively mitigating soil acidification, offering a viable alternative to traditional lime application. This study provides a more sustainable and environmentally friendly alternative solution for soil acidification. Full article

Bioplastics are plastics derived from natural resources like corn starch, biomass, sugarcane bagasse, and food waste. Unlike fossil-fuel-based plastics, they are entirely or partially bio-degradable. Cellulose- and starch-based bioplastics are already used for applications like packaging, cutlery, bowls, straws, and shopping bags. With the aim of developing eco-friendly biofilms for various applications, cellulose nanocrystals (CNCs) were obtained by sulfuric acid hydrolysis of waste cellulose and functionalized by transesterification with exhausted oils. The resulting transesterified nanocellulose (TCNC) was used as a reinforced material of PLA at different concentrations to develop biofilms using the solvent casting method. The biofilms composed of PLA and TCNC were assessed through Fourier-transform infrared spectroscopy (FTIR), mechanical properties, moisture barrier property (water vapor permeability rate—WVTR), and measurements of the water contact angle (WCA). A scanning electron microscopy (SEM) analysis confirmed the high compatibility of the PLA blended with TCNC at 1% and 3%. The inclusion of transesterified cellulose nanocrystals (TCNCs) to PLA increased the hydrophobicity, the film tensile strength, and the water vapor barrier properties of the final composite films. Full article

With the increasing global food production year by year, the effective return of crop straw to the field has become an urgent problem to be solved. This study examined the impact of straw decomposition under different return methods on soil ecosystems, focusing on changes in soil biological characteristics. Simulating modern mechanized agricultural practices, an orthogonal experiment was conducted in the haplic Phaeozem region of Northeast China. The factors studied included the amount, length, and burial depth of straw returning. A comprehensive analysis model was built using path analysis, factor analysis, and response surface methodology to investigate the response of soil ecosystem during straw decomposition. This was assessed from four aspects: soil basic nutrients, organic carbon pool, enzyme activity, and microbial community structure. The study found evidence of a strong synergistic relationship between the soil enzyme system and straw decomposition. Notably, during the mid-phase of straw return (60 days), phosphatase and particulate organic carbon (POC) acted as “mirror” antagonistic indicators. Catalase, soil nitrate nitrogen, and POC were identified as key response indicators in the soil ecosystem post-straw return. The appropriate supplementation of nitrogen during the early (0–45 days) and late (75–90 days) stages of straw return was found to facilitate straw decomposition. These findings provide experimental evidence for the return of corn straw in cold haplic Phaeozem regions and offer scientific support for sustainable agricultural practices and national food security. Full article

Steroidal pharmaceutical wastewater, such as stock liquid and cell lysate, is conventionally treated at a high cost due to its complex composition and high organic content. To treat steroidal pharmaceutical wastewater, make it harmless, and utilize it as a resource, engineering exploration of large-scale biogas engineering was carried out based on its anaerobic digestion characteristics, and the microbial population in the digestion process was analyzed. The results showed that, at a medium temperature of 35 °C and a total solid percentage of 6.5% ± 0.5%, both stock liquid and cell lysate wastewater could be anaerobically fermented normally, with the potential for anaerobic digestion treatment. The cumulative biogas production of lysate gas from the supernatant could reach 758 mL/gVS, which was significantly better than that of traditional raw materials such as straw and feces. The methane content reached 78.9%, and the total VFAs reached 10,204 mg/L on the ninth day. Moreover, we found that co-digestion of steroidal pharmaceutical wastewater with corn straw (CS) significantly enhanced system stability and biogas production efficiency, with synergistic improvement reaching up to 42%. This approach effectively shortened the lag phase observed in the mono-digestion of steroidal pharmaceutical wastewater. Actual treatment in a large-scale biogas project revealed that, after the addition of two kinds of wastewater, the main and auxiliary reactors presented serious acidification problems. Of these, the total volatile fatty acids in the main reactor reached up to 21,000 mg/L, and the methane content in the biogas production decreased to 25%. Additionally, 16S rRNA high-throughput sequencing analysis showed that, after the addition of steroidal pharmaceutical wastewater, the archaea community in the anaerobic reactor changed significantly due to the stress of changes in the fermentation environment. Euryarchaeota became the absolute dominant bacteria, and the methanogenic pathway also changed to the hydrogen trophic methanogenic pathway with Methanothermobacter as the absolute dominant bacterium. This is the first successful industrial-scale application of biogas engineering for treating steroid wastewater, demonstrating its technical feasibility and energy recovery potential. These research outcomes provide critical engineering parameters and practical experience for large-scale resource recovery from similar wastewater streams, offering important reference values for advancing pharmaceutical wastewater treatment from compliance discharge to energy utilization. Full article

Forage rape (Brassica napus L.) is increasingly becoming a valued forage choice in livestock production. However, research on the application of whole-plant rape silage (including pod shells) in goats remains limited. To evaluate the effects of whole-plant rape silage on goat growth performance, meat quality, antioxidant capacity, and intestinal health, a 90-day feeding trial was performed using 36 healthy 6-month-old Chongming white goats. The goats were fed ad libitum and divided into two groups: a control group (CON, n = 18) fed corn straw silage and a treatment group (TRT, n = 18) fed a diet containing a 1:1 mixture of whole-plant rape silage and corn straw silage. Results showed that a 50% substitution with whole-plant rape silage increased carcass weight (p = 0.005), enhanced total antioxidant capacity (p < 0.01) in plasma, reduced bitter amino acids (such as leucine, isoleucine and phenylalanine; p < 0.05) in muscle, promoted intestinal villi proliferation (p < 0.05), and increased the abundance of beneficial bacteria involved in carbohydrate metabolism (e.g., Family_XIII_AD3011_group; p = 0.028) and propionic acid metabolism (e.g., Phascolarctobacterium; p = 0.026). In conclusion, our findings demonstrated that whole-plant rape silage can serve as a viable alternative to corn straw silage for Chongming white goats. Full article

Raw biomass presents challenges for energy use due to its high moisture content, low bulk density, and susceptibility to biological degradation, which hinder storage, transport, and utilization. An experimental setup was developed to investigate exothermic behavior during torrefaction of agricultural and food industry wastes. Exothermic reactions were observed between 190 °C and 450 °C, with more prominent effects in corn waste, sugarcane bagasse, and straw compared to sunflower husks, palm residues, and coffee skin. A series of tests performed on a torrefaction reactor with a core-type wall heating system showed that the heat generated by exothermic reactions makes it possible to reduce the torrefaction time by a factor of 1.5 (from 120 to 80 min) to obtain biochar of the required quality, with only a slight process temperature increase (15%, from 200 to 230 °C). These findings offer practical pathways for transforming waste into valuable biochar, fostering environmental resilience and socio-economic benefits in communities reliant on biomass resources. Full article

The present study investigated the impact of genetic engineering strategies to produce a cell-free xylanase for applications in the baking industry. The xynA1 gene from the nonpathogenic bacterium Caulobacter vibrioides was integrated into the pAS22 vector with a xylose-inducible promoter and introduced back into the bacteria, resulting in the creation of the BS-xynA1. This construct exhibited substantial secreted xylanase 1 (XynA1) activity, reaching 17.22 U/mL, and a specific activity of 278.64 U/mg after an 18 h growth period with 0.3% (v/v) xylose plus 0.2% (w/v) corn straw. RT-qPCR analysis confirmed that higher xylanase activity in C. vibrioides cells was correlated with increased transcription of the xynA1 gene in the induction medium. Moreover, BS-xynA1 cells coexpress other enzymes, including xylanase 2 (XynA2), cellulase, pectinase, α-amylase, β-glucosidase, β-xylosidase, and α-L-arabinosidase, at low levels (≤2 U/mL). In vitro comparison of cell-free xylanases from BS-xynA1 with three commercially available xylanase-containing mixtures commonly utilized in baking protocols revealed its superior specific activity (163.4 U/mg) across a broad temperature range (30–100 °C), with optimal performance at 50 °C. In practical baking tests, the addition of cell-free XynA1 led to a reduction in dough kneading time and increase in bread height compared to those of the control. Notably, the incorporation of XynA1 resulted in enhanced alveolar structure formation within the bread crumb. Specifically, the following changes were observed in the mass parameters compared to those of the control: an increase in extensibility, elasticity, and deformation energy, and subsequent improvements in strength. Additionally, XynA1 addition led to a reduction in toughness and toughness/elasticity index, indicating a reduction in the mass stiffness of the enzyme-treated bread. To date, this is the first successful application of recombinant XynA1 from C. vibrioides in biotechnological processes related to baking, underscoring the potential and prospects in the food industry. Full article

This study investigated the effect of lignite addition on maturity acceleration and bacterial community assembly mechanisms through high-throughput sequencing and iCAMP null model analysis in Co-composting of goat manure and corn straw. Three treatments were compared: 0% (CK), 5% (T1), and 10% (T2) lignite amendments (based on total solids). Results demonstrated that the 10% lignite addition significantly enhanced composting efficiency: the peak temperature increased by 0.83 °C, nitrogen loss and biotoxicity were reduced, the bacterial community structure was improved with elevated diversity and enriched keystone taxa, and the GI value was enhanced by 68.48 ± 2.99%. Notably, the relative abundances of key species, including Acinetobacter_indicus, Thermobacillus_composti, Pseudomonas_flexibilis, and Chelatococcus_thermostellatus, showed a significant positive correlation with the lignite addition gradient. The analysis of the symbiotic network centered on core microorganisms revealed that T2 showed the highest network complexity (254 links and 175 nodes), which was 46.8% and 48.3% higher than CK, respectively. Cooperative interactions dominated T2 networks, evidenced by a 13% increase in positive links for Acinetobacter (reaching 51.16%) and strengthened associations between humification-related genera (Chelatococcus and Thermobacillus links increased 1.4- and 3.2-fold, respectively). Using iCAMP null modeling, we further quantified assembly mechanisms: lignite addition increased stochastic processes (dispersal limitation increased from 47.57% in CK to 56.52% in T2) while reducing deterministic selection (homogeneous selection decreased from 25.57% to 18.47%). Acinetobacter, Chelatococcus, Ureibacillus, and Thermobacillus exhibited significant responsiveness to these ecological shifts. Collectively, 10% lignite amendment improved co-composting of goat manure and corn straw by synchronously accelerating maturity and restructuring bacterial assembly, providing a practical strategy for manure management via microbial regulation. Full article

In the global agricultural production system, maintaining and improving soil quality are core elements for ensuring food security and sustainable agricultural development. As a key indicator of soil quality, the content and dynamic change in soil organic carbon have a profound impact on the physical, chemical and biological properties of soil, and play a decisive role in soil fertility, structural stability, water and fertilizer conservation capacity and microbial activity. However, its decomposition is slow, and a large number of straws returning to the field will impact crop growth; its combination with irrigation is a more reasonable solution, as it can significantly improve the soil environment, increase soil moisture and promote straw decomposition. Therefore, in order to further study the effects of different irrigation methods and straw-returning combinations on soil active-carbon content, an experiment was carried out in long-term arid and semi-arid areas under in-field corn cultivation during 2019–2020. Three irrigation modes were designed—flood irrigation (BI), shallow drip irrigation (SD) and drip irrigation under film (DP)—and straw returning (CS) and no straw returning (CK) were set up, with irrigation applied at critical corn growth stages (internode elongation, heading, bell mouth stage) to support plant growth. The results are as follows: (1) The content of soil organic carbon in different treatments had a gradual upward trend with the advance of growth period; the content of soil organic carbon in DP treatment was significantly higher than that in SD and BI treatment under the same straw returning mode, indicating that drip irrigation under film and straw-returning mode can synergistically improve soil fertility and organic carbon content. (2) Different irrigation methods and straw-returning methods have significant effects on the content of soil active organic carbon components. Different drip irrigation modes can significantly improve the content of soil POC and MBC compared with flood irrigation. The Kos of SD treatment is significantly higher than that of other irrigation treatments, and the CPMI is lower than that of the other two irrigation methods, indicating that the soil organic carbon of SD treatment is more stable. Therefore, under straw-returning conditions, drip irrigation can significantly improve the carbon content of soil components and the management index of soil carbon pool, thus significantly increasing the accumulation of soil organic matter. This study discussed the effects of straw returning on soil organic carbon composition and soil carbon pool index under different irrigation methods to provide theoretical and practical bases for the selection and promotion of straw-returning methods and rational irrigation methods in semi-arid areas. Full article

Different types of organic materials demonstrate varying efficacy in ameliorating saline–alkali soils, while the combined application of organic materials can potentially enhance the remediation effects on saline–alkali land. To verify this assumption, our study conducted a pot experiment with spinach in saline–alkali soil, observing the improvement effect of saline–alkali soil and the growth of crops when acid fermentation products of vegetables, humic acid-like substances, and corn straw were applied either individually or in combination. The results revealed that both the sole and combined application of organic materials could enhance the yield of spinach. Particularly, humic acid-like substances increased spinach yield to six times that of the chemical fertilizer treatment. Although the application of organic materials led to a decline in the diversity and richness indices of the microbial community in saline–alkali soil (except fungal richness), the combined use of organic materials contributed to a healthier trend in the soil microbial community structure. Beyond its effects on soil nutrients such as total carbon and total nitrogen, the improvement in soil organic matter activity caused by the joint application of organic materials was identified as the primary factor responsible for enhancing the health of the soil microbial community and the remediation effects on saline–alkali soil. Full article

Hericium erinaceus, a rare edible–medicinal fungus, has attracted great attention in food and pharmaceutical fields due to its rich nutritional and bioactive components. However, its traditional cultivation relies heavily on wood chip substrates, causing resource unsustainability. The “wood-replacing-with-grass” technology can address this issue, contributing to ecological conservation and alleviating resource conflicts between edible fungus cultivation and forestry development. This study focused on straw substitution for wood chips, initially screening suitable straw types and optimal addition ratios from 7 straw varieties, and systematically investigating the agronomic trait variations in H. erinaceus under different substrate formulations via cultivation experiments. Results showed the following: (1) Rapeseed straw, soybean straw, and corn straw substituting 20%, 30%, and 40% of wood chips, respectively, promoted better mycelial growth of H. erinaceus. (2) All screened straw formulations enabled fruiting. With increased straw addition, the mycelial full colonization time shortened (up to 5 days shorter in 40% corn/soybean straw treatments). The 20% corn straw treatment showed significantly higher biological efficiency and average fresh weight than the control (CK); the 20% soybean straw treatment had no significant difference in biological efficiency but significantly higher average fresh weight than CK; and the 20% rapeseed straw treatment showed no significant differences in both indexes from CK. However, when straw addition exceeded 20%, fruiting body firmness, yield, and biological efficiency decreased progressively. (3) The 40% soybean straw treatment yielded fruiting bodies with the highest crude protein, manganese, and iron contents, while the 40% rapeseed straw treatment had the highest crude fat, potassium, phosphorus, calcium, zinc, and selenium contents. These findings provide a theoretical basis and practical reference for optimizing H. erinaceus cultivation substrate formulations, improving product quality, and promoting sustainable industrial development. Full article

High-molecular-weight polycyclic aromatic hydrocarbons (PAHs), such as pyrene, are persistent environmental pollutants that threaten soil health and agricultural productivity due to their resistance to degradation. This study evaluated the efficacy of domesticated bacteria isolated from contaminated farmland soil and activated sludge, used alone and in combination with corn (Zea mays L.), to remove pyrene from soil, enhance plant growth, improve tolerance, and ensure crop safety. Six bacterial strains were isolated: three from polluted farmland soil (WB1, WB2, and WF2) and three from activated sludge (WNB, WNC, and WH2). High-throughput 16S rRNA amplicon sequencing profiled bacterial communities after 30 days of treatment. Analytical tools, including LEfSe, random forest, and ZiPi analyses, identified biomarkers and core bacteria associated with pyrene degradation, assessing their correlations with plant growth, tolerance, and pyrene accumulation in corn straw. Bacteria from activated sludge (WNB, WNC, and WH2) outperformed farmland soil-derived strains and the inoculant strain ETN19, with WH2 and WNC achieving 65.06% and 87.69% pyrene degradation by days 15 and 30, respectively. The corn–bacteria consortium achieved up to 97% degradation. Activated sewage sludge (ASS)-derived bacteria were more effective at degrading pyrene and enhancing microbial activity, while soil-derived bacteria better promoted plant growth and reduced pyrene accumulation in straw. Microbial communities, dominated by Proteobacteria, exhibited high species richness and resilience, contributing to xenobiotic degradation. The corn-domesticated bacteria consortia effectively degraded pyrene, promoted plant growth, and minimized pollutant accumulation in crops. This remediation technology offers a promising strategy for rapid and sustainable bioremediation of agricultural soils contaminated with organic compounds such as PAHs or other complex pollutants, while promoting the development of efficient bacterial communities that enhance crop growth. Full article

In agricultural systems, excessive application of nitrogen fertilizer often leads to low nitrogen use efficiency and environmental pollution. In order to solve this problem, we studied the synergistic effect of biochar and nitrogen fertilizer on pepper yield, quality and rhizosphere soil health. This study was conducted under a temperate continental monsoon climate in Changchun, China. Using ‘Jinfu 803’ pepper (Capsicum annuum L.) as the test material, biochar was prepared from corn straw under oxygen-limited conditions at 500 °C. the comprehensive effects of the combined application of biochar (0, 0.7% soil mass ratio) and nitrogen fertilizer (0, 75, 375, 675 kg/hm² pure nitrogen) on pepper yield, fruit quality, rhizosphere soil physicochemical properties, and microbial community structure were studied. Redundancy analysis (RDA), high-throughput sequencing, and multivariate statistical methods were used to analyze the association patterns between soil environmental factors and microbial functional groups. The results showed that the combined application of biochar and nitrogen fertilizer significantly improved soil porosity (increased by 12.3–28.6%) and nutrient content, increased yield, and improved quality, among which the treatment of 0.7% biochar combined with 375 kg/hm² nitrogen fertilizer (B1N2) had the best effect. Under this treatment, the pepper yield reached 24,854.1 kg/hm², which was 42.35% higher than that of the control (B0N0). Notably, the nitrogen partial factor productivity (PFPN) of the B1N2 treatment (66.3 kg/kg) was significantly higher than that of the corresponding treatment without biochar and was not significantly lower than that of the high-nitrogen B1N3 treatment. The contents of soluble sugar and vitamin C in fruits increased by 51.18% and 39.16%, respectively. Redundancy analysis (RDA) revealed that the bacterial community structure was primarily shaped by soil pH, organic matter, and porosity, while the fungal community was predominantly influenced by alkaline hydrolyzable nitrogen and total nitrogen. Furthermore, the B1N2 treatment specifically enriched key functional microbial taxa, such as Chloroflexi (involved in carbon cycling) and Mortierellomycota (phosphate-solubilizing), which showed significant positive correlations with improved soil properties. In conclusion, B1N2 is the optimal treatment combination as it improves soil physical conditions, increases nutrient content, optimizes microbial community structure, and enhances pepper yield and quality. Full article

Lignocellulosic agricultural residues represent a rich source of potential feedstock for biorefinery applications, but their valorization remains challenging. The white-rot fungus Irpex lacteus J2 exhibited a promising degradation effect, but its molecular mechanisms of lignocellulose degradation remained largely uncharacterized. Here, we performed high-quality whole-genome sequencing and untargeted metabolomic profiling of I. lacteus J2 during the degradation of corn straw as the sole carbon source. The assembled I. lacteus J2 genome contained 14,647 protein-coding genes, revealing a rich genetic repertoire for biomass degradation and secondary metabolite synthesis. Comparative genomics showed high synteny (mean amino acid sequence identity 92.28%) with I. lacteus Irplac1. Untargeted metabolomic analysis unveiled a dynamic metabolic landscape during corn straw fermentation. Dominant metabolite classes included organic acids and derivatives (27.32%) and lipids and lipid-like molecules (25.40%), as well as heterocyclic compounds (20.41%). KEGG pathway-enrichment analysis highlighted significant activation of core metabolic pathways, with prominent enrichment in global metabolism (160 metabolites), amino acid metabolism (99 metabolites), carbohydrate metabolism (24 metabolites), and lipid metabolism (19 metabolites). Fermentation profiles at 3 and 15 days demonstrated substantial metabolic reprogramming, with up to 210 upregulated and 166 downregulated metabolites. Correlation analyses further revealed complex metabolic interdependencies and potential regulatory roles of key compounds. These integrated multi-omics insights significantly expand our understanding of the genetic basis and metabolic versatility, enabling I. lacteus J2 to efficiently utilize lignocellulose. Our findings position I. lacteus J2 as a robust model strain and provide a valuable foundation for developing advanced fungus-based strategies for sustainable bioprocessing and valorization of agricultural residues. Full article