Recovery of microbial community in strongly alkaline bauxite residues after amending biomass residue.

The aim of this study was to characterize the effects of cornstalk biomass amendments on microbial communities in bauxite residues (BRs) by phylogenetic analysis. Improvements in soil geochemical, physical, and biological properties were assessed to identify the major factors controlling microbial community development in BRs. After one year of incubation, the salinity and structure of the amended BRs had gradually improved, with pH dropping from 11.39 to 9.89, the exchangeable sodium percentage (ESP) dropping from 86.3% to 35.2%, and the mean weight diameter (MWD) rising from 0.12 mm to 0.38 mm. Further analysis of community level physiological profiles (CLPP) showed that the microbial utilization of different carbohydrates had shifted significantly, in addition to increases in the diversity index H' (0.7-7.34), U (2.16-3.14), and the average well color development (0.059-1.08). Over the one-year outside incubation, the dominant fungal phyla in the BRs had shifted gradually from Ascomycota (85.64%) to Ascomycota (52.07%) and Basidiomycota (35.53%), while the dominant bacterial phyla had shifted from Actinobacteria (38.47%), Proteobacteria (21.39%), and Gemmatimonadetes (12.72%) to Actinobacteria (14.87%), Proteobacteria (23.53%), and Acidobacteria (14.37%). Despite these shifts, microbial diversity remained lower in the amended BRs than in the natural soil. Further redundancy analysis indicated that pH was the major factor driving shifts in the bacterial community, while aggregates were the major factor driving shifts in the fungal community. This study demonstrated that amendment with cornstalk biomass shifted the microbial community in the BRs from halophilic groups to acidogenic groups by improving the soil environmental conditions.

Removal of Cd(II) using dithiocarboxyl cornstalk and the waste filtrate.

A novel adsorbent, called dithiocarboxyl cornstalk (DTCS), was developed, and the effects of various parameters on the adsorption performance for Cd(II) with DTCS were investigated in this work. The results suggested that DTCS presented the efficient removal capacity for Cd(II) when the pH values, adsorption temperature, and oscillation rate were 3.0 to 6.0, 313 K, and 150 rpm, respectively. The adsorption kinetic data were more agreed with pseudo-second-order kinetic model, and the isotherm data could be characterized by Freundlich model. The thermodynamic data indicated the adsorption process was endothermic and spontaneous. The FTIR and SEM confirmed the chemisorption between Cd(II) and DTCS. Furthermore, to eliminate the secondary pollution, the waste filtrate generated in the preparation of DTCS was employed to remove Cd(II) through flocculation experiments. The results showed that the waste filtrate is a potential flocculant for the treatment of wastewater containing Cd(II).

Antifungal activity of water-soluble products obtained following the liquefaction of cornstalk with sub-critical water.

Cornstalks are the leftover leaves and stems in a field after corn harvest. They are a potential biomass resource but are underutilized in agricultural production systems. To examine the chemical components in cornstalks and their corresponding functions, blocky cornstalks were treated in water at temperatures of 190, 210, 230, 250, and 270 °C in a high-pressure reactor. Water-soluble products (WSPs) were extracted from these treatments, and their chemical compositions were analyzed using gas chromatography-mass spectrometry (GC-MS), and their antifungal activities were determined using a bioassay. It was found that WSPs contained 28.7-40.1% phenols, 27.9-36.6% ketones, 0-2.6% alcohols, 4.9-10.1% esters, 5.4-7.8% organic acids, 1.3-12% aldehydes, and 5.5-18.4% of other organic compounds such as nitrogen- and sulfur-containing compounds, furan compounds, and benzene compounds. The inhibition the growth of the plant pathogen Fusarium oxysporum by WSPs was affected by temperature. WSP-270 (obtained at 270 °C) exhibited the best growth-inhibition efficacy. Under a biomicroscope, WSP-270-treated F. oxysporum showed a deformed and swollen hypha, and an increased number of bifurcations, as well as an expansion of growing apexes of new bifurcations. Therefore, the antifungal activity of WSPs could be used to manage soilborne plant pathogens.

Effect of Cornstalk Biochar Immobilized Bacteria on Ammonia Reduction in Laying Hen Manure Composting.

NH3 emission has become one of the key factors for aerobic composting of animal manure. It has been reported that adding microbial agents during aerobic composting can reduce NH3 emissions. However, environmental factors have a considerable influence on the activity and stability of the microbial agent. Therefore, this study used cornstalk biochar as carriers to find out the better biological immobilization method to examine the mitigation ability and mechanism of NH3 production from laying hen manure composting. The results from different immobilized methods showed that NH3 was reduced by 12.43%, 5.53%, 14.57%, and 22.61% in the cornstalk biochar group, free load bacteria group, mixed load bacteria group, and separate load bacteria group, respectively. Under the simulated composting condition, NH3 production was 46.52, 38.14, 39.08, and 30.81 g in the treatment of the control, mixed bacteria, cornstalk biochar, and cornstalk biochar separate load immobilized mixed bacteria, respectively. The cornstalk biochar separate load immobilized mixed bacteria treatment significantly reduced NH3 emission compared with the other treatments (p < 0.05). Compared with the control, adding cornstalk biochar immobilized mixed bacteria significantly decreased the electrical conductivity, water-soluble carbon, total nitrogen loss, and concentration of ammonium nitrogen (p < 0.05), and significantly increased the seed germination rate, total number of microorganisms, and relative abundance of lactic acid bacteria throughout the composting process (p < 0.05). Therefore, the reason for the low NH3 emission might be due not only to the adsorption of the cornstalk biochar but also because of the role of complex bacteria, which increases the relative abundance of lactic acid bacteria and promotes the acid production of lactic acid bacteria to reduce NH3 emissions. This result revealed the potential of using biological immobilization technology to reduce NH3 emissions during laying hen manure composting.

Simultaneous production of propionic acid and vitamin B12 from corn stalk hydrolysates by Propionibacterium freudenreichii in an expanded bed adsorption bioreactor.

Vitamin B12 and propionic acid that were simultaneous produced by Propionibacterium freudenreichii are both favorable chemicals widely used in food preservatives, medicine, and nutrition. While the carbon source and propionic acid accumulation reflected fermentation efficiency. In this study, using corn stalk as a carbon source and fed-batch fermentation process in an expanded bed adsorption bioreactor was studied for efficient and economic biosynthesis of acid vitamin B12 and propionic. With liquid hot water pretreated corn stalk hydrolysates as carbon source, 28.65 mg L-1 of vitamin B12 and 17.05 g L-1 of propionic acid were attained at 168 h in batch fermentation. In order to optimize the fermentation outcomes, fed-batch fermentation was performed with hydrolyzed corn stalk in expanded bed adsorption bioreactor (EBAB), giving 47.6 mg L-1 vitamin B12 and 91.4 g L-1 of propionic acid at 258 h, which correspond to product yields of 0.37 mg g-1 and 0.75 g g-1, respectively. The present study provided a promising strategy for economically sustainable production of vitamin B12 and propionic acid by P. freudenreichii fermentation using biomass cornstalk as carbon source and expanded bed adsorption bioreactor.

Pleurotus ostreatus decreases cornstalk lignin content, potentially improving its suitability for animal feed.

BACKGROUND: The capacity of Pleurotus ostreatus to degrade lignin was investigated in the fermentation of cornstalk. Cornstalk was incubated with P. ostreatus for 30 days, and acid-soluble and acid-insoluble lignins were assessed. The microscopic structure of cornstalk samples was studied by scanning electron microscopy (SEM), and spectroscopic characteristics were measured by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and solid state nuclear magnetic resonance (13 C NMR) spectroscopy. RESULTS: During fermentation of cornstalk, the proportion of acid-soluble lignin did not vary significantly (P > 0.05), but that of acid-insoluble lignin decreased gradually from 17.8% on day 0 to 7.6% on day 30 (P < 0.01). SEM revealed that the surface of cornstalk was gradually damaged with cavities increasing in number and size, forming a quasi-network structure. Crystallinity decreased from 35.0 on day 0 to 15.2 on day 30. FTIR and cross-polarization magic angle spinning (CPMAS) 13 C NMR spectra showed that the intensity of the peaks corresponding to lignin, cellulose and hemicellulose also decreased gradually over 30 days. CONCLUSION: Cornstalk can be effectively degraded by P. ostreatus within 30 days. Pleurotus ostreatus decreases cornstalk lignin content, potentially improving its suitability for animal feed. © 2016 Society of Chemical Industry.

Green Strong Cornstalk Rind-Based Cellulose-PVA Aerogel for Oil Adsorption and Thermal Insulation.

Cellulose-based aerogel has attracted considerable attention for its excellent adsorption capacity, biodegradability, and renewability. However, it is considered eco-unfriendly due to defibrillation of agriculture waste and requires harmful/expensive chemical agents. In this study, cornstalk rind-based aerogel was obtained via the following steps: green H2O2/HAc delignification of cornstalk rind to obtain cellulose fibers, binding with carboxymethyl cellulose (CMC)/polyvinyl alcohol (PVA) and freeze-drying treatment, and hydrophobic modification with stearic acid. The obtained aerogel showed high compressive strength (200 KPa), which is apparently higher (about 32 kPa) than NaClO-delignified cornstalk-based cellulose/PVA aerogel. Characterization of the obtained aerogel through SEM, water contact angle, etc., showed high porosity (95%), low density (0.0198 g/cm-3), and hydrophobicity (water contact angle, 159°), resulting in excellent n-hexane adsorption capacity (35 g/g), higher (about 29.5 g/g) than NaClO-delignified cornstalk-based cellulose/PVA aerogel. The adsorbed oil was recovered by the extrusion method, and the aerogel showed excellent recyclability in oil adsorption.

Flight Phenology of Elasmopalpus lignosellus (Lepidoptera: Pyralidae) in the Northwest Florida Panhandle.

Elasmopalpus lignosellus Zeller (Lepidoptera: Pyralidae), the lesser cornstalk borer (LCSB), is an economically important peanut pest in the southeastern U.S. region, and its occurrence and abundance have been associated with warm and dry conditions. In the Northwestern Florida Panhandle (USA), the LCSB occurrence and abundance are unknown. Thus, a study in this region used commercial sex pheromones to capture male moths year-round from July/2017 to June/2021. Our results indicated that the LCSBs were present in the region from April to December, with higher abundance in August. Moths were also caught from January to March in only 2020. In addition, the number of moths collected increased when the temperature increased. Our results indicate a different pattern for LCSB abundance than previously documented, with peak occurrence in warm and wet conditions (August). These results support that region-specific weather information should be considered when designing IPM recommendations based on the phenology of pest occurrence in the agroecosystem.

Multi-omics analysis provides insight into the phytotoxicity of chicken manure and cornstalk on seed germination.

To minimize environmental risks and the phytotoxic influence of organic materials on crop growth, it is necessary to test their phytotoxicity and maturity when they were used in farmland. However, the stress response of seed germination to chicken manure and cornstalks is not clear. This study used multi-omics analysis to investigate the inhibition mechanism of seed germination by chicken manure and cornstalk. Chicken manure caused destructive inhibition of seed germination with higher phytotoxicity (GI = 0). Cornstalk also had a low GI (8.81 %), while it mainly inhibited radicle growth (RL = 9.39 %) rather than seed germination (GR = 93.33 %). The response of radish seed germination to chicken manure and cornstalk phytotoxic stresses was accompanied by metabolic adjustments of storage substance accumulation, antioxidant enzyme activity change, phytohormone induction, and expression of specific proteins and gene regulation. Combined transcriptomic and proteomic analysis revealed that differential expression of 13,090 (5944 upregulated/7146 downregulated) and 3850 (2389 upregulated/1461 downregulated) genes (DEGs), and 1041 (82 upregulated/932 downregulated) and 575 (111 upregulated/464 downregulated) proteins (DEPs) at chicken manure and cornstalk treatment, respectively. Most down-regulated genes and proteins were involved in phenylpropanoid biosynthesis under chicken manure stress, which caused irreversible inhibition of seed germination. Down-regulation of phytohormone signal transduction-related genes under cornstalk stress resulted in inhibition of radicle growth, but the inhibitory stress was restorable. These findings provide new insight into the phytotoxicity of livestock manure and cornstalk on seed germination.

The efficient solution to decline the greenhouses emission and enrich the bacterial community during pig manure composting: Regulating the particle size of cornstalk.

In present study, four lengths of chopped cornstalks were amended with pig manure respectively for 100 days aerobic fermentation, which aimed to evaluate the impact of different length of agricultural solid wastes on gaseous emission and dominating bacterial community succession and connection. The result revealed that the maximum ammonia volatilization was observed in 5 cm of straw samples attributed to the prominent mineralization, which was opposite to the emission of CH4 and N2O. As for global warming potential, the minimum value was detected in 5 cm of straw samples, which decreased by 5.03-24.75% compared with other samples. Additionally, the strongest correlation and complexity of bacterial community could be detected in 5 cm of straw treatment, representing the most vigorous bacterial metabolic ability could be recorded by optimizing the microbial habitat. Therefore, in order to decline the greenhouse effect in livestock manure composting, the 5 cm of corn straw was recommended.

Effects of further composting black soldier fly larvae manure on toxic metals and resistant bacteria communities by cornstalk amendment.

Rapid composting by black soldier fly larvae (BSFL) may be insufficient to maturation and humification of composting and further composting is necessary. The purpose of this study was to explore cornstalk addition on toxic metals (Cu, Zn, Pb and Cd), toxic metals resistance bacterial (TMRB) destiny and their relationship with physicochemical factors during BSFL manure composting. High-throughput sequencing was performed by six treatments, namely T1 to T6, where T1 to T3 were BSFL manures from chicken, pig and dairy manure, respectively, and T4 to T6 were same manures and utilized cornstalk to adjust C/N to 25. The results showed that cornstalk amendment could enhance the toxic metals immobilization rate compared to control treatments in the ultimate product. TMRB indicated that the major potential hosts bacteria were Firmicutes, Bacteroidota, Proteobacteria, Acidobacteriota and Actinobacteriota, and the sum relative abundance were 63.33%, 90.62%, 83.62%, 69.38%, 50.66% and 90.52% in T1 to T6 at the end of composting. Bacteria diversity and heat map revealed composting micro-ecology with additive cornstalk to remarkably effect main resistant bacterial distribution via adjusting environmental factors and potential hosts bacterial. Finally, T5 treatment was able to greatly decrease the TMRB abundance, and improve the ability of composting and ultimate product quality.

The biological and abiotic effects of powdered activated carbon on the anaerobic digestion performance of cornstalk.

To comprehensively evaluate the biological and abiotic influence of powdered activated carbon (PAC) on the anaerobic digestion of cornstalk, mesophilic and thermophilic digestion were conducted. Adding PAC (10 g/L) under thermophilic system obtained the maximum cellulose degradation rate and methane yield (MY), which were 57.47% and 128.19 L/kg VS. However, adding same dose of PAC at mesophilic system decreased the MY by 8.16% while increased the cellulose degradation rate and methane production rate by 6.48% and 17.92%. Under mesophilic conditions, the enhancement of PAC was owing to the enrichment of cellulolytic microorganisms, improvement of the syntrophic process and direct interspecies electron transfer. The lower methane yield was attributed to the adsorption of carbon source by PAC and CH4 consumption by Norank_c_Bathyarchaeia. The good performance of thermophilic system was owing to the lower adsorption capability of PAC, absence of Norank_c_Bathyarchaeia, and concentrated carbon flow to methane.

Enhanced cornstalk decomposition by a psychrotrophic bacterial consortium comprising cellulose, hemicellulose, and lignin degraders with biochar as a carrier for carbonneutrality.

To explore an effective approach for accelerating cornstalk decomposition and return under low temperature, nine psychrotrophic cellulose-, hemicellulose-, and lignin-degrading bacterial strains were used with biochar as the carrier to prepare a novel psychrotrophic stalk-degrading bacterial consortium (PSBC). With PSBC, the maximum cornstalk degradation rate reached 59.3% after 50 d at 10-15 °C, which accelerated cornstalk decomposition, resulting in increases in organic matter, phosphorus, and potassium in the soil. Microbial community analysis demonstrated that PSBC enhanced microbial community diversity and altered specific selection. Genera Arthrobacter, Pseudomonas, and Pantoea in PSBC became dominant in the soil microbiota, which benefited cornstalk degradation. Therefore, this work provides a promising strategy to facilitate the degradation of cornstalks in cold regions, which has potential application value for carbon neutrality.

Preparation and characterization of cornstalk microspheric hydrochar and adsorption mechanism of mesotrione.

In this study, cornstalk was pyrolysed to obtain hydrochar (HC), which was used to remove mesotrione from aqueous solutions. HC characterization and batch experiments were conducted to investigate mesotrione adsorption and the underlying mechanism. The characterization revealed microspheres on the HC surface. FT-IR spectra showed that the HC contained a large number of -OH groups, C=C bonds of aromatic rings, C-H groups in aromatic rings and phenolic C-O bonds. The adsorption results showed that the mesotrione adsorption ability gradually increased as the HC preparation temperature increased. The quasi-second-order kinetic equation (R2 ≥ 0.9860, p < 0.05) agreed well with the mesotrione adsorption process. The maximum monolayer adsorption capacity, which was obtained at pH 7 and 45°C with HC prepared at 240°C, was 3181.7 mg kg-1 with the Langmuir isotherm model (R2 ≥ 0.9491, p < 0.05). Van der Waals and dipole forces and hydrogen bonds were inferred as the main adsorption mechanisms. HC has potential as an effective and energy-saving adsorbent for mesotrione to reduce environmental pollution.

Evaluation of cornstalk as bulking agent on greenhouse gases emission and bacterial community during further composting.

The aim of current work was to explore the impact of Cornstalk (CS) on greenhouse gaseous emission and maturation during further composting and analyzed its impact on bacterial diversity. Three kinds of immature fertilizers were collected from chicken, pig and dairy manure namely T1, T2 and T3 as control, T4, T5 and T6 were added CS into T1 to T3 and adjusted C/N to 25 namely treatment. The results illustrated that gases (N2O, CH4 and NH3) emission of CS added treatments decreased by 6.39%-24.68%, 10.60%-23.23% and 13.00%-19.58%, respectively. But the CS amendment increased CO2 emission by 15.53%-30.81%. The mineralization of carbon and nitrogen was mainly correlated to Firmicutes, Actinobacteria, Proteobacteria and Bacteroidota, CS amendment increased abundance by 22.28%, 17.79%, 1.48% and 35.90%, respectively. The strategy of employing CS would be the most feasible approach for recycling of immature manure, considering its compost quality and environmental from farm.

Pest categorisation of Elasmopalpus lignosellus.

The European Commission requested the EFSA Panel on Plant Health to conduct a pest categorisation of Elasmopalpus lignosellus (Zeller) (Leipidoptera: Pyralidae) for the territory of the EU following interceptions of the organism within the EU and its addition to the EPPO Alert List. E. lignosellus feeds on over 70 species; hosts include cereals, especially maize, legumes, brassicas and a range of grasses. Seedlings of ornamental and forest trees can also be hosts. E. lignosellus is established in tropical and subtropical areas of North, Central and South America. Eggs are usually laid in the soil or on the lower stem of hosts. Larvae develop in the soil and feed on roots and stems causing stunting and yield losses. Plants for planting, rooted with growing media, or with stems cut close to the soil, and fresh vegetables harvested with stems, such as asparagus and cabbage, provide pathways for entry. Population development is favoured by dry and hot conditions (27-33°C). Adults fly and can be carried in air currents. Adults are recorded from temperate areas within the Americas contributing some uncertainty regarding the limits of its establishment potential in the EU. Although cultivated and wild hosts are distributed across the EU, impacts are likely to be confined to production areas on sandy soils around the coastal Mediterranean during hot dry years. Phytosanitary measures are available to inhibit the entry of E. lignosellus. E. lignosellus satisfies the criteria that are within the remit of EFSA to assess for it to be regarded as a potential Union quarantine pest.

The synergistic effect of rumen cellulolytic bacteria and activated carbon on thermophilic digestion of cornstalk.

To explore the bioaugmentation of rumen cellulolytic bacteria (RCB) and activated carbon (AC) on thermophilic digestion of cornstalk, biochemical methane potential tests were carried out. Adding RCB or AC can improve methane production, while simultaneous existence of AC (10 g/L) and RCB (5%) obtained the best performance. The maximum cellulose degradation rate, methane production rate and methane yield were 66.92%, 32.2 L/(kgVS·d), and 144.9 L/kgVS, which increased by 30.23%, 51.17%, and 20.35% compared with control group. The cellulolytic and fermentative bacteria (Hydrogenispora), syntrophic acetate-oxidizing bacteria (norank_o_MBA03), and hydrogenotrophic Methanothermobacter were crucial for thermophilic digestion of cornstalk. The enhancement of AC was due to the enrichment of Hydrogenispora and Methanothermobacter, while RCB can increase the abundance of cellulolytic bacteria (Halocella and norank_o_M55-D21) and mixotrophic Methanosarcina. The synergetic effect of AC and RCB owing to the enriched cellulolytic bacteria, the enhanced syntrophic acetate oxidation and the concentrated carbon metabolic flow to methane.

Composited Gels from Nature Growing Scaffold: Synthesis, Properties, and Application.

As a nature ultralight, well-aligned porous and anisotropy feedstock, cornstalk pith (CSP) has not been exploited for material design. Herein, we use CSP as substrate to prepare multifunctional elastic composite gels. First, CSP is pretreated by ferric chloride then immersed in an unsaturated monomer solution, following by a polymerization to form enhanced networks. The ferric ions act as junction sites for the combination between the polymer chains and the CSP matrix, therefore, dynamically reversible bonds are constructed. The bonds dissipate the compression force by breaking the dynamic bonds and reconstruct when the loading is removed. The reconstructed dynamic bonds endow an antifatigue performance of the prepared gels, in the cyclic compression test conducting 100 times with a 50% strain, and the gel holds a 94% elastic recovery. Furtherly, oil/water separation, cushioning system and biobased sensor are developed on the basis of what the matrix endows and what the reversible bonds exhibit. The preparation method in this study enriches a simply and high value-added method to utilize biobased material.

Residue cornstalk derived biochar promotes direct bio-hydrogen production from anaerobic fermentation of cornstalk.

In this study, an innovative approach was proposed based on the implement of biochar derived from residue cornstalk left after anaerobic bio-hydrogen production (RCA-biochar) to improve direct bio-hydrogen production from anaerobic fermentation of cornstalk. The bio-hydrogen production potential and maximum bio-hydrogen production rate increased from 156.2 to 286.1 mL H2/g substrate and 3.5 to 5.7 mL H2/g substrate/h, respectively, following the added RCA-biochar increased from 2.5 to 15.0 g/L. Cornstalk chemical component analysis showed the cellulose and hemicellulose content decreased by 17.9-33.7% and 14.4-25.2%, and lignin content increased by 20.3-42.8%, respectively, after 96 h anaerobic fermentation with RCA-biochar 2.5-15.0 g/L. Further analyses revealed that RCA-biochar not only provided more specific surface area for hydrogen-producing bacteria attachment, but also promoted the cellulolytic enzyme activity, thereby resulted in increased substrate conversion to bio-hydrogen.The findings obtained in this study may provide supports for effective and sustainable lignocellulosic bio-hydrogen production in the future.

Role of residue cornstalk derived biochar for the enhanced bio-hydrogen production via simultaneous saccharification and fermentation of cornstalk.

Biochar derived from residue cornstalk left after anaerobic bio-hydrogen production (RCA-biochar) was confirmed to enhance bio-hydrogen production from cornstalk hydrolysate. However, the role of RCA-biochar in simultaneous saccharification and fermentation (SSF) during bio-hydrogen production from cornstalk has not yet been revealed. This study therefore aims to fill this knowledge gap. It was observed that with the increase in RCA-biochar concentration from 0 g/L to 10.0 g/L, the maximal cumulative SSF bio-hydrogen yield varied from 24.3 ± 1.1 mL/g-substrate to 154.3 ± 3.6 mL/g substrate under varying pH values - 5.5, 6.0, 6.5, 7.0. The increasing bio-hydrogen production was observed to correlate with both RCA-biochar level and initial pH. Batch tests confirmed that the initial pH had an obvious effect an saccharification, while RCA-biochar affected anaerobic fermentation a lot. The findings revealed the role of previously unrecognized RCA-biochar in SSF bio-hydrogen production from cornstalk, which can provide an alternative approach for lignocellulosic bio-hydrogen production.