Hydrolysis Performance Research Articles

Enzymatic Activity of Fungi for Hydrolysis of Wheat Bran and Cultivation of Oleaginous Yeasts

Sustainable alternatives to petrochemical raw materials in oleochemical, laundry detergent and personal care industry need to be implemented. Presently, palm oil is the predominant cost-efficient option. While it is a renewable source, it has negative environmental and socioeconomic implications. Therefore, the request for ecologically certified and palm oil-free cleaning agents and household care products is rapidly growing, supported by concepts of waste-free biorefinery. Oleaginous yeasts are currently the most promising source for microbial lipid production. Additionally, wheat bran is a cereal milling by-product, which is available in high quantities and provides an excellent feedstock. Enzymatically generated wheat bran hydrolysate provides an excellent microbial cultivation medium for the sustainable production of high value biological additives. Indeed, wheat bran consists predominantly of lignocellulose, and therefore of cellulose, hemicellulose and lignin, which can be hydrolyzed by established enzyme systems. Currently, such enzymatic systems are mainly obtained for the market from genetically modified organisms (GMO). This represents a problem because GMO products or process components cannot be included in eco-certified household care formulations. Therefore, innovative GMO-free biotechnological processes need to be implemented, as well as the isolation of novel GMO-free hydrolase enzyme systems. Fungal strains are an interesting source for the efficient screening and isolation GMO-free hydrolases (see figure).This contribution is part of a project, which aims to use a holistic biotechnological approach to convert mill residues into customized specialty ingredients of eco-certified detergents. The project focuses on three main tasks:investigation of a microbial group of eight Ascomycete fungi,production of enzymes for hydrolysis of wheat bran, anduse of the resulting biomass hydrolysate to cultivate oleaginous yeasts.Hydrolase producing fungal strains were cultivated on different substrates to investigate their ability to generate specific enzyme systems capable of hydrolyzing wheat bran. The activity of the enzymes was qualitatively and quantitatively characterized to determine the optimal strains for the degradation of wheat bran and suited to implement a large-scale process. Supernatants of different fungal strains cultivations were tested in the hydrolysis step to compare the hydrolysis performances of differently active enzyme mixes. The biomass hydrolysate was used to cultivate lipid generating yeasts to investigate their ability to grow on the microbial cultivation medium.

Ultrasound-induced yield increase of yuba (protein-lipid film from soybean milk) and changes in structural, physicochemical, and digestive properties during film-peeling process

Yuba, as a traditional soybean food, is protein-lipid film from soybean milk. This study proposed a novel ultrasound-assisted yuba preparation strategy and investigated the structural, physicochemical, and digestive properties of yuba during the film-peeling process. The process parameters of yuba preparation were optimized using response surface method and Box-Behnken design. The results showed that total yield of 5 yuba films was 39.8 ± 0.3% under the optimum conditions (315 W ultrasound power, 8 min ultrasound time, and 1:9 solid-to-liquid ratio) with an increase rate of 12.6%, compared with that of the control group. With the increasing yuba film-peeling times, protein and lipid contents in yuba decreased, whereas carbohydrate content displayed an increasing trend. The analyses of mechanical properties, protein secondary structure, X-ray diffraction, disulfide bond, and microstructure showed that the protein network structure of yuba films became looser with film-peeling progression. Furthermore, in vitro simulated digestion experiments indicated that yuba obtained in the early film-peeling stage (the first four films) exhibited better protein degradation performance and higher degree of lipid hydrolysis. This study provides technical references for the process innovations of yuba and theoretical basis for systematically evaluating yuba quality and better utilizing its nutritional value.

Influence of Surface Basic Sites and Oxygen Vacancies on the Performance of Metal-Modified Rod-Like Ceria Catalysts for Low-Temperature Hydrolysis of Carbonyl Sulfide.

This study utilized a hydrothermal method to synthesize various metal-modified rod-like ceria catalysts (Fe, Co, Cu, Ni, La), achieving efficient COS removal at low temperatures. The research identified surface oxygen vacancies and basic sites as critical factors that influence the catalytic performance of COS hydrolysis. The addition of different metals to pristine ceria rods increased the specific surface area, oxygen vacancy content (Ov), and basicity, which enhanced the catalysts' sulfur resistance and stability. Among all the catalysts tested, 10La-CeO2 demonstrated the highest COS removal rate. This is because La doping significantly augmented Ov, providing more H2O adsorption and activation sites. Furthermore, 10La-CeO2 showed enhanced Lewis basicity, making it easier for COS to adsorb and promote hydrolysis. The in situ DRIFTS results confirmed that appropriate oxygen vacancies and basic sites favored the formation of intermediates such as HCO3 - and HSCO2 -, promoting the decomposition of COS into H2S and CO2.

Modulating composition and electronic structure enhance the catalytic performance of Co2MO4 (M=Fe, Ni, Cu) for NaBH4 hydrolysis

The synergistic effect between metals is of great significance for improving the performance of materials, but the mechanism of synergistic catalytic of bimetallic has rarely been reported in the hydrolysis of sodium borohydride (NaBH4, SB). In this paper, a flower shaped Co2FeO4 catalyst with high catalytic performance was selected from a series of CoxM3-xO4 (M = Fe, Ni, Cu) catalysts by controlling the composition. Based on the results of XPS characterization and density functional theory (DFT) calculation, the influence of component control on catalytic performance was discussed and explained from the perspective of electronic structure, and the "valence band center" and "D-band center" descriptors were introduced into the SB hydrolysis reaction. The simulation analysis results showed that the synergistic effect between Co–Fe elements resulted in the smallest center shift of the D band, the smallest binding energy of the hydrolysis reaction, and the best promoting effect on the electronic structure, manifested as the best catalytic performance. The calculation results were consistent with the XPS characterization results and the experimental results of hydrolysis performance testing, revealing the principle of bimetallic synergistic effect on catalytic performance.

Oxygen vacancies-promoted removal of COS via catalytic hydrolysis over CuTiO2-δ nanoflowers

Catalytic hydrolysis was considered as an efficient technology to remove carbonyl sulfide (COS). The introduction of oxygen vacancy (Ov) is a promising strategy to improve the catalytic performance of COS hydrolysis by promoting the adsorption and activation of reactants. Herein, we reported a Cu-doped TiO2 nanoflower with abundant oxygen vacancies for COS hydrolysis. The Cu species successfully entered the crystal lattice of TiO2 and induced more oxygen vacancies than pure TiO2. The Ov sites can effectively reduce the adsorption and activation energy of COS and H2O. Benefiting from the ample Ov sites, the resulting CuTiO2-δ-F achieved nearly 100 % COS conversion at 70 °C and 93.5 % H2S yield at 130 °C, which is better than that of pure TiO2. Furthermore, in situ FT-IR measurements and density functional theory (DFT) calculations were performed to reveal the reaction pathway in COS hydrolysis.

Sustainable wheat straw pretreatment process by self-produced and cyclical crude lactic acid

The purpose of this study was to investigate an environmentally friendly and recyclable pretreatment approach that would enhance the enzymatic digestibility of wheat straw. Wheat straw was pretreated using self-produced crude lactic acid obtained from enzymatic hydrolysate fermentation by Bacillus coagulans. Experimentally, crude lactic acid at low concentration could achieve a pretreatment effect comparable to that of commercial lactic acid. After pretreatment at 180 °C for 60 min with 2.0 % crude lactic acid, hemicellulose could be effectively separated and high recovery of cellulose was ensured, achieving cellulose recovery rate of 95.5 % and hemicellulose removal rate of 92.7 %. Excellent enzymatic hydrolysis was accomplished with a glucose yield of 99.7 %. Moreover, the crude lactic acid demonstrated acceptable pretreatment and enzymatic hydrolysis performance even after three repeated cycles. This not only effectively utilizes the pretreatment solution, but also offers insights into biomass pretreatment using other fermentable acids.

High activity retention Al–Bi–Zn-base composite powder with mild hydrogen generation

Al–10Bi–7Zn and Al–10Bi–7Zn–1.5X (X: Cu, Fe, Ni, in wt.%) composite powders were designed and prepared through phase diagram calculation and gas atomization method. The effects of Cu, Fe, and Ni on the hydrolysis of Al–Bi–Zn-base composite powders for hydrogen production were investigated respectively. The composition and morphology of powders were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM) with energy disperse spectroscopy (EDS) analyses. Hydrolysis performance test results indicate that the additions of Cu, Fe, or Ni can modify the hydrogen production rate and enhance oxidation resistance in Al–10Bi–7Zn ternary alloy composite powder. In the quaternary composite powder system, Al–10Bi–7Zn–1.5Ni (wt.%) exhibits the best performance with the hydrogen generation yield of 75.3% (954.1 mL/g) within 500 min when reacting with distilled water at 60 °C and maintains a hydrogen yield of 57.9% (733.7 mL/g) within 1500 min after being stored (30 °C, relative humidity of 60%) for 7 d. In addition, the mechanism investigation suggested that the additions of Cu, Fe, or Ni in Al–Bi–Zn-base composite powders can stabilize the Al matrix to retain the high activity of powders resulting from inhibiting the cracking of composite powders in the air.

Hydrogen generation by hydrolysis of Sc–Sn alloy over a wide temperature range as low as 0 °C

A series of Sc–Sn alloys are prepared by the arc-melting method and their hydrogen generation performance of hydrolysis in pure water is investigated. It was found that only Sc element reacts with water in Sc–Sn alloy, while Sn element is retained as an elemental metal. The reaction temperature of Sc with water can be reduced below 0 °C after Sc and Sn are alloyed. The Sc3Sn2 alloy has the best hydrogen generation performance. Its hydrogen conversion rate is up to 90% at 0 °C for 100 min as well as when the water temperature dropped from 60 °C to 0 °C, the average conversion rate in the first 30 min only dropped from 19.95 mL/min∙g to 14.31 mL/min∙g. The hydrogen generation performance of Sc–Sn alloys depends on the reaction activity after Sc and Sn alloying, the effect of micro galvanic cells and the solidification microstructure in the alloy ingot.

Life cycle assessment of bioproducts from bamboo residues with biphasic phenoxyethanol-acid based biorefinery technology

Utilizing bamboo residues to produce decarbonization energy products or materials diverts wastes from low-value treatment and supports the circular bioeconomy at the same time. This study develops a cradle-to-grave life-cycle assessment (LCA) for a biorefinery converting bamboo residues into bioproducts (ethanol, polylactic acid (PLA), and bio-based wood adhesive) in China. To combat the low enzymatic hydrolysis performance of bamboo residues and valorize the lignin, this study adopts a biphasic pretreatment by coupling phenoxyethanol and sulfuric acid solution (1%) to achieve high fermentable sugar production. The LCA study is coupled with a process simulation for an industrial-scale biorefinery based on the experimental data. Our results show that the life-cycle Global Warming Potential (GWP) is 17.0–32.1 gCO2e/MJ for ethanol cases and 3.2–3.7 kgCO2e/kg for PLA cases, when biphasic pretreatment is adopted. The lower GWP values are achieved by using 1:1 phenoxyethanol: acid solution, though it has a lower product yield than 4:1 phenoxyethanol: acid solution cases. Without biphasic pretreatment, the GWP is 135.8 gCO2e/MJ ethanol and 4.4 kgCO2e/kg PLA. For the perspective of treating 1 dry t bamboo residues, with biphasic pretreatment, the GWP is −174 to −66 kgCO2e for ethanol cases and −542 to −432 kgCO2e for PLA cases. The lower GWP is also from using 1:1 phenoxyethanol: acid solution (1%). These GWP ranges are lower than conventional landfilling (2969 kgCO2e) and landfilling with landfill gas recovery (−28 kgCO2e).

Metal-organic skeleton derived RuCoMoCuOx/C porous nanosheet as an efficient dual-function electrocatalyst for superior water decomposition

Polymetallic composites can significantly affect the structure and active sites of materials. In this study, we prepared polymetallic organic structures using a metal-organic framework (MOF) synthesis strategy and a hydrothermal method. We controlled and adjusted the ratio of metals to create precursors, which were then calcined to produce targeted polymetallic oxides. The polymetallic oxides prepared (RuCoMoCuOx/C) demonstrated excellent properties for both HER and OER in 1.0 M KOH, with an overpotential of 136 mV @ 10 mA cm−2 for HER and 296 mV @ 10 mA cm−2 for OER. The efficient catalytic performance of dual hydrolysis is attributed to the lamellar porous structure of RuCoMoCuOx/C and the synergistic effect of each metal element in the polymetallic catalyst. DFT theoretical calculations show that when H2O molecules adsorb around Ru, Co, and Mo sites, OH* adsorbs at electron-deficient centers, while H+ is more readily adsorbed by electron-rich Cu sites. This unique configuration is more conducive to water dissociation.

Facilitating effects of the synergy with zero-valent iron and peroxysulfate on the sludge anaerobic fermentation system: Combined biological enzyme, microbial community and fermentation mechanism assessment

This study evaluated a synergetic waste activated sludge treatment strategy with environmentally friendly zero-valent iron nanoparticles (Fe0) and peroxysulfate. To verify the feasibility of the synergistic treatment, Fe0, peroxysulfate, and the mixture of peroxysulfate and Fe0 (synergy treatment) were added to different sludge fermentation systems. The study demonstrated that the synergy treatment fermentation system displayed remarkable hydrolysis performance with 435.50 mg COD/L of protein and 197.67 mg COD/L of polysaccharide, which increased 1.13–2.85 times (protein) and 1.12–1.49 times (polysaccharide) for other three fermentation system. Additionally, the synergy treatment fermentation system (754.52 mg COD/L) exhibited a well acidification performance which was 1.35–41.73 times for other systems (18.08–557.27 mg COD/L). The synergy treatment fermentation system had a facilitating effect on the activity of protease, dehydrogenase, and alkaline phosphatase, which guaranteed the transformation of organic matter. Results also indicated that Comamonas, Soehngenia, Pseudomonas, and Fusibacter were enriched in synergy treatment, which was beneficial to produce SCFAs. The activation of Fe0 on peroxysulfate promoting electron transfer, improving the active groups, and increasing the enrichment of functional microorganisms showed the advanced nature of synergy treatment. These results proved the feasibility of synergy treatment with Fe0 and peroxysulfate to enhance waste activated sludge anaerobic fermentation.

Investigation of hydrolysis properties of MgH2 in different anionic/cationic salt solutions

MgH2 is a promising metal hydride for high-density hydrogen storage, offering advantages such as operational safety, high hydrogen yield, and cost-effectiveness in hydrolysis-based hydrogen generation. However, challenges persist in this field, including reaction interruption caused by the formation of passivating layers and sluggish kinetics. In this study, MgH2 hydrolysis experiments were conducted, utilizing various solutions including 1 M AlCl3, Al2(SO4)3, Al(NO3)3, NiCl2, NiSO4, Ni(NO3)2, FeCl3, Fe2(SO4)3, and Fe(NO3)3 at different temperatures. The resulting hydrolysis products were analyzed using X-ray diffraction and scanning electron microscopy to examine their phases and morphology. Through comprehensive analysis of the hydrolysis mechanism and kinetics, chloride ion solutions were identified as highly efficient, demonstrating excellent rates and yields. Notably, AlCl3, NiCl2, and FeCl3 outperformed other solutions, exhibiting kinetic performance with hydrolysis activation energies of 17.3 ± 1.7, 24.2 ± 1.3, and 14.7 ± 1.7 kJ/mol, respectively. Furthermore, we extended our investigation to compare the hydrolysis effects of different cations, incorporating MnCl2, CoCl2, and CuCl2. Mechanistic analysis pinpointed Al3+ and Fe3+ as catalysts with exceptional hydrolysis performance and remarkable kinetic properties. The aforementioned remarkable MgH2 hydrolysis properties are of significant interest for investigating the corresponding Mg-based alloy hydrides, which are worthwhile to consider.

Assessing Hydrolysis Performance of Ce(OH)4@PIM-1 Composites Functionalized with Amidoxime, Aldoxime, and Carboxylate Groups Toward Dimethyl 4-Nitrophenylphosphonate, a Nerve Agent Simulant

Assessing Hydrolysis Performance of Ce(OH)₄@PIM-1 Composites Functionalized with Amidoxime, Aldoxime, and Carboxylate Groups Toward Dimethyl 4-Nitrophenylphosphonate, a Nerve Agent Simulant

Performance boosting by induction heating for hydrolysis of carbonyl sulfide using magnetic ordered mesoporous alumina as catalyst

Hydrolysis of carbonyl sulfide (COS) has been recognized as an efficient way for COS removal, however, searching for an effective way of minimizing the catalyst deactivation is always the most important task to realize its industrial application. In this study, a high-performance alkali-free catalyst of magnetic ordered mesoporous Al2O3 has been synthesized for the COS hydrolysis. At the same time, induction heating has been introduced as a novel heating method to boost the performance of the catalyst. Results show that the inducting heating can boost the performance of COS hydrolysis, as well as minimize the catalyst deactivation compared to the joule heating under the same reaction conditions. The reaction performance under induction heating mode, in terms of COS conversion, is at least 7.0% on average higher than the joule heating mode. This is attributed to precise control of the localized temperature on active sites since the heat is generated directly from the catalyst under induction heating mode. While in the joule heating mode, the heat should be transferred to the catalyst from environments, which induces a huge temperature gradient. This study implies that induction heating can be used as a unique way of minimizing the side reactions over the gas-solid heterogeneous catalytic processes and boosting the catalyst performance.

Hydrolysis behavior and mechanistic insights of CaMg2InX (X = 0.1, 0.3, 0.5, 0.7) ternary alloy for sustainable hydrogen production

The hydrolysis behavior of CaMg2In0.1, CaMg2In0.3, CaMg2In0.5, and CaMg2In0.7 ternary alloys in an MgCl2 solution following casting and hydrogenation were investigated. The hydrolysis mechanism of these alloys is elucidated through an analysis of microstructure, phase composition, and kinetics before and after hydrolysis. The nucleation-growth Avrami model is employed to accurately model the hydrolysis kinetics, revealing improved hydrolysis yields and reaction rates following hydrogenation. Notably, CaMg2In0.1 has demonstrated exceptional hydrolysis characteristics, exhibiting a yield of 1140 mL/g, an initial hydrolysis rate of 113 mL/g·s, and an activation energy of 24.3 ± 1.7 kJ·mol−1. The yield of H-CaMg2In0.1 further escalates to 1800 mL/g with a rate of 221 mL/g·s, attributed to the formation of Ca4Mg3H14 and In phases subsequent to the hydrogenation of In2Ca and Mg3In phases in the alloy. These newly formed phases act as catalysts and actively participate in the hydrolysis process, providing active sites for hydrogen production, thus enhancing hydrolysis yields and kinetics. It is observed that with increasing In content, the order of hydrolysis performance of the alloy is as follows: CaMg2In0.1 > CaMg2In0.3 > CaMg2In0.5 > CaMg2In0.7, consistent with the trend after hydrogenation. These findings indicate that the addition of In significantly enhances the hydrolysis performance of CaMg2 alloys, offering a promising strategy for preparing magnesium-based alloys with high yields and favorable kinetic properties.

MgH2@Mg(BH4)2 Core-Shell-like Nanostructures: Synthesis, Hydrolysis Performance, and Promotion Mechanism.

The hydrolysis of hydrides, represented by MgH2, delivers substantial capacity and presents an appealing prospect for an on-site hydrogen supply. However, the sluggish hydrolysis kinetics and low hydrogen yield of MgH2 caused by the formation of a passivation Mg(OH)2 layer hinder its practical application. Herein, we present a dual strategy encompassing microstructural design and compounding, leading to the successful synthesis of a core-shell-like nanostructured MgH2@Mg(BH4)2 composite, which demonstrates excellent hydrolysis performance. Specifically, the optimal composite with a low Ea of 9.05 kJ mol-1 releases 2027.7 mL g-1 H2 in 60 min, and its hydrolysis rate escalates to 1356.7 mL g-1 min-1 H2 during the first minute at room temperature. The nanocoating Mg(BH4)2 plays a key role in enhancing the hydrolysis kinetics through the release of heat and the formation of local concentration of Mg2+ field after its hydrolysis. This work offers an innovative concept for the design of hydrolysis materials.

Superior hydrogen production rate by corrosion of recycled aluminum alloys: Feeding a PEM fuel cell

Aluminum is one of the most versatile materials for the dynamic global economy due to its mechanical properties, recyclability, and lightweight. The production of hydrogen from aluminum via hydrolysis in alkaline media offers another advantage of it. Recycling the post-consumer aluminum scraps leads to the formation of some undesirable intermetallic particles which are not only detrimental to mechanical properties but also to repeated recycling. In this study, the hydrolysis performance of a recycled aluminum alloy was compared with that of the primarily produced one. The results showed that the Mg solutes at the grain boundaries (GBs), Fe-containing and Mg2Si particles, stress concentration around the GBs, and thickness of the passive layer can affect the hydrogen generation rate of the specimens. The specimens were also tested in a proton-exchange membrane fuel cell to evaluate their hydrogen generation performance. The recycled aluminum alloy that can increase the hydrogen yield significantly increases the power of PEMFC.

Preparation of ZrO2/γ-Al2O3 albumen type catalyst and its catalytic performance for carbonyl sulfide hydrolysis

Preparation of ZrO2/γ-Al2O3 albumen type catalyst and its catalytic performance for carbonyl sulfide hydrolysis

Nanorod Al2O3 catalysts for simultaneous hydrolytic removal of COS and CS2 via crystal surface modulation: Experimental and theoretical studies

The undesirable stability and vulnerability to poisoning of catalysts have posed a great obstacle to the development of organosulfur hydrolysis technology. In this paper, H-K0.1Al2O3 nanorod catalysts with exposed Al2O3(111) crystal plane were prepared by hydrothermal synthesis. The results indicated that the COS and CS2 hydrolysis activity at low temperatures of the H-K0.1Al2O3 catalyst was significantly higher than that of K0.1Al2O3. In the presence of 0.01 vol% HCl, there was no decrease in the COS conversion of H-K0.1Al2O3 after 12 h of reaction. The CS2 conversion was stable at about 65 %. Characterization results revealed that the improved hydrolysis performance was mainly related to enhanced surface alkalinity and more oxygen vacancies, which strengthened the adsorption capacity of the reactive molecules. The results of DFT calculations proved the stronger adsorption ability of the Al2O3(111) plane than the Al2O3(110) plane. The suppressed HCl adsorption contributed to the enhanced resistance to chlorine poisoning. Reaction path calculations demonstrated that the H2O molecules on the Al2O3 (111) dissociated more rapidly to produce –OH, and the intermediates -CS2OH and -HSCO were more easily generated with lower reaction energy barriers.

Secretory production and characterization of a highly effective chitosanase from Streptomyces coelicolor A3(2) M145 in Pichia pastoris.

In this study, a glycoside hydrolase family 46 chitosanase from Streptomyces coelicolor A3(2) M145 was firstly cloned and expressed in Pichia pastoris GS115 (P. pastoris GS115). The recombinant enzyme (CsnA) showed maximal activity at pH 6.0 and 65°C. Both thermal stability and pH stability of CsnA expressed in P. pastoris GS115 were significantly increased compared with homologous expression in Streptomyces coelicolor A3(2). A stable chitosanase activity of 725.7±9.58 U mL-1 was obtained in fed-batch fermentation. It's the highest level of CsnA from Streptomyces coelicolor expressed in P. pastoris so far. The hydrolytic process of CsnA showed a time-dependent manner. Chitosan oligosaccharides (COSs) generated by CsnA showed antifungal activity against Fusarium oxysporum sp. cucumerinum (F. oxysporum sp. cucumerinum). The secreted expression and hydrolytic performance make the enzyme a desirable biocatalyst for industrial controllable production of chitooligosaccharides with specific degree of polymerization, which have potential to control fungi that cause important crop diseases.