Simultaneous Hydrolysis Research Articles

Tailorable cellulose II nanocrystals (CNC II) prepared in mildly acidic lithium bromide trihydrate (MALBTH)

Cellulose II nanocrystals were prepared from bleached kraft pulpviasimultaneous hydrolysis of disordered cellulose and polymorph transformation in mildly acidic lithium bromide trihydrate followed by ammonium persulfate oxidation.

Photoinduced Reorientation and Photofunctional Control of Liquid Crystalline Copolymers with in Situ-Formed N-Benzylideneaniline Derivative Side Groups.

The influence of the annealing conditions on the thermally stimulated photoinduced molecular reorientation of a photoinactive liquid crystalline polymethacrylate with phenyl aldehyde and benzoic acid side groups (P1) doped with 4-methoxyaniline, which forms photoalignable 4-methoxy-N-benzylideneaniline (MNBA) side groups in situ, was investigated. Light exposure and subsequent thermal stimulation under a N2 atmosphere realized sufficient cooperative molecular reorientation (D > 0.7), but the simultaneous thermal hydrolysis of the MNBA groups under humid air lowered the molecular reorientation performance. By contrast, subsequent thermal hydrolysis of MNBA after molecular reorientation introduced different aromatic amines into the reoriented P1 film, which regulated the birefringence and photofunctionality of the oriented film.

Simultaneous catalytic hydrolysis of HCN, COS and CS2 over metal-modified microwave coal-based activated carbon

In this work, a series of metal oxides modified microwave coal-based activated carbon (MCAC) catalysts were prepared for simultaneously catalytic hydrolysis of hydrogen cyanide (HCN), carbonyl sulfide (COS) and carbon disulfide (CS2). The influences of metal species, precursor, metal oxides amount and calcination temperature were investigated. The interaction between Al2O3 and MCAC improved the dispersion of Al and enhanced the removal efficiency of catalyst. Al2O3 was the main active component and it provided the adsorption and hydrolysis abilities. The alkaline and strong oxidation sites were responsible for removing HCN, COS and CS2. Meanwhile, the adsorbed water was beneficial to the catalytic hydrolysis reactions. Al2O3 was attributed to the decomposition of aluminum salt. Under excessive high calcination temperature, Al2O3 reacted with surface functional groups. The formation of Al2(SO4)3 and Al(NO3)3 resulted in the deactivation of catalyst.

Synthesis of silicon oxycarbonitride nanosphere as cathode host for lithium–sulfur batteries

Silicon oxycarbonitride (SiOCN) composites with different carbon contents were synthesized by pyrolysis of precursors generated from aldimine condensation of 3-aminopropyltriethoxysilane (APTES) with different aldehydes and simultaneous hydrolysis of APTES. Both SiOCN-1 and SiOCN-5 composites, derived from formaldehyde and glutaraldehyde respectively, display similar bulky structure composed by aggregated nanospheres with a diameter of 70–100 nm. SiOCN-5 has a higher carbon content of 30.4% than 15.9% for SiOCN-1, while a lower specific surface area of 38.2 m2 g−1 than 76.0 m2 g−1 for SiOCN-1. SiOCN/S cathodes with sulfur loading of 1.2–1.5 mg cm−2 were fabricated using SiOCN as sulfur host on different current collector of aluminum foil (AL) or carbon paper (CP). When using aluminum foil as current collector, SiOCN-5/S-AL cathode exhibits better electrochemical performance than SiOCN-1/S-AL, primarily due to the higher electrical conductivity of SiOCN-5 comparing with SiOCN-1. When using porous carbon paper as current collector, SiOCN-5/S-CP cathode shows the best cycling performance with a discharge capacity of 648.9 mA h g−1 at 0.2C after 100 cycles. Even at a high rate of 1C, SiOCN-5/S-CP also exhibits an excellent cycling stability, delivering a reversible discharge capacity of 374.5 mA h g−1 after 500 cycles with a capacity retention of 73.0%.

Stable high thermal conductivities in BaTiO3 ceramic composites utilizing core-shell Ag@BaTiO3 particles

Ceramic/metal composites have drawn much attention in heat dissipations due to excellent performances, however, issues rise with the uncontrollable architecture and unstable properties resulting from metal-particle fusions at the high-temperature sintering. This study reports a BaTiO3 (BT) composite at a high Ag loading of 60 vol% with a stable composite architecture achieved by utilizing core-shell Ag@BT particles. Conformal-coated Ag@BT particles are prepared by simultaneous hydrolysis. The BT shell is vital in keeping Ag particles separately distributed and the shape well-retained in the BT matrix before and after the sintering to exhibit controllable structures. A high thermal conductivity of 84 W/mK is obtained in the composite at 25 °C, 35-fold enhanced compared with that of the BT ceramic of 2.4 W/mK. Low thermal barrier resistances as well as the nonpercolative behavior attributing to high thermal conductivities are owing to the unique composite architecture. The composite exhibits small fractures at Ag-BT interfaces while no macro fractures across the material are observed after the thermal cycling test. This study presents a BT/Ag@BT composite for various heat dissipation applications.

Expression and functional identification of two homologous nicotine dehydrogenases, NicA2 and Nox, from Pseudomonas sp. JY-Q

Nicotine contamination in tobacco waste effluent (TWE) from tobacco industry is a serious threat to public health and environment. Microbial degradation is an impending approach to remove nicotine and transform it into some other high value chemicals. Pseudomonas sp. JY-Q exhibits high efficiency of degradation, which can degrade 5 g/L of nicotine within 24 h. In strain JY-Q, we found the co-occurrence of two homologous key enzymes NicA2 and Nox, which catalyze nicotine to N-methylmyosmine, and then to pseudooxylnicotine via simultaneous hydrolysis. In this study, recombinant NicA2 and Nox were expressed in E. coli BL21(DE3) and purified. In vitro, the activity of recombinant NicA2 and Nox was accelerated by adding co-factor NAD+, suggesting that they worked as dehydrogenases. The optimal reaction conditions, substrate affinity, catabolism efficiency, pH-stability and thermal-stability were determined. Nox showed lower efficiency, but at a higher stability level than NicA2. Nox exhibited wider pH range and higher temperature as optimal conditions for the enzymatic reaction. In addition, The Nox showed higher thermo-stability and acid-stability than that of NicA2. The study on enzymatic reaction kinetics showed that Nox had a lower Km and higher substrate affinity than NicA2. These results suggest that Nox plays more significant role than NicA2 in nicotine degradation in TWE, which usually is processed at low pH (4–5) and high temperature (above 40 °C). Genetic engineering is required to enhance the affinity and suitability of NicA2 for an increased additive effect on homologous NicA2 and Nox in strain JY-Q.

Application of Jerusalem artichoke and lipid-extracted algae hydrolysate for docosahexaenoic acid production by Aurantiochytrium sp. KRS101

Microalgae-derived docosahexaenoic acid (DHA) production has been considered an alternative technology to overcome several disadvantages of fish oil-based DHA production. Despite its potential, efficient production methods for DHA have been rarely reported. Accordingly, in this study we investigated the potential application of Jerusalem artichoke and lipid-extracted algae (LEA) hydrolysates as inexpensive sources of carbon and other nutrients for DHA production using Aurantiochytrium sp. KRS101. Response surface methodology (RSM) with central composite design (CCD) was used to determine the maximum point of DHA productivity in the presence of 51.9 g L−1 fructose and 4.9 g L−1 yeast extract. Hydrolysis of 76.6 g L−1 Jerusalem artichoke powder with 0.25 N sulfuric acid at 70 °C yielded the desired concentration of fructose for use as the medium. Cultivation of the microalgae using the Jerusalem artichoke hydrolysate (JAH) and JAH + LEA (JLH-1) resulted in 27.8% and 31.3% improvements in biomass productivity, respectively, compared with the basal medium control. In addition, simultaneous one-step hydrolysis of Jerusalem artichoke and LEA (JLH-2) resulted in 7.2% higher biomass and 47% higher DHA yields than that obtained from hydrolyzing the two components separately (JLH-1). These results suggested that a strategy using JAH combined with LEA could replace expensive nutrient sources and produce efficient and eco-friendly DHA from Aurantiochytrium sp. KRS101.

Simultaneous hydrolysis and fermentation of defatted rice bran and defatted soybean meal for nisin production with engineered Lactococcus lactis

This work aimed to study the potential of defatted rice bran (DRB) and defatted soybean meal (DSM) as carbon and nitrogen sources for Lactococcus lactis growth and nisin production. First, a maximum nisin yield of 3630 IU/mL was achieved using 40% DRB hydrolysates and 30% DSM hydrolysates, which was 1.13 times greater than that found in commercial media. Second, to simplify the operation and shorten the length of the entire process, the processes of combined hydrolysis of DRB-DSM followed by fermentation, and simultaneous hydrolysis and fermentation of DRB-DSM were developed. Neutral proteinase enhanced the saccharification of DRB by cellulase and α-amylase. Furthermore, the strategy of NADH oxidase expression and hemin addition was innovatively proposed to overcome the oxygen stress in a simultaneous hydrolysis and fermentation process, which could alleviate the lag period following inoculation of L. lactis and result in a 77.3% increase in nisin titer.

Improvement and Metabolomics-Based Analysis of d-Lactic Acid Production from Agro-Industrial Wastes by Lactobacillus delbrueckii Submitted to Adaptive Laboratory Evolution.

To decrease d-lactic acid production cost, sugarcane molasses and soybean meal, low-cost agro-industrial wastes, were selected as feedstock. First, sugarcane molasses was used directly by Lactobacillus delbrueckii S-NL31, and the nutrients were released from soybean meal by protease hydrolysis. Subsequently, to ensure intensive substrate utilization and enhanced d-lactic acid production from sugarcane molasses and soybean meal, adaptation of L. delbrueckii S-NL31 to substrates was performed through adaptive laboratory evolution. After two-phase adaptive laboratory evolution, the evolved strain L. delbrueckii S-NL31-CM3-SBM with improved cell growth and d-lactic acid production on sugarcane molasses and soybean meal was obtained. To decipher the potential reasons for improved fermentation performance, a metabolomics-based approach was developed to profile the differences of intracellular metabolism between initial and evolved strain. The in-depth analysis elucidated how the key factors exerted influence on d-lactic acid biosynthesis. The results revealed that the enhancement of glycolysis pathway and cofactor supply was directly associated with increased lactic acid production, and the reinforcement of pentose phosphate pathway, amino acid metabolism, and oleic acid uptake improved cell survival and growth. These might be the main reasons for significantly improved d-lactic acid production by adaptive laboratory evolution. Finally, fed-batch simultaneous enzymatic hydrolysis of soybean meal and fermentation process by evolved strain resulted in d-lactic acid levels of 112.3 g/L, with an average production efficiency of 2.4 g/(L × h), a yield of 0.98 g/g sugar, and optical purity of 99.6%. The results show the applicability of d-lactic acid production in L. delbrueckii fed on agro-industrial wastes through adaptive laboratory evolution.

Synergistic effect of Fe2O3 and CuO on simultaneous catalytic hydrolysis of COS and CS2: Experimental and theoretical studies

In this work, experimental and theoretical methods were used to investigate the synergistic effect of Fe2O3 and CuO on simultaneous catalytic hydrolysis of COS and CS2. Experimental results indicated that Fe2O3 mainly focused on the removal of CS2, and CuO mainly focused on the removal of COS. Meanwhile, Fe2O3 and CuO had the synergistic effect on simultaneous removal of COS and CS2. Theoretical results indicated that the adsorption priority order over Fe2O3(0 0 1)/CuO(1 1 0) was H2O > CS2 > COS. Furthermore, H2O was easy to migrate onto the surface of CuO(1 1 0), and CS2 was easy to migrate onto the surface of Fe2O3(1 1 0). Meanwhile, COS was preferentially adsorbed on Fe2O3(0 0 1). Fe2O3(0 0 1) and CuO(1 1 0) surfaces were beneficial for the adsorption of –OH groups. Fe2O3(0 0 1) enhanced the first step hydrolysis of CS2. CuO(1 1 0) enhanced the COS hydrolysis. The synergistic effect of Fe2O3 and CuO was attributed to the different hydrolysis priority of COS and CS2. Firstly, CS2 was adsorbed on Fe2O3 surface and the first step hydrolysis of CS2 occurred. Then, the hydrolysis product COS migrated from Fe2O3 to CuO and the COS hydrolysis occurred. The theoretical results were consistent with the experimental results.

Simultaneous amylase production, raw cassava starch hydrolysis and ethanol production by immobilized Aspergillus awamori and Saccharomyces cerevisiae in a novel alternating liquid phase–air phase system

As a solution to the problems of mass transfer limitation in submerged cultures and scale up of solid-state/liquid-surface cultures, an alternating liquid phase–air phase bioreactor was developed. It consisted of a bioreactor equipped with a siphon system and a reservoir. Aspergillus awamori was immobilized in loofa sponge inside the bioreactor and culture broth was pumped from the reservoir into the bioreactor. Each time the culture broth level reached a critical level, the broth automatically siphoned back into the reservoir. Thus the immobilized cells were alternatingly submerged and exposed to air. The duration of each phase was controlled by the pumping rate and with an on-off timer. During amylase production from soluble starch and raw cassava starch, the optima ratios of the liquid to air phases were 12 h : 12 h and 3 h : 6 h respectively. Saccharomyces cerevisiae IR2 was immobilized in the reservoir and the system was used for simultaneous amylase production, hydrolysis and ethanol production from raw cassava starch. The process was very stable for more than 7 batches with high ethanol yield of 0.46 g-ethanol/g-starch and productivity of 1.73 g-ethanol/L/h. These values are high, the system can be scaled up, and thus it has many potential applications.

New plant to produce sustainable chemicals from pulp and paper industry residues

Alkaline pulping using sodium hydroxide (NaOH), also known as soda pulping, is predominantly used to extract cellulose for pulp and papermaking. The NaOH was responsible for the dissolution and removal of lignin but unfortunately, simultaneous hydrolysis of cellulose could not be avoided. Modification for improved lignin removal and cellulose stabilization are always a technical challenge for the pulp and paper industry. Therefore, ethylenediaminetetraacetic acid (EDTA) was considered as an additive to minimize cellulose hydrolysis and thus improve the total yield of cellulose pulp. Response surface methodology (RSM) with central composite design (CCD) was employed for statistical modeling and optimization of NaOH and EDTA charges for maximum pulp yield, lignin removal, and cellulose content. Analysis of variance (ANOVA) revealed a significant interaction effect of NaOH and EDTA charges on pulp yield and its cellulose content. Using the predicted optimum condition of 17.7% NaOH and 10% EDTA, pulping of banana stem at 100 ± 5 °C for 30 min resulted in increasing pulp yield, lignin removal, and cellulose content by approximately 18.5%, 1.1%, and 0.6%, respectively, as compared to pulping without EDTA. Changes in the functional groups monitored using Fourier transform infrared (FTIR) revealed the presence of ester and C–N stretching bands from cellulose extracted with NaOH/EDTA due to successful esterification of EDTA on the cellulose pulp. Further analysis on the viscosity average degree of polymerization found that the cellulose pulp extracted with NaOH/EDTA also has a higher degree of polymerization compared to the pulp extracted without EDTA. Based on these findings, it was concluded that esterification with EDTA has successfully protected the cellulose against alkaline hydrolysis by NaOH. Therefore, the addition of EDTA is a promising approach to improve the pulp yield with high degree of polymerization.

Surface characterization of metal oxides-supported activated carbon fiber catalysts for simultaneous catalytic hydrolysis of carbonyl sulfide and carbon disulfide

The sol–gel method was used to synthesize a series of metal oxides-supported activated carbon fiber (ACF) and the simultaneous catalytic hydrolysis activity of carbonyl sulfide (COS) and carbon disulfide (CS2) at relatively low temperatures of 60°C was tested. The effects of preparation conditions on the catalyst properties were investigated, including the kinds and amount of metal oxides and calcination temperatures. The activity tests indicated that catalysts with 5 wt.% Ni after calcining at 400°C (Ni(5)/ACF(400)) had the best performance for the simultaneous catalytic hydrolysis of COS and CS2. The surface and structure properties of prepared ACF were characterized by scanning electron microscope-energy disperse spectroscopy (SEM-EDS), Brunauer–Emmett–Teller (BET), X-ray diffraction (XRD), carbon dioxide-temperature programmed desorption (CO2-TPD) and diffuse reflectance Fourier transform infrared reflection (DRFTIR). And the metal cation defects were researched by electron paramagnetic resonance (EPR) method. The characterization results showed that the supporting of Ni on the ACF made the ACF catalyst show alkaline and increased the specific surface area and the number of micropores, then improved catalytic hydrolysis activity. The DRFTIR results revealed that -OH species could facilitate the hydrolysis of COS and CS2; -COO and -C–O species could facilitate the oxidation of catalytic hydrolysate H2S. And the EPR results showed that high calcination temperature conditions provide more active reaction center for the COS and CS2 adsorption.

REE(III) recovery from spent NiMH batteries as REE double sulfates and their simultaneous hydrolysis and wet-oxidation

Efficient recovery of REEs present in the battery waste is a modern problem that has proven to be difficult to solve in an efficient manner. The raw material investigated in the current study is mixed alkaline rare earth element (REE) double sulfate (DS) precipitate, originating from the sulfuric acid leachate of nickel-metal hydride battery (NiMH) waste. Typically, REE can be precipitated as a mixture of REE double sulfates, however the real challenge is the separation of REEs from each other’s into pure fraction. The study elucidates the process by which the DS are transformed into hydroxides with simultaneous in-situ conversion of Ce(III) to Ce(IV) by air. Air flow rate (0–1 L/h), temperature (30–60 °C), liquid-solid ratio (L/S, 12.5–100 g/L), 3REE/NaOH mol ratio (1–1.6) and time (60–240 min) were varied in the study of oxidation and double sulfate conversion. Best oxidation achieved was 93% along near-complete dissociation of double sulfate matrix (52767 ppm Na reduced to 48 ppm Na). After parameter optimization, a larger batch was produced to conduct selective dissolution of REE(III) into HNO3 media, leaving concentrated impure Ce(OH)4 as the end product.

Facile approach for Z-scheme type Pt/g-C3N4/SrTiO3 heterojunction semiconductor synthesis via low-temperature process for simultaneous dyes degradation and hydrogen production

The platinum/graphite-like carbon nitride/strontium titanate (Pt/g-C3N4/SrTiO3) heterojunction semiconductor was synthesized using a facile approach for simultaneous photocatalytic dye degradation and hydrolysis of hydrogen production from simulated dyeing wastewater. Using SrTiO3, trace Pt, and the addition of an appropriate amount of electron donors, it can effectively absorb sunlight and achieve 93% dye degradation and 471 μmol h−1 g−1 hydrogen yield. The analysis result indicates that the semiconductor is a Z-scheme type composite. It was also showed that the addition of electron donors effectively promoted the degradation rate, whereas the addition of Pt changed the photocatalytic reaction pathway, which resulted in a reduced degradation rate and a significant improvement of hydrogen evolution. A reaction mechanism for this phenomenon is also proposed.

Fluorescence quenching based detection of p-nitrophenol using luminescent silicon nanocrystals and insights into the quenching mechanism

We demonstrate a simple, rapid, selective and sensitive method for the detection of p-nitrophenol (pNP) using luminescent colloidal silicon nanocrystals (Si NCs). Aqueous suspension of green luminescent Si NCs was prepared at room temperature by simultaneous hydrolysis and redox reaction of (3-aminopropyl)triethoxysilane (APTES) in a remarkably simple one-step method. Trace addition of pNP significantly quenched the luminescence of the Si NCs and the quenching was found to be linearly dependent on the pNP concentration in the range of 0–20 μM of pNP in solution. Beyond 20 μM pNP concentration the quenching varied exponentially. Analysis of steady state absorption and emission, along with photoluminescence decay dynamics revealed that formation of ground state complexes (static quenching) and primary inner filter effect played a combined role in affecting quenching at relatively lower concentration range (0–20 μM); whereas both static and dynamic quenching came into effect at concentrations above 20 μM. Finally, we demonstrate a simple, pH-paper-type sensor based on Si NC coated filter paper and aluminium tape, for detection of aqueous as well as airborne pNP.

Xylitol Production from Oil Palm Empty Fruit Bunches (OPEFB) Via Simultaneous Enzymatic Hydrolysis and Fermentation Process

Oil palm empty fruit bunches (OPEFB) are the waste of palm oil processing and lignocellulosic biomass that can be used as raw material for xylitol production. In this research, bioconversion of xylitol using the Simultaneous Saccharification and Fermentation (SSF) process in one reactor with a short time and could save the cost. Pretreatment requires to degrade the lignin compound with thermal pretreatment. Hydrolysis of OPEFB performs enzymatically by commercial xylanase enzyme that is Cellic Htec2 and continued with fermentation by yeast Debaryomyces hansenii. The research used experimental and descriptive analysis that covers of variation of OPEFB substrate concentration (7.5%, 10%, 15%, 20%) on specific growth rate (µ), the yield of xylitol and substrate utilization. The results showed that an increase of OPEFB substrate concentration affected by the increase of specific growth rates (μ) are 0.091/h, 0.094/h, 0.095/h and 0.126/h. It also affected to the decreasing of xylitol yield on 42 hours fermentation are 0.201 g/g; 0.189 g/g; 0.170 g/g; and 0.104 g/g.

From a Cerium-Doped Polynuclear Bismuth Oxido Cluster to β-Bi2O3:Ce.

The simultaneous hydrolysis of Bi(NO3)3·5H2O and Ce(NO3)3·6H2O results in the formation of novel heterometallic bismuth oxido clusters with the general formula [Bi38O45(NO3)24(DMSO)28+δ]:Ce (DMSO = dimethyl sulfoxide; cerium content <1.50%), which is demonstrated by single-crystal X-ray diffraction analysis. The incorporation of cerium into the cluster core is a result of the interplay of hydrolysis and condensation of the metal nitrates in the presence of oxygen. Diffuse-reflectance UV-vis and X-ray photoelectron spectroscopy reveal the presence of CeIV in the final bismuth oxido clusters as a result of oxidation of the cerium source. The cerium atoms are statistically distributed mainly on the bismuth atom positions of the central [Bi6O9] motif of the [Bi38O45] cluster core. Hydrolysis and subsequent annealing of the bismuth oxido clusters in the temperature range of 300-400 °C provides β-Bi2O3:Ce samples with slightly lowered band gaps of approximately 2.3 eV compared to the undoped β-Bi2O3 (approximately 2.4 eV). The sintering behavior of β-Bi2O3 is significantly affected by the cerium dopant. Finally, differences in the efficiency of the as-prepared β-Bi2O3:Ce and undoped β-Bi2O3 samples in the photocatalytic decomposition of the biocide triclosan in an aqueous solution under visible-light irradiation are demonstrated.

Simultaneous hydrolysis of cheese whey and lactulose production catalyzed by β-galactosidase from Kluyveromyces lactis NRRL Y1564.

β-Galactosidase was produced by the yeast Kluyveromyces lactis NRRL Y1564 in cheese whey supplemented with yeast extract under the optimal temperature of 30°C, delivering an enzymatic activity of 4418.37U/gcell after 12h of process. In order to develop more stablebiocatalysts, the enzymeproduced by fermentation was immobilized on 2.0% w/v chitosan activated with glutaraldehyde, epichlorohydrin or glycidol, producing ahighly active and stable biocatalyst capable of hydrolyzing lactose and producing lactulose simultaneously. The biocatalyst obtained by immobilization in chitosan-glutaraldehyde showed high storage stabilities (100% of its activity when stored at 4°C 105days). Regarding the milk lactose hydrolysis by both the soluble and the immobilized enzyme, the conversions obtained were 38.0% and 42.8%, respectively. In this study, by using a biocatalyst deriving from enzyme immobilization to chitosan support, a lactulose production of 17.32g/L was also possible.

Electrophilic addition to the multiple bond of 1-carboxymethyl-5-fluorouracil

1-Carboxymethyl-5-fluoro-5-halogeno-6-hydroxy-5,6-dihydrouracils and 1-carboxymethyl- 5-fluoro-6-hydroxy-5-nitro-5,6-dihydrouracil were synthesized in high yields by oxidative halogenation or nitration of 1-carboxymethyl-5-fluorouracil. Oxidative halogenation or nitration of 5-fluoro-1-(methoxycarbonylmethyl)uracil in acidic media results in the addition of the corresponding groups at the C(5) atom of uracil and simultaneous hydrolysis of the ester group. Bimolecular ions of the obtained compounds were detected in the negative ion mass spectra.