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Background: The preparation of broad bean koji is a key process in the production of Pixian broad bean paste (PBP). Protease is essential for degradation of proteins during PBP fermentation. To obtain broad bean koji with high protease activity using the co-cultivated strains of Aspergillus oryzae QM-6 and Aspergillus niger QH-3, optimization of acid and neutral protease activities was carried out using Box-Behnken design with response surface methodology. Results: The optimum conditions were found to be as follows: inoculation proportion (X 1 ), 3:1 ( A. oryzae QM-6: A. niger QH-3, w/w); culture temperature (X 2 ), 33°C; inoculum size (X 3 ), 0.5% (w/w); incubation time (X 4 ), 5 d. The acid and neutral protease activities were 605.2 ± 12.4 U/g and 1582.9 ± 23.7 U/g, respectively, which were in good agreement with the predicted values. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis profiles revealed that the broad bean koji extracellular proteins in the case of co-cultivation were richer compared to those in the case of A. oryzae QM-6 or A. niger QH-3 strain only. In addition, the free amino acids (FAAs) in the fermentation product were 55% higher in the co-cultivation process than in that involving only A. oryzae QM-6, further confirming the diversity of proteases in the fermentation products. Conclusions: The optimal conditions of koji-making in PBP were obtained using RSM. The co-cultivation of A. oryzae and A. niger increases the overall enzyme activities in the culture medium and the FAAs content which would thus have potential application in the PBP industry. Normal 0 false false false EN-US X-NONE X-NONE /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Tabla normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin-top:0cm; mso-para-margin-right:0cm; mso-para-margin-bottom:8.0pt; mso-para-margin-left:0cm; line-height:107%; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri",sans-serif; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;}

A novel Klebsiella pneumoniae strain (BPBA052) capable of degrading 3-phenoxybenzoic acid (3-PBA) was isolated from soybean rhizosphere soil. The strain was obtained by screening after enrichment, isolation, and purification using 3-PBA as the sole carbon and energy source. It could degrade 96.37% of 3-PBA (100 mg/L) within 72 h, and its growth and 3-PBA degradation followed kinetics models of logistic growth (XBPBA052 = 0.0883 × e0.0947t / [1 − 0.0792 × (1 − 0.0883 × e0.0947t)]; μm = 0.0947 h–1, X0 = 0.0883, and Xm = 1.1145) and first-order degradation (CBPBA052 = 101.8194 × e–0.0403t, k = 0.0403, t1/2 = 17.22 h), respectively. Based on Box–Behnken response surface analysis, the optimal temperature, pH, and 3-PBA concentration for K. pneumoniae BPBA052 were 35.01 °C, 7.77, and 150 mg/L, respectively. Moreover, pyrethroid pesticides (PPs) (such as β-cypermethrin, permethrin, bifenthrin, deltamethrin, and fenvalerate) and 3-PBA metabolites (including phenol, catechol, and protocatechuate) were efficiently utilized by BPBA052. We propose a novel microbial metabolic pathway for 3-PBA, based on metabolite identification; enzyme-degrading activity; and cloning of the phenol hydroxylase, catechol 1,2-dioxygenase, and protocatechuate 3,4-dioxygenase genes. This study provides a fundamental platform for further studies to reveal the mechanism of biodegradation of 3-BPA and show K. pneumoniae BPBA052 as a potential microbial resource for bioremediation of environments polluted with 3-PBA or PPs.

Fenvalerate is a pyrethroid insecticide with rapid action, strong targeting, broad spectrum, and high efficiency. However, continued use of fenvalerate has resulted in its widespread presence as a pollutant in surface streams and soils, causing serious environmental pollution. Pesticide residues in the soil are closely related to food safety, yet little is known regarding the kinetics and metabolic behaviors of fenvalerate. In this study, a fenvalerate-degrading microbial strain, CD-9, isolated from factory sludge, was identified as Citrobacter freundii based on morphological, physio-biochemical, and 16S rRNA sequence analysis. Response surface methodology analysis showed that the optimum conditions for fenvalerate degradation by CD-9 were pH 6.3, substrate concentration 77 mg/L, and inoculum amount 6% (v/v). Under these conditions, approximately 88% of fenvalerate present was degraded within 72 h of culture. Based on high-performance liquid chromatography and gas chromatography-mass spectrometry analysis, ten metabolites were confirmed after the degradation of fenvalerate by strain CD-9. Among them, o-phthalaldehyde is a new metabolite for fenvalerate degradation. Based on the identified metabolites, a possible degradation pathway of fenvalerate by C. freundii CD-9 was proposed. Furthermore, the enzyme localization method was used to study CD-9 bacteria and determine that its degrading enzyme is an intracellular enzyme. The degradation rate of fenvalerate by a crude enzyme solution for over 30 min was 73.87%. These results showed that strain CD-9 may be a suitable organism to eliminate environmental pollution by pyrethroid insecticides and provide a future reference for the preparation of microbial degradation agents and environmental remediation.

Deltamethrin and its major metabolite 3-phenoxybenzoic acid (3‐PBA) have caused serious threat to the environment as well as human health, yet little is known about their degradation pathways by bacterial co-cultures. In this study, the growth and degradation kinetics of Acinetobacter junii LH-1-1 and Klebsiella pneumoniae BPBA052 during deltamethrin and 3-PBA degradation were established, respectively. When the inoculum proportion of the strains LH-1-1 and BPBA052 was 7.5:2.5, and LH-1-1 was inoculated 24 h before inoculation of strain BPBA052, 94.25% deltamethrin was degraded and 9.16 mg/L of 3-PBA remained within 72 h, which was 20.36% higher and 10.25 mg/L lesser than that in monoculture of LH-1-1, respectively. And the half-life of deltamethrin was shortened from 38.40 h to 24.58 h. Based on gas chromatography–mass spectrometry, 3-phenoxybenzaldehyde, 1,2-benzenedicarboxylic butyl dacyl ester, and phenol were identified as metabolites during deltamethrin degradation in co-culture. This is the first time that a co-culture degradation pathway of deltamethrin has been proposed based on these identified metabolites. Bioremediation of deltamethrin-contaminated soils with co-culture of strains LH-1-1 and BPBA052 significantly enhanced deltamethrin degradation and 3-PBA removal. This study provides a platform for further studies on deltamethrin and 3-PBA biodegradation mechanism in co-culture, and it also proposes a promising approach for efficient bioremediation of environment contaminated by pyrethroid pesticides and their associated metabolites.

Research related to the effect of roughness on the sealing performance was reviewed, and the orientation effect of a microstructure with orderly roughness was introduced to improve the performance of dry gas seal. A microstructure was established for the flow field of dry gas film in a pair of seals. The results showed that the microstructure improves the opening performance while maintaining a reasonable leakage rate. The microstructure depth, width, and spacing significantly impact the orientation effect. Both the groove and microstructure depths have optimal values for increasing the opening force while maintaining lower leakage rate. The opening force of the microstructure has a positive influence on microscale operation. This makes the microstructure of the dry gas seal more stable and thus more suitable for high-speed and high-pressure working conditions.

In this study a type of colloidal particles with a cross-linked poly(divinylbenzene) (poly(DVB)) core and a poly(acrylic acid- r -styrene) (PAS) shell were directly prepared by reversible addition-fragmentation chain transfer (RAFT)-mediated cross-linking copolymerization. The particle size, morphology, zeta potential and pH responsibility were studied. The emulsification study showed that PAS-Poly(DVB) colloidal particles were effective particulate emulsifiers when homogenized with various oils including toluene, white oil, isooctyl palmitate, dicaprylyl carbonate, silicone oil, and propylheptyl caprylate. Additionally, the emulsification performance of PAS-Poly(DVB) colloidal particles at different pH values were investigated. Gelled white oil- in -water high internal phase emulsions (HIPEs) were formed at a high oil volume fraction of 80% when the colloidal particles were flocculated at low pH value. The addition of base can trigger the demulsification of the HIPEs, exhibiting a pH-responsive behavior. The effects of oil phase volume fraction on emulsion rheological properties were investigated. Both the emulsion viscosity and storage modulus (G′) progressively increased with the increasing of oil phase volume fraction. These results suggest that our work provides a convenient and feasible way to prepare effective particulate emulsifiers via the direct chemical reaction, and the PAS-Poly(DVB) colloidal particles have promising potential application in the oil industry and preparation and exploitation of smart materials.

The spent activated carbon (AC) loaded with zinc acetate from the vinyl acetate synthesis industry has been used as a raw material to prepare AC-ZnO porous adsorbents using microwave irradiation technique with three different activating agents. The morphology and surface chemical compositions of the prepared samples were characterized by X-ray diffraction, scanning electron microscope, Fourier transform infrared spectroscopy, and N2 adsorption–desorption isotherm. The regenerated AC-ZnO composites exhibited a well-developed porous structure with Brunauer–Emmett–Teller surface area in excess of 1,100 m2/g, and the ZnO nanoparticles decomposed from zinc acetate loaded on the surface of the regenerated AC without aggregation. The adsorption performance of the AC-ZnO composites was further evaluated by adsorbing Congo Red (CR) from aqueous solutions. The experimental isotherms data were analyzed using Langmuir, Freundlich, and Temkin models. Langmuir and Temkin models were found to satisfactorily matc...

In this study, a series of random copolymer poly(acrylic acid-co-styrene) (P(AA-co-St)) and block copolymer poly(acrylic acid)-b-polystyrene (PAA-b-PSt) with similar chemical composition but different chain microstructure were synthesized. The self-assembly behavior of random and block copolymers in selective solvent was investigated, and the structural evaluation of random and block copolymers micelles was carried out by transmission electron microscopy (TEM), dynamic light scattering (DLS) measurement, and X-ray photoelectron spectroscopy (XPS). Moreover, together with experimental characterization, the theoretical method dissipative particle dynamics (DPD) approach was applied to investigate the morphological structures of micelles composed from random and block copolymers. Results revealed that the structure of polymeric micelles is significantly affected by the distribution sequence of hydrophilic and hydrophobic monomers in copolymer chains. Furthermore, polymeric micelles based on P(AA-co-St) and PAA-b-PSt with about 50 mol% hydrophilic composition were chosen as the model to investigate the influence of micellar structure on emulsifying performance. For PAA-b-PSt micelles (B48), stable water-in-oil (w/o) emulsions could only obtained when the pH values were lower than 5. As a comparison, the P(AA-co-St) micelles (R49) had an excellent emulsification performance at 4-10 pH, and the pH-induced phase inversion derived from obtained emulsions observed at pH higher than 6. Preliminary results confirm that the micellar structure controlled by chain microstructure plays an important role in the interface behavior of polymer micelles. Compared with PAA-b-PSt micelles, P(AA-co-St) micelles have better interfacial performance and are more tailorable and controllable; thus they can be used as a model for further study of polymeric particulate emulsifiers. This paper provides new insight into the principles governing extremely high emulsifying efficiency of polymeric particulate emulsifiers and pH-responsive properties of the formed emulsions.

A simple, green and effective process is developed to fabricate hyaluronic acid (HA)/chitosan (CS) complex colloidal particles through electrostatic interactions. The obtained complexes can be used as biocompatible emulsifiers and novel potential carriers for papain loading. An HA/CS mass ratio of 2 is the optimal condition leading to the smallest Dh (420.9 nm). The complexes with eight different mass ratios are used to stabilize white oil/water emulsions. The structure of the complexes at the oil-water interface varies in response to the mass ratio and can be classified into two typical structures, similar to typical polymeric surfactants and solid particulate emulsifiers. Furthermore, papain is introduced into the complex systems. Formation of the papain/HA/CS complexes in a compact form can protect the enzyme. Here, a novel strategy is introduced to fabricate a biocompatible emulsion from the HA/CS complexes and demonstrate that the stable complex is a suitable enzyme delivery system.

The nanohybrid particulate emulsifiers based on poly(styrene-alt-maleic anhydride) (SMA) were facilely prepared via the direct chemical self-assembly triggered by the aminolysis of SMA with 3-aminopropyltriethoxysilane (APTES) and the in situ polycondensation of APTES under refluxing in acetone. Transmission electron microscopy and scanning electron microscopy confirmed the spherical-like morphology of the nanohybrids. Dynamic light scattering and electrophoresis revealed the structure transition of the nanohybrids in response to pH change. The emulsification study showed that the nanohybrids were effective particulate emulsifiers when homogenized with various oils including toluene, paraffin oil, silicone oil, isooctyl palmitate, dicaprylyl carbonate, and propylheptyl caprylate. The nanohybrid particulate emulsifiers exhibited pH-sensitivity, and the diameter of paraffin oil droplets remarkably increased with pH of the nanohybrid aqueous dispersion decrease. Also, the reduced dynamic interfacial tension predicted the thermodynamically unstable state of the emulsions prepared at high pH values. Most interesting, the paraffin oil-in-water high internal phase emulsions (HIPEs) with a high oil volume fraction of 83.3% were formed when the nanohybrids were heavily flocculated by adding HCl. The HIPEs were pH-responsive and capable of demulsification with the addition of an alkaline solution showing a potential application in the oil industry.

Polymeric micelles could be used as model polymeric particulate emulsifiers to elucidate the correlation between the micellar structure and their emulsifying performance. Photo-cross-linkable and pH-responsive micelles were prepared with amphiphilic random copolymers, poly(7-(4-vinylbenzyloxyl)-4-methylcoumarin-co-acrylic acid) (PVMAA), via the self-assembly in selective-solvent DMF/H2O and then used as polymeric particulate emulsifiers to stabilize toluene-in-water emulsions. Primary micelles, based on PVMAA with 12 mol % of hydrophobic composition, were chosen as model to investigate the influence of photo-cross-linking on the emulsifying performance. The larger shrinkage degree by photo-cross-linking (SDC) the micelles have, the lower emulsifying efficiency the micelles exhibit. Furthermore, the structural transitions of micelles with SDC of 0% and 95% in response to pH change were comparatively confirmed by a combination of electrophoresis, dynamic light scattering (DLS), and transmission electron microscopy (TEM). The micelles of various states, manipulated by photo-cross-linking and pH changes, were used as emulsifiers to stabilize toluene-in-water or styrene-in-water emulsions. For the un-cross-linked micelles, polymer chains gradually protrude from micelles with pH increasing, which benefits the increase in the emulsifying efficiency of micelles. However, as pH elevated over 8, the stability of emulsions significantly decreases due to the disintegration of micelles. On the contrary, micelles with SDC of 95% keep their structural integrity and become more rigid as pH increase, leading to lower emulsifying efficiency of micelles and worse stability of the emulsions. This paper provides a new insight into the principles governing the extremely high emulsifying efficiency of polymeric particulate emulsifiers and pH-dependent or pH-responsive properties of the formed emulsions.

Background: There are no satisfactory biomarkers for screening pancreatic cancer. The surface-enhanced laser desorption/ionization time-of-flight mass spectrometry (SELDI-TOF-MS) technique has been used to identify biomarkers for different types of cancers. A new and reliable SELDI proteomic method for diagnosing pancreatic cancer is needed. Methods: Four hundred and fifty-five serum samples were tested by SELDI-TOF-MS matching on a gold chip. Samples were assigned to 1 of 2 subsets according to collection order, viz., a training set, and a testing set. The training set was used to identify statistically significant peaks and to develop the artificial neural network (ANN) model for diagnosing pancreatic cancer. The testing set was used in a blind test to validate the diagnostic efficiency of the ANN model. Results: A total of 62 proteins that differed between patients and controls were identified ( P

C18H15FN2O2, triclinic, P1̅ (no. 2), a = 7.8272(8) Å, b = 9.6662(10) Å, c = 10.9834(12) Å, α = 107.859(2)°, β = 92.559(2)°, γ = 99.415(2)°, V = 776.31(14) Å3, Z = 2, R gt(F) = 0.0407, wR ref(F 2) = 0.1187, T = 296 K.