Structural elucidation and targeted valorization of untractable lignin from pre-hydrolysis liquor of xylose production via a simple and robust separation approach.

Effective separation of lignin macromolecules from the xylose pre-hydrolysates (XPH) during the xylose production, thus optimizing the separation and purification process of xylose, is of great significance for reducing the production costs, achieving the high value-added utilization of lignin and increasing the industrial revenue. In this study, a simple and robust method (pH adjustment) for the separation of lignin from XPH was proposed and systematically compared with the conventional acid-promoted lignin precipitation method. The results showed that the lignin removal ratio (up to 60.

Recovery Processes of Organic Acids from Fermentation Broths in the Biomass-Based Industry.

The new movement towards green chemistry and renewable feedstocks makes microbial production of chemicals more competitive. Among the numerous chemicals, organic acids are more attractive targets for process development efforts in the renewable-based biorefinery industry. However, most of the production costs in microbial processes are higher than that in chemical processes, among which over 60% are generated by separation processes.

Structurally related ganoderic acids induce apoptosis in human cervical cancer HeLa cells: Involvement of oxidative stress and antioxidant protective system.

Ganoderic acids (GAs) produced by Ganoderma lucidum possess anticancer activities with the generation of reactive oxygen species (ROS). However, the role of oxidative stress in apoptotic process induced by GAs is still undefined. In this study, the effects of four structurally related GAs, i.

[Study on the pH-sensitive secondary structure of gamma-PGA embedded with magnetite nanoparticles].

The conformational transition of poly gamma-glutamic acid (gamma-PGA) embedded with magnetite nanoparticles under various pH conditions was investigated by Fourier transform infrared spectroscopy (FTIR). The secondary structure content was determined through the analysis of amide I bands of Fourier deconvolution spectra, secondary derivative spectra and the Gaussian curve fitting of the original infrared spectra. The results showed that the conformation of the gamma-PGA was affected by solution pH.

In situ magnetic separation and immobilization of dibenzothiophene-desulfurizing bacteria.

In situ cell separation and immobilization of bacterial cells for biodesulfurization were developed by using superparamagnetic Fe(3)O(4) nanoparticles (NPs). The Fe(3)O(4) NPs were synthesized by coprecipitation followed by modification with ammonium oleate. The surface-modified NPs were monodispersed and the particle size was about 13 nm with 50.

Spontaneous vesicle formation of poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) triblock copolymer.

A novel method has been developed to prepare vesicles from aqueous solutions of poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) triblock copolymer, by adding anionic surfactant sodium dodecyl sulfate (SDS) and inorganic salt NaF. As determined by TEM and dynamic light scattering (DLS) measurements, the average diameter of vesicles is about 800 nm having 50 nm outer shell thickness. Identifying hydrophobic interactions between the block copolymers and the microenvironments around the vesicles using FTIR, 1H NMR, and fluorescence spectroscopy techniques revealed the vesicle formation mechanism.

Temperature-responsive magnetite/PEO-PPO-PEO block copolymer nanoparticles for controlled drug targeting delivery.

In this study, temperature-responsive magnetite/polymer nanoparticles were developed from iron oxide nanoparticles and poly(ethyleneimine)-modified poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) (PEO-PPO-PEO) block copolymer. The particles were characterized by TEM, XRD, DLS, VSM, FTIR, and TGA. A typical product has an approximately 20 nm magnetite core and an approximately 40 nm hydrodynamic diameter with a narrow size distribution and is superparamagnetic with large saturation magnetization (51.

Probing paeonol-pluronic polymer interactions by 1H NMR spectroscopy.

By using a combination of 1H NMR spectroscopy, two-dimensional heteronuclear single-quantum coherence-resolved (1)H{(13)C} and homonuclear rotating-frame Overhauser enhancement NMR correlation experiments with diffusion ordered spectroscopy (DOSY), the location and distribution of a hydrophobic drug, paeonol, have been established with respect to the methyl groups of the poly(ethylene oxide)-poly(propylene oxide) -poly(ethylene oxide) (PEO-PPO-PEO) triblock copolymer. The interaction between them is adjustable according to the different temperature-dependent hydrophilicities or hydrophobicities of the triblock copolymer components. On the other hand, such interactions influence the self-assembly properties of the block copolymer amphiphiles in solution.

Oil-induced aggregation of block copolymer in aqueous solution.

The oil-induced aggregation behavior of PEO-PPO-PEO Pluronic P84 [(EO)19(PO)39(EO)19] in aqueous solutions has been systematically investigated by 1H NMR spectroscopy, freeze-fracture transmission electron microscopy (FF-TEM), and dynamic light scattering (DLS). The critical micellization temperature (CMT) for P84 in the presence of oils decreases with increasing oil concentration. The effectiveness of various oils in decreasing the CMT of block copolymer follows the order m-xylene (C(8)H(10)) > toluene (C(7)H(8)) > benzene (C(6)H(6)) > n-octane (C(8)H(18)) > n-hexane (C(6)H(14)) approximately cyclohexane (C(6)H(12)).

1H NMR spectroscopic investigations on the micellization and gelation of PEO-PPO-PEO block copolymers in aqueous solutions.

The effects of temperature, polymer composition, and concentration on the micellization and gelation properties of poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) (PEO-PPO-PEO) block copolymers in aqueous solutions were investigated by 1H NMR spectroscopy. It was found that the temperature-dependent behavior of PPO blocks, observed as changes in chemical shift, half-height width, and integral value, could be attributed as an intrinsic tool to characterize the transition states during unimer to micelle formation. The 1H NMR spectral analysis revealed that the hydrophobic part, PPO, of the Pluronic polymers plays a more significant role in the temperature-induced micellization, whereas the transitional behavior of Pluronic polymer, i.

Interaction of urea with pluronic block copolymers by 1H NMR spectroscopy.

Solution 1H NMR techniques were used to characterize the interaction of urea with poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) (PEO-PPO-PEO) triblock copolymers. The urea was established to interact selectively with the PEO blocks of the block copolymer, and the interaction sites were found not to change with increasing temperature. Such interactions influence the self-assembly properties of the block copolymer in solution by increasing the hydration of the block copolymers and stabilizing the gauche conformation of the PPO chain.

Salt-induced micellization of a triblock copolymer in aqueous solution: a 1H nuclear magnetic resonance spectroscopy study.

An aqueous micellar solution of a PEO-PPO-PEO triblock copolymer, pluronic F88 (EO103PO39EO103), in the presence of salt (KCl) has been investigated by 1H NMR spectroscopy. The hydrogen-bonding structure in water is directly changed by the strong polarization effect of added salt, which indirectly weakens the interaction of polymer molecules with water. Both EO and PO blocks are dehydrated by the addition of salt in a similar way, whereas the solubility of the PO blocks may be affected in a more pronounced way, which results in the decrease of the critical micellization temperature (CMT).

[Study on interaction of anionic surfactant SDS and bovine serum albumin by fourier transform infrared spectroscopy].

FTIR spectroscopy was applied to investigate the interaction of anionic surfactant Sodium Dodecyl Sulfate (SDS) and Bovine Serum Albumin (BSA). Amide band I of BSA was analyzed to obtain the change in secondary structure of BSA when different concentration of SDS was added and during different interaction period. In short interaction period and at low concentration of SDS, the alpha-helixes increased and the random coil decreased.

Effect of hydrophobicity inside PEO-PPO-PEO block copolymer micelles on the stabilization of gold nanoparticles: experiments.

In this paper we present the effect of poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) block copolymer micelles and their hydrophobicity on the stabilization of gold nanoparticles. Gold nanoparticles were prepared by a method developed by Sakai et al. (Sakai, T.

[Comparison of the desulfurization activity among several bacteria and analysis of the conservation of their desulfurization genes].

Several bacteria, Bacillus brevis R-6, Pseudomonas delafleldii R-8, Nocardia globerula R-9, Bacillus sphaericus R-16, Rhodococcus erythropolis LSSE8-1 and Gordonia nitida LSSEJ-1, which can convert dibenzothiophene into 2-hydroxybiphenyl and sulfate, were investigated. Desulfurization products were quantitively determined by HPLC. Result revealed that each of these bacteria desulfurize DBT at a different rate.

Purification of nattokinase by reverse micelles extraction from fermentation broth: effect of temperature and phase volume ratio.

Nattokinase is a novel fibrinolytic enzyme that is considered to be a promising agent for thrombosis therapy. In this study, reverse micelles extraction was applied to purify and concentrate nattokinase from fermentation broth. The effects of temperature and phase volume ratio used for the forward and backward extraction on the extraction process were examined.

Melt, hydration, and micellization of the PEO-PPO-PEO block copolymer studied by FTIR spectroscopy.

Fourier transform infrared (FTIR) spectroscopy was used to study the conformational changes of the polyethylene oxide-polypropylene oxide-polyethylene oxide (PEO-PPO-PEO) block copolymer, Pluronic P104, in a large concentration range in a polymer-water system as a function of temperature. The melt in which the conformational transition of the PEO blocks occurs gives remarkable changes in the spectral behavior. A small amount of water in Pluronic P104 can induce the PEO block amorphism.

Effect of sodium chloride on association behavior of poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) block copolymer in aqueous solutions.

The effect of sodium chloride (NaCl) upon the thermally induced association behavior of poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) (PEO-PPO-PEO) block copolymer, Pluronic P103, has been investigated using pyrene fluorescence spectroscopy. The critical micellization temperature (CMT) of Pluronic P103 in aqueous solution is decreased by the addition of NaCl. The standard enthalpy and entropy of micellization for Pluronic P103 in water are increased in the presence of small amounts of NaCl, but further addition of NaCl decreases the standard enthalpy and entropy of micellization.

Biodesulfurization of dibenzothiophene by microbial cells coated with magnetite nanoparticles.

Microbial cells of Pseudomonas delafieldii were coated with magnetic Fe3O4 nanoparticles and then immobilized by external application of a magnetic field. Magnetic Fe3O4 nanoparticles were synthesized by a coprecipitation method followed by modification with ammonium oleate. The surface-modified Fe3O4 nanoparticles were monodispersed in an aqueous solution and did not precipitate in over 18 months.

Immobilization of Pseudomonas delafieldii with magnetic polyvinyl alcohol beads and its application in biodesulfurization.

Pseudomonas delafieldii was immobilized in magnetic polyvinyl alcohol (PVA) beads using a hydrophilic magnetic fluid, which was prepared by a co-precipitation method. The beads had distinct super-paramagnetic properties and were compared with immobilized cells in non-magnetic PVA beads. Their desulfurizing activity was increased slightly from 8.