Preventive Effect of Lactobacillus fermentum CQPC03 on Activated Carbon-Induced Constipation in ICR Mice.

Background and objectives: Paocai (pickled cabbage), which is fermented by lactic acid bacteria, is a traditional Chinese food. The microorganisms of Paocai were isolated and identified, and the constipation inhibition effect of one of the isolated Lactobacillus was investigated. Materials and Methods: The 16S rDNA technology was used for microbial identification. A mouse constipation model was established using activated carbon. After intragastric administration of Lactobacillus (108 CFU/mL), the mice were dissected to prepare pathological sections of the small intestine. Serum indicators were detected using kits, and the expression of small intestine-related mRNAs was detected by qPCR assay. Results: One strain of Lactobacillus was identified and named Lactobacillus fermentum CQPC03 (LF-CQPC03). Body weight and activated carbon propulsion rate were all higher in mice intragastrically administered with LF-CQPC03 compared with the control group, while the time to the first black stool in treated mice was lower than that in the control group. Serum assays showed that gastrin (Gas), endothelin (ET), and acetylcholinesterase (AchE) levels were significantly higher in the LF-CQPC03-treated mice than in the control group, while somatostatin (SS) levels were significantly lower than in the control mice. Mouse small intestine tissue showed that c-Kit, stem cell factor (SCF), and glial cell-derived neurotrophic factor (GDNF) mRNA expression levels were significantly higher in the LF-CQPC03 treated mice than in control mice, while transient receptor potential cation channel subfamily V member 1 (TRPV1) and inducible nitric oxide synthase (iNOS) expression levels were significantly lower in the LF-CQPC03 treated mice than in control mice. Conclusions: There is a better effect with high-dose LF-CQPC03, compared to the lower dose (LF-CQPC03-L), showing good probiotic potential, as well as development and application value.

5-Fluorouracil monodispersed chitosan microspheres: Microfluidic chip fabrication with crosslinking, characterization, drug release and anticancer activity.

Different size and morphology monodispersed chitosan (CS) microspheres loaded with the anticancer drug of 5-fluorouracil (5-Fu) were prepared by the microfluidic method assisted by a crosslinking unit with crosslinkers of tripolyphosphate (TPP) and glutaraldehyde (GTA). The sizes, morphologies, drug loading, encapsulation efficiency, drug release and cytotoxicity of 5-Fu loaded CS microspheres were characterized and determined. Results indicated that the CS microspheres were uniform in size distributions. They possessed excellent encapsulation efficiency and drug loading. The TPP-crosslinked CS microspheres had rough surfaces and exhibited faster drug release, whereas the CS microspheres crosslinked with GTA had smooth surfaces and showed slower drug release. Furthermore, 5-Fu-loaded CS microspheres exhibited sustained drug release which well fitted the first-order kinetics model and were pH-responsive in that the drug cumulative release was greater at acidic environments than at neutral conditions. Finally, 5-Fu loaded CS microspheres provided sufficient cytotoxicity and were satisfactory in the cancer cell inhibition.

[Adsorption of Hg(â ¡) in Water by Sulfydryl-Modified Sepiolite].

In order to develop highly efficient and low-cost treatment technique for heavy metal wastewater and promote the resource utilization of sepiolite, natural sepiolite was modified by using thioglycollic acid and characterized by scanning electron microscope (SEM), X-ray diffraction (XRD), specific surface, Zeta potential and infrared spectrum (IR) analysis, and the adsorption kinetic and thermodynamic characteristics of the modified sepiolite to Hg(Ⅱ) in water were studied by static adsorption experiments. The results showed that sulfydryl groups were grafted onto sepiolite, and the surface of the modified sepiolite became smoother with more gaps and negative charges to improve the adsorption ability for Hg(Ⅱ). The optimal pH for Hg(Ⅱ) adsorption on the modified sepiolite was 6, and the adsorption process reached equilibrium in 60 min at 30℃. This process could be described by the pseudo second-order kinetic equation, and the initial adsorption rate constant was 0.063 mg·(g·min)-1. The adsorption thermodynamic characteristics could be well described by Langmuir isothermal adsorption model, and the maximum adsorption capacity was 3.256 mg·g-1. The investigation revealed that the adsorption process was a spontaneous endothermic process, resulting in physical adsorption and chemical adsorption, which was dominated by physical adsorption.

[Influence of Three Low-Molecular-Weight Organic Acids on the Adsorption of Phenanthrene in Purple Soil].

The effects of three low-molecular-weight organic acids (citric acid, malic acid and oxalic acid) on the adsorption of phenanthrene in purple soil were studied by static adsorption experiment. The results showed that the adsorption kinetic process of phenanthrene in purple soil could be described by the second-order kinetic model, and the adsorption rate constant would significantly decrease in the presence of the three low-molecular-weight organic acids ( LMWOAs). The adsorption thermodynamic process could be well described by linear adsorption model, which was dominated by distribution role. The three LMWOAs could promote the adsorption of phenantherene in purple soil when their concentrations were less than 5 mmol · L⁻¹, whereas inhibit the adsorption when their concentrations were more than 10 mmol · L⁻¹, and the inhibition would increase with increasing concentrations. Moreover, the inhibitory ability displayed a decreasing order of citric acid, oxalic acid, and malic acid when their concentrations were 20 mmol · L⁻¹, which is related to the molecular structure and acidity of the three LMWOAs. Compared with the control, the content of dissolved organic matter (DOM) released from purple soil showed a trend of first decrease and then increase with increasing LMWOAs concentration, and the adsorption capacity of phenanthrene in purple soil was negatively related to DOM content.

Microbial degradation of endosulfan in contaminated soil with the elution of surfactants.

In this work, an endosulfan-degrading strain was isolated from the aged soil contaminated by endosulfan, and identified as Ochrobactrum sp. EB-4 by 16S rDNA sequence analysis. The microbial degradation characteristics of endosulfan in three eluents (Tween 80 + SDS, Tween 80 + Na2SiO3, Tween 80 + SDS + Na2SiO3) were investigated. The results showed that the degradation percents of α-, ß-endosulfan in the three eluents were 86.83 %∼92.91 % and 88.90 %∼93.94 % in 15 days, respectively. The degradation process can be well described by the first-order kinetic model, and the half-times of α-endosulfan in eluent 1∼eluent 3 were 3.83, 5.29, and 4.53 days, while those of ß-endosulfan were 3.35, 4.50 and 3.79 days, respectively. The endosulfan diol and endosulfan sulfate as main metabolites were detected, and the former can be further degraded by this strain, which revealed that the simultaneously happened hydrolysis and oxidation reactions were the main degradation processes, and dominated by hydrolysis reaction. After 5 days of washing with the eluents, 56.00∼84.33 % of α-endosulfan, and 46.49∼68.56 % of ß-endosulfan in soil were eluted, respectively, and can be entirely biodegraded in 12 days, which indicated that the microbial degradation was the rate-determining step.