Advanced Materials Research Vols. 884-885

Abstract: Prior exposure of a vaccine to certain species of environmental mycobacteria can prime the immune system against common mycobacterial antigens, which can in turn reduce the subsequent efficacy of live attenuated mycobacterial vaccines (such as Mycobacterium bovis BCG), in both human and livestock vaccination programs. In this study, five strains of nontubeculous mycobacterium, all isolated from lymphonodi mandibulares and lymphonodi mesenterici samples of swine and cattle, were investigated to determine their growth characteristics and effects on the immune system in murine models. Markedly, different effects on the immune system were observed. The different results may be linked to the inherent growth characteristics of the five strains, The implications of these findings for BCG vaccination protocols are discussed.

Abstract: A group of petroleum-degrading bacteria were obtained from the sludge samples that collected from the Triassic Yanchang 6 reservoir. Of these, three strains with maximum degradation performance were tested in this study. The chromatographic analysis showed that the content of molecules with 30 or more carbons of oil was reduced by 18.36%. Core flood experiments with different flooding rate showed that the oil recovery of microbial flooding was increased by 8.76% than water flooding. The research ruled out that the three strains have well compatibility with the reservoir with remarkable result of petroleum-degrading.

Abstract: Microorganisms tolerant to 1, 3-propanediol (1, 3-PDO) were screened out from various environmental samples, and isolate CF-5 was found to produce 2.8 g/L 1, 3-PDO with glycerol as carbon source. Based on 16S rRNA gene sequence analysis, CF-5 was identified as a Citrobacter freundii strain. The fermentation conditions of strain CF-5 were analyzed. Higher biomass production was obtained in the medium supplemented with limited amount of glucose without repression of conversion efficiency of glycerol to 1, 3-PDO. Under the combined aerobic and oxygen limited incubation conditions, higher yield of 1, 3-PDO was reached. The fed-batch fermentation was performed in a 5 L bioreactor, 1, 3-PDO was found mainly produced in exponential growth phase cells of C. freundii CF-5 with the highest productivity 0.63 g/L*h, and the overall yield of 1, 3-PDO fermentation was 11.8 g/L within 36 h fermentation.

Abstract: In the synthesis of 2-ethoxycarbonyl-3, 4-diethyl-pyrrole (1) by the Barton-Zard reaction of 4-acetoxy-3-nitrohexane (1b) with ethyl isocyanoacetate, the organic base 1, 8-diazabicyclo [5.4.0] undec-7-ene (DBU) and the solvent tetrahydrofuran (THF) were replaced with K₂CO₃ and ethanol, respectively. Moreover, the preparation of the intermediate 1b from 1a by acetylation reaction was carried out by employing acetyl chloride in boiling toluene solution instead of acetic anhydride and the catalyst concentrated sulfuric acid. After treatment of 1 with excess LiAlH₄ at low temperature, the crude product 1c (α-hydroxymethyl-3, 4-diethyl-pyrrole) was immediately reacted via a tetramerization in the presence of the catalyst BF₃.OEt₂ in crude CHCl₃, followed by oxidation of 2, 3-dichloro-5, 6-dicyano-1, 4-benzoquinone (DDQ) to provide the corresponding octaethylporphyrin 2. The results indicate that using BF₃.OEt₂ as catalyst instead of p-toluenesulphonic acid (p-TsOH) in the synthesis of 2 from 1c can obviously increase the yield of product 2 up to 80% from 69%.

Abstract: The strain Enterococcus faeciumIN3531, a bacteriocin producer, was used as a starter culture for traditional fermentationpaocai in china. By single factor experiment, the technological conditionsof Chinese fermentation paocai using Enterococcus faecium IN3531 as a starterwere optimizated, andparameters of optimization included the initial saltconcentration, the inoculum size, the fermentation temperatureand the ratio of material to liquid. Theresearch results showed that,the suitable fermentationconditions were the initial saltconcentration of 2%,the inoculum size of 3%, the fermentation temperature of 37 °C, the ratio of materialto liquid of 30%, fermentation time of 108 hours. Titratable acidity in fermentationterminus was 0.80%.

Abstract: Dry anaerobic co-digestion of animal manure and straw was conducted to produce biogas. Startup characteristics and biogas production perform of dry digestion were studied, and the effect of operation temperature and incubation amount on dry digestion was also investigated. The study result showed that under the conditions of C/N=25-30, TS=20% and T=(36±1)°C,dry digestion can start up quickly with acclimated thickening sludge as incubation sludge. Compared to dry digestion of chicken manure and pig manure, dry digestion of cow manure proceeded steadily with high biogas yield. It is found that incubation is necessary in the process of dry digestion and biogas yield increases with more incubation amount. The appreciate incubation ratio is about 10%. Temperature change has apparent effect on biogas production, and it is suggested that mesophilic temperature should be chosen in the scaled project of dry digestion.

Abstract: Thymol (TH), which has antimicrobial effect on many food pathogens, was incorporated as antimicrobial agent into composite poly (lactic acid)/poly (trimethylene carbonate)(PLA-PTMC) films. Antimicrobial active films based on PLA-PTMC were prepared by incorporating thymol at five different concentrations: 0, 3, 6, 9 and 12 %(w/w). The mechanical characterization, water vapor permeability (WVP), and antimicrobial activity of all formulations composite film were carried out. A decrease in elastic modulus was obtained for the active composite film compared with neat PLA-PTMC film. The presence of thymol decreased water vapor permeability, with a significant antimicrobial activity. Antimicrobial activities of films were tested against Escherichia coli, Staphylococcus aurous, Listeria, Bacillus subtilis, and Salmonella. Increasing amount of the thymol in the film caused a significant increase in inhibitory zones. These results suggest that thymol incorporated PLA-PTMC films have a prospectively potential in antimicrobial food packaging.

Abstract: Lactic acid bacteria H6 was isolated from dried yak jerky by plate dilution method, and using the Listeria monocytogenes as indicator, the Oxford cup method was used to test the bacteriostasis effect. Lactic acid bacteria H6 were identified as Pediococcus pentosaceus by 16S rRNA sequence. The growth curve of Pediococcus pentosaceus H6 was determined by Turbidimetry, and the antibacterial activity of bacteriocin H6 was measured by two fold dilution method and the Oxford cup method. Studying on the thermal stability and pH stability, our results indicated that the barteriocin H6 has better antibacterial effect in acidic conditions or at 100 °C for 90min. The antibacterial spectrum of bacteriocin H6 proved its good inhibitory effect on proliferation of Listeria monocytogenes and other Gram-positive bacteria, and had a certain inhibitory effect on Escherichia coli and other Gram-negative bacteria, showing a broad-spectrum antibacterial property, which demonstrate its great potential in food preservation

Abstract: Young coconut juice (YCJ) from aromatic green dwarf variety fruit of Cocos nucifera L. (Family Arecaceae) is high valuated because of its nutritional and pharmacological properties (wound healing, anti-Alzheimer, anti aging). Due to the storage and handling problems, YCJ has been prepared in dry form by freeze-drying process in this study. The % yield of freeze-dried YCJ powder was 6.62 ± 0.28 %. Both of them (fresh and freeze-dried YCJ) were further studied on phytochemical, physical, chemical and microbiological properties. The results showed that β-sitosterol was isolated and identified by means of spectral data and their physical properties. The HPLC-parameters (linearity, repeatability, accuracy and specificity) were evaluated. The concentrations of β-sitosterol in HPLC analysis of both fresh and freeze-dried YCJ were 89.67 ± 0.01 and 31.84 ± 1.56 μg/ml, respectively. Furthermore, there was no significant (p>0.05) difference in physicochemical analysis in between both products. Therefore, the microbiological analysis of these products was within standard range of Thai community products standard (TCPS). In conclusion, Freeze-dried YCJ was observed to be the suitable technique to obtain the dry extract of young coconut juice.

Abstract: The controlled-release tablets of sasanquasaponin-sodium alginate-hydroxy-propyl methyl cellulose (SQS-SAL-HPMC) were prepared by using SQS, SAL and HPMC as the main drug and accessories. The effects of the preparation method of the controlled-release powder and the amount of ethanol on release rate respectively were studied. The release rate curve of the data of the prescription of the controlled-release tablets of SQS-SAL-HPMC were fitted as zero order, one order and Higuchi equation. The controlled-release tablet of SQS-SAL-HPMC was characterized by IR techniques. The releasing rate of the controlled-release tablets of SQS-SAL-HPMC are controlled by controlling the preparation method of the controlled-release powder and the amount of ethanol. The controlled- release tablets of SQS-SAL-HPMC release SQS by slowness and constant in 12h. The chemical bonds are formed among SQS, SAL and HPMC.