复合纳米二氧化硅的应用研究进展

全面综述了复合纳米二氧化硅在生物、医学、膜科学、催化剂、涂料、硅橡胶以及农药方面的应用研究进展。重点总结了其在生物、医学、膜科学领域的应用,并对复合纳米二氧化硅的应用前景进行了展望。     

天然保鲜剂延长红肠制品货架期的研究

将低温红肠制品用三种天然保鲜剂处理后分别在冷藏(0～4℃)和室温条件下贮藏,测定不同贮藏期低温红肠的感官评价、细菌总数、脂肪氧化值(TBARS)、H2S等指标,结果表明:低温红肠制品用Ⅰ组(2%壳聚糖+1%冰乙酸)、Ⅱ组(2%Na-AL+3%Gly+2%CaCl+2.0%香辛料提液)、Ⅲ组(1%Chitosan+1%冰乙酸+1%淀粉)保鲜剂处理后,货架期均优于对照组,且差异显著(P0.05)。     

2种作图法对大豆蛋白含量性状QTL定位的比较研究

【目的】比较复合区间作图法(CIM)和完备区间作图法(ICIM)对大豆高蛋白含量性状QTL的定位效果,总结2种方法进行QTL作图的优缺点,为QTL作图方法的选择及分子标记辅助选择培育高蛋白含量大豆品种研究提供参考。【方法】以高油大豆品种吉农18和高蛋白大豆品种吉育47杂交后获得的F2分离群体为材料,结合2年的分子数据和表型数据,采用CIM和ICIM法对大豆蛋白含量性状进行QTL定位。【结果】利用CIM和ICIM-ADD,在连锁群12(B2+C1)和17(M)上共检测到了5个高蛋白QTL,其中ICIM-ADD检测到的QTL略多于CIM;由CIM在F2∶3家系和ICIM-ADD在F2代、F2∶3家系的检测结果可以看出,2种作图法在satt285～satt636标记区间内均检测到显著LOD,且QTL距第一个标记(satt285)的遗传距离≤5.0cM,可认为此3个QTL为同一QTL,其贡献率分别为10.87%,17.09%和17.34%,说明该QTL的稳定性较好,可在进一步的高蛋白分子辅助育种中加以利用。【结论】2种作图法各有其优缺点,在实际应用中应根据分析对象综合运用、合理选择作图方法,以最大限度地提高QTL作图的精度和效率。对研究中所定位的SSR标记,特别是稳定标记可以在今后的大豆高蛋白分子标记辅助选择育种中加以利用。     

Optimization of alkaline hydrolysis of paddy straw for ferulic acid extraction

Response Surface Methodology (RSM) via Central Composite Design (CCD) was used to optimize the alkaline hydrolysis of paddy straw to improve ferulic acid extraction. The parameters involved, namely temperature (°C), concentration of NaOH (M) and duration of extraction (h) are screened by Full Factorial Studies (FFD). The result obtained from FFD was 0.518% (5.18 mg/g). The interactions between each parameters involved were studied using Central Composite Design (CCD). Upon optimization, the percentage of ferulic acid improved from 0.518% to 0.817% (8.17 mg/g). The optimum conditions obtained from this study are 125 °C, 3.90 M, 2.30 h for temperature, concentration of NaOH and extraction time, respectively. This result shows a significant improvement than the previous published work. Details of the experimental design, statistical analysis and interpretation are discussed below.     

低温蛋白质氨化复合菌系对沼气酸化液pH及产甲烷活性的影响

研究了低温蛋白质氨化复合菌系对3组不同处理酸化液的pH及产甲烷活性的影响.结果表明,接低温蛋白质氧化复合菌系的酸化液中氨态氮和pH均在5 d时达到最高和适宜的pH范围,较KHCO3调试的酸化液和自然发酵酸化液提前2 d,且产气量最高,15 d达到产气高峰时产气量较KHCO3调试的酸化液和自然发酵酸化液提高了45.45%...     

水玻璃制备SiO2/NR复合材料性能的研究

将廉价水玻璃制备的SiO2溶胶-凝胶在乳液状态下与天然胶乳共混-共凝制备SiO2/NR复合材料.采用热重分析(TG)和动态热机械分析(DMA)研究了复合材料的性能.结果表明,溶胶-凝胶法SiO2在天然橡胶中分散性较好,SiO2与天然橡胶的界面结合增强,复合材料的力学性能和热稳定性有了明显的改善.     

Screening of a Composite Microbial System and Its Characteristics of Wheal Straw Deqradation

To accelerate the decomposition of wheat straw directly returned to soil,we constructed a microbial system (ADS-3) from agricultural soil containing rotting straw residues using a 40-wk limited cultivation.To assess its potential use for accelerating straw decomposing,the decomposing characteristics and the microbial composition of ADS-3 were analyzed.The results indicated that it could degrade wheat straw and filter paper by 63.8 and 80％,respectively,during 15 d of incubation.Straw hemicellulose degraded dramatically 51.2％ during the first 3 d,decreasing up to 73.7％ by the end of incubation.Cellulose showed sustained degradation reaching 53.3％ in 15 d.Peak values of xylanase and cellulase activities appeared at 3 and 11 d,with 1.32 and 0.15 U mL-1,respectively.Estimated pH averaged 6.4-7.6 during the degradation process,which approximated acidity and alkalinity of normal soils.The microbial composition of ADS-3 was stable based on denaturing gradient gel electrophoresis (DGGE) analysis.By using bacterial 16S rRNA and fungal 26S rRNA gene clone library analysis,20 bacterial clones and 7 fungal clones were detected.Closest identified relatives of bacteria represented by Bacillus fusiformis,Cytophaga sp.,uncultured Clostridiales bacterium,Ruminobacillus xylanolyticum,Clostridium hydroxybenzoicum,and uncultured proteobacterium and the fungi were mainly identified as related to Pichia sp.and uncultured fungus.     

山茱萸果渣不溶性膳食纤维的制备工艺及性能研究

【目的】以山茱萸榨汁后的果渣为原料,研究制备不溶性膳食纤维(IDF)的最佳工艺。【方法】采用化学法提取工艺,通过预试验选择最佳工艺路线,并利用星点设计-响应曲面法优化工艺条件。以NaOH浓度、液料比、温度作为自变量,以产品质量、IDF含量和产品持水力三者所得综合指标(综合指标值=产品质量×0.1+IDF含量×0.01+持水力)作为因变量。对试验结果进行拟合,并对最佳工艺条件下制备的山茱萸果渣IDF的化学组成和部分特性进行分析。【结果】拟合方程结果显示,二次项回归方程优于线性方程和三次项方程,并以二次项回归方程建立了预测模型。用预测模型计算所得的制备山茱萸果渣IDF的最佳反应条件为:NaOH浓度0.421 4mol/L、液料比19.643mL/g、温度63.37℃,此条件下作用2h,所得产品的综合指标预测值为19.337 0。在相近的试验条件下对预测结果进行验证,结果显示综合指标值为18.578 6,接近预测值。与原料相比,最佳工艺条件下制备的山茱萸果渣IDF的IDF含量及溶胀力、持水力、持油力均有很大提高,而蛋白质、脂肪含量明显降低。【结论】得到了制备山茱萸果渣IDF的最佳工艺条件,且所得产品的化学组成和特性明显优于原果渣。