纳豆菌固定化材料优化的研究

为获得固定化纳豆菌材料,以海藻酸钠(SA)和聚乙烯醇(PVA)为包埋材料,采用固定化细胞技术对纳豆菌生产纳豆激酶进行了研究.结果表明:在PVA中加入SA进行细胞包埋可获得渗透性能好强度高的固定化细胞.通过正交试验进一步确定,当PVA的浓度为9%、SA的浓度为1%、硼酸的浓度为5%、CaCl2的浓度为6%时,固定化细胞的强度最好,采用摇床培养可连续发酵使用6次,活性也很高,产生的纳豆激酶酶活溶纤圈直径积达87.69 mm2·15μL-1.     

包埋厌氧氨氧化同步脱硫除氮菌B16对天然橡胶加工废水的处理研究

天然橡胶加工废水具有水质、水量变化大的特点,冲击负荷下厌氧生物处理通常效果不佳。针对这一问题,利用海藻酸钙（SA）、聚乙烯醇（PVA）复合材料对本实验室筛选到的同步脱硫除氮菌B16进行包埋,利用包埋固定化后的菌处理天然橡胶加工废水。结果表明：14 d后包埋菌株对实际废水氨氮、总氮及硫酸盐的去除效果分别为44.05％、46.29％和26.06％,并且氨氮去除速率最高可达110.59 mg/（L·d）,硫酸盐平均去除速率为13.8 mg/（L·d）,均高于游离菌株。包埋小球存在一个物料内外传递的时间差,可提供细菌对环境变化适应的一个缓冲的时间,使得包埋固定化后的菌对于水质的变化具有更好的适应性,非常适用于处理天然橡胶加工废水。     

山茶油微胶囊的复合凝聚制备工艺参数及其热氧稳定性研究

以明胶和阿拉伯胶为壁材,茶多酚为固化剂,采用复合凝聚法制备山茶油微胶囊。通过单因素和正交试验考察壁材比、pH、壁材浓度、凝聚时间、芯壁比等复合凝聚条件对山茶油微胶囊包埋率和微观形态的影响,确定山茶油微胶囊复合凝聚的最佳制备工艺,并对微胶囊化前后的山茶油氧化稳定性进行分析比较。结果表明：山茶油微胶囊的最佳复合凝聚制备工艺参数为壁材比1∶1 （W/W）、pH 4.2、壁材浓度1.0%、凝聚时间30 min、芯壁比3∶2 （W/W）,在此最佳条件下制备的山茶油微胶囊产品呈浅棕色粉末状,平均包埋率达82.36%,休止角39.2°,含水率3.67%。热稳定温度280 ℃,具有良好的流动性和热稳定性。同时,加速氧化贮藏试验表明微胶囊化显著提高了山茶油的氧化稳定性。     

春兰根状茎缓慢生长保存和包埋保存

以春兰根状茎为材料,研究培养基中不同MS盐含量、蔗糖浓度、甘露醇浓度及矮壮素（chlormequat chloride, CCC）浓度对根状茎缓慢生长保存的影响;研究不同浓度海藻酸钠（sodium alginate, SA）和氯化钙（calcium chloride, CC）对于根状茎包埋珠合格率和萌发率的影响,并以此为基础研究春兰根状茎的包埋保存。结果表明：根状茎在MS+10.0 g/L蔗糖+10.0 g/L甘露醇+7.5 g/L琼脂+1.0 g/L活性炭和MS+20.0 g/L蔗糖+7.5 g/L琼脂+1.0 g/L活性炭的培养基上保存,12个月后存活率达84.00%。利用3.5%（W/V）的SA,75.0 mmol/L CC制成的根状茎包埋珠合格率和萌发率达97.60%和92.00%。合格的包埋珠在4 ℃下保存180 d,萌发率和再生率最高,分别为68.00%和64.00%。本研究的结果可为春兰等国兰的种质资源保存和种苗生产提供理论和技术指导。     

几种化学药剂对杂交籼稻汕优63自然老化种子引发效果研究

用聚乙二醇（PEG）、聚乙烯醇（PVA）、KNO3、PEG＋KNO3、PVA＋KNO3等几种化学药剂对自然老化的杂交籼稻汕优63种子进行引发效果研究,以筛选最佳处理方法。结果表明,从引发效果和经济实用两方面考虑,以0.5%PVA＋1.0%KNO3处理1 d为最佳。经过该处理的汕优63自然老化种子的发芽率显著提高,比对照（63.0%）提高了11.7个百分点,活力指数、发芽势、苗高、苗重也均较对照显著提高,且成本较低。     

蒽酮比色法测定棉花成熟纤维中水溶性总糖含量

 采用正交实验,对棉花成熟纤维中水溶性总糖的最佳提取条件进行了选择,得到最佳提取条件为：料液比1∶30,盐酸浓度5 mol·L^-1,水解时间30 min,提取时间60 min。并对蒽酮比色法测定总糖含量w的条件进行了研究,最佳条件为：测定波长625 nm,显色剂用量9 mL,沸水浴中加热9 min。对棉花成熟纤维样品进行测定,实验表明：葡萄糖标准溶液在0～10 mg·mL^-1浓度范围内,吸光度（A）与葡萄糖浓度（C）的线性关系较好,线性回归方程为A=0.0401C+0.0036（r=0.9994）,变异系数为1.8%,平均回收率为99.15%。该方法准确度、精密度较好,可用于成熟棉花纤维中低含量水溶性总糖含量的测定。     

橡胶初加工废水污染土壤的微生物固定化修复

橡胶初加工废水产生大量富含高有机质,并具有高粘度、酸性和高有机物等特点。因其处理成本较高且经常存在厌氧处理失效导致后端废水处理不达标、甚至有较多废水直接排出而污染了周边土壤,但目前对于橡胶初加工废水污染土壤的危害及修复关注度不够。前期从天然橡胶加工厂附近的受污染土壤中分离和驯化出了一种以芽孢杆菌为优势菌属的高效降解菌群命名为WR-2。WR-2在橡胶初加工废水降解方面表现出优异的性能,但在应用上WR-2需要一定的准备期及环境适应期。因此,本研究采用包埋法,以海藻酸钠–木薯渣生物质炭、甘蔗渣、椰糠3种载体材料及1.5%、2%两种材料浓度下进行固定化小球制备实验,同时进行橡胶初加工废水中典型的胶清废水污染土壤的固定化小球模拟修复实验,研究WR-2的包埋固定化基础性能及其生物修复能力。经过6组固定化微球在机械性能和对污染土壤的修复效果方面比较发现,2%椰糠改良固定化微球不仅具有较优良的机械性能,在模拟修复实验中对污染土壤的有机质（TOC）降解率高达（96.7%）,土壤二硫化四甲基秋兰姆（TMTD）在14 d全部降解,且使土壤pH从4.42调节至中性,土壤阴阳离子总数降低并具有良好的微生物活性。2%椰糠固定化小球极大地改善了土壤微观结构及土壤通气性和排水性。因此,海藻酸钠2%椰糠作为WR-2的固定化小球制备方式,对优化橡胶初加工废水污染土壤的生物修复能力具有效果优和即时应用的作用。     

菠萝蜜种子淀粉制备香草兰微胶囊的工艺研究

以菠萝蜜种子淀粉为壁材,采用饱和水溶液法制备香草兰精油微胶囊,以包埋产率为指标,采用响应面分析法对微胶囊的包埋条件进行优化探讨。结果表明:5个单因素中,影响最显著的因素为壁芯材比例、包埋温度和包埋时间。响应面优化得到香草兰精油微胶囊的最佳工艺条件为壁芯材比例为7.5∶1;包埋时间72 min;包埋温度54℃,此条件下的包埋产率为(95.46±0.2)%,包埋率为(76.35±0.6)%,载油量为(27.73±0.3)%。试验证明,此条件结果与模型预测值相吻合,此工艺条件可为菠萝蜜种子淀粉包埋香草兰精油微胶囊工艺提供理论依据。     

三种诱抗剂处理对苎麻叶片 PPO 和 POD活力的影响

多酚氧化酶（PPO）及过氧化物酶（POD）对植物抗性起重要作用,可被诱抗剂诱导产生。因此,本研究应用三种诱抗剂（水杨酸SA、壳寡糖CO、茉莉酸甲酯MeJA ）及其不同浓度喷施“川苎8号”苎麻幼苗,测定喷施后不同时间其叶片内PPO及POD活性,根据酶活性升高程度来筛选能使苎麻产生较大抗性的合适诱抗剂及使用浓度。结果表明喷施上述三种诱抗剂均能使叶片内PPO及POD活性升高;0.8 mM SA、3 g/L CO和1 mM MeJA喷施均比同类诱抗剂的其他浓度酶活性要高;同时,三种诱抗剂相比,0.8mM SA喷后7-8d, PPO和POD酶活性均达到最大,效果较其他2种诱抗剂稳定。由此认为SA为诱导苎麻产生抗性的合适诱抗剂,0.8 mM浓度提前7 d喷施能达到较好效果。     

开花期喷施水杨酸对不同类型专用小麦品种籽粒淀粉及产量的影响

为给水杨酸（SA）在小麦高产和淀粉品质调优栽培中的应用提供理论依据，2003～2004年度在大田试验条件下以强、中、弱筋三种类型冬小麦品种豫麦34、豫麦49和豫麦50为供试材料，在开花前3d和开花后7d喷施浓度分别为0、0．5、1．0和1．5g／L的SA，研究其对三种类型专用小麦品种籽粒淀粉组成、特性与产量的影响。结果表明，开花期喷施适宜浓度的SA可以提高淀粉含量、淀粉的支／直比例、粘度参数和强筋小麦的膨胀势，有利于小麦淀粉品质的改善，但对不同类型专用小麦的千粒重、籽粒产量和总淀粉产量的调节效应明显不同，即开花期喷施SA可以提高强筋小麦的千粒重、籽粒产量和总淀粉产量，但1．5g／LSA处理对中筋小麦表现出负效应，与对照相比差异均达极显著水平，对弱筋小麦则无显著调节作用。在本试验条件下，从保证产量和改善小麦淀粉品质的角度来看，对于强筋和弱筋小麦而言，以1．5g／LSA处理效果最好；而中筋小麦以1．0g／LSA处理效果最好。     

Mineral composition of some traditional Mexican teas

Teas of plant origin traditionally consumed by the Mountain Pima of Chihuahua, Mexico, were analyzed for mineral nutritional content. Fe, Cu, Zn, Ca, and Mg composition was determined for native teas made from shoots ofTagetes lucida, T. filifolia, Elytraria imbricata, andHolodiscus dumosus, and from root xylem ofCeanothus depressus andPhaseolus ritensis. Native uses of these teas are also described.     

Studies on natural repellents against potato tuber moth (Phthorimaea operculella Zeller) in country stores

Summary The effects of the leaves of five plant species, one from each of the generaAmbrosia, Anemone, Eupatorium, Eucalyptus andLantana, on potato tuber moth were investigated under indigenous storage conditions at the Central Potato Research Station, Shillong (1800 m above sea level). Their action was compared with that of a biological insecticide (spores ofBacillus thuringiensis), a chemical insecticide (carbaryl), and an untreated control. The data collected after six months storage on tuber damage, sprout damage and the rotting indicated that the leaves ofLantana aculeata provided most protection to the tubers, reducing damage from over 70% in the check to below 5%, and sprout damage from over 45% to below 3%. Next best wasEucalyptus globulus followed byB. thuringiensis. They may be used on tubers stored for table use or for seed as they had no adverse effect on germination or on the yield of a subsequent crop.     

Comparative Assessment of the Efficacy of Various Nitrogen Fertilizers

Summary

The efficiency of N fertilizers is usually poor; often less than 50% of the applied N is taken up by the crop. This review focuses on various N fertilizers with respect to the significance of different N loss pathways, namely (i) ammonia volatilization, (ii) dinitrogen and nitrogen oxide emissions, and (iii) nitrate leaching. Further, the significance of biological N immobilization, ammonium fixation and, finally, the impact of nitrate vs. ammonium uptake on crop yield are also discussed. The reviewed literature shows that N fertilizers may differ markedly in their susceptibility to losses. There is, however, considerable scope to improve N efficiency of each N source by proper N management practices.     

Redox Status and Neuro Inflammation Indexes in Cerebellum and Motor Cortex of Wistar Rats Supplemented with Natural Sources of Omega-3 Fatty Acids and Astaxanthin: Fish Oil,Krill Oil,and Algal Biomass

Health authorities worldwide have consistently recommended the regular consumption of marine fishes and seafood to preserve memory, sustain cognitive functions, and prevent neurodegenerative processes in humans. Shrimp, crabs, lobster, and salmon are of particular interest in the human diet due to their substantial provision of omega-3 fatty acids (n-3/PUFAs) and the antioxidant carotenoid astaxanthin (ASTA). However, the optimal ratio between these nutraceuticals in natural sources is apparently the key factor for maximum protection against most neuro-motor disorders. Therefore, we aimed here to investigate the effects of a long-term supplementation with (n-3)/PUFAs-rich fish oil, ASTA-rich algal biomass, the combination of them, or krill oil (a natural combination of both nutrients) on baseline redox balance and neuro-inflammation indexes in cerebellum and motor cortex of Wistar rats. Significant changes in redox metabolism were only observed upon ASTA supplementation, which reinforce its antioxidant properties with a putative mitochondrial-centered action in rat brain. Krill oil imposed mild astrocyte activation in motor cortex of Wistar rats, although no redox or inflammatory index was concomitantly altered. In summary, there is no experimental evidence that krill oil, fish oil, oralgal biomass (minor variation), drastically change the baseline oxidative conditions or the neuro-inflammatory scenario in neuromotor-associated rat brain regions.     

Potential of dry fractionation of wheat bran for the development of food ingredients,part II: Electrostatic separation of particles

Wheat bran is a composite material made of several layers, such as pericarp, testa and aleurone. It could be fractionated into purified fractions, which might either be used as food ingredients, or serve as a starting material for extraction of bioactive compounds. The aim of this work was to evaluate the potential of using electrostatic separation as a way to obtain purified fractions from wheat bran. Ultrafine-ground bran obtained either by cryogenic grinding or by grinding at ambient temperature was used as starting material. The ultrafine bran was then charged by tribo-electrification and introduced in a chamber containing two high voltage electrodes, where bran particles were separated depending on their acquired charge, allowing positively and negatively charged fractions to be collected separately. The particle size distribution, microstructure and biochemical composition of the obtained fractions were studied. The charge of the particles was influenced by their biochemical composition: particles rich in highly branched and cross-linked arabinoxylans (pericarp) were separated from particles rich in β-glucan, ferulic acid and para-coumaric acid (aleurone cell walls). The testa and the intracellular compounds from aleurone were not highly charged, neither positively nor negatively. The most positively charged fraction represented 34% of the initial bran, and contained 62% of the ferulic acid present in the initial bran. The yield of the separation process was good (5.4% loss), and could be further increased.     

Pharmacokinetics of Marine-Derived Drugs

Marine organisms represent an excellent source of innovative compounds that have the potential for the development of new drugs. The pharmacokinetics of marine drugs has attracted increasing interest in recent decades due to its effective and potential contribution to the selection of rational dosage recommendations and the optimal use of the therapeutic arsenal. In general, pharmacokinetics studies how drugs change after administration via the processes of absorption, distribution, metabolism, and excretion (ADME). This review provides a summary of the pharmacokinetics studies of marine-derived active compounds, with a particular focus on their ADME. The pharmacokinetics of compounds derived from algae, crustaceans, sea cucumber, fungus, sea urchins, sponges, mollusks, tunicate, and bryozoan is discussed, and the pharmacokinetics data in human experiments are analyzed. In-depth characterization using pharmacokinetics is useful for obtaining information for understanding the molecular basis of pharmacological activity, for correct doses and treatment schemes selection, and for more effective drug application. Thus, an increase in pharmacokinetic research on marine-derived compounds is expected in the near future.     

In vitro antimicrobial activity of different accessions ofSolanum commersonii Dun. from Uruguay

Summary The in vitro antimicrobial activity of extracts from accessions ofSolanum commersonii Dun. collected in the south of Uruguay was investigated against five microorganisms including the pathogenRalstonia solanacearum. A total of 30 extracts corresponding to organic and aqueous extracts were studied. Interestingly, most of the positive results for growth inhibition were againstR. solanacearum. The extracts were also analyzed for the presence of glycoalkaloids and lectins. Six of the ten aqueous extracts showed lectin presence and a wide variation in the type and amounts of glycoalkaloids, was found. Results indicate that there is no clear relationship between the antimicrobial activity against the five microorganisms screened and the presence or amounts of lectins and glycoalkaloids, traditionally regarded as possible antimicrobial metabolites in theSolanum genus, which indicates the presence of as yet unidentified antimicrobial compounds.     

<Emphasis Type="Italic">Pulque</Emphasis>, An Alcoholic Drink from Rural Mexico,Contains Phytase. Its <Emphasis Type="Italic">in vitro</Emphasis> Effects on Corn Tortilla

Pulque is made by fermenting the agave sap or aguamiel of Agave atrovirens with a whole array of microorganisms present in the environment including several lactic acid bacteria and yeasts such as Saccharomyces cerevisiae. Ascorbic acid was determined in pulque and aguamiel, respectively. Phytase activity in lees, liquid and freeze-dried pulque was assayed by measuring the appearance of phosphate from phytate by a colorimetric method likewise phosphate from phytate present in fresh corn tortilla was measured after in vitro incubation with pulque. Iron, zinc, calcium, magnesium and selenium contents were measured in pulque and corn tortilla as well as in nixtamalized corn flour (NCF), the latter is used to make instant tortilla, since corn provides most of the energy as well as most of the phytate in the Mexican rural diet. Pulque showed phytase activity but much less ascorbic acid and iron than previously reported; additionally, phytase in pulque hydrolyzed most of phytate’s corn tortilla. Lees, which is mostly made of pulque’s microbiota, significantly accumulated iron and zinc but no selenium. NCF was fortified with iron by the manufacturers but poorly blended. There were significant differences on selenium content between tortillas samples, apparently some soils in central Mexico are selenium deficient. Moderate pulque intake appears to increase the bioavailability of iron and zinc bound by phytate in corn.