2株毒死蜱降解菌的分离鉴定及其混合降解特性研究

从生产毒死蜱农药厂采集的活性污泥中分离筛选得到2株降解效率较高的毒死蜱降解菌,命名为D1、D3,根据表型特征、生理生化特性和16 S rRNA基因序列相似性分析,将其鉴定为苍白杆菌属(Ochrobactrum sp.)和副球菌属(Paracoccus sp.)细菌。2株菌以最佳配比(1∶1.25)混合施用时,与单菌相比,毒死蜱降解效率可提高12%~26%;以混合菌株为研究对象,发现其对毒死蜱最适降解温度为30℃,最适降解pH值为7.0,最适NaCl浓度为0.5%;混合菌株施入土壤后,可保持较高的定殖能力和降解效率。     

一株低温秸秆纤维素降解菌的分离、鉴定及降解特性

本研究在18℃条件下,利用赫奇逊滤纸培养基分离纯化菌株,根据透明圈和滤纸降解情况筛选菌株,最终通过酶活分析和秸秆降解率确定目的菌株,通过形态学观察与ITS基因序列分析对目的菌株进行初步鉴定,分离筛选高效低温秸秆纤维素降解菌并研究其产酶特性。结果表明,从小兴安岭山区土壤中分离到1株在低温下具有较强纤维素降解能力的真菌菌株C1,15 d内对秸秆的降解能力达55.6%,滤纸酶活和CMC酶活分别为18.4 U/mL和54.3 U/mL,初步鉴定菌株C1为青霉菌属(Penicillium sp.),具有进一步研究开发的潜力。     

大豆杀虫剂氧化乐果降解菌的分离

采用富集驯化培养方法,从哈尔滨农药厂污水处理池的活性污泥中筛选获得2株能彻底降解氧化乐果的菌株.氧化乐果浓度为100 mg·L-1时,两株菌在1 d内可完成降解,氧化乐果浓度为400 mg·L-1时,两株菌在3 d内可完成降解,浓度在1 000 mg·L-1时7 d内可完成降解,浓度达2 000 mg·L-1时7 d内降解率可分别达到75.28%和72.42%;当农药浓度较高时,菌株生长速度表现为延后.降解谱实验表明:菌株具有较宽的有机磷农药降解谱;通过生理生化分析及16S同源性分析发现,这两株菌与假单胞菌属和气球菌属极其相似.     

呋喃丹降解菌的分离与特性研究

采用富集驯化培养方法,从长期施用呋喃丹的大豆田土壤中分离到1株可高效降解呋喃丹的菌株.生物降解表明,5 d内该菌株生物降解农药牢达到94.7%;降解后期培养液采用气质联用分析方法末能检测到原药呋喃丹,检测到有新的化合物生成,而对照培养液中末发现有该类化合物的生成.同时无机盐培养液后期有红色现象生成,可能与呋喃酚开环有关;无细胞提取液加入农药重新培养表明,菌株可通过分泌胞外诱导酶在周质空间内降解农药;经16S rDNA鉴定,初步认为该菌株属于沙雷氏菌属(Serratia sp.).     

玉米秸秆低温纤维素分解菌的筛选及分解效果测定

在低温条件下,从腐烂的秸秆与土壤的混合样品中分离出降解纤维素能力强的4株菌株,测定这4株菌在玉米秸秆发酵中的CMC酶活。结果表明,菌株A14和A41在整个培养过程中CMC酶的活性比较高,分别为8.341 U/g和8.792 U/g。采用A14、A41处理玉米秸秆10 d,降解率分别达30.80%和31.52%。确定菌株A14和A41的最佳产酶条件为摇床转速150 r/min,接菌量为菌悬液(108个孢子/mL)与秸秆用量比1/10(质量比)。     

木质纤维素酶高产菌株的筛选和鉴定

从海南省乐东、三亚和儋州等市县采集的23份土样中粗筛获得186株具有纤维素降解能力的菌株,11株具有木质素降解能力的菌株,经进一步筛选获得纤维素酶高产菌和木质素酶高产菌各2株,编号分别为12—4、3—5、6—1和3—3。在以香蕉茎叶粉为主要基质的培养基中30℃、120r/min振荡培养5d,12—4和3—5分解羧甲基纤维素钠(CMC)的酶活分别达到979U和226U,分解滤纸(FP)的酶活分别为46.4U和15.1U,6—1和3—3的木质素酶活分别为32.8U和16.4U。经初步鉴定,这些菌株分别属于Trichodermasp.,Penicillumsp.,Streptomycesflavus和ChoanephoraCurreysp.,可用于发酵香蕉茎叶生产饲料的进一步研究。      

阿特拉津降解菌W24的分离鉴定和土壤修复效果研究

从玉米田土壤中分离出1株阿特拉津降解菌W24,通过生理生化反应和16S rRNA序列分析,鉴定该菌株为类节杆菌(Paenarthrobacter sp.)。菌株W24能利用阿特拉津作为氮源生长,当底物浓度为100 mg/L时,在适宜温度(20℃～35℃)、pH值为6～9,该菌株对阿特拉津的降解率均在40%以上、在最适温度(30℃)、pH值为7条件下培养72 h后,降解率达94.2%;当底物浓度为500 mg/L时,阿特拉津降解率仍达到40.4%。污染土壤的生物修复结果表明,菌株W24在培养35 d时对污染土壤中阿特拉津(50 mg/kg)的降解率为83.5%,菌株W24表现出很好的应用潜力。     

阿特拉津降解菌节杆菌菌株TW-1的分离及其在大豆中的初步应用分析

为缓解药害，通过选择培养基富集培养，从黑龙江省安达市农田中分离出一株以阿特拉津为唯一氮源生长的降解菌TW-1，经鉴定该菌株为节杆菌属（Arthrobacter sp.）。菌株TW-1对培养基中100 mg/L的阿特拉津降解率在48 h内可达到99.5％。盆栽实验结果表明，菌株TW-1可使大豆植株的叶绿素含量提高，并且可增加过氧化氢酶与过氧化物酶含量，有效缓解大豆植株的阿特拉津药害，具有良好的应用潜力。     

穿刺巴斯德芽菌PPh01菌株鉴定及其对根结线虫的寄生性测定

从海南定安胡椒根部根结线虫体上分离到一株细菌PPh01,其形态特征与穿刺巴斯德芽菌相似。16S rDNA序列分析结果表明：该菌株与穿刺巴斯德芽菌的同源性达到99.3％,在发育树上聚为同一分支,亲缘关系最近,鉴定该菌株为穿刺巴斯德芽菌（Pasteuria penetrans）。寄生性试验结果表明：该菌株对南方根结线虫、爪哇根结线虫、花生根结线虫的2龄幼虫均具有寄生性和侵染能力。     

一株大麻脱胶菌株的分离鉴定及其产果胶酶发酵培养基的优化

为了分离和鉴定对大麻有脱胶效果的碱性果胶酶生产菌株,优化其产果胶酶培养基组成,试验选用果胶作为唯一碳源进行菌株筛选,并采用单因素和正交试验筛选果胶酶发酵培养基组成。结果表明:从沤麻水体中分离到14株具有脱胶能力的细菌,其中X-6菌果胶酶产量最高,该菌革兰氏阴性,大小为0.6～0.8μm×2～3μm,据其生理生化特征和16S r DNA鉴定,该菌株鉴定并被命名为产碱假单胞菌X-6(Pseudomonas alcaligenes X-6),该菌的最佳产果胶酶培养基组成为葡萄糖5 g/L,马铃薯淀粉4 g/L,酵母粉4 g/L,玉米浆4 g/L,氯化钙1.5 g/L,氯化钠0.5 g/L,经验证在该条件下果胶酶活力达到586 U/m L,采用发酵后的粗酶液对大麻进行脱胶试验,残胶率由38.9%降低至17.2%,脱胶效果较好。试验分离和鉴定出一株对大麻脱胶效果较好的菌株,并获得其产果胶酶发酵培养基。     

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.     

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.     

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.     

Novel food and non-food uses for sorghum and millets

Sorghum and millets have considerable potential in foods and beverages. As they are gluten-free they are suitable for coeliacs. Sorghum is also a potentially important source of nutraceuticals such antioxidant phenolics and cholesterol-lowering waxes. Cakes, cookies, pasta, a parboiled rice-like product and snack foods have been successfully produced from sorghum and, in some cases, millets. Wheat-free sorghum or millet bread remains the main challenge. Additives such as native and pre-gelatinised starches, hydrocolloids, fat, egg and rye pentosans improve bread quality. However, specific volumes are lower than those for wheat bread or gluten-free breads based on pure starches, and in many cases, breads tend to stale faster. Lager and stout beers with sorghum are brewed commercially. Sorghum's high-starch gelatinisation temperature and low beta-amylase activity remain problems with regard to complete substitution of barley malt with sorghum malt . The role of the sorghum endosperm matrix protein and cell wall components in limiting extract is a research focus. Brewing with millets is still at an experimental stage. Sorghum could be important for bioethanol and other bio-industrial products. Bioethanol research has focused on improving the economics of the process through cultivar selection, method development for low-quality grain and pre-processing to recover valuable by-products. Potential by-products such as the kafirin prolamin proteins and the pericarp wax have potential as bioplastic films and coatings for foods, primarily due to their hydrophobicity.