降香黄檀、檀香根际解钾菌的筛选与活性研究

为提高降香黄檀-檀香人工林的土壤肥力,从不同林龄的降香黄檀、檀香根际土壤中分离筛选高效解钾菌。从钾细菌富集培养基上初筛和解钾菌筛选培养基复筛得到可培养物89个。采用原子吸收分光光度法测定菌株解钾能力。结果表明,可溶性钾含量在70μg/m L以上的菌株有6株,其中菌株JT-K21、JT-K11和JT-K18的解钾率为80%以上。JT-K21培养液的可溶性钾含量高达132.68μg/m L,解钾率达到221.18%。基于形态学、生理生化特性及16S rDNA序列比较分析,初步鉴定JT-K21为恶臭假单胞菌Pseudomonas putida。不同碳氮源试验表明:JT-K21对蔗糖和硫酸铵的吸收效果最好。通过单因素试验及正交试验结果表明:菌株JT-K21液体发酵菌体浓度最大培养组最优组分为蔗糖(10 g/L)、硫酸铵(0.2 g/L)、氯化钠(0.1 g/L)、钾长石(5 g/L);JT-K21液体发酵解钾活性最佳时,培养基最优组分为蔗糖(10 g/L)、硫酸铵(0.2 g/L)、氯化钠(0.1 g/L)、钾长石(3 g/L)。     

山东茶园土壤高活性解钾细菌的筛选鉴定及肥效研究

为了筛选到适合山东茶园土壤环境的解钾菌株,以提高土壤钾素的高效转化效率,本研究经过菌株富集、分离、纯化等步骤,从山东茶园土壤中分离出9株解钾细菌。通过有效钾含量比较和菌株分类,筛选出1株活性最强菌株K2,经鉴定K2菌株为枯草芽孢杆菌（Bacillus subtilis）。发酵试验表明,菌株K2最适宜生长的条件为pH值6.0,温度35℃,以麦芽糖、淀粉、玉米粉为碳源,酵母膏为氮源。施用该菌剂后土壤速效钾和速效磷含量比对照最大分别提高28.40%和28.49%。茶叶产量最大提高36.30%,同时茶叶中氨基酸含量显著增加,酚氨比值降低,有利于茶叶品质的提升。菌株K2可能是一株茶园土壤高效解钾细菌,可作为后续进一步研究茶园专用微生物菌剂的参考。     

不同产区青稞根部可培养内生固氮菌的多样性研究

为认识青稞内生固氮菌群落组成,丰富内生固氮菌资源,明确产地对青稞内生固氮菌多样性的影响,本研究利用纯培养技术分别对在拉萨、林芝、日喀则栽培的藏青2000根部内生固氮菌进行分离、纯化,并测定各菌株的固氮酶活性及高固氮酶活性菌株的溶磷、溶钾及产IAA特性,最后,通过16SrDNA基因测序和构建系统发育树研究了高固氮酶活性菌株的分类学地位。结果显示,通过Ashby培养基分离、纯化得到内生固氮菌37株,其中,具有高固氮酶活性的11株,占总分离菌株27%,有6株菌株具有分泌IAA的能力,2株具有溶钾能力,1株具有溶磷能力。16S rDNA测序结果表明,11株高固氮酶活性的菌中,有5株菌属于Bacillus,为优势菌属,其余菌株分别属于Gemmatimonas、Sphingomonas、Devosia、Agrobacterium、Mesorhizobium和Burkholderia。     

玉米茎腐病拮抗菌筛选及发酵条件优化

采用平板稀释法进行菌种选育, 筛选玉米茎腐病的生防菌及对该菌株进行液体发酵。应用响应面法优化发酵条件, 以禾谷镰刀菌为指示菌测定生物活性。筛选得到1株较高活性菌株(YH-1), 将该菌株进行发酵条件优化, 抑菌圈直径由原来的20.60 mm增至25.80 mm。YH-1作为高效玉米茎腐病拮抗菌株, 可为生防菌剂开发奠定良好基础。     

一株花生白绢病菌拮抗细菌的筛选、鉴定及发酵液中活性物质稳定性研究

为筛选对花生白绢病菌(Sclerotium rolfsii Sacc.)具有高效拮抗活性的细菌菌株,采用平板对峙法和菌丝生长速率法对4株细菌进行抑菌活性的测定,并对筛选的高效拮抗菌株进行鉴定和活性物质稳定性研究。结果表明,菌株WS3-1对花生白绢病菌的抑制作用最强,其发酵滤液对病菌的抑菌率达95.04%。通过细菌形态特征、生理生化特征及16S rDNA和gyrB序列分析,将菌株WS3-1鉴定为解淀粉芽孢杆菌(Bacillus amyloliquefaciens)。菌株WS3-1发酵液中活性物质在温度为40℃、60℃、80℃以及pH为8～10的条件下,抑菌活性稳定,抑菌率均在80%以上,同时活性物质具有较好的抗紫外线分解能力。以上结果说明解淀粉芽孢杆菌WS3-1是一株具有开发和应用潜力的花生白绢病生防菌株。     

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。     

内生细菌BEB33的分离、鉴定及对香蕉枯萎病的生防作用评价

从健康香蕉植株根内分离得到1株对香蕉枯萎病病原菌FOC4具有强抗菌活性的内生细菌。通过形态观察、生理生化特性测定及分子分析,鉴定该菌为解淀粉芽孢杆菌,编号为BEB33。平板对峙和盆栽苗评价结果表明,该菌株对香蕉枯萎病具有较好的生防作用;该菌株发酵产物的拮抗活性对温度、pH不敏感;进一步研究表明,该菌株能够产IAA促进香蕉植株生长,同时产生铁载体,具有较好的生防潜力。     

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。     

高效油脂降解菌的筛选与鉴定

[目的]筛选并鉴定高效油脂降解菌。[方法]采用富集分离法从食堂下水道口的污泥、污水池、油脂加工厂和发霉菜籽饼中分离出8株具有油脂降解能力的菌种,经复筛最终得到1株降解油脂能力较高的菌株,通过从菌株形态和生理生化特征进行鉴定。[结果]菌株CS-4的初始酶活力为10 U/mL,在牛肉膏蛋白胨固体培养基上表面光滑,单菌落,湿润,革兰氏阳性杆菌,有运动性,好氧,葡萄糖发酵产酸,初步确定该菌为芽孢杆菌属。[结论]该研究为在油脂下脚料及油脂污染中采用生物降解提供一定的理论依据。     

芭蕉植株上乳酸菌的分离鉴定及抑菌菌株的初步筛选

为分析芭蕉植株(Musa basjoo Siebold)上附着的微生物菌群,并从中分离选育乳酸菌菌株,扩大植物源乳酸菌菌种库,为今后的青贮饲料发酵业和食品发酵工业等提供植物源乳酸菌,运用菌落计数法对样品中的乳酸菌、好氧细菌、霉菌、酵母、芽孢杆菌等进行菌落计数;分离纯化疑似乳酸菌的菌株,对疑似乳酸菌菌株进行生理生化试验、生长速率测定试验和产酸速率测定试验,以此来鉴定其生理生化特性以及属的分类;利用其发酵产物对大肠杆菌(Escherichia coli,E.coli)和沙门氏菌(salmonella)和单增李斯特菌(Listeria monocytogenes)进行抑菌试验。结果显示:样品中均含有好氧细菌(6.5~8.0 log cfu/g FM)、霉菌(6.0~7.7 log cfu/g FM)、酵母(2.0~3.3 log cfu/g FM)、芽孢杆菌(2.0~4.4 log cfu/g FM)及乳酸菌(6.5~7.5 log cfu/g FM);在芭蕉植株上共筛选出34株疑似乳酸菌菌株,对其进行生理生化鉴定,试验菌株均符合乳酸菌的生理生化特性,其中有4株菌株抑菌效果较好,经鉴定均为植物乳杆菌。     

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.     

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.     

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.     

La pourriture fongique des tubercules de pomme de terre en atmosphère contrôlée

Résumé Fusarium culmorum et, dans une moindre mesure,F. avenaceum, F. sambucinum, Colletotrichum coccodes etCylindrocarpon sp. ont été isolés de tubercules entreposés en atmosphère contr?lée (AC) et atteints de pourriture grave. Des expériences d'inoculation de tubercules avec 10 espèces ou variétés fongiques et conservation en AC à 8 et 10°C ont montré que: 1) les champignons non pathogènes en atmosphère normale (ex.:Cylindrocarpon sp.) le devenaient en AC, 2) ceux qui étaient faiblement pathogènes en atmosphère normale étaient nettement plus virulents en AC (ex.:F. culmorum), 3) les espèces ou variétés virulentes en conditions d'air normales (Fusarium sulphureum etPhoma exigua var.foveata) ne provoquaient pas de pourriture plus grave en AC et leur activité pouvait même être légérement freinée.

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Summary The extensive rotting of tubers which occurred during storage trials in controlled atmospheres has led to a mycological and pathological study of the rots. The most frequently isolated species wasFusarium culmorum althoughF. avenaceum, F. Sambucinum, Coletotrichum coccodes and aCylindrocarpon sp. were also present. Tubers of cvs Bintje and Ulla were inoculated with 19 isolates of 10 fungal species or varieties associated with rotting of stored tubers (Table 1). The tubers were incubated at 8 or 10°C in normal or controlled (2% O₂:1% CO₂, 2% O₂:6% CO₂, 2% O₂:12% CO₂, 6% O₂:6% CO₂) atmospheres and the extent of rotting was determined a month later (Tables 2 and 3 and Fig. 2). Species which were weakly virulent in a normal atmosphere (variousFusarium spp. andPhoma exigua var.exigua) were clearly more aggressive in the controlled atmosphere and this was especially evident in the case ofF. culmorum. Species ot pathogenic in a normal atmosphere under experimental conditions (Colletotrichum coccodes, Cylindrocarpon sp.,Phoma eupyrena) caused rotting in the controlled atmosphere. The two species which were virulent in a normal atmosphere (F. sulphureum andP. exigua var.foveata) were also virulent in the controlled atmosphere and in some cases the extent of rotting was even less. As a general rule, rotting caused by weakly virulent fungi was greater in both cultivars in the controlled than in a normal atmosphere.

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Zusammenfassung Eine starke F?ulnis von in Kontrotrollierter Atmosph?re gelagerten Kartoffelknollen veranlasste eine mykologische und pathologische Untersuchung. Der am h?ufigsten isolierte Pilz warFusarium culmorum. F. avenaceum, F. sambucinum, Colletotrichum coccodes undCylindrocarpon sp. wurden ebenfalls bestimmt. Neunzehn St?mme von 10 Pilzsorten oder-Arten welche bei Lagerf?ulnis vorkommen (Tab. 1) wurden auf Knollen der Sorten Bintje und Ulla inokuliert. Die Lagerung wurde bei 8 oder 10°C under Normalbedingungen oder kontrollierter Atmosph?re durchgeführt (2% O₂:1% CO₂, 2% O₂:6% CO₂, 2% O₂:12% CO₂, 6% O₂:6% CO₂). Der F?ulnisgrad (Abb. 1) wurde nach einem Monat bonitiert. Die Ergebnisse sind in den Tabellen 2 und 3 dargestellt und in der Abb. 2 illustriert. Unter in Normalbedingungen nur schwach virulente Arten (verschiedeneFusarien undPhoma exigua var. exigua) waren deutlich aktiver in kontrollierter Atmosph?re. Dies was besonders der Fall fürF. culmorum. Pilze, die im Versuch unter Normalbedingungen nicht pathogen waren (Colletotrichum coccodes, Cylindrocarpon sp., Phoma eupyrena), haben unter kontrollierter Atmosph?re Sch?den verursacht. Hingegen werden die beiden unter Normalbedingungen sehr pathogenen Arten (F. sulphureum undP., exigua var.foveata), durch kontrollierte Atmosph?re wenig beeinflusst. Es wurde sogar in einigen F?llen eine gewisse Verringerung des F?ulnisbefalls beobachtet. Ganz allgemein haben die getesteten kontrollierten Bedingungen die Entwicklung der Pilzf?ulnis an beiden Kartoffelsorten gef?rdert, speziell durch Pilzarten, welche unter Normal-bedingungen wenig Sch?den verursachen.

     

Citrus Flavonoids in Fruit and Traditional Chinese Medicinal Food Ingredients in China

Flavonoids-enriched tissues of citrus such as peel, immature fruit and flower are consumed as culinary seasonings, tea ingredients in China for centuries. This HPLC quantitative study on the five citrus flavonoids, naringin, hesperidin, neohesperidin, sinensetin and nobiletin on a wide range of Chinese citrus fruits and several Traditional Chinese Medicinal food ingredients in East China, revealed a great diversity in flavonoid composition. Huyou peel (C. paradisi cv. Changshanhuyou) was found to be the best naringin (3.25%) and neohesperidin (2.76%) source; C. aurantium, a major ingredient of several citrus-related TCM, is also a suitable source of naringin and neohesperidin, and a good juice source for flavanone glycosides; the peel of Wenzhoumiju (C. unshiu) is one of the richest local species in hesperidin (up to 6.25%); Zaoju (C. subcompressa) has the highest content of nobiletin (0.59%), a polymethoxylated flavone. LC-ES-MS analysis of Zanthoxylum genus for flavonoids revealed for the first time the presence of significant amounts (0.74%) of hesperidin in the root of Liangmianzhen (Z. nitidum (Roxb.) DC), a relative of Sichuan pepper, which is a spice widely used in China.     

Evolutionary aspects of the trade-off between seed size and number in crops

Whereas the concept that availability of resources drives seed production is sound in principle, it is incomplete as there are many solutions to the allocation of resources that derive from the trade-off between number and size. This paper examines evolutionary aspects of this trade-off in annual grain crops. The analysis is centred on the working hypotheses that, for a given species and environment, allocation of resources to reproduction involves (H1) high plasticity in seed number, which allows for variable resource availability, and (H2) a relatively narrow range of seed size that results from evolutionary and agronomic selection. Comparisons between crops and fish are used to highlight common evolutionary elements in taxa where parents provide little or no care to their offspring, with the consequence that both number and early survival of offspring, hence fitness of parents, are partially related to embryo size and reserves.

The plasticity of seed number in relation to availability of resources is analysed against the established relationship between offspring number and parent growth rate during critical stages. The notion that seed size is under stabilising selection is analysed against three conditions: (1) mean seed size is conservative for a given species and environment, (2) seed size affects fitness, and (3) seed size is heritable. Databases from published papers were compiled to analyse the relative variability of seed size and number, and the heritability of seed size. Evidence for and against the link between seed size and parental fitness is revised using the Smith–Fretwell model as framework (Am. Nat., 108, 499–506).

The proposal of high plasticity of seed number and narrow variability of seed size resulting from stabilising natural selection is generally consistent with evolutionary and genetic considerations. Agronomic selection may have reinforced natural selection leading to relatively narrow seed size in species such as wheat and soybean, where cultivated types retained high plasticity for seed number. In contrast, selection for one or few inflorescences in crops like sunflower and maize may have morphologically reduced seed number plasticity and increased variability of seed size and its responsiveness to resource availability in relation to their wild ancestors.     

Marine Pharmacology in 2016–2017: Marine Compounds with Antibacterial,Antidiabetic, Antifungal,Anti-Inflammatory,Antiprotozoal, Antituberculosis and Antiviral Activities; Affecting the Immune and Nervous Systems,and Other Miscellaneous Mechanisms of Action

The review of the 2016–2017 marine pharmacology literature was prepared in a manner similar as the 10 prior reviews of this series. Preclinical marine pharmacology research during 2016–2017 assessed 313 marine compounds with novel pharmacology reported by a growing number of investigators from 54 countries. The peer-reviewed literature reported antibacterial, antifungal, antiprotozoal, antituberculosis, and antiviral activities for 123 marine natural products, 111 marine compounds with antidiabetic and anti-inflammatory activities as well as affecting the immune and nervous system, while in contrast 79 marine compounds displayed miscellaneous mechanisms of action which upon further investigation may contribute to several pharmacological classes. Therefore, in 2016–2017, the preclinical marine natural product pharmacology pipeline generated both novel pharmacology as well as potentially new lead compounds for the growing clinical marine pharmaceutical pipeline, and thus sustained with its contributions the global research for novel and effective therapeutic strategies for multiple disease categories.     

Effects of Micronutrient Deficiencies on Human Health: Its Status in South Asia

SUMMARY

Vitamin A, iodine, and iron deficiencies affect large numbers of people worldwide. A deficiency of one or more of these micronutrients adversely affects the physical and mental abilities of humans. South Asia contains a high percentage of these individuals, not just because of its large population, but also the prevalence of deficiency is higher there than in many other parts of the world. The reasons for the high rates of deficiency in South Asia are many, but they include inadequate availability of micronutrient-rich foods, sub-optimal dietary habits, and high rates of infection. Across the region, national plans vary from (a) increasing availability of appropriate foods, (b) introducing new dietary behaviors, (c) improving health status, and (d) directly addressing deficiency through intervention programs. The extent to which each of the countries is making progress toward the goals of these plans can help in understanding the priorities for future efforts to address micronutrient malnutrition. This article discusses the adverse effects of micronutrient deficiencies in humans with special reference to South Asia.     

Effect of a continuous hot water treatment of potato tubers on seed-borne fungal pathogens

Summary The viability of five pathogens was decreased by treatment with hot water when tested in vitro.Polyscytalum pustulans was most sensitive andRhizoctonia solani least sensitive. Potato tubers were exposed to 55°C for 5 min in a commercial continuous hot water treatment plant using naturally contaminated seed tubers and tubers which had been inoculated by dipping in comminuted cultures. The frequency of eyes colonised byP. pustulans, Helminthosporium solani, andR. solani was reduced to virtually zero and the effect persisted on tubers subsequently stored at 4°C and at 15°C for up to 16 wk. Results withColletotrichum coccodes were inconclusive. Treatment suppressedPenicillium spp. which, however, rapidly recolonised the eyes during storage, leading to higher contamination levels in the treated than in the untreated tubers. With tubers inoculated withPhoma foveata, good control was achieved when the incubation period before treatment was 10 d but not when the period was 42 d.