水稻氧营养的生理、生态机制及环境效应研究进展

氧是水稻生命活动过程中重要的营养因子。水稻利用通气组织将大气中的氧从地上部分转运到根部,同时也能通过根系从生长介质中吸收一部分氧。良好的氧营养状况下水稻才能正常生长,不仅如此,氧营养还参与了水稻-土壤环境系统的作用过程,具有重要的生态效应。从氧营养的水稻生物学响应和根际生态效应两个方面综述了近年来稻田氧营养相关研究状况,重点总结了目前国内外有关水稻需氧性,氧营养对水稻形态学、解剖学特征的影响,相应的生理、生态机制以及环境效应的研究成果,同时比较了水稻生产上所采用的氧营养调控途径,并对水稻氧营养研究作了展望。

水源水库贫营养好氧反硝化菌群脱氮特性研究

为削减微污染水库中氮素的浓度,通过对西安市李家河水库沉积物进行定向富集驯化,筛选出以Pseudomonas菌为主、具有高效好氧反硝化特性的混合菌群-A1.摇床实验表明,贫营养好氧反硝化菌群A1在15h时硝酸盐氮去除率可达93.39%,硝酸盐氮平均去除速率为0.2073mg/(L·h);总氮去除率为52.11%,总氮平均去除速率为0.1153mg/(L·h),无亚硝酸盐积累.氮平衡分析表明,约45%的初始氮被去除转化为气体产物.响应面法(RSM)结果表明,C/N比9.96,温度22.67℃,pH8.01,转速91r/min,溶解氧8.55mg/L是去除总氮(TN)的最优条件.

剩余污泥厌氧消化过程中的物质转化及其资源化研究进展

资源化是剩余污泥处理处置的重要方向之一。剩余污泥厌氧消化会使大量的碳、氮、磷等营养物质释放出来,这些物质的再利用是剩余污泥资源化的重要途径。阐述了国内外剩余污泥厌氧消化过程中营养物质转化及其资源化方面的研究现状,总结了存在的问题,并对进一步研究发展方向提出建议。

金属依赖型厌氧甲烷氧化研究进展

甲烷(CH_(4))是一种温室气体,其温室效应是二氧化碳的26倍。减少甲烷排放,可以缓解温室效应,有助于保护大气环境。微生物介导的甲烷厌氧氧化是调节甲烷向大气排放的关键过程。金属氧化物或金属离子可以作为甲烷厌氧氧化的电子受体,且金属依赖的甲烷厌氧氧化是减小全球甲烷排放的一个重要途径。虽然研究表明金属依赖型厌氧甲烷营养古菌可以促进这一过程,但其菌种、代谢途径及胞外电子传递途径尚缺乏深入研究。文章从金属依赖型厌氧甲烷氧化菌、金属依赖型厌氧甲烷氧化机制及金属依赖型厌氧甲烷氧化菌胞外电子传递机制等方面对金属依赖型厌氧甲烷氧化研究现状进行了概述,分析了金属依赖型厌氧甲烷氧化研究存在的问题,并讨论了其今后的研究方向,为金属依赖型厌氧甲烷氧化研究提供参考。

生物产氢技术研究进展

Hydrogen is noted widely because it is a clean energy. Many countries in the world are studying and developing new methods for hydrogen production. Biological hydrogen production is one of such new methods with the advantages of utilizing renewable energy and wastes, and of low cost. In this paper, the characteristics of 5 modes of biological hydrogen production were summarized and compared according to hydrogen metabolic energetic. Furthermore, the molecular mechanism of biological hydrogen production by anoxygenic phototrophic bacteria was described. Finally, the newest progress of hydrogen production by anoxygenic phototrophic bacteria in the aspects of electronic donor, coupling to light energy, inhibition of ammonium, and genetic manipulation and exploiting of application system was reviewed. Fig 1, Tab 1, Ref

Effect of Different Arbuscular Mycorrhizal Fungi Strains on Mineral Nutrition and Antioxidant Enzymes of Chrysanthemum morifolium

[Objective] The purpose was to study the effects of different arbuscular mycorrhizal fungi strains（AMF）on the mineral nutrition and antioxidant enzymes of Chrysanthemum morifolium.[Method] The pot experiment was conducted in the greenhouse,C.morifolium ＇Jinba＇ was inoculated with five kinds of AMF,N,P,K,malondial dehyde（MDA）content,as well as the superoxide dismutase（SOD）,peroxidase（POD） and catalase（CAT） activity in roots,leaves and petals of C.morifolium were measured at seedling and flowering stages.[Result] The G.i,G.e and G.m treatments could promote mineral nutrient absorption,increase N,P,K content in roots,leaves and petals of C.morifolium compared with the control without inoculation.The G.d、G.e and G.m treatments could significantly reduce MDA content in roots and petals,thus alleviating membrane permeability and lipid peroxidation.The G.i treatments could also improve the SOD,POD and CAT activities of C.morifolium,thereby increasing the capability of scavenging oxygen free radicals.[Conclusion] According to the comprehensive analysis,G.i was screened out as the best strain to improve mineral nutrition and antioxidant enzyme activities of C.morifolium.

L-抗坏血酸棕榈酸酯的合成及应用

研究了一种以L-抗坏血酸和棕榈酸为原料,合成出L-抗坏血酸棕榈酸酯(AP)的改进方法,产率为86%。并探讨了AP作为抗氧剂在棉籽油中的应用,结果表明AP的抗氧效果优于BHA和BHT。

生物过滤处理微污染水机理分析

利用生物过滤处理微污染原水,分析了生物膜特性和生物相,对生物膜去除有机物、氨氮、铁、锰等的机理和生物膜净化作用特征进行研究.微污染原水中的氨氮和有机物是通过吸附、吸收、代谢、排出而得到去除的,其去除率分别为88%和30%,对铁的去除主要是接触氧化和生物的共同作用的结果,其去除率可达到94%以上,对锰的去除主要是依靠锰氧化细菌的催化作用,其去除率在90%以上.

Application Effect of Cassava Starch Anaerobic Fermentation Liquid on Watermelon Production

In order to find out a new way for environment-friendly and resourcelized utilization of cassava starch processing wastewater, the cassava starch anaerobic fermentation liquid was applied in watermelon production, and its effects on the growth and development, yield and fruit quality of watermelon were investigated. The results showed that the cassava starch anaerobic fermentation liquid significant- ly promoted the vegetative and reproductive growth and improved the yield and fruit quality of watermelon. Compared with conventional fertilization, the application of cassava starch anaerobic fermentation both with COD concentration of 1 200 mg/L according to the amount of 150 t/hm2 promoted the growth of vines and leaves of watermelon plants, brought forward the flowering, fruiting and harvest of watermelon and significantly increased the fruit number, fruit weight, yield, fruit size, fruit shape index, soluble solid content, soluble sugar content, soluble protein content and Vita- min C content of watermelon. At the same time of improving the yield and quality of watermelon, cassava starch anaerobic fermentation liquid was turned into treasure as a liquid fertilizer. This study provides a new ideal for the yield and quality im- provement of watermelon and the wastewater treating of starch factories.

High Potassium Aggravates the Oxidative Stress Inducedy by Magnesium Deficiency in Rice Leaves

Magnesium （Mg） deficiency in plant affects photosynthesis and many other metabolic processes. Rice （Oryza sativa L. cv. ＇Wuyunjing 7＇） plants were grown in hydroponics culture at three Mg and two potassium （K） levels under greenhouse conditions to examine the induction of oxidative stress and consequent antioxidant responses in rice leaves due to Mg deficiency. At low Mg （0.2 mmol L 1 Mg supply for two weeks after transplanting） and high K （6 mmol L^-1） for 21 days, the rice plants showed severe Mg deficiency and a significant decreases in the dry matter production. The Mg deficiency in leaves decreased chlorophyll concentrations, photosynthetic activity, and soluble protein, but significantly increased the concentrations of soluble sugars and malondialdchyde （MDA） and the activities of superoxide dismutase （SOLD, EC 1.15.1.1）, catalase （CAT, EC 1.11.1.6） and peroxidase （POD, EC 1.11.1.7）. In addition, Mg concentrations in the leaves and in the shoot biomass were negatively related to the activities of the three antioxidative enzymes and the concentration of MDA in leaves. There were very significant interactive effects between Mg and K supplied in the culture solution on shoot biomass yield, chlorophyll content, photosynthesis rate, the activities of SOD, CAT and POD, and MDA content in the leaves of rice. It is suggested that the high K level in the nutrient solution aggravated the effect of low Mg supply-induced Mg deficiency and created the oxidative damage in rice plants.

Enhanced Biological Nutrients Removal in Modified Step-feed Anaerobic/Anoxic/Oxic Process

In order to enhance phosphorus removal in traditional step-feed anoxic/oxic nitrogen removal process,a modified pilot-scale step-feed anaerobic/anoxic/oxic(SFA 2/O) system was developed,which combined a reactor similar to UCT-type configuration and two-stage anoxic/oxic process.The simultaneous nitrogen and phosphorus removal capacities and the potential of denitrifying phosphorus removal,in particular,were investigated with four different feeding patterns using real municipal wastewater.The results showed that the feeding ratios(Q1)in the first stage determined the nutrient removal performance in the SFA 2/O system.The average phosphorus removal efficiency increased from 19.17% to 96.25% as Q1 was gradually increased from run 1 to run 4,but the nitrogen removal efficiency exhibited a different tendency,which attained a maximum 73.61%in run 3 and then decreased to 59.62%in run 4.As a compromise between nitrogen and phosphorus removal,run 3 (Q1=0.45Qtotal) was identified as the optimal and stable case with the maximum anoxic phosphorus uptake rate of 1.58 mg·(g MLSS)-1 ·h-1.The results of batch tests showed that ratio of the anoxic phosphate uptake capacity to the aerobic phosphate uptake capacity increased from 11.96% to 36.85% with the optimal influent feeding ratio to the system in run 3,which demonstrated that the denitrifying polyP accumulating organisms could be accumulated and contributed more to the total phosphorus removal by optimizing the inflow ratio distribution.However,the nitrate recirculation to anoxic zone and influent feeding ratios should be carefully controlled for carbon source saving.

Enhanced biological nutrient removal in modified carbon source division anaerobic anoxic oxic process with return activated sludge pre-concentration

A pilot-scale modified carbon source division anaerobic anoxic oxic(AAO) process with pre-concentration of returned activated sludge(RAS) was proposed in this study for the enhanced biological nutrient removal(BNR) of municipal wastewater with limited carbon source. The influent carbon source was fed in step while a novel RAS pre-concentration tank was adopted to improve BNR efficiency, and the effects of an influent carbon source distribution ratio and a RAS pre-concentration ratio were investigated. The results show that the removal efficiency of TN is mainly influenced by the carbon source distribution ratio while the TP removal relies on the RAS pre-concentration ratio. The optimum carbon source distribution ratio and RAS pre-concentration ratio are 60% and 50%, respectively, with an inner recycling ratio of 100% under the optimum steady operation of pilot test, reaching an average effluent TN concentration of 9.8 mg·L-1with a removal efficiency of 63% and an average TP removal efficiency of 94%. The mechanism of nutrient removal is discussed and the kinetics is analyzed. The results reveal that the optimal carbon source distribution ratio provides sufficient denitrifying carbon source to each anoxic phase, reducing nitrate accumulation while the RAS pre-concentration ratio improves the condition of anaerobic zone to ensure the phosphorus release due to less nitrate in the returned sludge. Therefore, nitrifying bacteria, denitrifying bacteria and phosphorus accumulation organisms play an important role under the optimum condition, enhancing the performance of nutrient removal in this test.

An update on iron physiology

Iron is an essential micronutrient, as it is required for adequate erythropoietic function, oxidative metabolism and cellular immune responses. Although the absorption of dietary iron (1-2 mg/d) is regulated tightly, it is just balanced with losses. Therefore, internal turnover of iron is essential to meet the requirements for erythropoiesis (20-30 mg/d). Increased iron requirements, limited external supply, and increased blood loss may lead to iron deficiency (ID) and iron-deficiency anemia. Hepcidin, which is made primarily in hepatocytes in response to liver iron levels, inflammation, hypoxia and anemia, is the main iron regulatory hormone. Once secreted into the circulation, hepcidin binds ferroportin on enterocytes and macrophages, which triggers its internalization and lysosomal degradation. Thus, in chronic inflammation, the excess of hepcidin decreases iron absorption and prevents iron recycling, which results in hypoferremia and iron-restricted erythropoiesis, despite normal iron stores (functional ID), and anemia of chronic disease (ACD), which can evolve to ACD plus true ID (ACD + ID). In contrast, low hepcidin expression may lead to iron overload, and vice versa. Laboratory tests provide evidence of iron depletion in the body, or reflect iron-deficient red cell production. The appropriate combination of these laboratory tests help to establish a correct diagnosis of ID status and anemia.

Performance evaluation of a modified step-feed anaerobic/anoxic/oxic process for organic and nutrient removal

A pilot scale modified step-feed process was lmproved to increase nutrient/N ano P） ano organic removal operations from municipal wastewater. It combined the step-feed process and a method named ＂University of Cape Town （UCT）＂. The effect of nutrient ratios and inflow distribution ratios were studied. The highest uptake efficiency of 95% for chemical oxygen demand （COD） has been achieved at the inflow distribution ratio of 40/35/25. However, maximum removal efficiency obtained for total nitrogen （TN） and phosphorus at 93% and 78%, respectively. The average mixed liquor suspended solids （MLSS） was 5500 mg·L- 1. In addition, convenient values for dissolved oxygen （DO） concentration, and pH were obtained throughout different stages. The proposed system was identified to be an appropriate enhanced biological nutrient removal process for wastewater treatment plants owing to relatively high nutrient removal, sturdy sludge settle ability and COD removal.

Inorganic Carbon Parameters Responding to Summer Hypoxia Outside the Changjiang Estuary and the Related Implications

The eutrophication, hypoxia and coastal acidification are attracting more and more attention. In this study, inorganic carbon parameters, including dissolved inorganic carbon （DIC）, total alkalinity （TA） and calculated partial pressure of CO2 （pCO2）, obtained from a summer cruise in August, 2009, were used to investigate their integrated response to biological processes accompanying the oxygen depletion in the areas off the Changjiang Estuary. According to the observations, the typical hypoxia occurred in the bottom water just outside the Changjiang Estuary with Dissolved Oxygen （DO） lower than 2.00 mg L^-1. The biological uptake in the surface water and the decomposition of organic matter in the bottom water were fully coupled with each other. The high concentration of Chl_a （Chl_a = 10.9μgL^-1） and DO （9.25 mgL^-1）, profoundly decreased DIC concentration 0828 μmolkg^-1） and elevated pH （8.42） was observed in the surface water. The correspondingly increased DIC and depletion of oxygen were observed in the bottom water. The semi-quantitative analysis proved that the locally-produced phytoplankton, determined by primary productivity, was deposited to the bottom and contributed about 76% of total amount of the organic carbon decomposition in the bottom. However, in the bottom hypoxia （DO = 2.05 mgL^-1） area observed in the Southern Zhejiang coastal water, the responding patterns of inorganic carbon parameters deviated from the previous one. The expanding of Changjiang Diluted Water （CDW）, the adding of Hangzhou Bay water （with high DIC concentration） and Coastal Current together modify the DIC background value in this area, and the local degeneration and upwelling process may also help to offset the local DIC removed by net biological uptake in surface water. In addition when the mixing occurring in autumn, which may break the summer stratification, the excess release of high DIC in the bottom water to the subsurface water could have an important influence on coastal acidification and the CO2 uptake capacity in this area.

Why bortezomib cannot go with ‘green'?

Eat more‘green’or eat‘five a day’is one of the most important healthy lifestyle behaviours in the 21 century.Aiming to fight cancer effectively,more than half patients use vitamins or herbs concurrently with conventional anticancer treatment.Flavonoids or polyphenols existing in vegetables,fruits and green tea are common plant pigments with antioxidant properties and considered acting as cancer preventing or anti-cancer agents.Recently it was found that some flavonoids and vitamin C in diet or supplements have antagonistic effect with the anti-cancer drug bortezomib.Bortezomib is a specific inhibitor for proteasome and is currently used for treatment of relapsed and refractory multiple myeloma.Despite its successful rates in treating multiple myeloma and other solid tumors,it is unable to kill leukemic cells in the blood.It was recently revealed that some flavonoids and vitamin C present in green leaves and green teas in the blood can neutralize bortezomib by directly interaction between two chemicals.Here we summarize why dietary flavonoids should be avoided in patients who take bortezomib as chemotherapeutic drug.

Effect of Potassium Nutrition of Different Varieties of Rice on the Redox Status in Microzone Rhizosphere Soils

Being divided into three groups-strong, moderate and weak-according to the different kinetic parameters (Fmax, km, Cmin) of potassium uptake by crops, 21 cultivars of rice have been studied to find out the relationships between their potassium nutrition and the oxidation-reduction status in the rhizosphere soils.Results show that, with no application of K fertilizer, there were higher contents of active reducing substances and ferrous iron in rhizosphere soils planted with cultivars, such as Zhongguo 91, week in absorbing potassium than in soils cropped with cultivars, Shanyou 64, stronger in absorbing potassium. As a result of K application, however, these toxic substances were decreased appreciably in the soil, particularly in the root zone where weakly K-absorbing cultivars were growing, and the parameter of soil redox (pH +pE) was increased, the most striking example of this being found in the rhizosphere soil where the more strongly K-absorbing cultivars were growing. On and close to the root surface in soils where rice plants were supplied with potassium fertilizer, rather more iron oxide had been accumulated compared with rice receiving no potash, and even greater amounts of red iron oxide precipitated on the rice root in neutral paddy soils. As shown by the concentration distribution of active reducing substances and ferrous iron in a microzone of the profile, the redox range of rice roots supplied with potassium may extend as far as several centimeters from the root surface. It can thus be seen that potassium nutrition exerts its effect first on the morphological properties of rice roots and their exudation of oxygen, then on the content of soluble oxygen and the count and species of oxygen-consuming microbes in the rhizosphere soil, and finally on the redox status of the soil.

Nutritional Analysis and Physiological Activity Evaluation of Pneumatophorus japonicus Sauce

The nutritional composition of Pneumatophorus japonicus sauce was analyzed and compared with other fish sauces. The sodium chloride content of the sample Pneumatophorus japonicus sauce was greater than 25%. The total soluble nitrogen content was greater than 2.1 g/100mL, and the amino nitrogen content was greater than 1.2 g/100mL. The mineral content was abundant in the Pneumatophorus japonicus sauce, the calcium content and the magnesium content were 391.50±0.03 and 375.00±0.02 mg/L respectively, much higher than those in other samples. The iron content and the zinc content were 22.30±0.04 and 2.80±0.03 mg/L, respectively. The content of free amino acids was 5 552.17 mg/100mL, the content of essential amino acids was 2 666.00 mg/100mL,The taurine content was 113.05 mg/100mL. The antioxidant activity of the fermentation broth was 90.48%, while the TCA soluble peptide content was 29.04 mg/mL. Pneumatophorus japonicus sauce is nutritionally rich and has special physiological activity.

Preliminary Comparative Study on Antioxidant Capacities of Yak

The aim of the present experiment was to determine if there was an adaptation on plasma antioxidant capacities of yak under the malnutrition （fasting treatment）. Three castrated male yaks and equal numbers of indigenous male cattle and of castrated male cattleyak with mean body weight of 146 ± 5.0, 116 ±3.0 and 149 ± 5.0 kg, respectively, were used. The fasting period lasted for 6 d. Results showed that： plasma total antoxidative capacity （T-AOC） was no differences between the genotypes on the fasting 1 st, 3rd, and 6th （P 〉 0.05）, but the values were linear greater with fasting days for yak, however, it was inverse for indigenous cattle or cattle-yak; plasma xanthine oxidase （XOD） activities of indigenous cattle were less than yak＇s and cattleyak＇s on the fasting 1st and 3rd day （P 〈 0.05）, but the value of indigenous cattle was greater than yak＇s and cattleyak＇s on the fasting 6th day （P 〈 0.05）. In a conclusion, plasma antioxidant capacities indicated that yaks have evolved an ability to survive in a starvation than indigenous cattle, and their crossbred-cattleyak also has inherited some of the adaptive characteristics.

Dietary Fiber, Phytonutrients and Antioxidant Activity of Common Fruit Peels as Potential Functional Food Ingredientw

Mangiferaindica L. （carabao mango）, AnnonaMuricata L. （soursop）, Citrofortunellamicrocarpa（calamansi）, and Musa acuminate x balbisianaColla （ABB Group） （plantain banana） have long been used in the processed food industries. However, the peelsof these fruits are normally disposed as waste or at most used as fertilizer and feeds. The objective of the study is to characterize the peels of these fruits as functional food/ingredient. Freeze-dried fruits peels of carabao mango, soursop, calamansi and plantain banana were analyzed for proximate composition, dietary fiber and phytonutrients contents, fermentability invitro and antioxidant activity. Results showed soursop peels having significantly higher soluble （12.75 g/100 g sample） and insoluble （62.55 g/100 g sample） dietary fiber among the fruit peels studied. All peels produced significant amounts of short chain fatty acids, propionate 〉 acetate 〉 butyrate. Carabao mango peels produced the highest amount of acetate while calamansipeels, the highest propionate （215.8± 3.6 mg/100 g）. Carabao mango and soursop peels have significantly greater total polyphenols, flavonoids, anthocyanidins andantioxidant activity. The study showed that fruit peels of carabao mango, soursop, calamansi and plantain banana can be potential functional food ingredients.