利用纤维素水解液中的纤维二糖发酵制备丁二酸

纤维素水解液中通常含有纤维二糖。本文考察了Actinobacillus succinogenes NJ113利用纤维二糖厌氧发酵生产丁二酸的能力,并利用蔗渣纤维素制备纤维二糖作为碳源用于厌氧发酵生产丁二酸。3 L发酵罐厌氧发酵结果显示：以35 g/L纤维二糖作为碳源发酵制备丁二酸,其产量为23.51 g/L,产率达到67.17%;用含有18 g/L纤维二糖和17 g/L其它糖类的蔗渣纤维素水解液作为碳源发酵制备丁二酸,丁二酸的产量和产率分别为20.00 g/L和64.73%。因此,Actinobacillus succinogenes NJ113具有较强的利用纤维二糖生产丁二酸的能力,而且利用废弃的纤维素制备纤维二糖作为碳源高效、经济地发酵制备丁二酸具有可行性。     

Application of Cocultures of Fungal Mycelium during Solid-State Fermentation of Canola Meal for Potential Feed Application

In this study, the mono-, bi-, and tri-cultivation of Aureobasidium pullulans, Neurospora crassa, and Trichoderma reesei in solid-state fermentation were applied to improve the nutritional values of hexane extracted canola meal (HECM) along with the reduction of antinutritional factors for animal feed applications. Static fermentation trials of 50% moisture content HECM were conducted in 500 mL Erlenmeyer flasks for 168 hours at 30 °C. The results showed that fungal cultivation had positive effects on the level of protein, fiber, and, glucosinolates (GLS). Monoculture of N. crassa exhibited the highest protein level of 49%. The combination of A. pullulans and N. crassa provided the highest reduction of crude fiber, acid detergent fiber and neutral detergent fiber by 21.9%, 1.7%, and 9.1%, respectively. Bi-culture of A. pullulans and T. reesei resulted in the best GLS reduction by 81.3% (0.3 vs. 1.6 μM g⁻¹ GLS of uninoculated control). These results indicate that each fungal strain possesses different enzymatic ability and selectively can work with other fungi in synergistic relationship for better fungal conversion of canola meal.     

植酸的制备和应用

介绍了由玉米提取植酸的新方法,最佳条件是控制pH=6,提取植酸的钙镁盐--菲汀,然后在pH=2时用草酸溶解菲洒得植酸,并从植酸的性质介绍了植酸在各行业的广泛应用。     

Dryland wheat yield dependence on rainfall,applied N and mulching in preceding maize

To evaluate the response of dryland wheat (Triticum aestivum L.) to mulching in preceding maize and fertilizer N application field experiments were conducted for six years (1980–86) with maize-wheat sequence on a sandy loam soil in northern India. Four rates of N application viz. 0, 40, 60 and 80 kg N ha^–1 in wheat were combined with three mulch treatments viz. no mulch (M₀), paddy straw mulch (M_p) and basooti (Premma mucronate) mulch (M_b) applied at the rate of 4 tons ha^–1 on dry weight basis applied three weeks before harvest of maize. Mulching (M_p and M_b) increased (profile) stored moisture at wheat seedling by 31 to 88 mm. M_b also increased NO₃-N content by 33 to 42 kg ha^–1 in 0–120 cm profile over M₀ and M_p. Over the years, M_p increased wheat yield by 11 to 515 kg ha^–1 and M_b by 761 to 879 kg ha^–1. Wheat yield response to mulching was related to rainfall pattern during its growth season. Significant response to mulching was obtained only in years when rainfall during vegetative phase of the crop was low. Amount and distribution of rainfall during two main phases of crop development affected the N use efficiency by wheat. On an average, each cm of rain substituted for 3.5, 4.6 and 6.5 kg of applied N ha^–1 under M₀, M_p and M_b, respectively. Split rainfall for two main phases of crop growth, available stored water at seeding, fertilizer N and profile NO₃-N content accounted for 89 per cent variability in wheat yield across years and mulching treatments.     

Boron uptake and toxicity in wheat in relation to zinc supply

Zinc deficiency may enhance B absorption and transport to such an extent that B may possibly accumulate to toxic levels in plant tops. Therefore, a screen house experiment was conducted to investigate the effect of B levels (0, 2.5, 5.0, 7.5 and 10 mg B kg^–1 soil) as influenced by Zn levels (0, 10 and 20 mg Zn kg^–1 soil) on DM yield of wheat tops and tissue concentration and uptake of B, Zn, Cu, Mn, Fe, Ca, Mg, K and P. Application of B decreased the dry matter yield of wheat significantly at all levels of Zn. Conversely, increasing levels of Zn increased the wheat yield significantly. The application of B increased the tissue concentration and uptake of B by wheat plants more in the absence than in the presence of Zn application. Consequently, concentration of B in wheat plants decreased with increasing levels of Zn application to the soil. This decrease in tissue B concentration was not only due to increased growth of wheat plants. Zinc application appears to have created a protective mechanism in the root cell environment against excessive uptake of B, as evidenced by the reduction of B uptake in Zn treated plants. The uptake of Mn, Mg and P decreased while the uptake of Cu, Fe, and K by wheat plants increased with Zn application. Whereas, the uptake of all nutrients (Cu, Fe, Mn, Ca, Mg, K and P) decreased significantly with the application of B. However, this depressive effect of B on nutrient uptake was less marked in the presence of applied Zn.     

Investigation of the effect of temperature and alkaline concentration on the solubilization of phenolic acids from dilute acid-pretreated wheat straw

This work deals with the investigation of the effect of alkaline concentration and temperature on the solubilization of phenolic materials from wheat straw, an abundant agricultural waste found in Turkey. The solid residue obtained after dilute acid pretreatment of wheat straw (SPWS) was treated by alkaline to solubilize the lignin to phenolic acids. Four different alkaline concentrations at 120 °C and seven different temperatures with 2 M NaOH were evaluated for the degree of solubilization of the phenolic materials, and the antioxidant activities of the soluble phenolic materials were determined. It was found that coumaric and ferulic acids were the major phenolic acids in all of the conditions tested. The highest antioxidant capacity of the hydrolysate of SPWS was obtained with 2 M NaOH at 150 °C where DPPH*, FRAP and TEAC values were found to be 3.23, 10.27 and 13.70 μmol/g WS, respectively.     

A comparison of the lipids of triticale,wheat and rye grown under similar ecological conditions

Samples of triticale, wheat and rye grown in the same season at the same location in southern United States were analyzed for amounts and types of lipids and for fatty acid composition. Selected kernels of the 3 cereals were separated into anatomical parts (bran, endosperm and germ) and analyzed for amounts and types of lipids, and the anatomical parts of triticale were analyzed for fatty acid composition. The triticale contained several times more phosphatidylcholine and phosphatidylethanolamine than did the wheat and rye. Marked differences in lipid composition were found in the bran, endosperm and germ fractions; and some differences were found among corresponding fractions of the 3 cereals. The bran fractions were rich in steryl esters and contained no glycolipids or phospholipids. Fatty acid compositions of the lipids from the anatomical parts of triticale exhibited some difference. One of the facilities of the Southern Region, Science and Education Administration, U.S. Department of Agriculture.     

植酸的生产应用及其开发前景

介绍了植酸的生产方法、应用和开发前景。     

小麦秸秆接枝丙烯酸制备高吸水性树脂

以N,N'-亚甲基双丙烯酰胺为交联剂,过硫酸钾一硫代硫酸钠为引发剂,采用水溶液聚合法合成了小麦秸秆接枝丙烯酸系列高吸水树脂。研究了单体配比、丙烯酸中和度、引发剂及交联剂用量对吸去离子水的影响。结果表明,该树脂具有良好的吸水性能,吸收去离子水达617 g/g。     

Interaction between amino acid degradation,sensory attributes and lipid peroxidation in wheat rolls

The influence of lipid peroxidation and heating duration on the amino acid pattern of wheat rolls was assessed in a model baking test. Therefore, three different types of dough were prepared including dough without any fat and two doughs with fat. To estimate the impact of lipid peroxidation products on the amino acid pattern, the two doughs containing fat were both made with rapeseed oil, one with fresh oil, the other with oxidised rapeseed oil. All kinds of dough were baked for three different duration times (18, 24 and 30 min). The lipid peroxidation status of both rapeseed oils was measured with the peroxide value and the p‐anisidine value of the unbaked fat. The amino acid content was analysed by HPLC after acid and alkaline hydrolysis. Besides determining water content and protein content, a sensory analysis was performed. Whereas the amino acid content in the dough without fat was only affected by the baking time, the doughs with rapeseed oil additionally showed a significant increase in amino acid degradation caused by lipid peroxidation products. Especially in the dough prepared with oxidised rapeseed oil, the amino acid content was partly decreased in raw dough without any heating influence. Confirming the influence of lipid peroxidation products in dough prepared with oxidised rapeseed oil, sensory analysis also showed the significantly worst overall score.     

Incorporation of wheat starch and coupling agents into poly(lactic acid) to develop biodegradable composite

Abstract

Composites of poly (lactic acid) (PLA)/wheat starch and PLA/wheat starch/methyldiphenyldiisocyanate, were prepared and characterised in this study. The effects of incorporating different coupling agents on the physical properties and morphology of the composites were studied. Extrusion technology and injection moulding techniques were used to prepare standard tensile and impact test pieces. Tensometry was used to investigate the tensile properties of the composites and impact testing using falling weight technique was used to investigate impact strength. To investigate the thermal behaviour of the composites, differential scanning calorimetry was employed. Water absorption properties of the composites were also investigated. Scanning electron microscopy was used to investigate the morphology of the composites. Starch can be incorporated in a PLA matrix at 10% level without difficulty in processing by extrusion followed by injection moulding to make shaped mouldings in the presence of MDI. With 10% wheat starch and 2% MDI, blends of wheat starch/PLA can reach the tensile strength, elongation, impact strength properties of raw PLA. In the presence of 2% MDI and 10% glycerol, blends of PLA and starch make an entirely flexible material.     

黄腐酸分子结构比较研究的新思考

低聚糖作为构成生命体的最基本物质，同蛋白质、核酸一样可以参与生命过程。一些低聚糖在极微量（〈10^-9μg／L）水平上就可以表现出很强的生理活性。本文鉴于黄腐酸农药、医药应用的多元性、神秘性以及与低聚糖的某些相似性，提出了以衍化的有规结构低聚糖为模板，拟用分子模拟方法排除木质素对“黄腐酸”、“低聚糖”比较研究的干扰；结合同工酶的研究，希望能较好地解释黄腐酸基础研究中尚存的疑惑点，有利于提高黄腐酸的应用价值。     

Micellar enhanced ultrafiltration: A comparative study

A pilot plant study was carried out to evaluate the performance of continuous cross flow micellar enhanced ultrafiltration (MEUF) method for the simultaneous separation of phenol and ortho‐cresol from the aqueous phase using a cationic surfactant, cetyltrimethyl ammonium bromide. The membranes used in this study are polysulfone tubular hollow fibre membrane with 6 kDa and a ceramic membrane having pore diameter 50 nm with an active layer of microporous zirconia (ZrO₂) supported on α‐alumina, respectively. The work includes comparing the effectiveness of membranes based on pollutants structural parameters, membrane properties and membrane modules. The characteristic parameters such as the distribution coefficient (D), micelle binding constant (K_p) and micelle loading (L_m) were obtained at optimal experimental conditions. High initial rejections were observed (above 95%) for both the membranes and the permeate flux remained almost constant at 17 LMH. It was found that the polysulfone material membrane suited better for MEUF with higher and steady rejections over a period of time. High micelle leakage was observed in ceramic membrane. The energy consumption for hollow fibre polysulfone membrane was less than the ceramic membrane. © 2011 Canadian Society for Chemical Engineering     

Fibre-reinforced boroaluminosilicate geopolymers: A comparative study

This paper investigates the effect of fibres on the physical and mechanical behaviour of boroaluminosilicate geopolymers (BASG) compared to conventional aluminosilicate binders. The use of various types of fibres by the means of reinforcing geopolymers against flexural loads is very common. In this work, fly ash and ground granulated blast furnace slag (GGBS) are utilised as raw materials to generate geopolymer specimens. Different alkaline solutions comprising sodium hydroxide, sodium silicate, and borax are prepared to activate precursors. The sodium silicate solution is substituted with borax by 30?wt% and 70?wt% in order to produce fly ash and slag-based BASG respectively. Steel and polymer fibres are employed in the mixtures for reinforcement. Three-point bending and mini slump tests are conducted for assessing the flexural strength, elastic modulus, toughness, and flow of geopolymer specimens. A pair plotting interpretation is also used in order to illustrate the patterns. The obtained results indicate that the fly ash-based BASG mortar shows superior flexural strength to the GGBS-based BASG mortar. The flexural strength of fly ash-made aluminosilicate geopolymer declines from 7.3?MPa to 6.4?MPa with an increase in the content of steel fibres from 1% to 2%. Inversely, raising the percentage of steel fibres in the fly ash-based BASG mortar caused a slight growth in the flexural strength of specimens. The polypropylene fibres, when added sufficiently, play a significant role in improving the toughness of fly ash-based BASG and slag-based aluminosilicate mixtures, more than 0.8 and 0.7?J surge in the toughness respectively. In addition, the polypropylene and steel fibres perform well in improving the elastic modulus of slag-based BASG and fly ash-based aluminosilicate binders. While keeping the water to binder ratio constant, introducing the steel fibre increased the flow of fly ash-based geopolymers. Nonetheless, the polymer fibres declined the flow of mortars.     

A novel method of utilizing the biomass resource: Rapid liquefaction of wheat straw and preparation of biodegradable polyurethane foam (PUF)

In the paper, wheat straw was rapidly liquefied in the mild condition. The optimum liquefaction effect was obtained at steam-explosion pre-treatment of wheat straw, liquefaction temperature of 140 °C, solvent/wheat straw ratio of 6:1, glycol (EG):glycerol = 5, sulfuric acid of 5%, and wheat straw of water content of 150%. During the liquefaction, cellulose, semi-cellulose and lignin are decomposed, which results in changes of hydroxyl value, acid value, viscosity and weight-average molecular weight of the reaction system. The liquefaction product was used to prepare polyurethane foam. Compared with the normal PUF, the foam had similar mechanical properties and better water absorption and biodegradability.     

Foliar urea fertilization of cereals: A review

It has been suggested that there are several potential benefits of providing nitrogen to cereals via the foliage as urea solution. These include: reduced nitrogen losses through denitrification and leaching compared with nitrogen fertilizer applications to the soil; the ability to provide nitrogen when root activity is impaired e.g., in saline or dry conditions, and uptake late in the season to increase grain nitrogen concentration. Factors that influence the degree of foliar absorption in field conditions have not, however, been clearly defined and losses to the atmosphere and soil can occur. Foliar urea applications may also hinder crop productivity although the explanations for this vary, and include desiccation of leaf cells, aqueous ammonia and urea toxicity, biuret contamination and the disruption of carbohydrate metabolism. It has not yet been determined which one, or combinations, of these mechanisms are most important in field situations. When damage has not been severe, foliar urea applications have increased grain yield, particularly when applied before flag leaf emergence and when nitrogen availability is limiting. Increases in grain nitrogen content are often larger when applications of nitrogen fertilizers to the soil are reduced, and when the urea solution is sprayed either at anthesis or during the following two weeks. It is during this period that foliar urea sprays can be of greater benefit than soil applications with regard to nitrogen utilization by the crop. Increases in wheat grain nitrogen concentration following urea application can improve breadmaking quality. Responses in loaf quality may, however, be variable particularly when increases in grain nitrogen content have been large, and/or when the nitrogen: sulphur ratio in the grain is increased. These circumstances have lead to alterations in the proportions of the different protein fractions which influence breadmaking potential.To exploit the full potential benefits of foliar urea application to cereals, more needs to be known about the mechanisms, and thus how to prevent losses of nitrogen from the foliage, and to reduce the phytotoxic influences of sprays. More information is also required to exploit the reported effects that urea may have on limiting the development of cereal diseases.     

植酸的生产及应用开发

综述了植酸产品的应用及国内植酸生产工艺的研究开发;分析了植酸产品的市场开发前景。     

Increase in bioethanol production yield from triticale by simultaneous saccharification and fermentation with application of ultrasound

BACKGROUND: Bioethanol produced from renewable biomass, such as sugar, starch or lignocellulosic materials, is one of the alternative energy resources that is environmentally friendly. Triticale crops have a high yield as well as a high starch content and amylolytic enzyme activity and are therefore considered to be ideal for bioethanol production. RESULTS: This study examined the feasibility of ultrasound pretreatment to enhance the release of fermentable sugars from triticale meal during pretreatment and consequently increase bioethanol yield in the simultaneous saccharification and fermentation (SSF) process by Saccharomyces cerevisiae yeast. Ultrasonic pretreatment effectively increased the glucose and maltose content after liquefaction by 15.71% and 52.57%, respectively, compared with the untreated control sample under determined optimal conditions of sonication (5 min, 60 °C). The ultrasound pretreatment consequently improved bioethanol production during SSF processing since the bioethanol content was increased by 10.89%. CONCLUSION: Taking into consideration significant process parameters obtained in the SSF process of triticale meal with ultrasound pretreatment at 60 °C, the process time may be reduced from 72 to 48 h. At that point of the SSF, maximum bioethanol content of 9.55% (w/v), bioethanol yield of 0.43 g g^?1 of triticale starch, and percentage of the theoretical bioethanol yield of 84.56% were achieved. Copyright © 2011 Society of Chemical Industry