Less hazardous alternative herbicides to control weeds in immature oil palm

In 2002, the Malaysian government had banned the use of the hazardous herbicide, paraquat. Most growers perceive that paraquat is the most effective herbicide and provides the fastest mode of action to control weeds. An experiment was conducted at MAB Agriculture-Horticulture, Sepang, Selangor, Malaysia, from February 2004 to February 2005 to evaluate the efficacy and ability of the less hazardous herbicides, glufosinate ammonium and glyphosate, as an alternative to the hazardous herbicide, paraquat, in controlling weeds in immature oil palm (<3 years old). The results showed that paraquat needed high rates, 600 and 800 g ha⁻¹, to control weeds effectively. However, lower rates of glufosinate ammonium (200 g ha⁻¹) and glyphosate (400 g ha⁻¹) gave excellent weed control. The results showed that the efficacy of glufosinate ammonium and glyphosate were much better than paraquat. The results also showed that, with no direct contact with the plants, paraquat, glufosinate ammonium, and glyphosate had no adverse effect on the vegetative and generative growth of oil palm in this study. These results proved that the less hazardous herbicides, glufosinate ammonium and glyphosate, could be used as an alternative to paraquat to control weeds in immature oil palm.     

In vitro susceptibility of Brachyspira hyodysenteriae to organic acids and essential oil components

The antibacterial potential of organic acids and essential oil components against Brachyspirahyodysenteriae, the causative pathogen of swine dysentery, was evaluated. Minimum inhibitoryconcentrations (MIC) of 15 compounds were determined at pH 7.2 and pH 6.0, using a broth microdilution assay.In addition, possible synergism was determined. MIC values for the three tested strains were similar. Fororganic acids, MIC values at pH 6.0 were lower than at pH 7.2. B. hyodysenteriae was mostsensitive to cinnamaldehyde and lauric acid, with MIC values <1.5 mM. Most antibacterial effects of binarycombinations were additive, however, for thymol and carvacrol, synergism could be observed. Invitro results demonstrate the antibacterial action of certain essential oil components and organicacids against B. hyodysenteriae.     

稻草降解及产油菌的筛选

本文筛选出了六株纤维素降解菌,其中菌株f8在稻草固态发酵培养基中产CMC酶活和FPA酶活最大分别为260.32 U和18.90 U,经初步鉴定为康宁木霉。菌株f3既能降解纤维素,又能产油脂,且在PDA液体培养基上油脂产率达到25%。经初步鉴定为绿色木霉。     

不同来源吸附载体大豆糖蜜对奶牛瘤胃内环境的影响

为考察不同来源吸附载体大豆糖蜜对奶牛瘤胃内环境的影响,采用3×3拉丁方试验设计,选用3头年龄相同(3胎次)、体重相近[(500±50)kg]且安装永久性瘤胃瘘管的中国荷斯坦奶牛为试验动物,分别饲喂基础日粮、豆皮糖蜜和麸皮糖蜜日粮。结果表明,豆皮糖蜜组和麸皮糖蜜组瘤胃pH均极显著高于对照组(P0.01),而豆皮糖蜜组和麸皮糖蜜组之间瘤胃pH没有显著差异(P0.05);麸皮糖蜜组瘤胃NH_3-N浓度显著低于对照组(P0.05),但与豆皮糖蜜组没有显著差异(P0.05);各处理间奶牛瘤胃各单个挥发性脂肪酸(volatile fatty acid,VFA,包括乙酸、丙酸、异丁酸、丁酸、异戊酸和戊酸)浓度、总VFA浓度和乙丙比均没有显著差异(P0.05);但与对照组相比,豆皮糖蜜组瘤胃总VFA浓度有降低趋势;而麸皮糖蜜组瘤胃总VFA浓度有提高趋势。结果显示,在奶牛饲料中可用豆皮糖蜜替代15%玉米以及用麸皮糖蜜替代6%玉米和10%麸皮,均具有调控瘤胃稳衡的作用,且麸皮糖蜜替代效果优于豆皮糖蜜。     

蒽酮比色法测定大豆乳清废水中总糖含量

本文研究了用蒽酮比色法测定大豆乳清废水中可溶性总糖含量,本法可溶性总糖测定的回收率为98%~105%,标准偏差1.032×10-3,本法灵敏度高,可靠性强,误差小,而且设备简便、迅速、准确。     

脱脂椰子种皮提取物抗氧化活性研究

以脱脂椰子种皮为试验材料,分别用异丙醇、正己烷和乙醚提取其中的酚类化合物,采用Folin-Ciocalteu比色法测定3种提取物的总酚含量,并对3种提取物的总抗氧化活性及对猪油的氧化稳定性进行评价.结果表明,正己烷提取物的总酚含量最高,其次是异丙醇提取物,乙醚提取物最低;异丙醇提取物的抗氧化能力最高,正己烷提取物和乙醚提取物次之.3种溶剂提取物对猪油的氧化均有一定的抑制作用,其中异丙醇提取物对猪油的氧化抑制效果最明显.     

硫酸香茅醛显色法测定莪术油微囊载药量与包封率

为评价莪术油/(麦芽糊精-Povacoat)微囊的质量,建立了硫酸香茅醛显色测定其载药量和包封率的方法。对莪术油乙醇溶液进行波长扫描,确定508nm为最大吸收波长,显色稳定性试验表明,反应液在150min内吸光度较稳定。莪术油检测浓度在0.199 2μg/mL~9.960μg/mL范围内线性关系良好(A=0.094 7C-0.001 2,r=0.999 3),微囊的载药量测定和包封率测定的方法回收率分别为99.6%和99.1%。经测定,3批微囊的载药量为51.5mg/g~53.2mg/g,包封率为88.2%~90.7%。     

仙人掌挥发油化学成分GC-MS分析

[目的]为仙人掌植物的合理开发和综合利用提供科学依据。[方法]采用水蒸气蒸馏法,从仙人掌中提取挥发油,用气相色谱-质谱联用法（GC-MS）对其进行分析。[结果]鉴定了35种化合物,主要成分为植醇（36.57%）、雪松烯（10.89%）、匙叶桉油烯醇（8.35%）、香树烯（7.24%）、石竹烯（5.90%）、棕榈酸（5.45%）、愈创木烯（3.05%）、苯乙醛（2.74%）、己醛（2.36%）等。[结论]与文献报道相比,组分和百分含量均有差别。     

微波对大豆蛋白氧化聚集体结构及功能特性的影响

为了探究不同时间微波处理对大豆蛋白氧化聚集体的结构和功能性质的影响,由偶氮二异丁脒盐酸盐（2,2'-azobis (2-amidinopropane) dihydrochloride,AAPH）诱导构建大豆蛋白氧化反应体系,采用功率为350 W的微波对其照射不同时间(0、10、20、30、40、50、60、70 s),探究微波处理对氧化聚集大豆蛋白的结构特性和加工特性的影响。结果表明,氧化可诱导形成粒径、分子量更大,结构更致密的蛋白质聚集体,同时对加工特性造成损害。适当时间（<30 s）的微波处理会导致氧化聚集体的分子结构打开、粒径降低和浊度降低,无序结构减少,进而改善了起泡性、乳化性和持水、持油性。长处理时间（＞30 s）的微波处理导致已解聚的大豆蛋白分子重新形成更大的分子聚集体,降低功能性质。这表明微波物理场可以通过改变大豆蛋白氧化聚集体的结构和聚集行为调节其功能性质,为大豆蛋白功能性质的改善及微波在大豆蛋白氧化聚集体行为调控的应用方面提供参考。     

Temporal Changes in the State of a Pine Stand in a Bog Affected by Air Pollution in Northeast Estonia

We used the needle trace method to investigate changes in the state of a Scots pine (Pinus sylvestris L.) stand in a bog (Voorepera) in the north-eastern part of Estonia, the most polluted area of the country. Additionally, we chose six sampling sites in other parts of Northeast Estonia (polluted area) and eight sites in southern Estonia (unpolluted area) to compare the state of pine stands in different bogs. During the period of 1964–1997, the radial growth had increased from 0.27 to 2.16 mm yr^–1 and the annual shoot length from 0.10 to 0.28 m in Voorepera. Mean values of the period (1.13 mm yr^–1 and 0.26 m, respectively) were two and four times higher in Voorepera than the average of the other bogs (0.5 mm yr^–1 and 0.06 m, respectively). Maximum needle age fluctuated between three and five growing seasons in Voorepera, the mean (four growing seasons) was similar to that of other bogs (four growing seasons). Except radial growth, which was 0.6 mm yr^–1 in the polluted area and 0.4 mm yr^–1 in the unpolluted area, other indices of trees' health (shoot growth, needle age, nitrogen concentration in needles) and substrate conditions (water pH and N concentration) did not show clear differences between polluted and unpolluted areas. We conclude that air pollution from oil shale industry (thermal power plant and chemical factories) enhances the growth of pines in bogs, which can induce drastic changes in these ecosystems. However, the effect is currently obvious only in the vicinity of pollution sources.