犊牛腹泻病中沙门氏菌的分离与鉴定

近年来,随着新疆塔里木地区养牛业的迅速发展,奶牛头数的不断增多,犊牛腹泻的发病率也是呈上升趋势。从12头1月龄腹泻犊牛的粪样中进行细菌学分离27株菌株,其中分离得到5株沙门氏菌,药敏实验发现5株为沙门氏菌对诺氟沙星、环丙沙星极敏感,对阿莫西林产生耐药性,使用红霉素、庆大霉素时需要加大剂量。     

不同年代水稻品种齐穗后叶片保护酶活性及膜脂过氧化作用比较分析

以辽宁省20世纪70年代以来有代表性的4个水稻主栽品种和新育成的水稻超高产品种为试材，比较分析齐穗后叶片中保护酶活性的变化，结果表明：随品种更替叶片超氧化物歧化酶(SOD)、过氧化物酶(POD)活性增加，膜脂过氧化产物MDA含量减少，这种趋势在倒3叶上尤为突出。表明超高产品种清除活性氧的能力增强，尤其是下位功能叶片，且在籽粒灌浆的中后期更为显。     

Effects of Autumn Warming on Energy Consumption of Diapausing Fall Webworm (Lepidoptera: Arctiidae) Pupae

Since its invasion into China in 1979, the fall webworm, Hyphantria cunea Drury, has spread from Dandong city (about 40°N) in Liaoning Province to Nanjing city (about 32°N) in Jiangsu Province, and to other areas. Owing to geographic and latitudinal gradients in temperature, H. cunea will encounter temperature changes during the spreading process. In this study, we verified the hypothesis that autumn warming accelerates the energy consumption of H. cunea diapause pupae. We found that, after autumn warming, the body size and mass of diapause pupae decreased significantly and raised constant temperature accelerated carbohydrate and protein consumption in female pupae, while fluctuating temperature changes had a more pronounced effect on carbohydrate and protein consumption in male pupae. Contrary to expectations, the lipid content of diapause pupae did not decrease after autumn warming, and even increased significantly. We conclude that warming in autumn accelerates energy consumption by diapause pupae, and the autumn energy consumption of diapause pupae is dominated by carbohydrates, supplemented by protein when carbohydrates are overconsumed, while lipid use is dominated by anabolic metabolism during autumn.     

Fucoidan and Fucoxanthin Attenuate Hepatic Steatosis and Inflammation of NAFLD through Modulation of Leptin/Adiponectin Axis

Non-alcoholic fatty liver disease (NAFLD) is the emerging cause of chronic liver disease globally and lack of approved therapies. Here, we investigated the feasibility of combinatorial effects of low molecular weight fucoidan and high stability fucoxanthin (LMF-HSFx) as a therapeutic approach against NAFLD. We evaluated the inhibitory effects of LMF-HSFx or placebo in 42 NAFLD patients for 24 weeks and related mechanism in high fat diet (HFD) mice model and HepaRG^TM cell line. We found that LMF-HSFx reduces the relative values of alanine aminotransferase, aspartate aminotransferase, total cholesterol, triglyceride, fasting blood glucose and hemoglobin A1c in NAFLD patients. For lipid metabolism, LMF-HSFx reduces the scores of controlled attenuation parameter (CAP) and increases adiponectin and leptin expression. Interestingly, it reduces liver fibrosis in NAFLD patients, either. The proinflammatory cytokines interleukin (IL)-6 and interferon-γ are reduced in LMF-HSFx group. In HFD mice, LMF-HSFx attenuates hepatic lipotoxicity and modulates adipogenesis. Additionally, LMF-HSFx modulates SIRI-PGC-1 pathway in HepaRG cells under palmitic acid-induced lipotoxicity environment. Here, we describe that LMF-HSFx ameliorated hepatic steatosis, inflammation, fibrosis and insulin resistance in NAFLD patients. LMF-HSFx may modulate leptin-adiponectin axis in adipocytes and hepatocytes, then regulate lipid and glycogen metabolism, decrease insulin resistance and is against NAFLD.     

动物油脂热压联合提取装置设计与试验

提高病死畜禽胴体中的油脂提取率是实现病死畜禽进一步资源化的关键,为此该研究设计了一种动物油脂热压联合提取装置。首先基于静力学和热传递分析,结合动物油料特性,对关键部件压力机构和油脂提取机构进行了设计,并对加热、加压和可编程控制系统分别进行了关键参数设计和设备选型,最后选取板油进行了装置性能试验,并对提取的油脂进行了黏度测试。结果表明：在70～150℃范围内,单独温度和热压联合两种油脂提取方法的最佳温度均为130℃,在此温度下油脂提取率最高分别可达到59.15%和81.35%。相同温度下,热压联合油脂提取率较单独温度作用最高可提升31.21个百分点。减小油料规格对单独温度作用可明显提高油脂提取率,而对热压联合油脂提取率无明显影响。在高于130℃试验温度下进行热压联合油脂提取,能够达到油脂完全提取效果,所提取油脂在70～150℃温度范围内测得黏度为0.004～0.091 Pa·s,符合工业用润滑油黏度标准。     

Aloe vera long-term saline irrigation increases contents of hydrogen peroxide,lipid peroxidation and phenolic compounds

Salt stress is more and more becoming a serious problem in the world especially if we consider its damaging effect on the plant growth and yield. The cultivation of medicinal plants, such as Aloe vera, might be an alternative for the saline water use and salt-affected soils occupation. Aloe vera, commonly known as aloe, is one of the primary medicinal plants with multipurpose applications going from pharmaceutical to cosmetic aspects with a promising economic return. Aloe plants were cultivated and irrigated, for 14 months, with drinking water (C0) and with two levels of salt (C1 and C2). Changes in growth, hydrogen peroxide (H₂O₂), lipid peroxidation and phenolic compounds were examined in leaves at harvest. Depressive effects of salt irrigation on the plant growth parameters and a perturbation in inorganic ion contents were found especially with a high level of salt in the irrigation water. The intracellular oxidative stress was evaluated with the H₂O₂ production. Our results showed that the H₂O₂ content increased with the accumulation of the toxic ion (Na) in the leaf tissues. In addition, lipid peroxidation, measured by the malondialdehyde (MDA) level, increased as well with salt augmentation in the irrigation water. In response to salt stress, Aloe leaves showed a significant increase in the levels of phenolic compounds too. These results suggest that Aloe can be planted in soils affected by salinity and irrigated with salt water at least at a moderate concentration used in the present study.     

The chemical nature of components of PG (Green fraction of P type humic acid)

P type humic acids showing characteristic absorption maxima at 615, 575, and 450 nm have been found in various types of soils around the world (3, 5, 7,8). P type humic acid was fractionated into a brown fraction (Pb) and a green fraction (Pg) by column chromatography using cellulose powder (4) or Sephadex gel (3). The Pg fraction which has a strong absorption maxima at 615, 575, and 450 nm causes the characteristic absorption pattern of P type humic acid.     

一种新发生的玉米细菌性叶腐病病原菌分离鉴定

为了明确一种引起玉米叶片腐烂的细菌性病害的病原菌种类, 于2021年7月在甘肃省景泰县条山农场玉米种植区采集病样, 经稀释分离法进行病原菌分离纯化, 并通过致病性测定?形态学观察?生理生化特征观察及16S rDNA和gyrB序列分析相结合的方法对病原菌进行鉴定?结果表明, 选取的代表性菌株B1-0和B2-1均能使玉米叶片发病, 为革兰氏阳性致病菌, 产芽胞; 该病原菌需氧性?运动性?明胶液化?接触酶试验?柠檬酸盐利用?马铃薯腐烂试验均为阳性; 甲基红试验阴性; 能利用D-甘露醇?麦芽糖和葡萄糖, 不能利用甘油和肌醇, 不能水解淀粉, 在4℃?40℃和5%NaCl条件下均能生长?构建基于16S rDNA和gyrB的系统发育树, B1-0和B2-1与短小芽胞杆菌Bacillus pumilus(ATCC7061?BKS1-108?AUEC29?BP-hd-1?NMTD17和17)亲缘关系最近, 聚在一个分支?因此, 将该病原菌鉴定为短小芽胞杆菌B. pumilus?研究结果将为玉米细菌性叶部病害的研究和综合防治提供基础数据?     

Traits Related to Chilling-Induced Photoinhibition in Leaves of indica and japonica Rice (Oryza sativa)

Physiological indices related to PS Ⅱ photochemical efficiency (Fv/Fm) and membrane lipid peroxidation were measured in leaves of indica rice cv Shanyou 63 and japonica rice 9516 at different temperatures and light intensities for four days. No obvious changes in Fv/Fm and MDA were observed in both indica and japonica rice at moderate temperature and medium PFD,implying neither photoinhibition nor photooxidation happened in these cases. In indica rice either at medium temperature with higher PFD or at lower temperature with medium PFD Fv/Fm dropped obviously with no changes in MDA contents, and photoinhibition appeared while photooxidation did not occur. However, D1 protein, Fv/Fm, (A Z)/(A Z V), and SOD activities dropped, and O2 -. production and MDA content increased accordingly, as well as both photoinhibition and photooxidation appeared in two rice varieties at lower temperature and higher PFD. Experiment with inhibitors at lower temperature and higher PFD showed that as compared with japonica rice the decrements appeared in D1 protein contents, SOD activities, and (A Z)/(A Z V) ratios, the xanthophyll cycle and non-photochemical quench (qN) were inhibited in a more degree, as well as increments of MDA content were greater, thus exhibiting more distinct photoinhibition and photooxidation in indica rice. It is suggested that Fv/Fm and membrane lipid peroxidation product-MDA were the key indices to predict and diagnose photooxidation.     

Physicochemical, Structural and Textural Properties of Tortillas from Extruded Instant Corn Flour Supplemented with Various Types of Corn Lipids

The chemical composition and the components of corn grain affect the quality of tortillas produced from extruded instant corn flour (EICF). We have studied the effects of various types of corn lipids added at several concentrations to the regular raw corn flour before processing. The structural properties of flour, the effective moisture diffusion coefficient and the weight loss during cooking of fresh masa, as well as the textural characteristics of tortillas were analysed as a function of concentration and type of corn lipid added. The concentration of added lipid ranged from 0·5 to 2% (w/w). Each type and concentration of lipid was observed to have a different effect in the quality of masas and tortillas. Commercially it is desired to have tortillas with good properties and a high yield, that is, optimum weight transformation from corn to tortilla. From our analysis, the lowest dehydration rate (lowest effective moisture diffusion coefficient) and the best physicochemical and textural characteristics of fresh masas and tortillas were obtained from flour supplemented with 0·5% (w/w) of the nonpolar lipid fraction III. The loss in starch crystallinity due to the cooking process of masa into tortilla was similar in all treatments.