裂盖马鞍菌提取物体内抗氧化活性研究

以新疆特色食用菌裂盖马鞍菌为材料,研究裂盖马鞍菌乙醇提取物、乙酸乙酯、氯仿、石油醚萃取物对小鼠体内的抗氧化活性,分高（2g/kg）、中（1g／kg）、低（0．2g／kg）三个剂量对小鼠灌胃给药测定小鼠肝脏和血清中丙二醛（MDA）含量和超氧化物岐化酶（SOD）活力。结果表明,与阴性对照（生理盐水）相比裂盖马鞍菌提取物能明显提高小鼠肝脏和血清中SOD的活力,降低MDA的含量（P〈0．01）;与阳性对照维生素E（VE）（1g/kg）相比乙醇提取物、其他溶剂萃取物高浓度（2g／kg）作用极显著（P〈0．01）;与维生素C（VC,1g／kg）相比乙醇提取物高浓度（2g/kg）作用极显著（P〈0．01）,提示裂盖马鞍菌提取物具有抗氧化活性。     

柴达木盆地唐古特白刺果实降血脂和抗氧化作用研究

为了研究柴达木盆地唐古特白刺果实的降血脂、抗氧化作用,本文采用高脂饲料诱导小鼠和大鼠建立高脂动物模型,灌胃给药4周,测定各组实验动物的血清血脂水平,并测定大鼠红细胞SOD活性和血清脂质过氧化物(LPO)分解产物丙二醛(MDA)的含量变化。结果显示唐古特白刺果实1．8g／kg和3．6g／kg剂量对高脂饲料诱导的小鼠和大鼠血清TC、TG及大鼠的LDL具有显著的抑制作用;同时可显著升高高血脂大鼠HDL／TC和HDL／LDL的比值,提高高血脂大鼠SOD活力和降低高血脂大鼠MDA含量;对大鼠体重和正常小鼠血脂水平无明显影响。表明唐古特白刺果实具有降血脂、防治动脉粥样硬化和抗氧化作用。     

富硒平菇干粉对小鼠的脏器指数与抗氧化能力的影响

目的探讨富硒平菇干粉对小鼠的脏器指数与抗氧化能力的影响。方法将60只20g左右的健康昆明种小鼠随机分为6组。1组为对照组;2组为亚硒酸钠组;3组为普通平菇干粉组;4～6组为富硒平菇干粉组,分别在基础日粮中添加低、中、高浓度的富硒平菇干粉。30d后测定小鼠脏器指数与肝脏和血浆中谷胱甘肽过氧化物酶(GSH-Px)、超氧化物歧化酶(SOD)和丙二醛(MDA)含量。结果富硒平菇干粉可显著提高小鼠脾脏、胸腺和肝体指数;可显著提高小鼠肝脏与血浆中GSH-Px、SOD的酶活,降低小鼠肝脏和血浆中MDA含量。结论富硒平菇干粉可显著提高小鼠脏器指数与抗氧化能力。     

灵芝发酵茶降低小鼠血清总胆固醇作用简报

报道灵芝发酵茶降低小鼠血清总胆固醇含量作用。试验采用BABL／c雄性小鼠,按体重随机分组,设高、中、低三个剂量和对照组,高、中、低三个剂量的试验组每天分别以4．198g／kg、3．358g/kg、2．798g/kg三个剂量灌服灵芝发酵茶提取液一次,对照组每天则以生理盐水灌服1次,连续给药10d,每天喂养高脂饲料。末次给药30min后,采用酶法测定小鼠血清总胆固醇含量。结果中剂量组试验小鼠血清总胆固醇含量和体重与对照相比分别降低了37．1％和7．7％。试验表明一定剂量的灵芝发酵茶对小鼠血清总胆固醇含量和体重的降低有显著作用。     

HDL能抵抗内毒素引起得小鼠损伤

目的:观察HDL、LPS和(HDL+LPS)对小鼠血液SOD及MDA的影响,研究HDL抗LPS的作用.方法:(1)用不同浓度的PEG-6000离心人血浆脂蛋白,提取HDL并脱脂;(2)给小鼠注射HDL,LPS或HDL+LPS,对照组小鼠注射生理盐水;观察小鼠存活时间,测定其血液中SOD活性及MDA含量.结果:(1)相比对照组及HDL组,LPS组和HDL+LPS组小鼠的存活时间明显缩短,且后两者之间存在显著性差异;(2)LPS组小鼠血浆中SOD活性降低,MDA含量升高,均和其他三组有显著性差异.结论:LPS能使内毒素损伤小鼠血浆中SOD活性降低,MDA含量升高,HDL有抗内毒素损伤的作用.     

罗汉果油的药理作用研究北大核心CSCD

采用小鼠灌胃给药研究罗汉果油的药理作用。给正常小鼠灌胃给药7d后,采用小鼠游泳方法及常压耐缺氧实验,观察罗汉果油对小鼠的抗疲劳和缺氧耐力作用。给正常小鼠灌胃给药10d后,测定血清中超氧化物岐化酶（SOD）活性及丙二醛（MDA）含量,观察罗汉果油的抗氧化作用。结果表明罗汉果油能明显延长小鼠游泳时间,并能延长常压耐缺氧时间及提高正常小鼠血清中SOD活性,降低MDA含量。罗汉果油具有明显的抗疲劳和耐缺氧,抗氧化等药理作用。     

连翘苷降血脂及抗氧化作用的实验研究

用高脂饲料造成营养性高脂血症模型,观察连翘苷的降血脂和抗氧化作用。结果显示,与高脂血症模型组相比较,连翘苷给药组动物的血浆总胆固醇(TC)、三酰甘油(TG),低密度脂蛋白胆固醇(LDL-C)、动脉粥样硬化指数(AI)均有不同程度下降,高密度脂蛋白胆固醇(HDL-C)有所上升,血中过氧化氢酶(CAT)、过氧化物酶(POD)活性增强,血浆中丙二醛(MDA)的含量降低,说明连翘苷具有降低营养性高脂血症小鼠血脂和抗氧化的作用。     

氦氖激光对大鼠心肌超微结构、SOD和MDA影响的观察

为了解低强度氦氖激光对心肌细胞超微结构、超氧化物歧化酶（SOD）和丙二醛（MDA）的影响,采用2．87J／cm^2,7.17J/cm^2和28.66J/cm^2三种剂量氦氖激光照射大鼠心前区,电镜观察心肌超微结构,测定心肌组织SOD和MDA的含量。结果发现心肌线粒体有轻微损伤,心肌组织SOD含量在7．17J／cm^2剂量显著下降（P＜0．05）,而在28．66J／cm^2剂量显著升高（P＜0．05）,心肌组织MDA含量在7．17J／cm^2和28．66J／cm^2两种剂量下降有显著升高（P＜0．01）,在2．87J／cm^2剂量,心肌组织SOD和MDA含量均无显著变化（P＜0．05）。结果提示心肌SOD含量和脂质过氧化随不同的激光剂量而变化。     

白鲜皮水提物对ApoE-/-小鼠动脉粥样硬化早期病变形成的抑制作用

目的研究白鲜皮水提物对载脂蛋白E基因缺损小鼠主动脉弓粥样硬化早期病变形成的影响。方法将40只ApoE-/-小鼠随机分成空白对照组和白鲜皮高、中、低三剂量组（白鲜皮水提物3.2、1.6、0.8 g/kg）给药,计算各组主动脉弓粥样硬化病变的面积。体内检测血清中的脂质含量以及抗氧化指标丙二醛（MDA）含量、超氧化物歧化酶（SOD）、过氧化氢酶（CAT）、谷胱甘肽-S转移酶（GST）的活性变化。测定白鲜皮水提物对Cu2＋介导的人血清低密度脂蛋白（LDL-C）氧化易感性的影响。结果与对照组相比,白鲜皮各给药组小鼠动脉粥样硬化早期病变面积均小于对照组,血清中MDA的含量降低,SOD、CAT活性增高,GST变化不明显,血清脂质含量组间没有显著差异。白鲜皮水提物明显延长Cu2＋介导的人血清LDL氧化滞留时间和达峰时间。结论白鲜皮水提物对ApoE-/-小鼠动脉粥样硬化早期病变形成具有显著的抑制作用,其作用机制可能是通过对抗脂蛋白的过氧化作用而实现。     

壳聚糖固定化德氏根霉脂肪酶的研究

研究了壳聚糖吸附和戊二醛交联对脂肪酶固定化条件,在室温条件下将0．4g酶粉溶于pH6．0缓冲液中,加入10g壳聚糖,摇匀,再加入浓度为0．6％戊二醛交联6h,得到固定化酶,酶活力回收率约为54．2％。固定化酶的半失活温度比游离酶的高,半失活温度由游离酶的47℃提高到100℃,最适反应温度由40℃上升至80℃,最适pH由6下降到5．5,固定化酶K’m值由游离酶的Km 50mg／mL增加到56mg／mL。该固定化脂肪酶用于酯的合成;在80℃条件下经过10批次连续水解植物油反应,固定化酶的活力仍保持在82．6％以上。     

Anaerobic biodegradation of ethylthionocarbamate by the mixed bacteria under various electron acceptor conditions

Biodegradation behavior and kinetics of ethylthionocarbamate under nitrate, sulfate and ferric reducing conditions by mixed cultures enriched from the anaerobic digester sludge was investigated. The results showed that ethylthionocarbamate could be degraded independently by the mixed cultures coupled to nitrate, sulfate, and ferric reduction, and meanwhile, nitrite, sulfide, and ferrous were accumulated as a result of nitrate, sulfate and ferric reduction, respectively. Ferric was a more favorable terminal electron acceptor compared to nitrate and sulfate. The order of the electron acceptors with decreasing biodegradation rates of the ethylthionocarbamate was: ferric>nitrate>sulfate, and the corresponding maximum biodegradation rate was 7.240, 6.267, and 4.602 mg/(L·d), respectively. The anaerobic biodegradation of ethylthionocarbamate under various electron acceptor conditions can be accurately described by first order exponential decay kinetics.     

双歧啤酒预防性减肥作用的实验研究

目的探讨双歧啤酒预防大鼠肥胖的作用及其对大鼠血脂、瘦素和胰岛素的影响。方法48只SD大鼠被随机分成双歧啤酒低剂量组[12．5ml／（kg·BW）]、中剂量组[25ml／（kg·BW）]、高剂量组[50ml／（kg·BW）]和市售啤酒组[25ml／（kg·BW）]、肥胖模型组以及基础组,进行预防性减肥实验,观察双歧啤酒在大鼠致肥过程中对大鼠的影响,测定指标包括大鼠体重、体脂、脂肪细胞直径、血脂水平和血瘦素、血胰岛素。结果实验结果显示,双歧啤酒各组除TCHO外的所有测定指标值都较肥胖组有明显好转,特别是腹膜下脂肪重量、TG和HDL水平都与正常组差异无显著性,低、中剂量组脂肪细胞直径也与正常组差异无显著性。市售啤酒组所有指标均与肥胖模型组差异无显著性。结论双歧啤酒能有效预防血TG的升高,有效预防啤酒肚的形成。对于预防体脂和体重的增加也有一定作用。     

Post‐translational regulation of acid invertase activity by vacuolar invertase inhibitor affects resistance to cold‐induced sweetening of potato tubers

Cold‐induced sweetening (CIS) is a serious post‐harvest problem for potato tubers, which need to be stored cold to prevent sprouting and pathogenesis in order to maintain supply throughout the year. During storage at cold temperatures (below 10 °C), many cultivars accumulate free reducing sugars derived from a breakdown of starch to sucrose that is ultimately cleaved by acid invertase to produce glucose and fructose. When affected tubers are processed by frying or roasting, these reducing sugars react with free asparagine by the Maillard reaction, resulting in unacceptably dark‐coloured and bitter‐tasting product and generating the probable carcinogen acrylamide as a by‐product. We have previously identified a vacuolar invertase inhibitor (INH2) whose expression correlates both with low acid invertase activity and with resistance to CIS. Here we show that, during cold storage, overexpression of the INH2 vacuolar invertase inhibitor gene in CIS‐susceptible potato tubers reduced acid invertase activity, the accumulation of reducing sugars and the generation of acrylamide in subsequent fry tests. Conversely, suppression of vacuolar invertase inhibitor expression in a CIS‐resistant line increased susceptibility to CIS. The results show that post‐translational regulation of acid invertase by the vacuolar invertase inhibitor is an important component of resistance to CIS.     

Chemical Purity of Shewanella oneidensis-Induced Magnetites

Magnetite is a common iron oxide produced both inorganically and biogenically. Biologically-induced magnetite is often originated, under appropriate conditions, as a result of the Fe³⁺ reduction by dissimilatory iron reducing bacteria, which are usually found in anoxic environments or at the oxic-anoxic interface. Such a Fe³⁺ bioreduction occurs upon this cation acting as an electron acceptor of an anaerobic respiration, thus creating favorable conditions for magnetite precipitation. This biologically-induced magnetite is an important biomineral in the environments inhabited by iron reducing bacteria. The presence of a variety of cations may influence both the biomineralization process and the resulting biomineral, however this phenomenon has not been investigated extensively. In the present study, we study the effect on the magnetite biomineralization process of the presence of calcium, magnesium and manganese in the culture medium where Shewanella oneidensis lives. We also test the incorporation of these cations into the crystalline structure of inorganic and biogenic magnetite induced by S. oneidensis. According to our findings, manganese ions likely become incorporated into the crystal structure of biologically produced magnetites, while magnesium ions are incorporated in inorganic magnetites, and calcium ions are excluded from the crystal structure of both inorganic and biotic magnetites. We hypothesize that the incorporation of cations into magnetite depends not only on the relative cation radii, but also on the mechanisms of magnetite formation.     

Release of a reducing substance by the ectomycorrhizal fungi Pisolithus tinctorius and Paxillus involutus

Culture solutions of the ectomycorrhizal fungi Pisolithus tinctorius and Paxillus involutus are shown to reduce a high valency oxide of manganese at a range of pH values from 3.0 to 13.0. Manganese reduction in unmoculated culture media was confined to pH values below 5.0 and above 10.0. The results are consistent with the release of a reducing substance from the fungal mycelium.     

双歧醋对大鼠预防性减肥的实验研究

目的探讨双歧醋预防大鼠肥胖的作用及相关机制研究。方法 48只SD大鼠被随机分成双歧醋低剂量组[1.8 mL/(kg.BW)]、中剂量组[3.4 mL/(kg.BW)]、高剂量组[6.8 mL/(kg.BW)]和市售醋组[3.4mL/(kg.BW)]、肥胖模型组以及基础对照组,进行预防性减肥实验,观察双歧醋在大鼠肥胖过程中对大鼠的影响,测定指标包括大鼠体重、体脂、Lee’s指数、脂肪细胞直径、血瘦素、血胰岛素。结果实验结果显示,双歧醋各组所有测定指标值都较肥胖组有明显好转,特别是血瘦素和血胰岛素水平,双歧醋的高、中剂量组与市售醋组差异有统计学意义。结论双歧醋能有效预防血瘦素和血胰岛素的升高,预防体脂、Lee’s指数和体重的增加也有一定作用。     

Kinetics of SO4−2 reduction under different growth media by sulfate reducing bacteria

Sulfate Reducing Bacteria (SRB) were used to reduce the SO₄ ^–2 concentration in waste water. The growth pattern of SRB was found by varying the concentration of nutrients and the biomass. The specific reaction constant was evaluated in each case.     

Photo‐induced chemiluminescent method for determination of reducing sugars

In the present study, a simple and sensitive photo‐induced chemiluminescence (CL) method for the quantitation of reducing sugars, including fructose, glucose, sucrose and lactose, was developed. This method was based on the on‐line photocatalytic reaction of the reducing sugars, using a home‐made photoreactor consisting of PTEF tube helically coiling around a high‐pressure mercury UV lamp. Reducing sugars were detected by direct CL emission resulting from the reaction between the photoproducts and luminol. To maximize the signal intensity, the effects of irradiation time, flow rate, luminol concentration, buffer pH and concentration were tested. Under optimum conditions, the linear dynamic ranges were all 0.36–18 mg/L and the relative standard deviations (RSDs) were 1.8–2.3%, with limits of detection (3σ) of 0.06 mg/L for fructose, glucose, sucrose and lactose. Finally, interference effects from ascorbic acid, amino acids (alanine, glycine, serine, leucine and methionine) and some metal ions and anions were also investigated. Copyright © 2008 John Wiley & Sons, Ltd.     

An overview of the factors affecting sugar content of potatoes

Potatoes destined for making chips, French fries and other fried products, need to have low sugar content to avoid browning of the finished product. The sugar content of potatoes is determined by the genotype and several pre‐ and post‐harvest factors. The major pre‐harvest factors affecting sugar content are crop maturity, temperature during growth, mineral nutrition and irrigation, while important post‐harvest factors are mechanical stresses and storage conditions. Each genotype requires an ideal pre‐and post‐harvest treatment to maintain low sugar levels; any kind of stress results in sugar accumulations.     

用硫酸盐还原菌处理重金属废水的研究

介绍了用硫酸盐还原菌处理重金属废水的几种主要方法和原理。硫酸盐还原菌处理含重金属废水主要是通过将可溶性的重金属离子转化成不溶性的金属硫化物、氢氧化物、碳酸盐的方式 ,或直接通过以菌体对重金属离子的吸附完成的。目前研究用硫酸盐还原菌处理重金属废水的主要方法有分批沉淀工艺、吸附处理工艺、化学法和硫酸盐还原菌的混合工艺、全混合处理工艺及硫酸盐还原菌的厌氧上流式污泥床和流化床工艺 ,并对其主要的工艺指标进行了比较。