棕榈酸抑制果蝇幼虫的生长发育及糖脂代谢

为探究棕榈酸（palmitic acid,PA）是否导致代谢综合征的发生,该实验选用模式生物黑腹果蝇,采用玉米粉酵母标准培养基作对照组,以在标准培养基中加入2.50%浓度的PA为实验组。分别对果蝇的幼虫体重、蛹化率与羽化率、蛹重、蛹面积、蛹体积、成虫体重、成虫爬行能力、成虫翅膀面积大小以及三龄幼虫体内海藻糖、甘油三酯、胰岛素样肽Dilp2、Dilp3、Dilp5的含量进行检测。结果表明：相比于CTRL组,PA导致果蝇的蛹化率及羽化率分别降低了3.75%和10.03%,蛹面积和蛹体积有所下降。PA组雌性成虫体重与CTRL组相比减小了0.13 mg,雄性成虫体重减少了0.10 mg。PA组雌蝇的运动活性降低了41.35%,雄蝇降低了22.78%。PA组雌性果蝇翅膀面积明显减小,而雄性果蝇无明显差异。PA组幼虫海藻糖和甘油三酯含量明显升高,而Dilp2、Dilp3、Dilp5的表达量显著下降。以上结果表明PA抑制果蝇的生长发育,扰乱了幼虫的糖脂代谢平衡,该研究可为探究高脂饮食引起代谢综合征的发生机制研究提供一定的科学依据。     

高温冲击对柞蚕卵繁殖赤眼蜂的影响

本文研究了柞蚕卵繁殖的赤眼蜂于预蛹期和蛹期经历6h35℃和6h44℃高温单次冲击处理,对当代羽化出蜂率、雌性产卵力、单卵雌蜂比、寿命等4个指标和处理子代羽化率、单卵雌蜂比等2个指标的影响。研究结果表明：当赤眼蜂处于预蛹期和蛹期,各处理当代易受高温冲击影响,尤以44℃高温不利影响明显,主要表现在羽化出蜂率、寿命及雌性产卵力3项指标明显降低。总体来看,高温冲击对子代蜂各指标未表现出明显影响。     

荆条蜜对果蝇生长发育和抗氧化能力的影响

在果蝇培养基中加入荆条蜜,测定果蝇的寿命、产卵量、成蝇鲜重、繁殖力、超氧化物歧化酶(SOD)活性和丙二醛(MDA)含量的变化,探讨荆条蜜对果蝇生长发育的影响.结果表明,添加荆条蜜后果蝇的平均寿命、最高寿命极显著延长(p＜0.01);产卵量增加;成蝇鲜重增加;发育周期缩短;繁殖力显著提高(p ＜0.05);SOD活性显著升高(p＜0.05),MDA含量降低(p＜0.05).结果表明,荆条蜜能够促进果蝇的生长发育,延缓衰老,提高繁殖能力.     

高糖饮食对果蝇发育和抗氧化能力的影响及其机理研究

为探究高糖饮食对果蝇发育、寿命及抗氧化能力的影响,以果蝇为研究对象,将含有高蔗糖的培养基喂养果蝇,并测定果蝇的寿命、运动能力与抗氧化能力;同时,对高糖组果蝇进行转录组测序,尝试从基因转录水平上探索高糖饮食影响果蝇发育的机理。结果表明,与对照组相比,高糖组雌性、雄性果蝇和雌雄混养果蝇的平均寿命分别缩短了35.01%、43.01%和34.15%,雄性果蝇和雌雄混养果蝇的生存曲线显著低于对照组（P<0.05）。高糖饮食降低了果蝇的化蛹率、羽化率和攀爬能力。高糖组雄性果蝇在生命后期体内T-SOD酶和CAT酶有不同程度的降低,而MDA含量均有所增加。通过转录组测序,发现高糖组果蝇的差异表达基因富集在果蝇发育过程、机体代谢活动调控及应激反应等方面。本研究表明高糖饮食显著降低果蝇的寿命、发育、运动能力及抗氧化能力,为健康饮食提供参考。     

牛肉粉对果蝇遗传学效应的影响

本文以果蝇(Drosophila melanogaster)为实验对象,探讨含有食品添加剂的牛肉粉的培养基对其生活历程、子代数目、体重和突变情况的影响,目的在于通过研究含有食品添加剂的牛肉粉对果蝇遗传学效应的影响,为人们合理使用提供参考。结果表明,在实验浓度范围内,随着牛肉粉浓度的增加,果蝇各代的发育历程逐渐延长;当牛肉粉浓度低于1.25%时,可以促进果蝇繁殖,增加子代数量,高于1.56%时,会抑制其繁殖,减少子代数量(P0.01),但是牛肉粉对果蝇雌雄比变化不显著。此外,牛肉粉培养的果蝇会产生畸形的个体,如褐眼、翘翅和小个体等,并随着遗传代数的增多,畸变率也增加。综上所述,牛肉粉对果蝇的负面影响,小到个体性状,大到种群遗传学效应,都随着牛肉粉剂量的增大而加深。     

玛咖多糖对果蝇性活力及繁殖力影响

目的:研究玛咖多糖对果蝇存活率、性活力和繁殖力的影响。方法:以黑腹果蝇为实验对象,用添加不同浓度玛咖多糖的培养基(0,0.03,0.08,0.24mg·m L~(-1))培养果蝇,统计果蝇存活率、观察果蝇性活力及其生长发育情况及统计果蝇繁殖后代的能力。结果:与对照组相比,各剂量组均能提高果蝇的存活率;性活力方面,各剂量组均能提高果蝇的交配率,添加了0.24mg·m L~(-1)玛咖多糖的培养基对延长交配时间和缩短交配潜伏期于对照组有显著性(P0.05)。繁殖力方面,各剂量组均能增加子代的数量,且对果蝇后代的雌雄比例产生一定影响,但对子代的体重无明显变化。结论:玛咖多糖可显著提高果蝇存活率,能在一定程度上加快果蝇的发育速度,提高果蝇性活力和繁殖能力。     

夏枯草水提物对黑腹果蝇寿命的影响

以夏枯草水提物为研究对象,采用"水提法"提取夏枯草并配制成1∶0(高浓度)、1∶10(中间浓度)、1∶100(低浓度)的溶液,收集24h内羽化的黑腹果蝇,混合48h后分开成雌雄果蝇,每种果蝇分为2组,分别在食物表面添加100μL高浓度的夏枯草水取物,用于黑腹果蝇的寿命、进食量、睡眠、产卵、热刺激等实验,以此来评价夏枯草水提物对果蝇寿命的影响。实验结果表明:高浓度夏枯草水提物相比于对照组可以延长雌性果蝇的平均寿命10.54%、最大寿命20%;提高雌性果蝇进食量24.42%和雄性果蝇进食量37.4%;提高热刺激条件下雌性果蝇平均寿命18.46%,在不影响总的睡眠时间前提下提高其每个睡眠间隙的时间33.44%;对雌性果蝇产卵没有影响。通过探究夏枯草的水提物对果蝇寿命的影响,为夏枯草作为功能性饮料添加剂提供了理论依据。     

高脂饮食对果蝇生长发育和氧化应激的影响

为探究高脂饮食对果蝇生长发育及氧化应激的影响,采用玉米粉酵母标准培养基作对照组,以标准培养基中加入30%猪油为试验组,分别对果蝇的羽化率、幼虫体积、成虫体重、成虫爬行能力、脂肪体细胞与脂滴的大小、脂肪体细胞死亡以及肠道活性氧自由基(reactive oxygen species, ROS)水平进行检测。结果表明:30%猪油抑制果蝇的羽化率,且增大幼虫体积与成虫体重,减弱成虫运动活性,通过增大脂滴大小增加脂肪储存,诱导脂肪体细胞的死亡并增加肠道ROS水平。高脂饮食抑制果蝇生长发育并能引起肠道出现氧化应激损伤。     

释放辐射不育雄虫防治烟青虫的效果研究

为明确X射线辐射不育烟青虫雄虫在田间应用的释放比例,通过交配竞争试验和性信息素诱集测定了不同释放比例对其子代卵孵化率、被害株率及田间成虫量的影响,并获得了相关防治效果。结果表明,蛹期接受不育剂量辐照对烟青虫雄蛹羽化率无显著影响,但显著缩短其成虫寿命;辐射不育烟青虫雄虫不同释放比例对雌虫交配率和平均产卵量均无显著影响,但卵孵化率随着释放比例的增加而降低;在田间罩笼试验中,其平均防治效果随着释放比例的增加而增加,在8∶1时可以达到91.11%;同时,在田间烟青虫成虫羽化初期按照8∶1的释放比例间隔1周连续释放3次可以显著减少田间子代雄成虫量,田间小区防治效果最高可以达到64.86%。本研究确定的8∶1的释放比例可以应用于田间烟青虫的防控。     

六个品种小麦对玉米象的抗虫性比较研究

试验选用产自河北、河南、山东等省的6个小麦品种,分别是良星66、泛麦8号、西农979、郑麦7698、济麦22和矮抗58。从田间获取的样品分别将其水分含量调节为12.5%左右,每16 g粮食感染6头母代玉米象成虫(雌雄比为4∶2),之后检查其子代成虫羽化数量,羽化时间,并计算发育历期和敏感系数。主要结果为:济麦22中的玉米象平均发育历期最短(40.8 d),子代成虫数量最多(46头),对玉米象的敏感系数为9.40;西农979中的玉米象平均发育历期为42.6 d,子代成虫数量为8头,对玉米象的敏感系数为4.98。抗虫性最小的济麦22中玉米象子代成虫羽化初现时间、羽化高峰和终止时间都相应地是最短,抗虫性最大的西农979中害虫初现时间和终止时间有所延长,但并非最大值。良星66中的玉米象羽化终止时间最长,但其抗虫性却小于西农979。由样品感染卵至成虫初现的过程中小麦品种间的重量变化量差异不显著。结果表明:试验小麦品种间对玉米象的抗虫性差异显著,子代成虫出现数量多的小麦品种其敏感系数也相应地小,但羽化时间长短与小麦的敏感系数大小变化趋势不完全一致,小麦感染害虫后重量下降量与其敏感性相关性不明显。     

Prediction of Listeria spp. growth as affected by various levels of chemicals, pH, temperature and storage time in a model broth

The effects of concentration of NaCl (0.5 to 12.5%), methyl paraben (0.0 to 0.2%), sodium propionate (0.3%), sodium benzoate (0.1%), potassium sorbate (0.3%), pH (>5.9) temperature (4 to 30°C), storage time (up to 58 d) and inoculum (>10⁵ to >10⁻² per ml) on the log₁₀ probability percentage of one cell of Listeria spp. to initiate growth in a broth system were evaluated in a factorial design study. At pH 5.96 and temperature ranging from 4 to 30°C the concentrations of sodium propionate, potassium sorbate, and sodium benzoate examined allowed growth of L. monocytogenes with lag phases at 4°C of 18, 27 and 21 days, respectively. For 0.1 and 0.2% methyl paraben growth of all Listeria spp. was initiated at 8°C and 30°C, respectively. At pH 6, concentration of 12% NaCl supported the growth of L. monocytogenes at 8 to 30°C, whereas 12.5% inhibited all Listeria species. Four regression equations were derived relating probability of growth initiation to temperature, concentrations of NaCl and preservatives storage time, and Listeria species specific effects. From these equations, the number of cells needed for growth initiation can be calculated. The impact of this type of quantitative study and its possible application on the development of microbial standards for foods is discussed.     

Development and progeny performance of Tribolium castaneum (Herbst) in brewer’s yeast and wheat (patent) flour at different population densities

The effects of brewer's yeast and wheat patent flour on Tribolium castaneum (Herbst) life parameters at different population densities (1, 2, 5 and 10 pairs) were examined. A standard diet (95% wheat flour + 5% brewer's yeast) was used as control. The effect was examined on the duration of egg, larval and pupal stages, total development cycle, first adult emergence, eclosion period, the total number of offspring, number of offspring per female and body weight of adult offspring. For each diet type and population density, adults were allowed to feed and oviposit for 7 days before removal from diets. A longer larval stage was recorded in brewer's yeast (between 23.88 and 26.25 days, depending on population density) and patent flour (17.63–23 days) compared to the standard diet (12.88 and 13.38 days). The longest eclosion period was recorded in patent flour (19–21.23 days), which was the only diet unaffected by population density. In the brewer's yeast and standard diet, the period of eclosion was prolonged with the increase in population density. The lowest number of progeny was recorded in patent flour (44.29–49.63 insects), followed by brewer's yeast (22.86–177 insects), while the highest number of progeny (107.25–313.38 insects) was recorded in the standard diet. Population density did not affect the total number of progeny in patent flour, which remained low at all densities, while in the brewer's yeast and standard diet the rise in population densities caused a rise in progeny numbers. The type of diet did not affect the body weight of adult progeny: the highest body mass of progeny was recorded at the lowest population density and the lowest mass at the highest. This study provides insight into poorly researched development cycle and reproductive strategies of T. castaneum on brewer's yeast and patent flour, which are important stored products.     

根皮素延缓雌性果蝇的衰老作用

本文探究了根皮素(phloretin,PT)对雌性果蝇延缓衰老作用的影响及其潜在机制。雌性果蝇干预根皮素后(1.15 mM、2.3 mM、4.6 mM),观察对寿命、爬行能力、抗应激能力、肠道屏障功能、肠道菌落总数、肠道前体细胞数目、内源抗氧化酶超氧化物歧化酶(superoxide dismutase,SOD)、过氧化氢酶(catalase,CAT)、谷胱甘肽过氧化物酶(glutathion peroxidase,GSH-PX)活力、脂质过氧化产物丙二醛(malonaldehyde,MDA)含量以及相关抗氧化基因SOD2、CAT、玛士撒拉(methuselah,MTH)和叉头蛋白(forkhead box o,foxo)的m RNA表达水平的影响。结果显示,雌性果蝇干预根皮素浓度为4.6 mM时,与空白组相比,平均寿命延长了23.98%,30d时爬行能力上调了44.96%,对双氧水和十二烷基硫酸钠损伤后的寿命延长了24.35%和23.94%,肠道前体细胞减少了15.59%,肠道微生物乳酸杆菌(lactobacilli,LMRS)、肠杆菌(enterobacteria,ENT)、醋酸杆菌(acetobacteria,ACE)及其他细菌(nutrientrichmedium,NR)分别下调了23.73%、33.33%、43.24%和27.50%,Mn-SOD、Cu/Zn-SOD、CAT、GSH-PX酶活性分别提高了17.85%、31.03%、32.07%和25.57%,MDA生成量降低了23.55%,foxo、CAT和SOD2 mRNA表达水平分别上调了67.21%、32.54%和36.27%,MTH mRNA表达量降低了27.16%。根皮素可以提高雌性果蝇抗氧化酶活力和抗氧化基因表达水平,提高机体抗应激能力,维持肠道稳态,延长果蝇寿命。     

Simultaneous determination of nine preservatives in food by liquid chromatography with the aid of coagulant in the clean-up process

ABSTRACT

A simple HPLC method was developed for the simultaneous analysis of nine preservatives in food including benzoic acid, sorbic acid, dehydroacetic acid, methyl paraben, ethyl paraben, isopropyl paraben, propyl paraben, isobutyl paraben and butyl paraben. Samples were extracted with 60 v/v% methanol containing poly-aluminium chloride (PAC) and sodium hydroxide prior to analysis. PAC, which is normally used as a coagulant, was successfully applied to remove interfering substances from the samples. The method showed good linearity with coefficients of determination higher than 0.999 over the range of 0.2–5 µg ml^–1 for all target preservatives. LOQs of the method were in the range of 0.002–0.008 g kg^–1. Method performance was evaluated in a variety of foods demonstrated to have quantitative recoveries of 81.7–102.5% with satisfactory intra-day precision of < 3.7% and inter-day precision of < 6.5%. The method also demonstrated applicability to real foods containing preservatives.     

3种常用防腐剂对秀丽隐杆线虫毒性作用的研究

目的研究苯甲酸钠、山梨酸钾、尼泊金甲酯3种常用防腐剂在食品常规剂量下对秀丽线虫的毒性作用。方法分别用1 g/L山梨酸钾、1 g/L苯甲酸钠、0.25 g/L尼泊金甲酯处理秀丽线虫24、48、72 h,观察秀丽线虫身体弯曲频率、头部摆动频率、触碰反应及体长;同时观察各组线虫的后代数目和寿命。结果 3种防腐剂均能显著降低线虫的生殖能力(P0.01)及线虫头部摆动频率(山梨酸钾作用24、48 h,P0.01;尼泊金甲酯和苯甲酸钠作用24、48、72 h,P0.01)。尼泊金甲酯能够显著降低线虫身体弯曲频率(作用48、72 h,P0.05)。尼泊金甲酯作用72 h,苯甲酸钠作用48、72 h后,线虫触碰反应迟钝(P0.05)。山梨酸钾作用24 h时线虫体长增加(P0.05),作用72 h时线虫体长减少(P0.05);尼泊金甲酯作用24、48 h时线虫体长增加(P0.05),但其效果随作用时间的增加而减弱;苯甲酸钠作用72 h时明显抑制线虫的体长发育(P0.05)。3种防腐剂的长期作用对线虫寿命无显著性影响。结论常规剂量的苯甲酸钠、山梨酸钾、尼泊金甲酯对秀丽线虫有一定的生殖毒性和神经毒性。     

不同方法检测食品中对羟基苯甲酸酯类防腐剂

目的建立高效液相色谱法(high performance liquid chromatography,HPLC)检测对羟基苯甲酸酯类防腐剂的方法。方法采用高效液相色谱法对样品中对羟基苯甲酸酯类进行测定,并比较此方法与标准中规定的气相色谱(gas chromatography,GC)法之间的差异。结果气相色谱法和液相色谱法测定对羟基苯甲酸酯类线性范围均良好,气相色谱法加标回收率在82.3%～111.3%之间,相对标准偏差(relative standard deviation,RSD)在1.8%～5.2%之间,高效液相色谱法加标回收率在85.4%～107.0%之间,RSD在0.2%～0.6%之间,且高效液相色谱法中对羟基苯甲酸甲酯类的检出限分别为0.04、0.06、0.09、0.16mg/kg,定量限分别为0.1、0.2、0.3、0.5mg/kg,均低于气相色谱法的检出限和定量限。结论 HPLC法具有简单快速、灵敏度高等优点,能够满足饮料类食品检测及安全的需要,为防腐剂的检测提供了实用的技术手段。     

甘薯汁对果蝇寿命及抗氧化能力的影响

为探讨甘薯汁抗氧化及防衰老的功效,选取果蝇为动物模型,在培养基中分别添加低、中、高剂量（分别为0.10、0.15、0.20 mg/mL）甘薯汁饲喂8 h内羽化未交配的雌、雄果蝇,通过果蝇生存实验及测定不同饲养时间果蝇体内的超氧化物歧化酶（superoxide dismutase,SOD）活力、总抗氧化能力（total antioxidant capacity,T-AOC）和丙二醛（malondialdehyde,MDA）含量,评价甘薯汁对果蝇寿命和抗氧化酶活性的影响。结果表明：与对照组相比,不同剂量甘薯汁组均能显著延长雌、雄果蝇的平均寿命（P＜0.05或P＜0.01）,且呈剂量依赖性。果蝇SOD活力、T-AOC在低、中、高剂量组中均显著增加（P＜0.05或P＜0.01）,中、高剂量组果蝇体内MDA含量显著降低（P＜0.05或P＜0.01）。其中,与对照组相比,高剂量组可使雌、雄果蝇平均寿命分别延长17.93%和16.00%,SOD活力分别提高50.51%、58.61%,T-AOC分别提高79.73%、62.67%,MDA含量分别下降35.59%、37.14%。结论：甘薯汁可以提高果蝇体内的抗氧化能力,具有一定的延缓衰老作用。     

Effects of temperature on development of the azuki bean weevil,Callosobruchus chinensis (Coleoptera: Bruchidae) on two leguminous seeds

The azuki bean weevil, Callosobruchus chinensis L., is one of the most serious stored product pests in the world. The temperature driven stage-specific development of C. chinensis was examined at eight constant temperatures of 15.97, 18.31, 22.09, 26.15, 30.50, 34.39, 38.00, and 40.00 °C on azuki bean (Vigna angularis [Wild.] Ohwi & Ohashi) and cowpea (Vigna unguiculata L.) seeds. Parameters for stage-specific development such as threshold temperatures and thermal constants were determined by linear and nonlinear models. The total developmental time (egg - adult) decreased with increasing temperature from 14 to 38 °C on both seeds. However, total developmental time varied from 127.93 to 122.25 days at 15.97 °C to 19.31 and 19.17 days at 38.00 °C on azuki bean and cowpea seeds, respectively. The nonlinear Logan-6 and Performance models estimated optimal temperatures as 37.3, 37.0, 36.5 and 37.1 °C on azuki bean, and as 36.7, 36.4, 34.5 and 36.6 °C on cowpea for egg, larva, pupa and egg to adult, respectively. The linear model estimated the lower temperature thresholds (T_min) of egg, larva, pupa and egg to adult as 16.97, 10.47, 1.36, and 10.28 °C on azuki bean, respectively, and 16.84, 10.33, 10.92, and 9.83 °C on cowpea, respectively. The thermal constants (K) for each stage completion was 35.13, 255.21, 233.11, and 503.41° days (DD) for egg, larva, pupa, and egg to adult on azuki bean, respectively and 32.45, 246.50, 107.04, and 490.02 DD for egg, larva, pupa, and egg to adult on cowpea, respectively. Temperature also influenced the adult longevity. These findings on thermal requirements and temperature thresholds can be used to predict the occurrence, number of generations and population dynamics of C. chinensis.     

黑米花青素延缓果蝇衰老作用研究

探究黑米花青素延缓衰老的能力及其作用机制。以2 d龄的野生型果蝇模型生物为研究对象,饲喂添加不同质量浓度(0、1、5 mg/mL)黑米花青素的培养基,采用寿命实验、饮食量检测和逆重力爬行实验方法研究黑米花青素对果蝇平均寿命和健康寿命的影响;采用蓝精灵实验检测黑米花青素对果蝇肠道完整性的影响;用荧光实时PCR测定果蝇体内抗氧化基因SOD、CAT、Rpn11 mRNA表达量的变化。研究发现,饲喂黑米花青素后果蝇平均寿命和健康寿命均高于对照组;黑米花青素对果蝇肠道有一定的保护作用;抗氧化基因mRNA表达水平显著提高(Cu/Zn-SOD,P<0.01;Mn-SOD、CAT和Rpn11,P<0.05)。研究认为,黑米花青素延缓衰老的作用可能是通过上调内源性抗氧化基因来实现的。