利用响应面法对柳小皮伞液体发酵培养基的优化

首先采用Plackett-Burman设计对影响柳小皮伞(Marasmiussalicicola)AS5.166发酵胞外多糖培养基的组成成分进行了筛选,所选取的10个相关因素为:葡萄糖、蔗糖、酵母膏、蛋白胨、K2HPO4、KH2PO4、CaCl2、FeSO4、MgSO4、VB1。在此基础上,再采用响应曲面法(ResponseSurfaceMethodology,RSM)对影响柳小皮伞发酵胞外多糖培养基的关键影响因素蔗糖、酵母膏和FeSO4的最佳水平范围作了进一步的研究与探讨,通过对二次多项回归方程求解得知,在上述自变量分别为蔗糖23.28g/L、酵母膏12.21g/L和FeSO447.80mg/L时,胞外多糖产量的最大预测值为94.74mg/100ml。     

灰树花泰山-1生物学特性研究

以培养温度、pH值及不同碳氮源对灰树花泰山-1菌丝生长的影响进行了初步试验,并通过正交试验对培养条件进行了优化。结果表明:泰山-1菌丝体培养最适温度为26~28℃,最适pH值为5~6;最适碳源为葡萄糖,最适氮源为酵母膏;各因素对菌丝体生长影响的大小顺序为葡萄糖酵母膏MgSO4KH2PO4,最佳培养基配方为:葡萄糖20 g/L、酵母膏5 g/L、KH2PO42 g/L、MgSO41 g/L。     

两种真姬菇摇瓶发酵产生菌丝体及 胞外多糖研究

;采用摇瓶培养法对2种真姬菇的发酵工艺进行研究,结果表明:真姬菇Ⅰ、Ⅱ发酵生产菌丝体及胞外多糖的碳源是葡萄糖,氮源是酵母膏;液体发酵培养基是葡萄糖3%、酵母膏0.4%、vitB110mg/100ml、KH2PO40.1%、MgSO40.1%,pH值为6.0;液体发酵的优化条件是初始pH 6.0～7.0,振荡速度110～130r/min,培养温度25～28℃,装液量150ml/250ml.2种真姬菇菌丝体及胞外多糖产量较高,真姬菇Ⅰ菌丝体干重、胞外多糖产量分别是3.92、8.83 mg/ml;真姬菇ⅠⅠ菌丝体干重、胞外多糖产量分别是3.25、7.69 mg/ml,即真姬菇Ⅰ摇瓶发酵菌丝体干重、胞外多糖产量高于真姬菇Ⅱ.     

鸡腿菇胞外多糖发酵条件的研究

以胞外多糖产量为指标对鸡腿菇(Coprinus comatus)的发酵条件进行研究.结果表明,其最佳培养基组成为:玉米粉3.0%,酵母粉1.0%,葡萄糖 2.0%,KH2PO4 0.20% ,MgSO4·7H2O 0.15%,VB1 15 mg·L-1;培养温度22℃,pH6.1,发酵时间为96 h.     

金针菇液体发酵培养基优化及其胞外多糖抗氧化活性研究

应用响应面分析法考查葡萄糖、蛋白胨、KH2PO4、果蔬汁用量对金针菇液体发酵胞外多糖的影响,分析胞外多糖抗氧化活性。试验结果表明,对金针菇胞外多糖影响大小依次为:蛋白胨KH2PO4果蔬汁葡萄糖,所确定的最优培养基质量分数为:葡萄糖2.46%,蛋白胨0.5%,KH2PO40.1%,果蔬汁15%,在此条件下胞外多糖质量浓度为0.83mg·mL~(-1)。通过测定金针菇液体发酵胞外多糖的抗氧化活性,证明金针菇胞外多糖对DPPH自由基和ABTS自由基都具有较强的清除作用,当胞外多糖质量浓度大于2mg·mL~(-1)时,其对DPPH自由基的清除率相比同质量浓度下的Vc要高;当胞外多糖质量浓度大于1.5mg·mL~(-1)时,其对ABTS自由基的清除率与同质量浓度下的Vc的清除率相近,达到99.87%。     

金针菇胞外多糖液体发酵培养基的优化

以金针菇胞外多糖、生物量和还原糖为参数,采用正交试验设计对金针菇胞外多糖液体发酵培养基碳源、氮源、无机盐和生长因子进行优化。结果表明,金针菇多糖的最佳培养基为:麸皮1.5%,蔗糖2%、硝酸铵0.5%、MgSO4·7H2O0.05%,KH2PO40.2%,VB10.005%、VB20.005%。试验表明采用正交试验设计对金针菇胞外多糖液体发酵培养基进行优化是可行的。     

榆黄菇胞外多糖液体发酵培养基的优化

榆黄菇发酵过程中各成分的比例对胞外多糖的产量有重要影响.正交试验结果表明,当发酵配方为马铃薯30%,蛋白胨0.1%,葡萄糖3%,KH2PO4+MgSO4·7H2O 0%时胞外多糖产量较高.     

鸡腿菇液体发酵工艺的优化

[目的]对鸡腿菇液体发酵培养基和培养条件进行筛选及优化。[方法]以鸡腿菇为供试材料,胞外多糖和菌丝体生物量为指标,通过单因素试验和正交试验对鸡腿菇液体发酵培养基配方及培养条件进行筛选及优化。[结果]鸡腿菇液体发酵产胞外多糖的最佳培养基组合为：葡萄糖2．0％,酵母膏0．75％,CaCl0．2％;鸡腿菇液体发酵产菌丝体的最佳发酵培养基组合为：葡萄糖2％,酵母膏0．75％,KH2PO4 0．2％;鸡腿菇液体发酵产胞外多糖和菌丝体的最佳发酵条件均为：起始pH值7．0,接种量20．0％,装液量120ml,培养天数6d;[结论]该研究为鸡腿菇的进一步开发提供了科学依据。     

绣球菌突变菌株液体发酵条件的研究

采用摇瓶培养法和正交试验对绣球菌突变菌株P1的液体发酵条件进行研究,实验得出最佳配方为:玉米淀粉 2%、酵母浸膏0.5%、KH2PO4 0.1%、MgSO4·7H2O 0.3%.最适发酵时间是6 d,而优化发酵条件得出最佳的发酵条件为:温度 28 ℃,转速 130 r/min、装液量150 mL/250 mL,在最适条件下绣球菌P1菌丝体生物量(干)及胞外多糖最高产量分别为10.3 g/L 、1 790 mg/L.     

产朊假丝酵母C-27利用甜高梁秸秆汁产SCP的培养基优化

应用二次正交旋转组合试验设计方法对产朊假丝酵母C-27产单细胞蛋白(SCP)的发酵培养基组分(甜高粱秸秆汁、葡萄糖、蛋白胨、MgSO4和KH2PO4)进行了优化.结果显示,甜高粱秸秆汁和蛋白胨的浓度对SCP的产量有显著的正效应,而其他组分未表现出显著的影响.产朊假丝酵母C-27产SCP最终的优化发酵培养基配方为:甜高粱秸秆汁220 mL/L、葡萄糖3.25 g/L、蛋白胨37.5 g/L、MgSO4 0.325 g/L 、KH2PO4 0.325 g/L.该优化的发酵培养基配方下SCP产量达8.72 g/L,比初始发酵培养基配方(甜高粱秸秆汁120 mL/L、工业葡萄糖20 g/L、工业蛋白胨20g/L、MgSO4·7H2O 2.0 g/L、KH2PO4 2.0 g/L)下的SCP产量(7.00 g/L)提高了24.57％.     

葡萄盆栽技术

葡萄盆栽技术,包括择土选种、露地扦插、田间管理、装盆及整形、肥水管理等内容,对葡萄盆栽爱好者有一定的指导意义。     

Yield and quality of maize stover: Variation among cultivars and effects of N fertilization

Biomass yields and concentrations of crude protein(CP), ether extract(EE), neutral detergent fiber(NDF), acid detergent fiber(ADF), and crude fiber(CF) were analyzed for five cultivars of summer-sown maize(Zea mays L.) stover grown in field trials at three rates of N fertilization, and sampled immediately after grain harvest.The results revealed differences in yields and concentrations of nutrients according to stalk height and hence harvest portion among the cultivars.N application greatly increased biomass yield and CP, especially in upper stalks and to a lesser extent, EE.Concentrations of NDF and ADF decreased as N rate increased.The results show that stovers from all local popular maize cultivars are suitable as animal fodder and that moderate N application improves feed quality of stover.     

民勤绿洲荒漠交错带三种沙丘类型的自然植被特征

基于对民勤沙井子地区植被调查数据,研究了固定沙丘、半固定沙丘和流动沙丘3种沙丘类型的自然植被特征.结果表明:从固定沙丘、半固定沙丘到流动沙丘,总盖度、灌木盖度下降,草本盖度增加.物种丰富度减小是物种多样性下降的主要原因.从植物的生活型来看,多年生草本和灌木类植物受沙丘类型的影响最大,而一年生草本和半灌木可存活于不同沙丘类型.白刺的生态优势度(重要值)由小到大依次为固定沙丘、半固定沙丘、流动沙丘.植物多样性与白刺的生态优势度呈负相关.不同沙丘类型白刺地上生物量变化明显,半固定沙丘白刺生物量最大.     

寄生虫引起的草鱼鳃病的组织病理比较研究

本文对草鱼的隐鞭虫病、车轮虫病、小瓜虫病、指环虫病、三代虫病及中华鱼蚤病六种寄生虫性鳃病的组织病理变化进行比较研究，寄生虫性鳃病均可引起鳃组织发生炎症反应，粘液分泌亢进，嗜酸粒细胞和淋巴细胞浸润；但又因病原体的种类不同，危害鱼的方式、方法不同，因此病理变化又有很大差别，对鱼危害较大的均为变质性炎，如隐鞭虫病；对鱼危害较小的则属增生性炎，如中华鱼蚤病．     

小菜蛾阿维菌素和虫酰肼抗性品系对几种新型药剂的交互抗性研究

以敏感品系为对照,利用室内筛选获得的虫酰肼和阿维菌素高抗品系Teb-R和Aba-R,测定了小菜蛾对几种新型杀虫剂的交互抗性。结果发现:小菜蛾对虫酰肼产生高水平抗性后(抗性倍数185.5倍),对阿维菌素表现出中等水平交互抗性(41.0倍),对茚虫威(11.4倍)和溴虫腈(5.3倍)仅表现出低水平交互抗性,对多杀菌素(1.7倍)和氯虫苯甲酰胺(1.4倍)则没有表现出明显的交互抗性。用阿维菌素筛选Teb-R品系39代后获得阿维菌素高抗品系Aba-R(593.8倍),该品系对茚虫威(12.3倍)表现出中等水平交互抗性,对多杀菌素(7.9倍)表现出低水平交互抗性,对溴虫腈(2.7倍)和氯虫苯甲酰胺(0.9倍)的交互抗性不明显;同时该品系对虫酰肼的抗性也由阿维菌素筛选前的185.5倍下降到筛选后的28.0倍,也没有交互抗性。基于上述研究结果认为,使用虫酰肼防治小菜蛾出现抗性后,可以使用多杀菌素和氯虫苯甲酰胺进行替代防治,但不宜用阿维菌素、茚虫威和溴虫腈进行替代防治;利用阿维菌素防治小菜蛾产生抗性后,可以用溴虫腈、氯虫苯甲酰胺和虫酰肼进行替代防治,但不宜用多杀菌素和茚虫威。     

Water quality,agriculture and food safety in China:Current situation,trends, interdependencies,and management

Water quality in China is becoming a severe challenge for agriculture and food safety,and it might also impact health of population via agriculture and food. Thus,it is causing widespread concern. Based on extensive literatures review and data mining,current situation of water pollution in China and its effects on food safety were analyzed. The 2nd National Water Resource Survey in China show that the surface water all over the country was under slight pollution and about 60% of groundwater is polluted. Drinking water quality is basically guaranteed in urban area but it is worrisome in rural areas. In addition,China is the largest consumer of fertilizer and pestici de in the world and the amounts of application still show increasing trends. Fertilizers and pesticides are the most important sources of pollution,which affect human health as persistent organic pollutants and environmental endocrine disruptors. Eutrophication of surface water and nitrate pollution of groundwater are serious threats to drinking water safety. Sewage irrigation is becoming a pollution source to China's water and land because of lacking of effective regulations. Although,with the advance in technology and management level,control of nitrogen and phosphorus emissions and reducing water pollution is still a major challenge for China.     

拟斯卑尔脱山羊草的FISH核型分析

【目的】建立拟斯卑尔脱山羊草的FISH核型,分析明确不同来源拟斯卑尔脱山羊草的FISH核型特点,比较不同拟斯卑尔脱山羊草及其与普通小麦的FISH核型差异。【方法】以荧光标记的寡核苷酸Oligo-pTa535和Oligo-pSc119.2为探针,利用荧光原位杂交(fluorescence in situ hybridization,FISH)技术分析pTa535和pSc119.2在不同拟斯卑尔脱山羊草、四倍体小麦和普通小麦染色体上的杂交信号分布特点;以禾本科植物着丝粒专化寡核苷酸Oligo-CCS1为探针,明确拟斯卑尔脱山羊草的着丝粒位置,测量拟斯卑尔脱山羊草染色体相关参数;通过FISH核型比较明确不同拟斯卑尔脱山羊草及其与小麦核型的多态性差异。【结果】Oligo-pTa535主要分布在小麦的D和A组染色体上,在小麦的B组染色体上仅有零星分布,在5份拟斯卑尔脱山羊草的染色体中未显示Oligo-pTa535杂交信号。Oligo-pSc119.2杂交信号主要分布在小麦的B组染色体上,在小麦的A、D组染色体中分布较少,但在5份拟斯卑尔脱山羊草染色体上均有广泛分布。根据Oligo-pTa535和Oligo-pSc119.2杂交信号在小麦染色体上的分布特点,可以将小麦的不同染色体相互区分开来。Oligo-pSc119.2杂交信号在不同倍性、不同品种的小麦B组染色体上的分布特点基本相似,而不同来源拟斯卑尔脱山羊草的Oligo-pSc119.2的FISH核型差异较大,甚至在同一细胞内的2条同源染色体上Oligo-pSc119.2杂交信号的分布也具有明显差异。不同来源的拟斯卑尔脱山羊草与小麦B染色体组的FISH核型存在明显差异。PI542238的7对染色体均为中间着丝粒染色体,核型公式为2n=14=14m。其余4份拟斯卑尔脱山羊草的4S染色体均为近中着丝粒染色体,其余染色体均为中间着丝粒染色体,核型公式皆为2n=14=12m+2sm。【结论】拟斯卑尔脱山羊草染色体上含有丰富的与pSc119.2高度同源的重复序列,不含有与pTa535高度同源的重复序列。不同来源的拟斯卑尔脱山羊草之间以及同一来源的拟斯卑尔脱山羊草的个体间甚至同一个体内的同源染色体间在pSc119.2的分布上均具有遗传多样性。以Oligo-pSc119.2为探针建立的拟斯卑尔脱山羊草染色体FISH核型与小麦B组染色体的核型具有显著差异。利用荧光标记的Oligo-pTa535和Oligo-pSc119.2为探针进行FISH分析,可以准确区分拟斯卑尔脱山羊草的不同染色体,并能将拟斯卑尔脱山羊草与小麦的染色体区分开来。     

芦荟多糖抗猪繁殖与呼吸综合征病毒作用试验

在安全浓度的基础上,将芦荟多糖稀释成不同浓度,作用于猪繁殖与呼吸综合征病毒,当病毒对照CPE达到70%～80%后,在酶联免疫检测仪上测定A490nm值,A490nm值越大,表明细胞生长越旺盛,抗感染效果越好。在先加芦荟多糖后接种病毒时,多糖对PRRSV感染有阻断作用,且作用显著;在加芦荟多糖之前先接种病毒,则芦荟多糖对PRRSV的抑制作用不明显;高浓度芦荟多糖对PRRSV具有直接杀灭作用。     

氮素用量对结球甘蓝生长及产量和品质的影响

研究了氮素用量对结球甘蓝生长及产量、品质的影响.结果表明,随着施氮量的增加,结球甘蓝生长势增加,产量增加,但氮素用量过多会导致产量下降.本试验条件下,施氮量为0.6 t/hm2时结球甘蓝产量较高,达85.9 t/hm2,而施氮量为1.05 t/hm2时结球甘蓝产量仅为70.3 t/hm2,前者比后者增产22%,但二者分别比CK增产174.9%、125%.此外,增施氮素可降低结球甘蓝干物质、纤维素、有机酸及可溶性糖含量,还显著提高了硝酸盐含量.     

Mycotoxin detection——Recent trends at global level

Mycotoxin contamination in agro-food systems has been a serious concern globally during the last few decades. Mycotoxins are toxic secondary metabolites produced by fungi when they grow in agro-food products and feedstuff. Several detection techniques have been developed in recent years to detect mycotoxins in the food and feed effectively. HPLC based techniques are very common in usage in the laboratories for the testing of mycotoxins. In recent years,immuno-based assays is widely used and have been reported at large due to its sensitivity and limited detection time. Immuno assay-based kits were developed effectively to be used in the fields and in storage systems to detect the mycotoxin levels. Microarray-based immunoassays developed in the recent years could simultaneously detect aflatoxin,ochratoxin,and zearalenone with the higher sensitivity. Aptamer-based assays could target the detection of ochratoxin and aflatoxins and fumonisins at high specificity in food products. In recent years,several assays reported for the simultaneous multiple detection of different mycotoxin was based on HPLC and LC-MS/MS. There is a need for the use of these advanced technologies in the commercial scale.