正交设计法优化Bt发酵培养基

采用正交实验方法,进行摇瓶发酵培养基筛选试验来优化苏云金芽孢杆菌发酵培养基,通过测量发酵液吸光度值来确定不同农副产品培养基成分对苏云金芽孢杆菌发酵的影响,从而使培养基优化过程简单易行。实验结果表明,不同培养基成分配比对发酵效果影响差别很大,试验所得的最佳培养基组合为:玉米粉2.0%、豆饼粉3.5%、鱼粉2.0%、花生饼粉2.0%、淀粉1.0%、K2HPO40.3%、CaCO30.3%。     

生物农药苏云金芽孢杆菌的研究进展

苏云金芽孢杆菌(Bacillus thuringiensis)制剂是目前应用广泛而有效的一种微生物杀虫剂.本文介绍了苏云金芽孢杆菌的菌种优选、发酵过程及剂型研究进展,具体阐述了发酵过程中培养基和发酵条件的优化、各种发酵方式和发酵设备等. 指出了目前发酵生产苏云金芽孢杆菌中存在的问题,提出了解决问题的建议并展望了其发展前景.     

枯草芽孢杆菌出芽培养条件优化

探索了提高枯草芽孢杆菌产生芽孢的方法,使用单批一次投料培养法研究了培养基成分、p H值、培养过程中通气量及装液体积比对菌体产芽孢的影响。试验结果说明:枯草芽孢杆菌最适生长和产生芽孢的碳源是糖蜜,最适氮源是酵母浸粉;二价锰离子和无机盐对菌体的生长和产芽孢有很大影响。菌体生长和产芽孢的最适培养基组成:糖蜜1.0%,酵母粉0.8%,(K2HPO4+KH2PO4)0.5‰,Mn SO4 0.2‰;产芽孢的最适条件:开始培养p H值为7.0,最适装液量为20%(体积比)。在5L半自动发酵罐中,溶氧大于70%,发酵24 h后,芽孢数量为5.1×1011CFU/m L,出芽率为98.0%。     

城市污泥可生产苏云金杆菌

日前,南京农业大学资源与环境科学学院利用未脱水的城市污泥作原料发酵苏云金杆菌菌种获得成功,并生产出生物杀虫剂。城市污泥含有丰富的有机碳氮和无机盐,有望作为发酵苏云金杆菌的培养基质。与常规利用黄豆粉作为培养基相比,该项研究芽孢大量形成时间约提前10小时,且芽孢在30     

质芽孢杆菌PM13菌株培养基的优化

对胶质芽孢杆菌PM13菌株进行了培养基成分的优化,考察了培养基各组分对菌体生长和发酵液粘度的影响. 由单因素、正交和均匀实验结果可知,碳源和氮源种类的影响最显著,优化的培养基配方为(g/L)：糖蜜3.67,淀粉5.5,豆粕粉7.0, CaCO3 8.5, K2HPO4 2.0, MgSO4×7H2O 1.4, NaCl 0.2. 在此配方下,胶质芽孢杆菌芽孢生成量达2.2×108 cfu/mL,且发酵液稠度系数显著降低到0.028 Pa×sn,可采用常规生物反应器进行规模化发酵.     

苏云金芽孢杆菌伴胞晶体产生菌BZ-1的分离筛选及鉴定

目的从被污染的蝴蝶兰初代培养基中分离筛选苏云金芽孢杆菌伴胞晶体产生菌,并进行鉴定。方法分离自被污染的蝴蝶兰初代培养基的苏云金芽孢杆菌经富集后,筛选伴胞晶体产生菌BZ-1,显微镜观察进行鉴定;采用PCR法分析菌株BZ-1的16S rDNA和脂肽抗生素合成相关基因,SDS-PAGE分析菌株的伴胞晶体;制备菌株发酵粗提液,提取活性物质,分别置于不同温度(50、60、80、100℃)30 min、用不同的蛋白酶(蛋白酶K、胰蛋白酶)于37℃处理30 min,以枯草芽孢杆菌作为指示菌检测菌株的抑菌活性;并检测菌株对小菜蛾的毒力。结果菌株BZ-1能产生芽孢,并在芽孢旁形成多个无规则伴胞晶体;该菌株的16S rDNA扩增产物测序结果经与GenBank中登录的16S rDNA核苷酸序列进行BLAST比对,与B.anthracis str.Ames(NR_074453)、B.cereus(NR_074540)和B.thuringiensis Bt407(NR_102506)菌株相似度达99%,表明菌株BZ-1属于芽孢杆菌属,结合扫描电镜观察结果,可初步确定该菌株为苏云金芽孢杆菌;该菌株可扩增出脂肽抗生素合成相关基因sfp、mycB、ituA、fenB;该菌株从培养2 d芽孢形成后开始分泌相对分子质量约130 000的晶体蛋白,4 d时蛋白表达量增加,6 d后蛋白表达量基本达到稳定;该菌株具有一定的热稳定性,对蛋白酶K具有一定的耐受性;该菌株于30℃培养6 d,对小菜蛾表现出较高的毒力。结论从被污染的蝴蝶兰初代培养基中分离筛选的苏云金芽孢杆菌伴胞晶体产生菌BZ-1所产的抗菌物质主要抑制革兰阳性细菌,具有较高的毒力,可作为原始菌株发酵进行田间生物防治,也可为构建杀虫基因工程菌以及培育抗虫转基因植物提供高毒力的候选基因,具有较好的应用前景。     

苏云金芽孢杆菌高浓度液体发酵培养基的优化研究

以葡萄糖和甘油作碳源进行苏云金芽孢杆菌液体发酵,其发酵效果明显优于原实验室优化培养基,680 nm处的吸光度增加了5～6倍,得到的高浓度培养基成分为:胰蛋白胨5.0g·L-1、酵母膏5.0 g·L-1、葡萄糖(或甘油)20 g·L-1、KH2PO4 0.3 g·L-1、Na2 HPO4 1.1 g·L-1、MgSO4·7H2O 1.0 g·L-1、FeCl2·6 H2O 0.02 g·L-1、CaCl20.02 g·L-1、EDTA 0.2g·L-1、微液1 mL·L-1,pH值7.2.用葡萄糖作碳源进行8 L发酵罐小试,发酵过程中菌体生长正常,工业发酵采用此培养基可以大大降低发酵成本.     

利用蓝藻厌氧发酵液制备苏云金芽孢杆菌杀虫剂

[目的]富营养化湖泊蓝藻暴发已成突出的环境问题,打捞蓝藻的处理和利用是目前的技术难题,探究蓝藻的农药化利用可行性。[方法]以新鲜蓝藻为基质自然厌氧发酵不同时间得到蓝藻沼液,并以4种培养基(LB、新鲜蓝藻、蓝藻发酵2个月沼液、蓝藻发酵6个月沼液)为原料,接种苏云金芽孢杆菌(B.thuringiensis GIM1.32),对比菌种在不同培养基中生长代谢特征、杀虫晶体蛋白产量,并以3龄小菜蛾为测试对象测定毒力效价。[结果]蓝藻自然厌氧发酵是一个产酸过程,自然状况下(20~25℃)直接打捞富集的蓝藻藻泥产气潜力为27.27 mL/g。随蓝藻自然厌氧发酵时间的增加,沼液中TS、VS、pH值、粗脂肪、蛋白质含量均呈现下降趋势,多糖含量呈现上升趋势,灰分变化不明显。当含固率3%、pH值为7、接种物种龄10 h、接种量2%、培养温度30℃时,不同阶段蓝藻沼液制备B.t.的晶体蛋白含量、LC50值、Tx均低于新鲜蓝藻培养基。[结论]新鲜蓝藻是B.t.GIM 1.32菌种的生长代谢良好的培养基,能够使其正常完成芽孢和伴孢晶体的合成,为蓝藻资源化利用提供了一条新的、高值处理利用途径,既将蓝藻变废为宝,又可有效降低苏云金芽孢杆菌生物农药生产成本。     

枯草芽孢杆菌液体发酵培养基成分优化研究

通过实验对枯草芽孢杆菌产孢培养基成分中的碳源、氮源、无机盐、生长因子等成分进行筛选与优化,以确定适合枯草芽孢杆菌产芽孢的最佳培养基配方。多次试验的结果表明,通过优化培养基配方,芽孢产率得到提高。通过对碳源、氮源以及无机盐的筛选与优化,实验最终确定枯草芽孢杆菌的最佳产孢培养基的配方为:蛋白胨10 g,硫酸铵2.5 g,牛肉浸出粉3 g,氯化钠5 g,磷酸氢二钾2 g,聚乙烯醇5 g,蒸馏水1000 m L。     

解淀粉芽孢杆菌(Bacillus amyloliquefaciens)FS6摇瓶发酵条件优化

[目的]对解淀粉芽孢杆菌(Bacillus amyloliquefaciens)FS6的摇瓶发酵工艺进行优化。[方法]通过对发酵培养基成分和发酵条件的单因素试验和正交试验,测定生防菌株FS6对人参立枯丝核菌的抑菌效果和菌体生长量,来确定其最适发酵培养基和发酵条件。[结果]最适摇瓶发酵培养基配方为葡萄糖30 g,酵母浸粉40 g,Mg SO_4·7H_2O_2 g,甘油10 m L,K_2HPO_42 g,H_2O 1000 m L;最优培养条件为接种量6%,摇瓶装液量50 m L/250m L,摇床转速160 r/min,初始p H值6.0,培养温度28℃,培养时间12 h。[结论]解淀粉芽孢杆菌FS6在最适摇瓶发酵培养基及发酵条件下,对人参立枯病菌的抑菌活性最好,为该菌株的工业化生产奠定了基础。     

Sapindaceae,cyanolipids, and bugs

Scentless plant bugs (Heteroptera: Rhopalidae) are so named because adults of the Serinethinae have vestigial metathoracic scent glands. Serinethines are seed predators of Sapindales, especially Sapindaceae that produce toxic cyanolipids. In two serinethine species whose ranges extend into the southern United States,Jadera haematoloma andJ. sanguinolenta, sequestration of host cyanolipids as glucosides renders these gregarious, aposematic insects unpalatable to a variety of predators. The blood glucoside profile and cyanogenesis ofJadera varies depending on the cyanolipid chemistry of hosts, and adults and larvae fed golden rain tree seeds (Koelreuteria paniculata) excrete the volatile lactone, 4-methyl-2(5H)-furanone, to which they are attracted.Jadera fed balloon vine seeds (Cardiospermum spp.) do not excrete the attractive lactone. Loss of the usual heteropteran defensive glands in serinethines may have coevolved with host specificity on toxic plants, and the orientation ofJadera to a volatile excretory product could be an adaptive response to save time.Mention of a commercial product does not consititute an endorsement by the USDA.     

Insect antifeedant properties of anthranoids from the genusVismia

Vismiones and ferruginins, representatives of a new class of lypophilic anthranoids from the genusVismia were found to inhibit feeding in larvae of species ofSpodoptera, Heliothis, and inLocusta migratoria.     

Direct observation of freeze-thaw instability of latex coatings via high pressure freezing and cryogenic SEM

Despite its industrial importance, the subject of freeze-thaw (F/T) stability of latex coatings has not been studied extensively. There is also a lack of fundamental understanding about the process and the mechanisms through which a coating becomes destabilized. High pressure (2100 bar) freezing fixes the state of water-suspended particles of polymer binder and inorganic pigments without the growth of ice crystals during freezing that produce artifacts in direct imaging scanning electron microscopy (SEM) of fracture surfaces of frozen coatings. We show that by incorporating copolymerizable functional monomers, it is possible to achieve F/T stability in polymer latexes and in low-VOC paints, as judged by the microstructures revealed by the cryogenic SEM technique. Particle coalescence as well as pigment segregation in F/T unstable systems are visualized. In order to achieve F/T stability in paints, latex particles must not flocculate and should provide protection to inorganic pigment and extender particles. Because of the unique capabilities of the cryogenic SEM, we are able to separate the effects of freezing and thawing, and study the influence of the rate of freezing and thawing on F/T stability. Destabilization can be caused by either freezing or thawing. A slow freezing process is more detrimental to F/T stability than a fast freezing process; the latter actually preserves suspension stability during freezing. Presented at the 82nd Annual Meeting of the Federation of Societies for Coatings Technology, October 27–29, 2004 in Chicago, IL. Tied for first place in The John A. Gordon Best Paper Competition.     

Many Drugs of Abuse May Be Acutely Transformed to Dopamine,Norepinephrine and Epinephrine In Vivo

It is well established that a wide range of drugs of abuse acutely boost the signaling of the sympathetic nervous system and the hypothalamic–pituitary–adrenal (HPA) axis, where norepinephrine and epinephrine are major output molecules. This stimulatory effect is accompanied by such symptoms as elevated heart rate and blood pressure, more rapid breathing, increased body temperature and sweating, and pupillary dilation, as well as the intoxicating or euphoric subjective properties of the drug. While many drugs of abuse are thought to achieve their intoxicating effects by modulating the monoaminergic neurotransmitter systems (i.e., serotonin, norepinephrine, dopamine) by binding to these receptors or otherwise affecting their synaptic signaling, this paper puts forth the hypothesis that many of these drugs are actually acutely converted to catecholamines (dopamine, norepinephrine, epinephrine) in vivo, in addition to transformation to their known metabolites. In this manner, a range of stimulants, opioids, and psychedelics (as well as alcohol) may partially achieve their intoxicating properties, as well as side effects, due to this putative transformation to catecholamines. If this hypothesis is correct, it would alter our understanding of the basic biosynthetic pathways for generating these important signaling molecules, while also modifying our view of the neural substrates underlying substance abuse and dependence, including psychological stress-induced relapse. Importantly, there is a direct way to test the overarching hypothesis: administer (either centrally or peripherally) stable isotope versions of these drugs to model organisms such as rodents (or even to humans) and then use liquid chromatography-mass spectrometry to determine if the labeled drug is converted to labeled catecholamines in brain, blood plasma, or urine samples.     

Ethanol and (−)-α-Pinene: Attractant Kairomones for Bark and Ambrosia Beetles in the Southeastern US

In 2002–2004, we examined the flight responses of 49 species of native and exotic bark and ambrosia beetles (Coleoptera: Scolytidae and Platypodidae) to traps baited with ethanol and/or (−)-α-pinene in the southeastern US. Eight field trials were conducted in mature pine stands in Alabama, Florida, Georgia, North Carolina, and South Carolina. Funnel traps baited with ethanol lures (release rate, about 0.6 g/day at 25–28°C) were attractive to ten species of ambrosia beetles (Ambrosiodmus tachygraphus, Anisandrus sayi, Dryoxylon onoharaensum, Monarthrum mali, Xyleborinus saxesenii, Xyleborus affinis, Xyleborus ferrugineus, Xylosandrus compactus, Xylosandrus crassiusculus, and Xylosandrus germanus) and two species of bark beetles (Cryptocarenus heveae and Hypothenemus sp.). Traps baited with (−)-α-pinene lures (release rate, 2–6 g/day at 25–28°C) were attractive to five bark beetle species (Dendroctonus terebrans, Hylastes porculus, Hylastes salebrosus, Hylastes tenuis, and Ips grandicollis) and one platypodid ambrosia beetle species (Myoplatypus flavicornis). Ethanol enhanced responses of some species (Xyleborus pubescens, H. porculus, H. salebrosus, H. tenuis, and Pityophthorus cariniceps) to traps baited with (−)-α-pinene in some locations. (−)-α-Pinene interrupted the response of some ambrosia beetle species to traps baited with ethanol, but only the response of D. onoharaensum was interrupted consistently at most locations. Of 23 species of ambrosia beetles captured in our field trials, nine were exotic and accounted for 70–97% of total catches of ambrosia beetles. Our results provide support for the continued use of separate traps baited with ethanol alone and ethanol with (−)-α-pinene to detect and monitor common bark and ambrosia beetles from the southeastern region of the US.     

2008～2009年世界塑料工业进展

收集了2008年7月～2009年6月世界塑料工业的相关资料,介绍了2008～2009年国外塑料工业的发展情况,提供了世界塑料产量、消费量及全球各类树脂的需求量及产能情况。按通用热塑性树脂(聚乙烯、聚丙烯、聚苯乙烯、聚氯乙烯、ABS树脂)、工程塑料(尼龙、聚碳酸酯、聚甲醛、热塑性聚酯、聚苯醚)、特种工程塑料(聚苯硫醚、液晶聚合物、聚醚醚酮)、通用热固性树脂(酚醛、聚氨酯、环氧树脂、不饱和聚酯树脂)不同品种的顺序,对树脂的产量、消费量、供需状况及合成工艺、产品应用开发、树脂品种的延伸及应用的进一步扩展等技术作了详细介绍。