Bt固态发酵条件的研究进展

苏云金芽孢杆菌制剂是目前世界上产、销量较大的一种生物农药,其发酵过程则是工业生产的关键步骤,固体发酵以其巨大的优越性正在逐步替代深层液体发酵。影响Bt固态发酵的一系列条件在文章中得到阐述。     

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.     

苏云金杆菌发酵培养基研究进展

苏云金杆菌前世界上用途最广、产量最大的微生物杀虫剂,本文综述了苏云金杆菌发酵研究所用的培养基的类型,包括传统发酵原料、城市污泥、工业废液、蓝藻、废弃物等及其特点,为企业选择适合的原料和工艺提供了借鉴作用,并对苏云金杆菌发酵培养基的研究进行了展望。     

功能性有机物料腐熟剂的生产与应用

将枯草芽孢杆菌、苏云金芽孢杆菌、深绿木霉菌、酿酒酵母菌、白腐菌分别通过固体发酵和液体发酵制备成菌剂,然后按一定的质量比进行混合,制得的粉状功能性有机物料腐熟剂具有效果好、能防控有害生物、使用方便的特点。通过玉米秸秆腐熟效果试验,证明该功能性有机物料腐熟剂可加速玉米秸秆的腐熟,提高小麦产量。     

苏云金杆菌固体发酵工艺研究

苏云金杆菌(BacillusThuringiensis简称B.t)是农业生产中最广泛应用的微生物杀虫农药。为了在降低生产成本、减少废水排放的同时,提高生产菌发酵水平和毒力效价,对本实验室选育的菌株B.tNH 1的固体发酵工艺条件的优化进行了进一步研究,确定了适合于B.tNH 1生长、产生芽孢的最佳条件。研究结果固体发酵水平基本稳定在2 37×1010个/g,粉剂烘干后,测其毒力效价,可以稳定在17000IU/mg以上,,超过国内文献报道固体发酵的最高水平。     

利用工业废水生产生物农药苏云金杆菌

苏云金杆菌是目前世界上应用最广的微生物杀虫剂,利用工业废水进行发酵生产可以达到降低成本、治理污染的目的。本文介绍了利用味精废水、酒糟废液、淀粉废液、丙酮-丁醇醪液、乳清以及污水处理厂废水发酵生产苏云金杆菌的研究进展。     

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     

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%。     

苏云金芽孢杆菌固态发酵培养基的优化

采用正交实验法,对苏云金芽孢杆菌固态发酵培养基进行优化,将发酵产品干燥粉碎后制成菌悬液,通过测量其吸光度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.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,确定最佳培养基组分为:麦麸63.9%、豆饼粉16.0%、玉米粉8.0%、酵母粉1.6%、米糠8.0%、KH2PO4 0.5%、FeSO4 0.3%、(NH4)2SO4 1.1%和MgSO4 0.6%.     

抓紧发展生物农药BT

BT即苏云金杆菌生物杀虫剂是高效、低毒、无残留的绿色农药。BT工艺为压力脉动固态发酵新技术。     

氢气纯度分析方法准确性的探讨

ONACCURACYOFANALYSISOFOFHYDROGEN1前言我公司目前应用的氢气纯度分析方法有两种,一种是爆炸反应法,另一种是焦性没食子酸吸收法。几年来,人们对两种分析方法的准确性曾有过褒贬不一的评论。这里我们也谈谈自己粗浅的观点。2爆炸法测定氢气纯度一定量的氢气样品与适量的空气之均匀混合物因反应后生成液体水而引起气体体积减少,减少的体积等于参加反应气体体积之和。其中l／3为氧气,2／3为氢气。根据氢气取样量和反应前后混气体体积之差,以及氢气在反应中的体积比例关系,可计算出样品的氢气纯度。计算公式式中：A一混…     

COMPARISON OF METHODS OF ANALYSIS OF GYPSUM1

The different analytical methods proposed for the evaluation of gypsum have been subjected to an experimental test. A combination method, consisting of a fusion with KHCO₃ and determination of CaO by KMnO₄ titration, the SO₃ by Andrews method of titration of BaCrO₄ has been found to give very reliable results with the least consumption of time.     

SEDIMENTATION OF BINARY MIXTURES OF PARTICLES OF UNEQUAL DENSITIES AND OF DIFFERENT SIZES

A model is developed for the sedimentation from a suspension of two particle species of unequal densities and of different sizes. The composition and the thickness of various layers in the sediments are predicted using graphical and analytical methods. The model predictions were in excellent agreement with experimental results, when the particle size ratio was ≥ 108. When size ratio of the particles was 2.60 and 4.31 the agreement occurred in about 50 percent of the cases.     

HEASUREHENT OF INSTANTANEOUS RATES OF LOSS OF VOIATILE COMPOUNDS DURING DRYING OF DROPS

A novel technique serves to monitor instantaneous rates of loss of a volatile solute from a suspended drop during drying. A highly sensitive electron capture detector is used to monitor concentrations of SF6 released into a flowing gas stream from a suspended, drying drop. Simultaneously, the appearance and morphological development of the drop are monitored with a video camera. This provides the wherewithal of relating instantaneous rates of loss of the volatile solute to particular events during the development of particle morphology.

Initial experiments have been carried out with drops of aqueous solutions of glucose, sucrose, maltodextrin and coffee extract. The results clearly display the onset of the volatiles-retentive selective diffusion phenomenon. There is also substantial loss of the volatile component later in the drying process, when the drops undergo repeated ex ansion, bursting and cratering due to the formation of internaf bubbles. These experiments appear to be the first quantitative demonstration of major losses accompanying changes in drop morphology.     

ANALYSIS OF RECENT MEASUREMENTS OF THE VISCOSITY OF GLASSES

Viscosity of Simple Soda-Silicate 500° to 1400°C Comparison of the results given by English with those of Washburn, Shelton and Libman, indicates a discrepancy in the absolute values of log₁₀ viscosity amounting to 0.6, those of Washburn et al., being relatively too high. If correction for this is made, the isothermal curves of log₁₀ viscosity as a function of soda content are smooth up to 50% Na₂O, showing no inflection. The observations as a function of temperature T are all represented within accidental error by an equation of the type where all three constants vary regularly with the composition. Change of Viscosity of Glass (6SiO₂, 2Na₂O) due to Molecular Substitution of CaO, MgO and Al₂O₃ for Na₂O The effect is clearly brought out by plotting (from the results of English) the change of log₁₀η due to the substitution as a function of temperature. The curves each show a sharp bend at a temperature between 840° and 1050°C, which is designated the aggregation temperature T_a. If we divide these curves by the corresponding percentage substituted, we get curves for each oxide which are straight and parallel below the aggregation temperatures, the slopes (increase of change of log₁₀η per 100°C) being −0.056 (CaO), −0.055 (MgO), −0.018 (A1₂O₃) per per cent oxide substituted. For substitution of 1/2 molecule the slopes are −0.325 (CaO), −0.23 (MgO) and −0.18 (Al₂O₃) per 100°. At the aggregation temperature the change of log₁₀η per per cent is a minimum, 0.03 to 0.06 for CaO, 0.12 for MgO, 0.07 for Al₂O₃. Evidence of Aggregation in Glasses, from viscosity Measurements The sharp bends in the plots of change of log₁₀η due to substitution of an oxide for Na₂O, suggest the beginning of molecular aggregation at these temperatures. These aggregation temperatures are close to the devitrification temperatures, but the effect on the viscosity curves cannot be due to actual devitrification since it does not change with time. Taking the aggregation temperatures as equal to devitrification temperatures, additional isotherms are roughly sketched into the equilibrium triangle of the system Na₂O-CaO-SiO₂. Change of Viscosity of Glass (4SiO₂, 2Na₂O) due to of Substitution of B₂O₃ for SiO₂ The change of log₁₀η (from the results of English) is plotted as a function of temperature, and also the change of log₁₀η per per cent B₂O₃. The curves are more complex than for the substitution for Na₂O.     

环氧树脂羟基值测定方法的研究

利用乙酸酐、吡啶和浓硫酸混合的乙酰化试剂测定环氧树脂中羟基值含量的方法具有操作简便、滴定终点明显和分析结果误差小等优点。     

骑式摩托车油箱喷涂工艺的改进

面对日益激烈的市场竞争,摩托车油箱外观质量越来越成为影响销售的因素之一。文章介绍了改进工艺后的油箱涂装,该涂装体系提高了油箱外观的丰满度,降低了油箱涂装的生产成本。     

几种针状焦性能对比

针状焦分石油系和煤系两大类,这主要取决于针状焦的原料来源。在同一系列中由于原料不同和工艺条件不同 ,针状焦的各自性能也不相同。针状焦是生产超高功率石墨电极和高功率石墨电极的主要原料 ,针状焦的性能对石墨电极的质量有至关重要的影响。所以对针状焦性能以及其对石墨电极质量影响的研究十分必要的。以下是常用的几种进口针状焦和国产针状焦的性能对比。１原料性能分析对比原料试样包括４种针状焦 ,其中两种为进口针状焦：三菱针状焦和新日化针状焦;另两种为国产针状焦：鞍山针状焦和锦州针状焦。其中除锦州针状焦是石油系针状焦外…     

茶多酚提取方法进展

本文综述了国内外现有茶多酚提取方法的现状以及近期的研究进展，并对其优缺点进行了评价。这将有助于中低档茶的综合利用和茶多酚的进一步开发应用。     

用两个形状指数表征粉煤灰颗粒形貌的研究

引用两个形状指数表征颗粒形状的概念,即先将颗粒形状近似为椭圆,再将椭圆图像分离:以圆为基准的颗粒宏观形状指数δ;以光滑椭圆为基准的颗粒轮廓凹凸度,即微观形状指数ζ。分析和发展了近似椭圆模型。并运用图像分析仪对粉煤灰、水泥样品进行实验。结果表明,粉煤灰颗粒的两个形状指数δ和ζ都大于水泥颗粒。证明粉煤灰颗粒的球形度、表面光滑度优于水泥,而且,随着粒径增大,δ和ζ呈下降趋势,表明磨制颗粒越粗。(?)粒形状越不规则。文中还运用近似椭圆模型再现了颗粒的模拟图像。