硫酸西棱霉素微生物检定法研究

以短小芽孢杆菌为检定菌,比较了培养基原料对抑菌圈的影响,进行了检定菌的分离和敏感活性测定,标准曲线的可倍限率检测,一剂量和二剂量法的可靠性试验,样品效价测定和统计分析,确认我们建立的硫酸西梭霉素的生测方法是准确、可行的。     

放线菌素23-21微生物检定法及HPLC法比较

采用微生物检定法测定放线菌素２３－２１的抗菌活性,检定菌为枯草芽孢杆菌。当放线菌素２３－２１的浓度为０．９１～４．３７μｇ／ｍｌ时,其抑菌圈直径与反应剂量有线性关系。经生物学统计分析,实验结果可靠。并与高效液相色谱法（ＨＰＬＣ）进行对照检测,实验结果基本吻合。     

离子注入利福霉素产生菌诱变选育研究

离子注入诱变利福霉素生产菌,首先利用利福霉素浓度梯度平均板理性化筛选出高抗性菌株,再以此抗性菌株为出发菌进行离子注入诱变筛选。初筛摇瓶效价达９０００μ／ｍｌ,经复菌筛菌株２９５３效价稳定提高１８％、。７ｍ＾３罐中试,放罐效价达６８６３μ／ｍｌ,较同期对照提高３５％;３０ｍ＾３罐生产实验,最高罐批效价为６１３７μ／ｍｌ,平均提高１０％。     

中国Bt Ken－Ag最佳发酵培养基的优选及其发酵生理学研究

用正交试验方法选出ＢｔＫｅｎ－Ａｇ菌株的发酵培养基Ｍ３和ＦＢＨ２两个配方,其发酵液菌数可稳定的保持７０亿／ｍｌ,芽孢晶体形成率达８０－９０％,用ＦＢＨ２配方,对棉铃虫的毒力效价在２０００ＩＵ／μｌ以上。同时研究了在发酵培养基上的生长,ｐＨ变化、芽孢晶体形成以及糖、氮的代谢情况。     

酪氨酸-铜体系电化学氧化行为的研究

在ｐＨ值３．９４的Ｂ－Ｒ缓冲溶液中,酪氨酸－铜络合物在玻碳电极出现氧化峰。用新极谱法测定,酪氨酸浓度在０．３μｇ／ｍｌ－３μｇ／ｍｌ范围内与氧化峰的２．５次微分值呈线性,检测下限０．２μｇ／ｍｌ。直接用于氨基酸药物样品的测定结果满意,并对酪氨酸－铜络合物的电化学氧化行为进行了研究。     

耐碱性芽孢杆菌碱性淀粉酶的研究：Ⅱ.菌株的诱变与产酶条件

耐碱性巨大芽孢杆菌（Ｂａｃｉｌｌｕｓ ｍｅｇａｔｅｒｉｕｍ）９－Ａ２经紫外线、甲基磺酸乙酯和硫酸二乙酯等多次诱变处理,获得一株产碱性α－淀粉酶能力较高的变异株Ｌ－４９。Ｌ－４９菌株比出发株的产酶能力提高近２．５倍,当以酵母膏为氮源,可溶性淀粉为碳源,初始ｐＨ９￣１０,种龄１８ｈ,接种量５％（Ｖ／Ｖ）,３０℃培养４８ｈ,酶活力可达７３０μ／ｍｌ。     

防腐剂对苏云金杆菌制剂活力毒力测定的影响

采用不同防腐剂剂处理苏云金杆菌制剂及毒力生物测定,结果表明,７＃（１００ｍｌ中含０．５ｍｌ１０％甲醛和１ｍｌ１５％尼泊金）防腐剂处理苏云金杆菌剂剂０－９６ｈ,抑制芽孢萌发和菌体活性的效果最佳,其次为２＃（１００ｍｌ中含１ｍｌ１５％尼泊金）,８＃（１００ｍｌ中含１ｍｌ１５％尼泊金和０．０５ｇ土霉素）;毒力生物测定７＃防腐剂最稳定,ＬＣ５０最小,灵敏度最高。     

芽孢杆菌A-30碱性β-1,4-聚糖酶发酵条件的优化

筛选到一株高产β－１,４－聚糖酶芽孢杆菌Ａ－３０,采用麸皮的主要碳源,尿素为主要氮源,在ＰＨ８．５、温度３２℃发酵６０ｈ,最高木聚糖酶活可达到４６０ＩＵ／ｍｌ,纤维素酶酶活最高可以达到１．２１ＩＵ／ｍｌ。离子Ｆｅ＾３＋、Ｆｅ＾２＋、Ａｌ＾３＋可以促进纤维素酶的合成,而Ｃｕ＾２＋、Ｚｎ＾２＋、Ｃｏ＾２＋、Ｈｇ＾２＋则起抑制作用。多数的氨基酸可以很大程度上促进β－１,４－聚糖酶的合成,在１５Ｌ发酵罐进     

生物保鲜剂对鼠伤寒沙门氏菌等5株病原菌的抑菌效果

利用河北省科学院微生物研究所研制的生物酶保鲜剂对鼠伤寒沙门氏菌等５株病原菌进行抑菌试验,结果表明,生物保鲜剂对３株沙门氏菌,２菌弧菌科病原菌作了敏感,当生物保鲜浓度为０．５－５％时,大多数抑菌圈直径在１５－２４．５毫米,可与０．０１％氟哌酸的抑菌效果相比。     

细菌吸附Pd2+的研究

从不同来源的细菌菌株中筛选获得一株吸附Ｐｄ＾２＋能力较强的菌株Ｒ０８,经鉴定为地衣芽孢杆菌（Ｂａｃｉｌｌｕｓ ｌｉｃｈｅｎｉｆｏｒｍｉｓ）Ｒ０８。Ｒ０８死菌体吸附Ｐｄ＾２＋的最适ｐＨ值３．５,其吸附作用是一种快速而非依赖温度的过程。吸附作用受菌体浓度和Ｐｄ＾２＋浓度影响。在起始Ｐｄ＾２＋浓度２００ｍｇ／Ｌ、菌浓度０．４ｇ／Ｌ、ｐＨ３．５和３０℃条件下,吸附４５ｍｉｎ,吸附量为２２４．８ｍｇ／ｇ。透     

The International Standard for sisomicin

An International Standard for Sisomicin has been established on the basis of a collaborative assay. There were seven participating laboratories in seven countries. The activity of the contents of each ampoule of the International Standard of Sisomicin is defined as 35,200 International Units of Sisomicin.     

Characterization in Micromonospora inyoensis of aminoglycoside acetyltransferase activity not previously encountered among actinomycetes

Extracts of Micromonospora inyoensis contain aminoglycoside acetyltransferase activity not previously encountered among actinomycetes. Neomycin and its derivatives (excluding butirosin) are good substrates as is the novel aminoglycoside apramycin, whereas the gentamicins and kanamycins are utilized poorly if at all. Sisomicin, which is produced by M. inyoensis, is not acetylated. When neomycin was modified by extracts of M. inyoensis the product, most probably 3-N-acetylneomycin, was inactive against cell-free protein synthesis.     

Characteristics of sisomicin fermentation supplemented with MgSO4 in stirred and air lift fermentors

Summary Sisomicin fermentations were carried out in stirred and air lift fermentors, and various concentrations of MgSO₄ were supplemented to improve antibiotic yield. The highest antibiotic yield was obtained at 80 mM in an air lift fermentor due to effective liberation of intracellular sisomicin by MgSO₄. The presence of high concentrations of MgSO₄, along with shear stress due to strong agitation in the stirred fermentor, resulted in low values of cell activity, rheological parameter(n) and cell viability in the stirred fermentor, compared with the air lift fermentor. The better physiological states of cells grown in the air lift fermentor resulted in improved antibiotic yields.     

Inhibition of the catalytic activity of trans-acting antigenomic delta ribozyme by selected antibiotics and their Cu2+ complexes

The effect of selected 10 antibiotics and their complexes with Cu(2+) ions on the catalytic activity of the trans-acting antigenomic delta ribozyme was investigated. Sisomicin, vancomycin, and actinomycin D displayed weak inhibitory properties. However, much stronger effects were detected with complexes of these antibiotics with Cu(2+) ions. The strongest inhibition was observed with actinomycin D-Cu(2+) complex, for which the calculated K(i) value was reduced ca. 35-fold upon metal ion complexation. We postulate that the antibiotic-Cu(2+) complexes are guided to the ribozyme metal ion binding site(s) presumably displacing the catalytically important metal ion(s). Moreover, we assume that, once positioned in appropriate distances to RNA phosphate groups and bases, the coordinated Cu(2+) ions become positively charged factors that enhance the affinity of the antibiotics to the ribozyme. These observations indicate that coordination of metal ions to antibiotics substantially changes their properties which might also have a biological relevance inside the cell.     

Study of the immunotropic activity of aminoglycoside antibiotics

The action of some aminoglycoside antibiotics on the immune system was studied on both intact mice and the animals with immune deficiency caused by administration of cyclophosphamide. The following tests were used: local hemolysis (the Herne test), lymphocyte transformation (LT), delayed hypersensitivity to sheep red blood cells and the local graft versus host reaction (GVHR). Amikacin was shown to have no significant action on the activity of lymphocytes in the intact mice and stimulated both cellular (LT and GVHR) and humoral (the Herne test) immunity in the animals with lowered immunological reactivity. Sisomicin had no significant action on the immune system of the animals. Gentamicin suppressed the immune response only in the intact mice. Kanamycin and streptomycin induced inhibition of humoral and cellular immunity in both the intact mice and animals with immune deficiency. On the basis of the results it was concluded that gentamicin, amikacin and sisomicin may be used in the treatment of diseases developing in the presence of immune deficiency whereas streptomycin and kanamycin should be recommended when inhibition of the immunity is needed.     

Cyclic nucleotides and haemoglobin concentration in rabbit bone marrow cell suspensions stimulated by purified erythropoietin

This study was conducted to determine the possible correlations between cyclic nucleotides cyclic adenosine monophosphate (cAMP) and cyclic guanine monophosphate (cGMP), and haemoglobin (Hb) concentration in nucleated cell suspensions of rabbit bone marrow incubated with erythropoietin (Ep). The levels of cAMP and cGMP were measured following the addition of different Ep concentrations to the suspensions. The Hb concentration was also measured in suspensions treated with Ep, dibutyryl cAMP (db-cAMP) or dibutyryl cGMP (db-cGMP), respectively. The following results were obtained: (1) upon the addition of 1 IU ml-1 Ep, an increase of cAMP levels was related to an increase in Hb concentration; while a decrease of Hb concentration was related to an increase of cGMP levels obtained when 0.1 IU ml-1 Ep was present in the incubation mixture. (2) A mimetic effect on Hb concentration was obtained upon the addition of db-cAMP or db-cGMP to the suspensions. (3) A quantitative correlation was found between the cAMP/cGMP ratio and Hb levels in cellular suspensions. This rapport was reviewed with respect to the controls as a decrease in Hb concentration when the ratio is less than one and an increase in Hb concentration when the ratio is greater than one.     

雌性小熊猫粪样中雌二醇与孕酮水平的变化与繁殖启动的关系

于1999年12月-2000年4月在成都动物园和成都大熊猫繁育研究基地,用放射免疫分析法测定了4只雌性小熊猫（Ailurus fulgens)粪样中雌二醇(E2)和孕酮(P)水平的变化,同时对其交配行为进行了观察。研究结果表明：雌性小熊猫进入发情期后,粪样中E2迅速升高,并多次出现峰值,表明小熊猫可能是季节性多发情动物。交配行为发生前E2出现峰值,P水平上升,说明E2和P是启动雌性小熊猫交配行为的重要因素;未伴随有P水平相对上升的E2峰值不能引起雌性小熊猫发生交配行为,该现象为暗发情。交配行为发生后P水平持续升高,据此推断小熊猫的排卵方式可能是诱导排卵,诱导因子是交配刺激。     

Solubilizing water involved in protein extraction using reversed micelles

The extraction of protein using reversed micelles was investigated in relation to the amount of solubilizing water in the reversed micellar organic phase. The minimal concentration of amphiphilic molecule di-2-ethylhexyl sodium sulfosuccinate (C(20)H(37)O(7)Na) (AOT) required for 100% cytochrome c extraction was recognized. This critical AOT concentration increased with protein concentration in the aqueous phase. On this minimal AOT condition, the molar ratio of solubilizing water to extracted protein was found to be a constant of 3500 under C(KCI) = 1.0 x 10(2) mol . m(-3) in this system. This ratio means the hydrophillic surroundings required for extracting one protein molecule into the micellar organic phase under the suitable pH and salt concentration for the forward extraction. In this regard, AOT molecules seemed to take the part of water solubilizing agent in the reversed micellar extraction. This role of AOT is important to extract protein under the suitable pH and salt concentration. The amount of solubilizing water in the protein-containing system was larger than in the protein-free system. This difference shows that the water molecules accompany the extracted protein into the reversed micellar organic phase at constant ratio 2200 under C(KCI) = 1.0 x 10(2) mol . m(-3), i.e., accompanying water molecules per one extracted protein. The minimal AOT concentration increased with ionic strength. On this minimal AOT condition, the molar ratio of solubilizing water to extracted protein also increased with ionic strength, so that in higher ionic strength, more solubilizing water was required. Then more AOT was required to provide the hydrophillic surroundings for protein. The pH affected the minimal AOT concentration required for 100% protein extraction.     

体积排阻液相色谱法质粒的含量测定

首次以体积排阻液相色谱法进行质粒提取液浓度的测定研究,通过纯质粒溶液在260 nm处的紫外吸峰面积与质粒浓度之间数据的线性最小二乘拟合,得到了反映质粒浓度和紫外吸收峰峰面积之间关系的标准曲线:Y=2×10~(-5) X,通过验证实验,确定了质粒提取液中不同组分,如核糖核酸,蛋白质等在色谱图中的出峰位置.结合标准曲线测定了自制的质粒提取液的质粒浓度为0.32 mg/mL.该方法方便,快捷,准确.     

Dependence on surface pH and surface substrate concentration of activity of microsome-bound arylsulfatase C and the surface charge density in the vicinity of the enzyme

Dependence on the salt concentration of the activity of microsome-bound arylsulfatase C [EC 3.1.6.1] from rat liver was examined. The activity increased with increasing salt concentration in the reaction medium in the whole pH range tested. This effect can be explained by the dependence of the reaction rate on the surface pH and the surface concentration of the ionic substrate. The dependence on salt concentration of the activity of the microsome-bound arylsulfatase C and the pH-dependences of Vmax and Km of the enzyme were used for the estimation of pH at the microsomal surface. The two values of the surface pH (surface potential) and the salt concentration were applied to the Gouy-Chapman equation. The value of -0.39 +/- 0.08 X 10(-3) elementary charge/A2 was obtained as the surface charge density in the vicinity of the microsome-bound arylsulfatase C. This was smaller than the over-all value for microsomes (-1.08 +/- 0.04 X 10(-3) elementary charge/A2; Masamoto, K. (1982) J. Biochem. 92, 365-371). This suggests that the anion concentration in the vicinity of the enzyme on microsomes is lower than that in the bulk aqueous phase and is higher than the average value at the microsomal surface when the salt concentration is low.