棒状链霉菌突变株CCRC11518-Ⅲ50克拉维酸发酵条件的研究

通过单因子和多因子摇瓶正交优化试验,确定了克拉维酸产生菌棒状链霉菌突变株Streptomyces clavuligerusCCRC11518-Ⅲ50的三角瓶发酵条件.发酵培养基组成(ρ/g L-1):甘油30,大豆蛋白胨60,麦芽浸膏7.5,K2HPO4·3H2O 1.0,MgSO4·7H2O 2.0,FeSO4-7H2O 1.0;培养基初始pH 6.5;接种量15％;培养基装量20 mL/250 mL三角瓶;培养温度25℃;发酵时间72 h.克拉维酸效价由优化前的834.8 μg mL-1提高到1 082.615 μg mL-1,提高了29.7％.还在1 600 mL发酵罐中进行了初步放大试验.当接种量15％,通气量1:0.5,转速450 r min-1,25℃发酵60h克拉维酸效价达到高峰1 025 μg mL-1.图12表1参12     

AN防御蜡梅酸致损伤最佳条件选择

本文以蜡梅光合速率、叶绿素含量、质膜透性为生理指标，研究了ＡＮ对酸雨引起蜡梅损伤的防御作用与最佳作用条件，实验结果表明，以酸雨处理前２４ｈ处理后４８ｈ时间内，喷施１００ｐｐｍＡＮ３次的防御效应最佳。     

Gas-phase degradation of CCl<Subscript>4</Subscript>, CHCl<Subscript>3</Subscript> and CH<Subscript>2</Subscript>Cl<Subscript>2</Subscript> over metallic Fe

We studied the hydrolysis of gas-phase carbon tetrachloride (CCl₄), chloroform (CHCl₃), and dichloromethane (CH₂Cl₂) over a metallic Fe surface for its application in combination with air stripping and soil vapour extraction. The effects of chlorocarbon concentration, type and preparation of the iron-containing material, humidity, and temperature on process performance are reported. The hydrolysis of chlorinated methane derivatives is catalysed by metallic iron resulting in a noticeable decrease of the reaction temperature. The reaction kinetics were found to be consistent with the Langmuir-Hinshelwood model.     

Egg coloration is correlated with female condition in eastern bluebirds (Sialia sialis)

Egg coloration has been hypothesized to reflect female condition. Because of the proposed physiological costs associated with deposition of biliverdin pigments and because of their conspicuousness, eggs with blue-green coloration may reliably convey information about female or brood quality. We tested the hypothesis that expression of blue-green coloration of eastern bluebird (Sialia sialis) eggs positively correlates to female condition. First, we documented the incidence of egg color polymorphism within the population. We observed that 98% of females laid blue-green eggs while less than 2% laid white eggs and less than 1% laid pink eggs. In a subset of clutches, we used full spectrum reflectance spectrometry (300–700 nm) to compare eggshell coloration to measures of female condition. We found that the color of eggs within clutches was more similar than the color of eggs from different clutches, and that the blue-green eggs have spectral peaks that are consistent with the characteristic absorbance spectra of biliverdin pigmentation. Females in better body condition and older females laid more colorful eggs. Moreover, individual females laid more colorful eggs later in the laying sequence. Overall, these data indicate that egg coloration covaries with female condition, suggesting that egg coloration could function as a reliable signal of female quality or that egg coloration may allow females to recognize eggs laid by conspecific brood parasites.     

Assessing Habitat Quality for a Migratory Songbird Wintering in Natural and Agricultural Habitats

Abstract:  As tropical forests are cleared, a greater proportion of migratory songbirds are forced to winter in agricultural and disturbed habitats, which, if poorer in quality than natural forests, could contribute to population declines. We compared demographic indicators of habitat quality for a focal species, the American Redstart ( Setophaga ruticilla ), wintering in Jamaican citrus orchards and shade coffee plantations with those in four natural habitats: mangrove, coastal scrub, coastal palm, and dry limestone forests. Demographic measures of habitat quality included density, age and sex ratio, apparent survival, and changes in body mass. Measures of habitat quality for redstarts in citrus and coffee habitats were generally intermediate between the highest (mangrove) and lowest (dry limestone) measurements from natural habitats. The decline in mean body mass over the winter period was a strong predictor of annual survival rate among habitats, and we suggest that measures of body condition coupled with survival data provide the best measures of habitat quality for nonbreeding songbirds. Density, which is far easier to estimate, was correlated with these more labor-intensive measures, particularly in the late winter when food is likely most limiting. Thus, local density may be useful as an approximation of habitat quality for wintering migrant warblers. Our findings bolster those of previous studies based on bird abundance that suggest arboreal agricultural habitats in the tropics can be useful for the conservation of generalist, insectivorous birds, including many migratory passerines such as redstarts.     

氢化可的松高转化菌株的选育及其发酵条件

利用酮康唑抗性突变选育氢化可的松高转化菌株，即将经过紫外线诱变处理的新月弯孢霉原生质体倾注于含有酮康唑最小抑制浓度(10μmoL／L)的培养基平板上，获得了136株酮康唑抗性突变株，氢化可的松转化率高于出发菌株的有14株．其中抗性突变株KA-91，其氢化可的松转化率为出发菌株的1．42倍，达到68．05％．研究了菌株的发酵性能，优化了培养基组成和发酵工艺条件，氢化可的松转化率达到73．6％．图7表3参5     

含磷酸盐的三氯化铁水解溶液的化学特征

通过对含磷酸盐三氯化铁水解溶液的ｐＨ驰豫，电导率，可见光光谱和不同化学反应活性组分的分布等一系列化学物理性质的表征，说明在ＦｅＣｌ３－ＮａＨ２ＰＯ４－ＮａＨＣＯ３溶液体系中，ＰＯ４＾３参与了Ｆｅ（Ⅲ）的水解－聚合反应，形成了Ｆｅ－ＯＨ－Ｆｅ－ＰＯ４－Ｆｅ结构共同控制溶液性质。使溶液性质发生了从量变到质变的过程，证明ＰＯ４＾３对Ｆｅ（Ⅲ）溶液的水解形态有重要影响。     

经济野生动物养殖管窥之见

本文对我国经济动物养殖业具有的高投入高产出,市场行情变化大,风险大,需要较特殊的养殖技术,以及易被炒种形成“养殖热”等特点进行了精辟的论述,并从此出发分析了经济野生动物的养殖必须具备足够的资金,懂法守法,懂得养殖技术,有较好的环境条件,种原优质和掌握市场行情等条件,对于我国经济动物养殖业大起大落以及产品价廉质差滞销的原因进行了深入分析,并就如何健康发展经济动物养殖业提出了针对性措施。     

多功能高铁絮凝剂电化学合成的机理和条件

本文研究了采用电解加复合稳定剂的方法制备ＦｅＯ４＾２－絮凝剂的电化学与溶液化学过程机制，分析了ＯＨ＾－膜平衡过程对ＦｅＯ４＾２－形成的影响，探讨了ＦｅＯ４＾２－水溶液分解的诱发因素，初步确定了ＦｅＯ４＾２－电化学合成的最佳条件。研究结果表明，适宜的电量参数，合理的电解液组成和高效的ＯＨ＾－膜渗透是顺利进行稳定化ＦｅＯ４＾２－电解合成的三个要素。