Microbial Penetration of Muslin- and Paper-Wrapped Sterile Packs Stored on Open Shelves and in Closed Cabinets

Microbial penetration of sterile packs was studied using single-wrap (two layers) muslin, double-wrap (four layers) muslin, and two-way crepe paper (single layer) to wrap 20 gauze sponges (2 by 2 inch). These packs were stored in the central sterile supply departments of two hospitals and processed for sterility at predetermined intervals. Microorganisms penetrated single-wrap muslin as early as 3 days and double-wrap muslin and single-wrap two-way crepe paper in 21 to 28 days stored in open shelves. The time required for microbial penetration was at least twice as long when closed cabinets were used. Single-wrap muslin packs stored in sealed, impervious plastic bags remained sterile for at least 9 months. All sterile materials in pervious wrappers should be handled as little as possible and then only with extreme care and caution. Closed cabinets offer more protection than open shelves, and single wrappers are not recommended.     

三类雄性不育水稻花药和叶片中抗氧化酶活性变化

为进一步了解水稻雄性不育现象,调查了光温敏核质互作不育系‘2310SA’、光温敏核不育系‘2310S’和核质互作不育系‘2277A’三类水稻及正常粳稻在不同光温环境下穗发育后期花药和剑叶中超氧化物歧化酶、过氧化物酶、过氧化氢酶等抗氧化酶的活性及丙二醛的含量和光合速率的变化。结果表明,水稻花药比叶片对光温胁迫更敏感,不育与可育花药活性氧代谢方面有明显差异。不同类型的不育水稻败育生理不尽相同,光温环境变化对光温敏核不育水稻‘2310S’有更明显的胁迫性,其不育花粉发育后期,上述3种抗氧化酶不能协同作用,SOD活性高,POD活性低,膜脂过氧化程度高和时间提前。其他两类不育系中POD活性也稳定较低,显示其可能与水稻不育花粉的形成更相关,同时,不育水稻中光合速率较低。     

RAPD标记鉴定水稻3种不同细胞质雄性不育类型的杂交种及其亲本

利用RAPD引物对3种不同细胞质雄性不育类型的杂交水稻组合及其亲本共21个材料进行了DNA多态性分析。从264个随机引物中筛选出具有非常明显多态性的引物25个, 对25个引物在3种不同细胞质不育类型的杂交组合及其亲本间的DNA扩增多态性差异进行比较,最终选出具有不同类型间特异性扩增带的引物7个,利用这些特异性扩增带能有效地区分和鉴定目前在生产上大面积种植和推广,或者是具有应用潜力的3种不同细胞质雄性不育类型—野败型(WA)、红莲型(HL)和包台型(BT))—的6种杂交水稻组合及其亲本。     

Decreasing Nitrogen Fertilizer Input Had Little Effect on Microbial Communities in Three Types of Soils

In this study, we examined the influence of different nitrogen (N) application rates (0, 168, 240, 270 and 312 kg N ha^-1) on soil properties, maize (Zea mays L.) yields and microbial communities of three types of soils (clay, alluvial and sandy soils). Phospholipid fatty acid analysis was used to characterize soil microbial communities. Results indicated that N fertilization significantly decreased microbial biomass in both clay and sandy soils regardless of application rate. These decreases were more likely a result of soil pH decreases induced by N fertilization, especially in the sandy soils. This is supported by structural equation modeling and redundancy analysis results. Nitrogen fertilization also led to significant changes in soil microbial community composition. However, the change differences were gradually dismissed with increase in N application rate. We also observed that N fertilization increased maize yields to the same level regardless of application rate. This suggests that farmers could apply N fertilizers at a lower rate (i.e. 168 kg N ha^-1), which could achieve high maize yield on one hand while maintain soil microbial functions on the other hand.     

Carbonate Mineral Precipitation for Soil Improvement Through Microbial Denitrification

Microbially induced carbonate precipitation (MICP) and associated biogas production may provide sustainable means of mitigating a number of geotechnical challenges associated with granular soils. MICP can induce interparticle soil cementation, mineral precipitation in soil pore space and/or biogas production to address geotechnical problems such as slope instability, soil erosion and scour, seepage of levees and cutoff walls, low bearing capacity of shallow foundations, and earthquake-induced liquefaction and settlement. Microbial denitrification has potential for improving the mechanical and hydraulic properties of soils because it promotes precipitation of calcium carbonate (CaCO₃) and produces nitrogen (N₂) gas without generating toxic by-products. We evaluated the potential for inducing carbonate precipitation in soil via bacterial denitrification using bench-scale experiments with the facultative anaerobe Pseudomonas denitrificans. Bench-scale experiments were conducted (1) without calcium in an N-rich bacterial growth medium in 2.0 L glass batch reactors and (2) with a source of calcium in sand-filled acrylic columns. Changes of pH, alkalinity, NO₃^? and NO₂^? in the batch reactors and columns, quantification of biogas production and observations of calcium-carbonate precipitation in the sand-filled columns indicate that denitrification led to carbonate precipitation and particle cementation in the pore water as well as a substantial amount of biogas production in both systems. These results document that bacterial denitrification has potential as a soil improvement mechanism.     

Three Types of Semiosis

The existence of different types of semiosis has been recognized, so far, in two ways. It has been pointed out that different semiotic features exist in different taxa and this has led to the distinction between zoosemiosis, phytosemiosis, mycosemiosis, bacterial semiosis and the like. Another type of diversity is due to the existence of different types of signs and has led to the distinction between iconic, indexical and symbolic semiosis. In all these cases, however, semiosis has been defined by the Peirce model, i.e., by the idea that the basic structure is a triad of ‘sign, object and interpretant’, and that interpretation is an essential component of semiosis. This model is undoubtedly applicable to animals, since it was precisely the discovery that animals are capable of interpretation that allowed Thomas Sebeok to conclude that they are also capable of semiosis. Unfortunately, however, it is not clear how far the Peirce model can be extended beyond the animal kingdom, and we already know that we cannot apply it to the cell. The rules of the genetic code have been virtually the same in all living systems and in all environments ever since the origin of life, which clearly shows that they do not depend on interpretation. Luckily, it has been pointed out that semiosis is not necessarily based on interpretation and can be defined exclusively in terms of coding. According to the ‘code model’, a semiotic system is made of signs, meanings and coding rules, all produced by the same codemaker, and in this form it is immediately applicable to the cell. The code model, furthermore, allows us to recognize the existence of many organic codes in living systems, and to divide them into two main types that here are referred to as manufacturing semiosis and signalling semiosis. The genetic code and the splicing codes, for example, take part in processes that actually manufacture biological objects, whereas signal transduction codes and compartment codes organize existing objects into functioning supramolecular structures. The organic codes of single cells appeared in the first three billion years of the history of life and were involved either in manufacturing semiosis or in signalling semiosis. With the origin of animals, however, a third type of semiosis came into being, a type that can be referred to as interpretive semiosis because it became closely involved with interpretation. We realize in this way that the contribution of semiosis to life was far greater than that predicted by the Peirce model, where semiosis is always a means of interpreting the world. Life is essentially about three things: (1) it is about manufacturing objects, (2) it is about organizing objects into functioning systems, and (3) it is about interpreting the world. The idea that these are all semiotic processes, tells us that life depends on semiosis much more deeply and extensively than we thought. We realize in this way that there are three distinct types of semiosis in Nature, and that they gave very different contributions to the origin and the evolution of life.     

Microbial Penicillinase in Soft Types of Cheese

Penicillinase activity was found in commercial samples of Limburger, Liederkranz, and Brick, as well as in Roquefort and Danish Blue cheeses. The numbers of penicillinase-producing bacteria in the cheese flora were estimated by use of the most probable numbers technique coupled with penicillinase determinations on the individual cultures. Although streptococci constituted the predominant flora in most of the samples, significant numbers of penicillinase-producing bacteria were also observed. Six of seven penicillinase-producing isolates that were studied in detail were micrococci; the other was an unidentified gram-positive, catalase-positive rod. The results suggest the widespread occurrence of penicillinase-forming micrococci on the surfaces of soft types of cheese.     

Chromatography of Microbial Lipids by Centrifugation Through Microparticulate Gel

An improved apparatus and a procedure are described by which the migration of sample components in column chromatography is accelerated by centrifugal force, thereby making it possible to use beds of densely packed gel prepared with ultrafine silica. This technique was used to resolve components of certain lipid mixtures where other methods have failed, and it has been found generally useful as an adjunct to other methods for the fractionation of lipids. Biologically active phosphoglycolipids from Mycobacterium tuberculosis and a phosphatidylglycerol-like substance from Mycoplasma pneumoniae which formed single spots on thin-layer chromatographic plates were each found to contain a major and several minor components by centrifugal chromatography. The method enabled us to isolate individual components of Wax D from M. tuberculosis rather than a spectrum of components. Minor components were resolved which, although present in insufficient quantity to influence results of chemical analyses, may be responsible for biological activity. The apparatus provides an essentially closed system which reduces highly volatile solvents to minimal evaporation during the chromatographic process. Samples are applied in solution and are not allowed to dry on the columns until after separation has been achieved. Consequently, polar, labile microbial lipids can be resolved without the use of harsh reagents which destroy some of their properties. Single components may be harvested by cutting and removing appropriate segments of the larger chromatograms or by eluting them from the columns.     

籼稻体细胞无性系雄性不育突变的类型

1984—1988年5年间所获得的由体细胞无性系变异起源的雄性不育突变,按它们的性质,可分为花粉败育型,无花粉型和花药退化(或部分退化)型3类。在IR54中,于不同年份(1985和1986年)及不同世代(R_1和R_2代)发现了表型基本相似,基因型可能也相似的两例无花粉型雄性不育突变。在花粉败育型雄性不育突变中,发现1例(54257)为核质互作型雄性不育。以多个品种与之测交,杂种一代中有的表现为育性恢复,有的仍然为雄性不育。能保持其雄性不育的品种有珍汕97、二九矮、新锦粘、162-5(来自IR 52的稳定的体细胞无性系),连续回交3代以上均能基本保持不育(但桂朝2号的回交后代不育性尚不稳定)。能使其育性恢复的品种有IR 24、IR 36、IR 54、双二粘、测64等。初步遗传研究表明,54257表现出十分复杂的核质关系,看来可能具有与野败细胞质完全不同的特性。     

Promoter Analysis for Three Types of EUL-Related Rice Lectins in Transgenic Arabidopsis

In this study, the promoter activity for three types of Euonymus-related lectins (EUL) from rice, further referred to as OrysaEULS2, OrysaEULS3, and OrysaEULD1A was analyzed. In silico promoter analyses showed that the EUL promoters from rice contain next to the typical promoter elements some motifs that are considered to be stress-responsive elements. Furthermore, Arabidopsis thaliana plants were transformed with a promoter::β-glucuronidase (GUS) construct for each of the proteins under study. Subsequently, one-insertion homozygous lines were selected and analyzed for GUS activity. Experiments were performed under normal growth conditions or after application of different stress conditions, in particular treatments with 150 mM NaCl, 100 mM mannitol, and 100 μM abscisic acid (ABA) for 24 h. GUS activity was detected with the OrysaEULS3 and OrysaEULD1A promoters especially in the cotyledons and the young true leaves, respectively, but not with the OrysaEULS2 promoter. The activity of OrysaEULS3 and OrysaEULD1A promoters was increased after ABA and mannitol treatments but decreased after NaCl treatment. We hypothesize that the Euonymus-related rice proteins have a role in sensing and responding to external stresses as well as in the growth of the plant.     

Microbial Communities of Three Sympatric Australian Stingless Bee Species

Bacterial symbionts of insects have received increasing attention due to their prominent role in nutrient acquisition and defense. In social bees, symbiotic bacteria can maintain colony homeostasis and fitness, and the loss or alteration of the bacterial community may be associated with the ongoing bee decline observed worldwide. However, analyses of microbiota associated with bees have been largely confined to the social honeybees (Apis mellifera) and bumblebees (Bombus spec.), revealing – among other taxa – host-specific lactic acid bacteria (LAB, genus Lactobacillus) that are not found in solitary bees. Here, we characterized the microbiota of three Australian stingless bee species (Apidae: Meliponini) of two phylogenetically distant genera (Tetragonula and Austroplebeia). Besides common plant bacteria, we find LAB in all three species, showing that LAB are shared by honeybees, bumblebees and stingless bees across geographical regions. However, while LAB of the honeybee-associated Firm4–5 clusters were present in Tetragonula, they were lacking in Austroplebeia. Instead, we found a novel clade of likely host-specific LAB in all three Australian stingless bee species which forms a sister clade to a large cluster of Halictidae-associated lactobacilli. Our findings indicate both a phylogenetic and geographical signal of host-specific LAB in stingless bees and highlight stingless bees as an interesting group to investigate the evolutionary history of the bee-LAB association.     

Three Types of Sensitivity to Metalaxyl in Plasmopara viticola

The sensitivity of Plasmopara-isolates to metalaxyl was determined by a leaf disc test. For the first time this permitted the distinction and clear characterization of not only sensitive and resistant isolates but also of isolates belonging to a third type of sensitivity, termed the reduced sensitive type.     

Effect of pH on Penetration of Naphthaleneacetic Acid and Naphthaleneacetamide Through Isolated Pear Leaf Cuticle

Penetration of naphthaleneacetic acid through enzymatically isolated upper pear (Pyrus communis L. cv. Bartlett) leaf cuticle increased as the donor pH was decreased. Naphthaleneacetamide penetration was not influenced by donor pH. The effect of pH on naphthaleneacetic acid penetration was reversible. Higher receiver (simulated leaf interior) pH favored penetration of naphthaleneacetic acid. Changes in the degree of dissociation, and hence polarity, as controlled by hydrogen ion concentration was the prime factor in the response of naphthaleneacetic acid to pH. At pH values lower than the pK (4.2 for naphthaleneacetic acid), the molecule was primarily undissociated, lipophilic, and penetrated into the cuticle; whereas, at pH values above the pK naphthaleneacetic acid was ionized, hydrophilic, and penetrated the cuticle with difficulty or not at all. Data presented are consistent with the hypothesis that naphthaleneacetic acid and naphthaleneacetamide penetration through the cuticle takes place by diffusion.     

见于贵州的三种Miltenberger血型糖蛋白

对贵州省荔波县间日疟高发区检出的 3种类型血型糖蛋白 (GP)变种 1 9例 ,现每类型各选 1个家系分析其基因结构异常 .以先证者及家系成员的红细胞制备溶血液 ,从其白细胞核沉淀物提取基因组 DNA,再进行免疫印迹及限制性核酸内切酶图谱分析 ,确证它们分别属于 Mi GP(δN-α-δs) ,Mi V(J.L .) GP(αM-δS)和 Mi GP(δN- α- δs) ,均为 GPA和 GPB的基因杂化体 .前两类 GP变种为国内首次报道     

三种舌运动类型遗传方式的研究 Studies of Hereditary Mode on Three Tongue Moving Types

采用Penrose先证者同胞法和分离分析方法对72个家系资料的分析表明：卷舌、尖舌均为常染色体单基因显性遗传,阳性为显性性状;翻舌为常染色体单基因隐性遗传,阳性为隐性性状。虽然环境因素对这类特征的表现也有一定的影响,但遗传因素仍起主要作用。 Abstract:The data of 72 families were analyzed by the method of proband′s sib and the method of segregation analysis.The results showed that the hereditary mode of rolling tongue or pointed tongue is the dominant heredity of single gene of autosome,and the positive type of them is the dominant character;Twisting tongue is the recessive heredity of single gene of autosome,while the positive type is the recessive character.Present study suggested,although environmental might affect these characters,hereditary factors seemed to be dominant.     

Distribution of Microbial Physiologic Types in an Aquifer Contaminated by Crude Oil

Abstract We conducted a plume-scale study of the microbial ecology in the anaerobic portion of an aquifer contaminated by crude-oil compounds. The data provide insight into the patterns of ecological succession, microbial nutrient demands, and the relative importance of free-living versus attached microbial populations. The most probable number (MPN) method was used to characterize the spatial distribution of six physiologic types: aerobes, denitrifiers, iron-reducers, heterotrophic fermenters, sulfate-reducers, and methanogens. Both free-living and attached numbers were determined over a broad cross-section of the aquifer extending horizontally from the source of the plume at a nonaqueous oil body to 66 m downgradient, and vertically from above the water table to the base of the plume below the water table. Point samples from widely spaced locations were combined with three closely spaced vertical profiles to create a map of physiologic zones for a cross-section of the plume. Although some estimates suggest that less than 1% of the subsurface microbial population can be grown in laboratory cultures, the MPN results presented here provide a comprehensive qualitative picture of the microbial ecology at the plume scale. Areas in the plume that are evolving from iron-reducing to methanogenic conditions are clearly delineated and generally occupy 25–50% of the plume thickness. Lower microbial numbers below the water table compared to the unsaturated zone suggest that nutrient limitations may be important in limiting growth in the saturated zone. Finally, the data indicate that an average of 15% of the total population is suspended. Received: 28 October 1998; Accepted: 26 February 1999