Cellular Fatty Acid Composition of Selected Pseudomonas Species

The cellular fatty acid composition of 10 reference strains representing eight species of Pseudomonas was determined by gas-liquid chromatography. A variety of acids were detected in these organisms, including branched and straight-chained acids, cyclopropane, and hydroxy acids. Comparison of the presence and relative amounts of these acids among strains was useful for distinguishing various Pseudomonas species.     

Effect of method of preparation on the States of chlorophyll in euglena chloroplast fragments as determined by fluorescence spectroscopy

The state of chlorophyll in chloroplast fragments is affected by such factors as the ionic strength and pH of the suspending medium. With increasing ionic strength or at pH values other than neutrality, there is a decrease in the fluorescence yield of the form of chlorophyll with fluorescence maximum at 715 to 736 mμ (aggregate) and an increase in the yield of the form with fluorescence maximum at 685 mμ (monomer). (Positions of maxima cited are for 77°K.) These changes in yield are accompanied by modifications in absorption and fluorescence excitation spectra. It is also noted that these effects are similar to the ones brought about by pancreatic lipase, wheat germ lipase, pancreatic trypsin or urea. An interpretation is given which is consistent with the experimental data, namely, that the effects originate in conformational changes in the proteins to which the pigments are attached. These conformational changes give rise to an increase in the size of the aggregate and a decrease in the probability of energy transfer between the monomer and aggregates.     

Embodied narratives of disaster: the expression of bodily experience in Aceh,Indonesia

The devastating Indian Ocean tsunami of 26 December 2004 caused massive destruction to coastal Aceh, Indonesia, and left countless numbers of people dead or wounded. This article focuses on the embodied narratives of three Acehnese women who survived the disaster and, like many others in Aceh, told their stories ‘through’ their bodies. A detailed ethnographic account of their narratives reveals how the body stretches temporally between the ‘narrated event’ and the ‘narrative event’, both through the representation of the body in narratives and through the embodied performance of narratives. Moving beyond meaning‐centred analyses of narratives, I argue that the central accomplishment of these narratives is that they convey poignant bodily experiences to others and thereby create a shared, post‐disaster, world. Ultimately, through these embodied narratives of disaster people remake their world, with others, in the wake of its ‘unmaking’.     

Plant ABC proteins--a unified nomenclature and updated inventory

The ABC superfamily comprises both membrane-bound transporters and soluble proteins involved in a broad range of processes, many of which are of considerable agricultural, biotechnological and medical potential. Completion of the Arabidopsis and rice genome sequences has revealed a particularly large and diverse complement of plant ABC proteins in comparison with other organisms. Forward and reverse genetics, together with heterologous expression, have uncovered many novel roles for plant ABC proteins, but this progress has been accompanied by a confusing proliferation of names for plant ABC genes and their products. A consolidated nomenclature will provide much-needed clarity and a framework for future research.     

Natriuretic peptides modify <Emphasis Type="Italic">Pseudomonas fluorescens</Emphasis> cytotoxicity by regulating cyclic nucleotides and modifying LPS structure

Background  

Nervous tissues express various communication molecules including natriuretic peptides, i.e. Brain Natriuretic Peptide (BNP) and C-type Natriuretic Peptide (CNP). These molecules share structural similarities with cyclic antibacterial peptides. CNP and to a lesser extent BNP can modify the cytotoxicity of the opportunistic pathogen Pseudomonas aeruginosa. The psychrotrophic environmental species Pseudomonas fluorescens also binds to and kills neurons and glial cells, cell types that both produce natriuretic peptides. In the present study, we investigated the sensitivity of Pseudomonas fluorescens to natriuretic peptides and evaluated the distribution and variability of putative natriuretic peptide-dependent sensor systems in the Pseudomonas genus.     

Involvement of a phospholipase C in the hemolytic activity of a clinical strain of <Emphasis Type="Italic">Pseudomonas fluorescens</Emphasis>

Background  

Pseudomonas fluorescens is a ubiquitous Gram-negative bacterium frequently encountered in hospitals as a contaminant of injectable material and surfaces. This psychrotrophic bacterium, commonly described as unable to grow at temperatures above 32°C, is now considered non pathogenic. We studied a recently identified clinical strain of P. fluorescens biovar I, MFN1032, which is considered to cause human lung infection and can grow at 37°C in laboratory conditions.     

Colonisation and mass rearing: learning from others

Mosquitoes, just as other insects produced for the sterile insect technique (SIT), are subjected to several unnatural processes including laboratory colonisation and large-scale factory production. After these processes, sterile male mosquitoes must perform the natural task of locating and mating with wild females. Therefore, the colonisation and production processes must preserve characters necessary for these functions. Fortunately, in contrast to natural selection which favours a suite of characteristics that improve overall fitness, colonisation and production practices for SIT strive to maximize only the few qualities that are necessary to effectively control populations.However, there is considerable uncertainty about some of the appropriate characteristics due to the lack of data. Development of biological products for other applications suggest that it is possible to identify and modify competitiveness characteristics in order to produce competitive mass produced sterile mosquitoes. This goal has been pursued - and sometimes achieved - by mosquito colonisation, production, and studies that have linked these characteristics to field performance. Parallels are drawn to studies in other insect SIT programmes and aquaculture which serve as vital technical reference points for mass-production of mosquitoes, most of whose development occurs - and characteristics of which are determined - in an aquatic environment. Poorly understood areas that require further study are numerous: diet, mass handling and genetic and physiological factors that influence mating competitiveness. Compromises in such traits due to demands to increase numbers or reduce costs, should be carefully considered in light of the desired field performance.     

Trichoderma theobromicola and T. paucisporum: two new species isolated from cacao in South America

Trichoderma theobromicola and T. paucisporum spp. nov. are described. Trichoderma theobromicola was isolated as an endophyte from the trunk of a healthy cacao tree (Theobroma cacao, Malvaceae) in Amazonian Peru; it sporulates profusely on common mycological media. Trichoderma paucisporum is represented by two cultures that were obtained in Ecuador from cacao pods partially infected with frosty pod rot, Moniliophthora roreri; it sporulates sporadically and most cultures remain sterile on common media and autoclaved rice. It sporulates more reliably on synthetic low-nutrient agar (SNA) but produces few conidia. Trichoderma theobromicola was reintroduced into cacao seedlings through shoot inoculation and was recovered from stems but not from leaves, indicating that it is an endophytic species. Both produced a volatile/diffusable antibiotic that inhibited development of M. roreri in vitro and on-pod trials. Neither species demonstrated significant direct in vitro mycoparasitic activity against M. roreri.