Purple non‐sulphur bacteria and plant production: benefits for fertilization, stress resistance and the environment

Purple non-sulphur bacteria (PNSB) are phototrophic microorganisms, which increasingly gain attention in plant production due to their ability to produce and accumulate high-value compounds that are benefi- cial for plant growth. Remarkable features of PNSB include the accumulation of polyphosphate, the pro- duction of pigments and vitamins and the production of plant growth-promoting substances (PGPSs). Scattered case studies on the application of PNSB for plant cultivation have been reported for decades, yet a comprehensive overview is lacking. This review highlights the potential of using PNSB in plant pro- duction, with emphasis on three key performanceindicators (KPIs): fertilization, resistance to stress (biotic and abiotic) and environmental benefits. PNSB have the potential to enhance plant growth performance, increase the yield and quality of edible plant biomass, boost the resistance to environmental stresses, bioremediate heavy metals and mitigate greenhouse gas emissions. Here, the mechanisms responsible for these attributes are discussed. A dis- tinction is made between the use of living and dead PNSB cells, where critical interpretation of existing literature revealed the better performance of living cells. Finally, this review presents research gaps that remain yet to be elucidated and proposes a roadmap for future research and implementation paving the way for a more sustainable crop production

Prochlorophyte picophytoplankton and the carbon cycle in the photic layer of the oligotrophic Gulf of Eilat. Joint German-Israeli Research Projects Final scientific report

Ultraphytoplankton is the phytoplankton size fraction responsible for 90-97% of primary production in the Gulf of Aqaba at all locations and during all seasons. Ultraphytoplankton go through a unique seasonal succession in the Gulf of Aqaba. Eukaryote ultraphytoplankton species dominate in nutrient-rich waters during winter mixing. The cyanobacterium Synechococcus is the main component of the spring bloom. The prochlorophyte Prochlorococcus is the numerically dominant ultraphytoplankter in the Gulf of Aqaba during the stratification period when it makes up more than 50% of photosynthetic biomass. Prochlorococcus cell numbers fall below detection when the depth of convective mixing reaches down to >400 m. The factor responsible for the reduction in prochlorophyte numbers is as yet not known. Return of Prochlorococcus populations to recently stratified waters of the Gulf of Aqaba depends on important of such populations with advection of prochlorophyterich, nutrient-poor surface waters from the northern Red Sea. Marine Synechococcus and Prochlorococcus dominate nutrient deplete waters and especially surface populations of these organism may be deprived of essential nutrients for several months. Nitrogen, one of these nutrients, occurs in the see in various inorganic and organic forms. The uptake of these nitrogenous compounds is strictly regulated and tuned to the available compound under control of the ntcA gene in marine Synechococcus and Prochlorococcus. The ntcA gene expression in the marine environment can now be assessed from use of molecular probes against the gene and its gene products. (orig.)Available from TIB Hannover: F99B281+a / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEBundesministerium fuer Bildung, Wissenschaft, Forschung und Technologie, Bonn (Germany); Ministry of Science and Technology, Jerusalem (Israel); Forschungszentrum Juelich GmbH (Germany). Projekttraeger Biologie, Energie, Umwelt (BEO)DEGerman

Comparative study of the fatty acid composition of some groups of purple nonsulfur bacteria

The fatty acid composition (FAC) of 43 strains of purple nonsulfur bacteria belonging to six genera—Rubrivivax, Rhodopseudomonas, Rhodoplanes, Blastochloris, Rhodobium, and Rhodomicrobium—was studied by capillary gas chromatography. The cultures were grown on standard medium under standard conditions. Automatic identification of the fatty acid methyl esters and statistical processing of the results were performed by the computerized Microbial Identification System (MIS). Significant differences between the FACs of different genera, species, and, sometimes, strains were revealed. 16S rRNA genes of some of the new isolates, primarily those having a specific FAC, were sequenced. The taxonomic status of a number of the strains in question was determined using the FAC characteristics as one of the criteria. It was shown that the FAC characteristics may be used both for affiliating isolates to known species and for revealing new taxa

Genomic Comparison, Phylogeny and Taxonomic Reevaluation of the Ectothiorhodospiraceae and Description of Halorhodospiraceae fam. nov. and Halochlorospira gen. nov.

The Ectothiorhodospiraceae family represents purple sulfur bacteria of the Gammaproteobacteria found primarily in alkaline soda lakes of moderate to extremely high salinity. The main microscopi-cally visible characteristic separating them from the Chromatiaceae is the excretion of the intermediate elemental sulfur formed during oxidation of sulfide prior to complete oxidation to sulfate rather than storing it in the periplasm. We present a comparative study of 38 genomes of all species of phototrophic Ectothiorhodospiraceae. We also include a comparison with those chemotrophic bacteria that have been assigned to the family previously and critically reevaluate this assignment. The data demonstrate the separation of Halorhodospira species in a major phylogenetic branch distant from other Ectothiorhodospiraceae and support their separation into a new family, for which the name Halorho-dospiraceae fam. nov. is proposed. In addition, the green-colored, bacteriochlorophyll-containing species Halorhodospira halochloris and Halorhodospira abdelmalekii were transferred to the new genus Halochlorospira gen. nov. of this family. The data also enable classification of several so far unclassified isolates and support the separation of Ectothiorhodospira shaposhnikovii and Ect. vacuolata as well as Ect. mobilis and Ect. marismortui as distinct species. © 2022 by the authors. Licensee MDPI, Basel, Switzerland.Open access journalThis item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]

Modélisation des phénomènes électromagnétiques et mécaniques couples : application à l'analyse vibratoire des machines électriques

La réduction des bruits et vibrations dans l'appareillage et les machines électriques préoccupe un grand nombre de constructeurs ; la demande dans ce domaine se fait de plus en plus pressante. A travers nos travaux qui portent essentiellement sur les machines tournantes à courant continu, nous présentons une analyse qualitative, puis quantitative, des vibrations d'origine électromagnétique. Cette dernière nous a conduit au développement d'un logiciel de calcul de magnéto-mécanique basé sur la méthode des éléments finis, afin de permettre la prédiction des différents niveaux vibratoires en régime de fonctionnement permanent. Quelques exemples permettent d'illustrer la faisabilité du logiciel et montrent que les résultats obtenus sont très prometteurs

Modélisation des phénomènes électromagnétiques et mécaniques couples : application à l'analyse vibratoire des machines électriques

Manufacturers in electrical machinery are becoming highly interested in the reduction of noise and vibrations ; this is due to the increasing awareness of the problem. In this paper, a qualitative and quantitative analysis of electromagnetic vibrations in D.C. machines is proposed. Then, the software which has been developed for the calculation of vibration levels in the case of steady state is presented and examples show that results are very promising.La réduction des bruits et vibrations dans l'appareillage et les machines électriques préoccupe un grand nombre de constructeurs ; la demande dans ce domaine se fait de plus en plus pressante. A travers nos travaux qui portent essentiellement sur les machines tournantes à courant continu, nous présentons une analyse qualitative, puis quantitative, des vibrations d'origine électromagnétique. Cette dernière nous a conduit au développement d'un logiciel de calcul de magnéto-mécanique basé sur la méthode des éléments finis, afin de permettre la prédiction des différents niveaux vibratoires en régime de fonctionnement permanent. Quelques exemples permettent d'illustrer la faisabilité du logiciel et montrent que les résultats obtenus sont très prometteurs