Search

Research background. Cellulose is an ingredient of waste materials that can be converted to other valuable substances. This is possible provided that the polymer molecule is degraded to smaller particles and used as a carbon source by microorganisms. Because of the frequently applied methods of pretreatment of lignocellulosic materials, the cellulases derived from thermophilic microorganisms are particularly desirable. Experimental approach. We were looking for cellulolytic microorganisms able to grow at 50 °C and we described their morphological features and biochemical characteristics based on carboxymethyl cellulase (CMCase) activity and the API® ZYM system. The growth curves during incubation at 50 °C were examined using the BioLector® microbioreactor. Results and conclusions. Forty bacterial strains were isolated from fermenting hay, geothermal karst spring, hot spring and geothermal pond at 50 °C. The vast majority of the bacteria were Gram-positive and rod-shaped with the maximum growth temperature of at least 50 °C. We also demonstrated a large diversity of biochemical characteristics among the microorganisms. The CMCase activity was confirmed in 27 strains. Hydrolysis capacities were significant in bacterial strains: BBLN1, BSO6, BSO10, BSO13 and BSO14, and reached 2.74, 1.62, 1.30, 1.38 and 8.02 respectively. Rapid and stable growth was observed, among others, for BBLN1, BSO10, BSO13 and BSO14. The strains fulfilled the selection conditions and were identified based on the 16S rDNA sequences. BBLN1, BSO10, BSO13 were classified as Bacillus licheniformis, whereas BSO14 as Paenibacillus lactis. Novelty and scientific contribution. We described cellulolytic activity and biochemical characteristics of many bacteria isolated from hot environments. We are also the first to report the cellulolytic activity of thermotolerant P. lactis. Described strains can be a source of new thermostable cellulases, which are extremely desirable in various branches of circular bi, Pozadina istraživanja. Celuloza je sastojak otpadnih tvari koji se može preraditi u korisne spojeve. To je moguće ako se molekule polimera razgrade na manje čestice koje mikroorganizmi mogu iskoristiti kao izvor ugljika. Celulaze proizvedene s pomoću termofilnih mikroorganizama su naročito zanimljive zbog njihove učestale primjene u prethodnoj obradi lignoceluloznog materijala. Eksperimentalni pristup. Istražili smo celulolitičke mikroorganizme koji rastu na 50 °C te opisali njihove morfološke i biokemijske značajke na osnovi aktivnosti karboksimetil celulaze i ostalih enzima ispitanih sustavom API® ZYM. Krivulje rasta tijekom inkubacije pri 50 °C ispitane su uzgojem bakterija u mikrobioreaktoru BioLector®. Rezultati i zaključci. Četrdeset sojeva bakterija izolirano je iz fermentirane slame, geotermičkog izvora u kršu, termalnog vrela i geotermalnog jezera s temperaturom od 50 °C. Većina bakterija bile su Gram-pozitivne i štapićastog oblika, a najviša temperatura pri kojoj su rasle je iznosila najmanje 50 °C. Također smo potvrdili veliku raznolikost biokemijskih značajki među ispitanim mikroorganizmima. Aktivnost karboksimetil celulaze potvrđena je u 27 sojeva. Sojevi bakterija sa značajnim hidrolitičkim kapacitetom bili su: BBLN1 s 2,74; BSO6 s 1,62; BSO10 s 1,30; BSO13 s 1.38 i BSO14 s kapacitetom od 8,02. Sojevi BBLN1, BSO10, BSO13 i BSO14 rasli su brzo i stabilno. Ispunjavali su odabrane preduvjete pa su identificirani 16S rDNA sekvenciranjem. Sojevi BBLN1, BSO10 i BSO13 klasificirani su kao sojevi bakterije Bacillus licheniformis, dok je soj BSO14 potvrđen kao soj Paenibacillus lactis. Novina i znanstveni doprinos. Opisali smo celulolitičku aktivnost i biokemijska svojstva velikog broja bakterija izoliranih iz lokacija gdje vladaju velike vrućine. Prvi smo izvijestili o celulolitičkoj aktivnosti termotolerantne bakterije P. lactis. Opisani bi sojevi mogli biti izvor novih termički stabilnih celulaza, što je izuzetno poželjno u različitim granama cirkularne bioe

The exact timing, route, and process of the initial peopling of the Americas remains uncertain despite much research. Archaeological evidence indicates the presence of humans as far as southern Chile by 14.6 thousand years ago (ka), shortly after the Pleistocene ice sheets blocking access from eastern Beringia began to retreat. Genetic estimates of the timing and route of entry have been constrained by the lack of suitable calibration points and low genetic diversity of Native Americans. We sequenced 92 whole mitochondrial genomes from pre-Columbian South American skeletons dating from 8.6 to 0.5 ka, allowing a detailed, temporally calibrated reconstruction of the peopling of the Americas in a Bayesian coalescent analysis. The data suggest that a small population entered the Americas via a coastal route around 16.0 ka, following previous isolation in eastern Beringia for ~2.4 to 9 thousand years after separation from eastern Siberian populations. Following a rapid movement throughout the Americas, limited gene flow in South America resulted in a marked phylogeographic structure of populations, which persisted through time. All of the ancient mitochondrial lineages detected in this study were absent from modern data sets, suggesting a high extinction rate. To investigate this further, we applied a novel principal components multiple logistic regression test to Bayesian serial coalescent simulations. The analysis supported a scenario in which European colonization caused a substantial loss of pre-Columbian lineages.

The exact timing, route, and process of the initial peopling of the Americas remains uncertain despite much research. Archaeological evidence indicates the presence of humans as far as southern Chile by 14.6 thousand years ago (ka), shortly after the Pleistocene ice sheets blocking access from eastern Beringia began to retreat. Genetic estimates of the timing and route of entry have been constrained by the lack of suitable calibration points and low genetic diversity of Native Americans. We sequenced 92 whole mitochondrial genomes from pre-Columbian South American skeletons dating from 8.6 to 0.5 ka, allowing a detailed, temporally calibrated reconstruction of the peopling of the Americas in a Bayesian coalescent analysis. The data suggest that a small population entered the Americas via a coastal route around 16.0 ka, following previous isolation in eastern Beringia for ~2.4 to 9 thousand years after separation from eastern Siberian populations. Following a rapid movement throughout the Americas, limited gene flow in South America resulted in a marked phylogeographic structure of populations, which persisted through time. All of the ancient mitochondrial lineages detected in this study were absent from modern data sets, suggesting a high extinction rate. To investigate this further, we applied a novel principal components multiple logistic regression test to Bayesian serial coalescent simulations. The analysis supported a scenario in which European colonization caused a substantial loss of pre-Columbian lineages.

Zweck des vorliegenden Beitrags ist es, das demographisch-soziale Bild der Posener Familie der 1. Hälfte des vorigen Jahrhunderts anhand von Tauf-, Trauungs- und Sterberegistern zu rekonstruieren. Die Arbeit will zeigen, wie der Alltag, insbesondere das Familien- und das gesellige Leben, weitgehend unabhängig von der 'großen' Politik verläuft. Der Zeitraum wurde gewählt, da der Feudalismus seinem Ende entgegenging und aus der ständischen Gesellschaft sich eine Klassen- bzw. Schichtengesellschaft entwickelte. Im Zentrum der Ausführungen steht die Familie im engeren Sinne, d.h. wie reflektiert sich der gesellschaftliche Umbruch in dem Verhältnis zwischen Eltern und Kindern. (pmb)

Eines der wichtigsten Symptome der Entstehung moderner Gesellschaften ist das Phänomen des Durchbrechens sozialer Schranken. Ausgehend von diesem generellen Charakteristikum wird die spezifische Natur des Abbruchs sozialer Schranken in den polnischen Gebieten untersucht. Im Zentrum der Analyse steht die Darstellung des objektiven Maßstabs für die Spannweite sozialer Barrieren, die in modernen Gesellschaften bestehen, d. h. auf die Auswahl der Ehefrau. Beim Vergleich der Berufe von Ehemann und Ehefrau wird einerseits das Verschwinden alter sozialer Gruppen und andererseits die Bildung neuer, für den Kapitalismus typischer Gruppen beobachtet. Begrenzt wird die Forschung auf die Bevölkerung von Poznan und Warschau. Die Auswahl dieser Städte ermöglicht den Vergleich des Phänomens des Durchbruchs sozialer Barrieren in der Hauptstadt einer bäuerlichen Provinz (Poznan) mit dem entsprechenden Prozeß in der Hauptstadt einer sich dynamisch entwickelnden Industrieregion (Warschau). (KWübers.), 'One of the most important symptoms of the emergence of modern societies was the phenomenon of the breaking of social barriers. Keeping this general characteristic in mind, we examine the specific nature of the breaking of social barriers in the Polish territories. The limited nature of this paper does not permit us to answer fully this question. Therefore, we concentrate on presenting the most objective measure of the elasticity of social barriers functioning in modern societies, i. e., the selection of a wife. By comparing the professions of husband and wife we can observe on the one hand the disappearance of old social divisions and on the other the emergence of new divisions typicalof capitalism. This same factor also forced us to limit our research to the population of Poznan and Warsaw. The selection of these cities enabled a comparison of the phenomenon of the breaking of social barriers in the main urban center of an agricultural province (Poznan) with the analogical process in a city was the capital of a dynamically developing industrial region (Warsaw).' (author's abstract)